Assoc Prof John Golding

Consistent fruit size and high soluble solids concentration (SSC) in peach and nectarine (Prunus persica (L.) Batsch) are important components of fruit quality. Variation in fruit size and dry matter content, within a tree and within individual branches, has been related to heterogeneity in light interception, fruit proximity to carbohydrate sources, fruit load, and interfruit competition. Causes of variation in SSC within a tree are less well understood, although they are to some extent related to differences in carbohydrate supply and fruit developmental stage. Previous research has investigated source¿sink relationships affecting dry matter accumulation, without clearly establishing how dry matter is partitioned between and within individual fruits. Sink strength of an individual fruit is likely to be a significant factor in determining the rate of sugar accumulation and in explaining variation in SSC, both at the whole-tree level and among fruits within single branches. The effect of fruit sink size and activity on carbohydrate demand and utilization, as mediated by temperature and mesocarp anatomy, is yet to be fully determined. Although it has been demonstrated that fruits with higher cell numbers have higher dry matter content, the relationship between cell number and SSC is poorly understood. Differences in sugar concentration and composition among fruits may be associated with differences in cell size distribution within peach and nectarine mesocarp. Further anatomical studies are necessary to determine the effect on sugar concentration of cell size distribution as influenced by sink size and activity. This chapter examines the environmental, tree management, and anatomical factors impacting fruit size (dry matter content) and SSC variation in peach and nectarine trees. Important effects of fruit sink activity and anatomy on variation in fruit quality are highlighted in this chapter. Knowledge gaps in relation to peach and nectarine sink strength and carbohydrate utilization have also been discussed. Future research is proposed with an emphasis on the use of nondestructive vis-NIR to measure SSC in fruit and physiological maturity in the orchard. Use of this technology in combination with fruit temperature monitoring is likely to improve our understanding of carbohydrate utilization within fruit as affected by developmental stage and rate of fruit maturation.

The increased frequency and intensity of extreme bushfires has had a wide-ranging impact on primary industries and particularly perennial horticultural productions. However, not much is known about bushfire effects on vegetative and reproductive abilities of fruit trees. This study aimed at providing a clearer understanding of the immediate effects of extreme bushfires on apple trees affected by spot-fires during the 2019-20 Australian bushfires. The evaluation was carried out on 'Royal Gala' apple trees on M26 rootstocks, with four identified fire-impact levels. The nutrient concentrations variability of leaves, in time and space, and important vegetative and reproductive attributes including tree canopy size, crop load and fruit quality at maturity, were assessed in the growing season following the bushfires in the previous summer. Mean comparison of macro- and micronutrients in leaves, across the four impact levels revealed lowest but non-significantly different values in leaf nutrient concentrations of severely impacted trees except for manganese with a significantly lower concentration (20.7 mg kg-1). Summer nutrient values were generally lower than the standard nutrient range for macro- and micronutrients. The only nutrients with concentrations within the standard nutrient range and across most impact levels were P, B and Cu. Potassium nutrient concentrations were higher than the standard nutrient range except for severely impacted trees (1.45%). In addition, canopy recovery assessed through leaf area index (LAI) measurement, in summer (0.57±0.13) was lowest for severely impacted trees. Similarly, fruit quality parameters including average weight, firmness, soluble solid contents, pH and malic acid content indicated reduced quality of fruits from severely impacted trees compared to other impact levels. In terms of yield, total yield of severely impacted trees was significantly higher than the other damage levels, although with much smaller fruits. These findings confirm the potential negative effect of bushfires on fruit tree nutrition, vegetative/reproductive performances and fruit quality at harvest. Enhanced management strategies to reduce the detrimental effects of bushfire must be pursued in order to ensure optimal orchard productivity.

Blueberry (Vaccinium corymbosum, Northern Highbush, 'Brigitta') fruit were subject to gamma irradiation (0, 150, 400 and 1000 Gy) at the Australian Nuclear Science and Technology Organisation. The experimental design was a split plot design with three replicates of four irradiation treatments and two storage times. After treatment, fruit were stored at 0°C for three or ten days before assessment of fruit quality and proximate and nutritional analysis. The dosimetry of the irradiation treatment was excellent with high levels of precision and accuracy. Results showed that irradiation at any dose (=1000 Gy) did not affect blueberry quality (overall fruit quality, colour, firmness (subjective and objective measures), shrivel, weight loss, TSS, TA levels, TSS/TA ratio and juice pH), or the nutritional or proximate contents (contents of ash, carbohydrate, dietary fibre, energy, moisture, protein, sodium, potassium, total sugars, fructose, ascorbic acid, anthocyanin, citric and malic acids) of treated fruit which had been stored for either three or ten days. As expected, the length of time in storage affected some fruit quality parameters and nutritional and proximate contents (overall fruit quality, firmness, weight loss, TA levels and juice pH, carbohydrate, dietary fibre, energy, protein, potassium, total sugars, glucose, ascorbic acid, citric and malic acids), with longer storage periods resulting in lower quality fruit, irrespective of irradiation. However, the overall fruit quality over the entire trial was good. There was no interaction between irradiation treatment and storage time, indicating that irradiation did not affect the quality characteristics of blueberry fruit.

Peaches may suffer chilling injury (CI) during prolonged cold storage and the severity of this disorder may be affected by storage temperature, fruit maturity at harvest and treatment with 1-methylcyclopropene (1-MCP). The aim of this study was to identify how these factors affect gene expression during the onset of CI in early and late maturity 'Zee Lady' peaches treated with and without 1-MCP then stored at 0 or 5°C before being ripened at 20°C for 5 days. CI was assessed through reductions in juice recovery and the development of flesh browning. All of the factors listed above affected gene expression. 87 genes showed differential expression due to treatment with 1-MCP in early maturity cool stored whilst only 61 changed expression in late maturity fruit; these genes were mainly involved in membrane metabolism, cell wall synthesis and degradation and reaction to stress. 13 of these genes were common to fruit of both maturities. The development of CI was increased in 1-MCP-treated early fruit but was reduced in 1-MCP-treated late fruit compared to relevant controls. However, gene expression patterns in these fruit during CI development were consistent with the severity of CI.

Queensland Fruit Fly Bactrocera tryoni (Froggatt) (QFF) is a major quarantine pest for many Australian summerfruit and cherry producers, particularly as treatment to combat infestation can often affect fruit quality, restrict marketing flexibility and affect grower returns. The current cold disinfestation treatment (in air) for 14 days is too long and inflexible, as the storage and shelf life of summerfruit and cherries are often less than 28 days. This project examined the potential of a high carbon dioxide (CO2) treatment in combination with cold storage to reduce the time in cold disinfestation. A range of different peach and cherry varieties was infested with QFF and the fruit were treated with 95% CO2 at 0°C for varying lengths of time before storage in air. To examine if high CO2 had any effects on fruit quality, storage trials were conducted on peaches and cherries. The results showed that a 95% CO2 treatment at the beginning of the cold disinfestation period significantly reduced the time to kill first instar QFF. It is important that any potential disinfestation treatment does not affect fruit quality. Storage trials showed that there were no adverse effects of the high CO2 treatment on fruit quality across a range of treatment times, varieties with different removals. The results demonstrated that a short-term high CO2 treatment at 0°C temperature was effective in reducing the time in cold disinfestation without detriment to fruit quality during storage.

Microarray technology has allowed the large scale transcriptomic analysis of fruit ripening. The µPEACH1.0 microarray containing 4,806 probes corresponding to genes expressed in peach fruit tissues has been used in a heterologous fashion in two studies of plums ripening behavior. Gene expression of different cultivars of plums treated with the ethylene antagonist, 1-methylcyclopropene (1-MCP) and stored for short periods at room temperature or for longer periods of cold storage was examined. In the first study, mature fruit of a suppressed ethylene climacteric cultivar 'Shiro' and a cultivar characterized by a typical increase of ethylene production during ripening ('Santa Rosa') were harvested and incubated for 24h in air (control) or 1-MCP and allowed to ripen at room temperature. Different levels of transcripts of genes implicated in cell wall metabolism, hormone (ethylene and auxin) regulation, stress and defense, and in the transcription/translation machinery, as well as others involved with ripening were identified. In the second study, the effects of 1-MCP on gene expression in relation to the development of chilling injury (CI) in the climacteric cultivars 'Ruby Red' (RR) and 'October Sun' (OS) and 'Zee Lady' peaches (ZP) were analyzed. The fruit were treated for 24h at room temperature with 1-MCP prior to storage at 0°C. For RR, there was no significant effect of 1-MCP on the level of CI symptoms, while 1-MCP significantly reduced CI symptoms in OS fruit and an increase of CI in treated ZP fruit. Microarray analysis showed that immediately following treatment, 186, 134 and 56 genes were differentially expressed between the control and 1-MCP-treated fruit of these cultivars, respectively: after 4 weeks cold storage, 311, 52 and 224 genes for RR, OS and ZP, respectively, were differentially expressed between control and treated fruit. Thus, for OS, the number of differentially expressed genes reduced during storage while the number increased in RR and ZP. Comparisons of the data suggest that the transcript profile is altered by 1-MCP more in plums than peaches. These studies, carried out within an international collaborative network, will increase our understanding of the regulation of pathways involved in plum fruit ripening and in metabolic processes related to storage and shelf life.

A prototype portable near infrared (NIR) spectrometer was evaluated using several varieties of peaches and nectarines, including fruit ranging from immature to tree ripe. The NIR unit was pre-calibrated with different varieties of peaches and nectarines. A series of NIR measurements were made on up to 12 locations on each fruit. Cores of flesh were removed from each of these locations and juice was expressed to enable measurements of soluble solids concentrations (SSC) with a temperature compensated digital refractometer. The NIR and SSC readings were highly correlated. SSC values at different locations within each fruit varied by up to 4%. Based on these data we suggest that a minimum of two NIR readings on opposite sides of the fruit in the equatorial plane are required to give a reliable measure of the average value for each fruit. We found that the NIR unit gave accurate measurements of SSC over four harvests of a yellow flesh peach variety ranging from small immature fruit to large tree ripe fruit.

Fruit to fruit variability is inherent in horticulture and can contribute to uneven ripening and presentation of fruit of inconsistent eating quality to the consumer. This is often the case in controlled ripening or conditioning of peaches and nectarines, whereby a sub-sample of the population does not ripen as quickly as the majority of the fruit resulting in fruit of mixed softness/ripeness at the retail store. This can lead to an unacceptable eating experience and poor return sales. A non-destructive measure of fruit firmness (the Sinclair iQ¿ system) was assessed as an alternative to the manual destructive penetrometer to develop a model to predict when the fruit from a 'Ripe and Ready' program (controlled ripening/conditioning) were ready for retail distribution. As expected there were large variations in firmness among the fruit of each cultivar following commercial harvest. Fruit firmness data from the Sinclair iQ¿ system during conditioning was also modelled to predict the required length of conditioning from the initial firmness readings. This work was conducted over two seasons and showed important seasonal differences. The model is being further evaluated and refined. Its commercial application would be of significant benefit for the peach and nectarine fruit conditioning programs by ensuring fruit at a consistent stage of ripeness are offered to consumers.

There is a potential market for Australian vegetables in distant markets if they arrive in good condition and with adequate shelf life at a competitive price. Sea freight is slower than air freight but has cost advantages and offers good temperature control. In addition, sea freight containers which provide a modified atmosphere (MA) or controlled atmosphere (CA) can potentially increase product storage life compared to air alone. However, as loads often contain two or more types of vegetables, the storage atmosphere used may need to suit multiple products. We examined how quality attributes of broccoli, cauliflower and lettuce deteriorated during storage in different atmospheres with a view to shipping these products from Australia to the United Arab Emirates, a journey of approximately 23 days. Products were stored in 11% O2 + 10% CO 2, 2% O2 + 2% CO2, humidified air or commercial packaging in air. Quality attributes were evaluated after 3, 4, 5 or 6 weeks storage at 0.3°C and again following 2 days simulated shelf life at 20°C. It was estimated that broccoli could be stored for a maximum of 3 weeks in crushed ice, 4 weeks in humidified air or 5 weeks under a controlled or modified atmosphere and still retain good outturn quality and adequate shelf life. Cauliflower storage life was increased from 4 weeks to 5 weeks by storage in 2% O2 + 2% CO2. Lettuce did not benefit from CA and had the most variable quality of the vegetables tested. It was concluded that there are only marginal benefits of using CA or MA to ship broccoli, cauliflower and lettuce from Australia to Dubai. Air storage at 0.3°C should provide good outturn condition and adequate shelf life so long as products are handled correctly and water loss is minimised.

'Pink Lady'¿ apples were harvested from two growing regions (South Australia and Victoria) and at two harvest maturities (early and late). Fruit were treated with aminoethoxyvinylglycine (AVG, ReTain ®) at two different times in the orchard (7 and 21 days before harvest). Fruit were harvested according to maturity and stored at 0°C in controlled atmosphere (CA) storage (2% O2and 1% CO2) or regular air storage. Fruit quality (internal ethylene concentration, firmness, background colour, starch, soluble solids content) were assessed at two monthly intervals for up 10 months storage. Fruit were subject to a two week shelf life at 20°C after six months storage. All air stored fruit were removed at six months storage. The ReTain® treatment significantly reduced ethylene production across all treatment and storage regimes, compared to the untreated control. Ethylene production was also lower in the ReTain ® treatments during the 14 days shelf life at 20°C after six months storage. Flesh firmness (measured by penetrometer) was generally higher in the fruit stored in CA and in the ReTain® treated fruit. This effect was maintained during the® entire storage period. The results show that the preharvest application of ReTain® on 'Pink Lady' ¿ apples can be a useful tool for managing harvest and ensuring postharvest fruit quality after both air and CA storage.

Superficial scald (scald) is one of the major physiological disorders that occur during long term cold storage of apples. Scald is currently controlled by the postharvest application of diphenylamine (DPA), however there is a growing need to seek alternative control methods. A promising reliable alternative to DPA is 1-methylcyclopropene (1-MCP, SmartFresh¿). The aim of this storage project was to assess 1- MCP (SmartFresh¿) on apple quality and superficial scald development during storage. Preclimacteric 'Granny Smith' and climacteric 'Red Delicious' apples were treated with SmartFresh¿, DPA (current approved rate) or left untreated (control) before storage at 0oC in either air or controlled atmosphere (CA, 2% O2 and 1% CO2). SmartFresh¿ was applied in an air tight container as soon as possible after harvest. The results showed that both the commercial DPA and SmartFresh¿ treatments controlled superficial scald equally well in both 'Red Delicious' and 'Granny Smith' apples stored in air and CA for up to eight and ten months, respectively. CA storage maintained the quality of untreated and SmartFresh¿ treated fruit. However even under CA storage, some quality benefits such as retention of firmness in 'Red Delicious' apples were observed in SmartFresh ¿ treated fruit during storage and after storage compared to untreated control or DPA treated fruit. The prestorage SmartFresh ¿ treatment also significantly reduced the levels of internal ethylene in both apple varieties in air and CA stored fruit and at all removal times for up to ten months storage. The lowering of ethylene production and action in the treated fruit reduced or lowered subsequent physiological effects during storage. This was evident in the retention of flesh firmness and green background colour in SmartFresh¿ treated fruit.

The yield and fruit quality of mini cucumbers (Cucumis sativus L. cv. Tandora), grown using different substrates in a run-to-waste system, was examined during a 17 week greenhouse experiment. The substrates included coir (Cocos nucifera), sawdust (Pinus radiata), rockwool, perlite and cucumber mix (a commercial soil conditioner). The management of the crop, including the nutrient and irrigation regime, was the same for each medium. At each harvest, cucumber fruit number and fresh weight were recorded for each experimental plant. Additionally, quality and storability was assessed using fruits harvested at 7 weeks (early), 11 weeks (mid) and 16 weeks (late season) after planting. Fruit was stored for two weeks at 10°C. After an additional day at 20°C, the cucumbers were assessed for weight loss, colour change and textural quality (crush strength and firmness). There was no significant effect of substrate on plant dry weight, cucumber number, cucumber weight or average weight per cucumber, or on the fruit quality measurements. However there were differences in colour, deformation, crush strength and dry matter between harvests. There was no significant linear trend of yield over time for any media treatment. These results demonstrate that a range of growth media can be successfully used for hydroponic cucumber production. However, to maximise yields and fruit quality, further work is needed to tailor crop management for each substrate.

Peel colour is an important component of consumer acceptance of apples (Malus x domestica). We examined the effects of postharvest temperature on the postharvest development of peel colour. 'Rome' apples were bagged in the orchard during the growing season to obtain physiological mature but anthocyanin-free fruit. Postclimacteric bagged fruit were harvested, and exposed to a range of postharvest temperatures (-2, 0, 5, 10, 15, 20, 25, 30 and 35 °C). All fruit received the same continuous quantity and quality of cool-white fluorescent light (15 ?molm-2s-1) to simulate anthocyanin production. Colour development was recorded every 2 days and ethylene production measured periodically during storage. Colour was correlated to anthocyanin production. The results showed that temperature is a very important component of colour development in apples. Optimal colour development occurred at 20-25 °C, whilst at lower temperatures, colour development was significantly slowed. At higher storage temperatures (30 °C) anthocyanin accumulation was retarded, whilst at 35 °C, anthocyanin accumulation was completed prevented.

The red colour in apple peel is caused by anthocyanin pigments and is a major part of consumers' choice of apples. 'Rome' apple fruit were bagged with double lined paper bags in the orchard several months before harvest. This prevented any preharvest anthocyanin development. A factorial experiment using 1-methyl cyclopropene (MCP) and storage under fluorescent light at 20°C was conducted on preclimacteric apples. Peel colour, chlorophyll fluorescence and internal ethylene were measured for 28 days after harvest. Light was shown to be absolutely essential for the development of peel anthocyanins. All bagged apples stored in the dark did not develop full colour. Bagged fruit stored in the dark and treated with MCP remained green for the entire experiment whilst those bagged fruit without MCP treatment showed some red colouration and chlorophyll degradation. Bagged apples stored in the light, which did not receive MCP treatment, began to develop colour within one day, where MCP treated fruit produced some colour, but never to the same extent as fruit not treated with MCP. Colour development was also enhanced in control (non-bagged) fruit stored in the light but not those stored in the dark. Further work is continuing on the regulation of anthocyanin production.

Initial low oxygen stress (ILOS, 0.5% O2 for 3 weeks) followed by controlled atmosphere (CA) storage at 1.5 - 3% O2 has been shown to successfully control superficial scald (scald) in apples during long term storage. Preclimacteric 'Law Rome' apples were stored in either air, CA, or ILOS / CA regime. During the first few months of storage, internal ethanol, acetaldehyde, ethylene, and peel alcohol dehydrogenase (ADH) activity were measured to investigate the possible role of ADH in scald development. ADH catalyses the interversion of ethanol and acetaldehyde and is commonly induced under stress such as hypoxia. In this study both ILOS / CA and CA inhibited ripening and suppressed the development of scald. In addition, fruit subject to ILOS / CA produced significantly higher levels of ethanol and acetaldehyde during storage. High levels of internal ethanol were detected within one week of ILOS treatment and continued for several months after removal from ILOS into CA. ADH activity was also induced within one week in both CA treatments, and remained high throughout the storage period. Further investigations are currently underway to determine the role of ADH in scald development.

Superficial scald is a physiological storage disorder of apples, which is characterised by browning of the skin. Scald is thought to be due to an uncontrolled polyphenol oxidase (PPO) system oxidising the vacuolar phenolics. Phenolics have been implicated in numerous physiological processes during the storage of fruit. Therefore, it is important to understand the role of phenolics in long term storage and the development of superficial scald. In these experiments, phenolics were identified and quantified from the peel of pre-climacteric 'Granny Smith' and 'Crofton' apples during air storage at 0°C. The phenolics from both scald affected and apparently healthy green peel tissue from the same control 'Granny Smith' apples were extracted, separated and quantified with diode array HPLC. Analysis of scalded and non scalded peel tissue from the same 'Granny Smith' apples showed there was a significant decline in the concentration of all the phenolics, particularly the flavonols, in scalded tissue. A new phenolic compound, benzoyl-ß-D-glucose, not previously identified in apples, was detected in the scalded peel tissue. These changes in phenolic profile may have significant implications concerning the role of phenolics in the storage physiology and the development of scald in apples. © ISHS 1998.

The study aimed to enhance the shelf life of fresh-cut strawberries and dragon fruits by understanding their respiration behavior under modified atmosphere packaging (MAP) conditions, an essential factor in improving fruit preservation. Using a closed system at 4 ± 0.5°C, we examined the respiration dynamics of these fruits and developed a mathematical model based on the Michaelis¿Menten enzymatic kinetics to predict their respiration rates. The findings revealed that fresh-cut strawberries exhibited higher maximum respiration rates (Vm) than dragon fruit, with the fermentation threshold occurring at 51 h for strawberries and 156 h for dragon fruit. Specifically, the critical O2 and CO2 concentrations for strawberries were 2.89% O2 and 13.91% CO2, while for dragon fruits, they were 5.22% O2 and 11.01% CO2. This study is novel in its use of uncompetitive inhibition enzyme kinetics to model gas concentration effects and provide new insights into the respiration characteristics of fresh-cut strawberries and dragon fruits under storage. The results offer a theoretical foundation for optimizing MAP conditions, thus improving storage strategies, enhancing fruit quality, and extending shelf life. The findings also pave the way for broader applications in the food industry, potentially benefiting other fresh-cut fruits and guiding future research on MAP development for better preservation.

Postharvest sprouting is a major problem for the storage of sweet potato. This study compared the effect of D-fenchone with methyl naphthacetate (MENA) treatments on the sprouting of 'Yan 25' sweet potato. The untreated control roots sprouted within 4 days however the roots fumigated with 200 µL / 23 L D-fenchone or MENA completely inhibited the sprouting of freshly harvested 'Yan 25' during 14 days storage at 30 ¿. Furthermore, treating established sprouts (0.5 cm) with MENA or D-fenchone resulted in damaged sprouts after seven days following treatment with higher MDA content and these sprouts eventually died. Transcriptomic analyses revealed that both D-fenchone and MENA inhibited cell wall synthesis and disrupted auxin and cytokinin pathways in the storage roots, by which suppressed the sprouting. The RNA-seq results of established sprouts showed that both D-fenchone and MENA promoted ethylene and reactive oxidative species (ROS) pathways, which were correlated with the physical damage. In addition, D-fenchone and MENA inhibited auxin pathway, MENA changed cytokinin and D-fenchone disrupted polyamine, cell division and cellulose biosynthesis pathways which all may have contributed to sprout suppression.

The increasing consumption of fresh fruits and vegetables has led to the development of eco-friendly and active preservation materials which have slow-release effect of antioxidant/antifungal agents. The propolis microcapsules (PM), utilizing calcium alginate as the wall material, incorporating ethanolic extract of propolis (EEP) as the core material, were prepared by ionic gelation method and conducted a investigation of its characteristics After optimization by single factor experiment and theoretical response models, PM which was prepared by dropping 9.3 g L-1 100 mL sodium alginate solution containing 9.8 mL EEP into 0.22 mol L-1 calcium chloride solution showed an encapsulation efficiency of 69.29±1.12 %. Prepared microcapsules were spherical with a dense surface which protected propolis well from the environment, retained a large number of bio-active compounds and improve thermal stability of propolis. Moreover, the microcapsules exhibited good slow-release effect and good inhibitory influence on the development of Alternaria Alternata growth which the colony diameter of the control was 41.38 % higher than the treatment at day six. With 5.0 g PM placed in the small non-woven bag in the application on sweet cherries with non-direct contact method, the decay rate and weight loss of fruits were reduced by 47.5 % and 17.6 %, concurrently the PM also effectively maintain the good appearance, hardness, antioxidant capacity by slowing the reduction in the content of total phenols, flavonoids and enzymatic activities. Therefore, the PM with superior antioxidant and antifungal capacity have the great potential to design as a practical active materials for fruits preservation.

Phytosanitary irradiation uses ionising irradiation (< 1000 Gy) as an end-point treatment of quarantine insect pests in fresh produce to facilitate market access and trade. While this market access treatment has limited international acceptance, its commercial use is growing and new X-ray irradiation treatment facilities are being built around the world. In most fruit tolerance studies, phytosanitary irradiation does not have any commercial effects on final product quality, nutrition and proximate content and this treatment is accepted and used as a commercial market access treatment in some countries. However, in selected instances, irradiation can negatively affect some aspects of quality, such as the development of storage disorders e.g. surface pitting in mandarins. On the other hand, other studies have shown that irradiation can reduce some storage disorders such as superficial scald in apples. In some cases where irradiation induced storage disorders have been identified, applied research has provided practical solutions to reduce these disorders which has enabled commercial use of the treatment and allowed international trade. Most research on the fruit tolerance responses to phytosanitary irradiation has been empirical in nature with little understanding of the molecular, biochemical and physiological processes affected by irradiation treatment. This review focuses on the effects of phytosanitary irradiation on fruit quality and provides some commercial solutions to overcome some potential irradiation induced issues.

Extreme bushfire is having considerable negative effects on the sustainability of agricultural landscapes in various parts of the world. Fire-induced damages to tree crops have led to significant effects on perennial horticultural production systems with associated lower returns and decline in economic sustainability. Australia is one of the most fire-prone countries in the world and contributes to global horticultural production with production forecast level estimated at $18.2 billion in 2023¿24, according to the Australian Department of Agriculture, Fisheries and Forestry. Bushfire-related damages to horticultural production may however threaten this promising potential. This review provides a commentary on the history, scale and impacts of extreme bushfires in Australia. The effects of bushfire on horticulture, including soil nutrient availability, fruit tree physiology and carbohydrate sink-source dynamics are discussed. Given the increasing frequency and severity of bushfires as a result of climate change, the negative effects of heat and fire damage on fruit tree production are expected to increase. Based on the Australian experience with bushfires in horticultural landscapes, this review outlines proactive responses for minimising bushfire impacts on horticultural production in temperate regions, with particular reference to the Rosaceae family. Adaptation strategies must be planned and set up before orchard establishment and should include defensible space or safety zones around the orchard, as well as internal and external fuel reduction strategies for the orchard lifespan.

Fusarium solani-induced quality deterioration in stored sweet potato is poorly characterized and understood. This study examined the effects of F. solani infection in Xinxiang sweet potato roots during storage. The results showed that while there were no external symptoms following F. solani infection, upon cutting the roots, the cut surface of the infected root rapidly turned black, whereas the untreated control roots remained unaffected. The metabolites and transcriptive differences between F. solani-infected and control sweet potato roots were investigated with high-performance liquid chromatography, metabolomic analysis, and an Illumina Novaseq platform. The results showed that levels of the toxic ipomeamarone accumulated as high as 2.36 mg/kg DW in tissue after F. solani inoculation and 6 days storage at 28 °C, where the control tissue sample did not accumulate any ipomeamarone. Metabolomic analysis showed that isochlorogenic acid and l-tyrosine significantly increased in the infected tissue and associated with the darkening cut surface of the infected sweet potato. In transcriptomic analysis, a total of 13, 14, and 6 key genes in ipomeamarone, isochlorogenic acid, and l-tyrosine biosynthesis pathways, respectively, were identified. A conceptual model elucidating the physiological and molecular mechanism of F. solani-induced quality deterioration in sweet potato is proposed.

Edible coatings of gum Arabic (GA) (6.0 and 8.0 %) with Shirazi thyme (Zataria multiflora) (0.3 and 0.5 %) were assessed as potential postharvest treatments to protect the quality of fresh in-hull pistachio when stored at 85 ± 5 % RH and 2 ± 1 °C for up to 36 days. The results showed that 6 % GA combined with thyme at the concentrations of 0.3 and 0.5 % decreased color change and PPO activity of fresh pistachio in comparison with untreated control fruits. Treated fruit (6 % GA alone with the addition of 0.3 % thyme) also had higher PAL activity and total phenolics. Higher free fatty acid and peroxide value were also found in fruits coated with GA (8 %) containing thyme (0.5 %). Both 0.3 % thyme and 6 % GA solutions were found to be the most effective on saturated and unsaturated fatty acids of kernel.

BACKGROUD: A common lenticel disorder which occurs in the peel of 'Xinli No. 7' pears (Pyrus bretschneideri Rehd.) had not previously been described. Symptoms of this lenticel disorder include enlarging and bulging of the lenticels which results in significant commercial losses. Understanding the physiological basis of lenticel disorder and developing practical methods to control it is crucial for the successful marketing of this pear. RESULTS: The development of this lenticel disorder was found to be closely related to the endogenous ethylene production during storage. 1-Methylcyclopropene (1-MCP) combined with an ethylene absorbent (EA) treatment was found to significantly reduce the development of the disorder by inhibiting the expression of ethylene related genes, PbACS1, PbACS2 and PbACO. It is proposed that the enlarged lenticels may result from increased lignin accumulation in the peel cells, which is inhibited by this combined postharvest treatment. It was shown that the expression of six lignin related genes decreased following the treatment. The results suggest that PbPAL, Pb4CL and PbCAD could be critical in regulating the development of this lenticel disorder. CONCLUSION: Endogenous ethylene plays a key role in the development of this lenticel disorder in 'Xinli No. 7' pear. The enlarged lenticels which is characteristic of this disorder maybe related to increased lignin accumulation in the peel cells, which were inhibited with 1-MCP combined with an EA treatment. These results provide a practical method for managing the development of lenticel disorder in 'Xinli No. 7' pear and helps clarify the developmental mechanisms of this disorder. © 2020 Society of Chemical Industry.

Alternaria alternata and Alternaria citri are two major pathogens affecting sweet cherries and citrus respectively which can lead to significant postharvest losses. Alternaria sp. can be controlled with synthetic fungicides, but due to the development of resistance and the need to find sustainable disease control solutions, alternative control measures need to be developed. We have previously shown that extracts derived from lemon waste (pomace) contain bioactive compounds with high levels of antioxidant, antifungal, and antibacterial activities. The aim of this study was to investigate the in vitro antifungal activity of lemon waste aqueous extracts at different concentrations (14, 7, 3.5 and 1 mg mL-1) against both A. alternata and A. citri. The results showed that lemon aqueous extracts suppressed the mycelial growth and spore germination of both species in a concentration-dependent manner. The mycelial growth inhibition (MGI) for A. alternata varied between 31 to 68%, while for the A. citri the MGI varied between 14 to 49%. Scanning electron microscopy showed that lemon waste extracts affected the morphology of both species.These results indicate that the aqueous extracts of lemon by-products contain bioactive compounds which could be potentially useful as an alternative to synthetic fungicides for controlling Alternaria.

Postharvest fungal rots are the limiting factor in the storage and marketing of sweet cherry fruit, where the major decay organisms are Monilinia fructicola (cause of brown rot) and Botrytis cinerea (cause of gray mold). Postharvest decay can be controlled with postharvest fungicides, but many countries do not have registered postharvest treatments and consumers prefer organic postharvest treatments. In these experiments, a range of organic treatments (a combination of potassium bicarbonate with potassium silicate, a rhamnolipid biosurfactant, a fatty acid soap, and a combination of these treatments) were assessed for their efficacy at 20°C over 7 days on sweet cherry fruit infected with either M. fructicola or B. cinerea. The results from the preventative experiment showed there were significantly lower levels of rot due to Botrytis infection when fruit were dipped in the fatty acid soap while the rhamnolipid treatment also reduced rots due to both fungi at 3 days. Fruit quality was also assessed and a significant negative effect of the combination of potassium bicarbonate with potassium silicate was observed. All treatments from the second experiment failed to significantly reduce fruit rots caused by M. fructicola. These results show limited promise at suppressing postharvest cherry rots and it appears that alternative treatments or combinations of treatments, possibly with physical treatments, are needed to reduce the incidence of decay during storage.

Internal browning is physiological storage disorder in many apples often associated with high CO2 during controlled atmosphere (CA) storage. However the underlying molecular mechanisms leading to internal browning are poorly understood. This study examined changes in the apple transcriptome associated with internal browning related to high CO2 in CA storage by comparing the responses of a CO2 sensitive cultivar 'Han Fu' and the CO2 tolerant cultivar 'Golden Delicious'. The apples were harvested at optimum maturity for long term storage and stored in a CA of 3 % O2 and 6 % CO2 at 4 ¿ for 60 d. The CO2 sensitive 'Han Fu' showed severe browning symptoms within 30 d storage in CA, while no internal browning symptoms were detected in 'Golden Delicious' even after 60 d storage under the same storage conditions. PPO activity was higher in 'Han Fu' apples after 30 d storage. Differences in the expression profile between cultivars were assessed using RNA-sequencing techniques to identify candidate genes associated with internal browning in a cultivar specific manner. The RNA sequencing results showed that higher expression of the related to apetala 2 (RAP 2) and pyruvate decarboxylase (PDC) encoding genes in 'Golden Delicious' apples were associated with higher CO2 tolerance in this cultivar. Conversely, the higher expression of key genes from lactate production (lactate dehydrogenase, LDH), lipid catabolic (patatin-like protein, PLP), polyphenol biosynthesis (phenylalanine ammonia-lyase, PAL), polyphenol oxidase (PPO) were associated with the internal browning development in 'Han Fu' apple in CA storage condition. A conceptual model elucidating the molecular mechanism of browning development in 'Han Fu' and CO2 acclimation in 'Golden Delicious' during storage in CA is proposed. The further elucidation of this mechanism will lead to a theory to optimize cultivar breeding in apple.

Antimicrobial activity of epigallocatechin-3-gallate (EGCG) and two native Australian plants blueberry ash (BBA) fruit and macadamia (MAC) skin extracts against nine pathogenic and spoilage bacteria and seven strains of fungi, using an agar well diffusion assay were investigated. The minimum inhibitory concentrations (MIC) of these compounds were calculated using 96-well microtiter plates method. Finally, active antimicrobial packaging films were prepared by incorporation of EGCG, BBA and MAC extracts at 1-, 2-, 3-, and 4-fold of their correspondence MIC values into edible films based on pea starch and guar gum (PSGG). The antimicrobial activity of films was investigated against target microorganisms by agar disc diffusion technique and quantified using the viable cell count assay. Among the test microorganisms, Salmonella typhimurium and Rhizopus sp. were the most resistance to active films. Films containing EGCG showed the highest activity against all test strains. As the concentration of compounds increased higher than 2¿×¿MIC, the mechanical characteristics of the films were affected considerably. The results indicated that EGCG-PSGG, BBA-PSGG and MAC-PSGG films can be used as active food packaging systems for preserving food safety and prolonging the shelf-life of the packaged food.

The influence of process variables (pea starch, guar gum and glycerol) on the viscosity (V), solubility (SOL), moisture content (MC), transparency (TR), Hunter parameters (L, a, and b), total color difference (dE), yellowness index (YI), and whiteness index (WI) of the pea starch based edible films was studied using three factors with three level Box-Behnken response surface design. The individual linear effect of pea starch, guar and glycerol was significant (p < 0.05) on all the responses. However, a value was only significantly (p < 0.05) affected by pea starch and guar gum in a positive and negative linear term, respectively. The effect of interaction of starch × glycerol was also significant (p < 0.05) on TR of edible films. Interaction between independent variables starch × guar gum had a significant impact on the b and YI values. The quadratic regression coefficient of pea starch showed a significant effect (p < 0.05) on V, MC, L, b, dE, YI, and WI; glycerol level on dE and WI; and guar gum on dE and SOL value. The results were analyzed by Pareto analysis of variance (ANOVA) and the second order polynomial models were developed from the experimental design with reliable and satisfactory fit with the corresponding experimental data and high coefficient of determination (R2) values (>0.93). Three-dimensional response surface plots were established to investigate the relationship between process variables and the responses. The optimized conditions with the goal of maximizing TR and minimizing SOL, YI and MC were 2.5 g pea starch, 25% glycerol and 0.3 g guar gum. Results revealed that pea starch/guar gum edible films with appropriate physical and optical characteristics can be effectively produced and successfully applied in the food packaging industry.

Background Sweet cherries (Prunus avium L.) are a nutritious fruit which are rich in polyphenols and have high antioxidant potential. Most sweet cherries are consumed fresh and a small proportion of the total sweet cherries production is value added to make processed food products. Sweet cherries are highly perishable fruit with a short harvest season, therefore extensive preservation and processing methods have been developed for the extension of their shelf-life and distribution of their products. Scope and approach In this review, the main physicochemical properties of sweet cherries, as well as bioactive components and their determination methods are described. The study emphasises the recent progress of postharvest technology, such as controlled/modified atmosphere storage, edible coatings, irradiation, and biological control agents, to maintain sweet cherries for the fresh market. Valorisations of second-grade sweet cherries, as well as trends for the diversification of cherry products for future studies are also discussed. Key findings and conclusions Sweet cherry fruit have a short harvest period and marketing window. The major loss in quality after harvest include moisture loss, softening, decay and stem browning. Without compromising their eating quality, the extension in fruit quality and shelf-life for sweet cherries is feasible by means of combination of good handling practice and applications of appropriate postharvest technology. With the drive of health-food sector, the potential of using second class cherries including cherry stems as a source of bioactive compound extraction is high, as cherry fruit is well-known for being rich in health-promoting components.

A short, high carbon dioxide (CO2) pre- Treatment in combination with cold storage has been shown to be an effective disinfestation treatment to kill quarantine pests such as fruit flies in horticultural produce. However, the effects of high CO2 and cold treatments on fruit quality, including the development of chilling injury and offflavours, needs to be thoroughly examined. In this study, Navel oranges were treated with either air or 95% CO2 in air for 48 h at 2°C then stored in air for up to 18 days at 2°C. Following treatment and storage, there was no evidence of any chilling injury and no significant changes in fruit soluble solids content (SSC) or titratable acidity (TA). Another storage trial examined the time taken for Navel oranges to recover from the 95% CO2 treatment. In this experiment, fruit were stored at 2°C and ventilated with either air or 95% CO2 in air for 70 h. After treatment, the fruit were stored in air and sampled after 1, 2, 3, 4, 5, 8, 9 and 10 days. The results showed that after the high CO2 treatment, the levels of acetaldehyde significantly increased in CO2- Treated fruit and ethanol whereas levels of ethanol decreased. However, within three days storage in air, levels of acetaldehyde returned to pre- Treatment concentrations. These results show the potential of using high CO2 combination treatments as postharvest disinfestation treatments, which do not adversely affect fruit quality after treatment and storage. However more research is recommended to fully understand these fruit responses and their role in overall fruit quality.

The storage of citrus is an important component in the supply chain. It is often necessary to store oranges for distant markets, however a number of fruit quality issues can occur during storage and transport. In this trial, 'Navelina' oranges were subjected to a constant low flow of air or 0.5 µL L-1 ethylene at either 5 or 20°C and stored for four weeks. TSS, TA, peel colour and ethanol content were measured every week. In addition informal taste tests on the juice from treated fruits were conducted after three and four weeks of storage. There was no effect of continuous ethylene treatment on TSS or TA levels at either storage temperature, however ethylene treated fruits had significantly higher ethanol levels at 5°C storage. The results of the informal sensory tests showed consumers had a clear preference for air- Treated fruit after three and four weeks of storage across both storage temperatures. The levels of fruit rots were low throughout the experiment and not affected by ethylene treatment. These results show that although many of the traditional quality parameters of citrus quality were generally not affected by continuous ethylene treatment, its effects on off-flavours and consumer acceptability warrant continuing research work.

Consistent fruit size and high soluble solids concentration (SSC) in peaches and nectarines are important components of fruit quality and consumer acceptability. At harvest, differences in size between fruit within a tree can be greater than 100 g, and SSC can vary by as much as 5-10% w/w, even in well managed commercial orchards. The causes of variation in fruit quality are complex and yet to be fully determined. In this paper, we discuss the influence of physiological, environmental and anatomical factors on variation in fruit size and SSC within trees. Experimental data from recent orchard trials and histological studies conducted on commercial nectarine cultivars demonstrate the specific effects of these factors on fruit quality. Variation in SSC between fruit within a tree was found to be influenced by differences in fruit sink efficiency as determined by local carbohydrate availability, relative sink size of competing fruit (i.e., cell number), sink activity (i.e., developmental stage and fruit temperature), and differences in cell size distribution within mesocarp tissue. An empirical model based on these factors and their interactions during fruit growth may explain much of the variation in fruit quality normally found in commercial peach and nectarine trees.

The effects of different solvents on the recovery of (i) extractable solids (ES), (ii) total phenolic compounds (TPC), (iii) total flavonoid content (TFC), (iv) vitamin C, and (v) antioxidant activity from lemon pomace waste were investigated. The results revealed that solvents significantly affected the recovery of ES, TPC, TFC, and antioxidant properties. Absolute methanol and 50% acetone resulted in the highest extraction yields of TPC, whereas absolute methanol resulted in the highest extraction of TFC, and water had the highest recovery of vitamin C. 50% ethanol, and 50% acetone had higher extraction yields for TPC, and TFC, as well as higher antioxidant activity compared with their absolute solvents and water. TPC and TFC were shown to be the major components contributing to the antioxidant activity of lemon pomace.

Summary: Gac (Momordica cochinchinensis Spreng.) is a tropical vine originating from South and South-East Asia. Gac fruit has traditionally been used in Asia to provide red colour for cuisines and enhance visional health. Recently, Gac fruit has emerged as a potential source of carotenoids, especially lycopene and ß-carotene. Carotenoids and other identified bioactives from this fruit including phenolics, flavonoids and trypsin inhibitors are associated with many beneficial bioactivities such as antioxidant, anticancer and provitamin A activities. In addition to the traditional utilisation, commercial products like Gac powder and Gac oil have been manufactured as natural colourants and medicinal supplements. This paper is a review of the scientific literature on the nutritional composition, biological activities and processing of Gac fruit.

© 2015 Elsevier Ltd. Ascorbic acid and calcium ascorbate are used commercially in dip solutions to inhibit the development of browning on the surface of fresh-cut apple slices. A sodium chloride dip has also been shown to inhibit browning and this study examined its interaction with various forms of ascorbate on the postharvest life of apple slices. Comparison of the effectiveness of ascorbate moieties showed that the concentration of ascorbic acid required to achieve any desired postharvest life was twice that of calcium ascorbate, but calcium, sodium and potassium ascorbates were equally effective in inhibiting browning. The inclusion of 0.1mol/l sodium chloride into a dip requires only half the concentration of ascorbate to maintain the same postharvest life. The very low cost of sodium chloride means that materials in such a dip are about half the cost of an ascorbate-only solution. Since 0.1mol/l sodium chloride does not affect the taste of apple slices and is an allowable food additive, it should be considered as a cost effective partial replacement of ascorbate in commercial dips. There also seems to be a cost advantage of sodium ascorbate over calcium ascorbate.

BACKGROUND: The postharvest life of fresh-cut apple slices is limited by browning on cut surfaces. Dipping in halide salt solutions was examined for their inhibition of surface browning on 'Granny Smith' apple slices and the effects on biochemical factors associated with browning. RESULTS: Delay in browning by salts was greatest with chloride = phosphate > sulfate > nitrate with no difference between sodium, potassium and calcium ions. The effectiveness of sodium halides on browning was fluoride > chloride = bromide > iodide = control. Polyphenol oxidase (PPO) activity of tissue extracted from chloride- and fluoride-treated slices was not different to control but when added into the assay solution, NaF > NaCl both showed lower PPO activity at pH 3-5 compared to control buffer. The level of polyphenols in treated slices was NaF > NaCl > control. Addition of chlorogenic acid to slices enhanced browning but NaCl and NaF counteracted this effect. There was no effect of either halide salt on respiration, ethylene production, ion leakage, and antioxidant activity. CONCLUSION: Dipping apple slices in NaCl is a low cost treatment with few impediments to commercial use and could be a replacement for other anti-browning additives.

Response surface methodology (RSM) was used to optimise the parameters for phenolic extraction from apple pomace using water, extraction time, extraction temperature and pomace to water ratio. The responses from these parameters were evaluated by measuring the total phenolic content and antioxidant activity of extracts. The optimum extraction parameters found in this study were 30 min extraction time, 85°C extraction temperature and 0.05 pomace to water ratio. A verification experiment of these extraction parameters was performed, along with three other corroborative sets of parameters. There was no significant difference between the predicted and actual values, confirming that the predictions using the models obtained through RSM were valid.

Variation in soluble solids concentration (SSC) in fruit within a tree can significantly reduce the proportion of harvested peach and nectarine that meets consumer requirements. Accumulation of SSC during fruit growth may be influenced by cell number and size in mesocarp tissue. The relationship between sucrose, the major component of SSC, and both cell size and number was investigated in Prunus persica 'Summer Flare 26' nectarine. Variation in sucrose concentration within, and between fruit, was partly explained by cell size as measured by cell area or cell number per fixed area of tissue. This correlation was consistent within fruit categorised as ripe and unripe. Sucrose concentration was moderately correlated to cell number per fixed area in small and medium-sized fruit but not in large fruit. Total sucrose content in fruit within three positions in a tree was strongly correlated to total cell number but the relationship was mediated by cell size, particularly in fruit from the middle and bottom of the tree. Sink size (i.e., total cell number) and sink activity (i.e., cell size), were able to explain 77% of variation in sucrose content between fruit within a single tree. Further anatomical studies on a larger fruit population are being conducted to confirm these findings.

This study aimed to evaluate the effects of extraction time, extraction temperature and water to pomace ratio on the total phenolic content and antioxidant activity of apple pomace aqueous extracts. Pomace was extracted using water (20-90°C) for 5-60 min. The extracts were evaluated for their total phenolic content (Folin Ciocalteu assay) and antioxidant activity (DPPH, FRAP and ABTS assays). A methanol extract of the pomace was used as control. It was found that water to pomace ratio (p < 0.001), extraction temperature (p < 0.001) and time (p < 0.001) were significant factors in extracting the polyphenolics from apple pomace, with the optimum extraction conditions utilising water to pomace ratio of 20:1 at 90°C for 15 min yielding the most polyphenolic compounds (1148 µg g-1 fresh pomace Gallic Acid Equivalents). These results indicated that water was a good solvent for extracting polyphenolics from apple pomace, however, as compared to the methanol extract (control), the aqueous extracts had lower total phenolic content (63%) and antioxidant activity (73-80%).

The aims of this study were to develop optimal conditions for decaffeination and spray drying procedures to produce decaffeinated and high caffeine powders from green tea (Camellia sinensis). Blanching the tea leaves with water at 100. °C for 4. min at a water-to-tea ratio of 20:1. mL/g removed 83% of the caffeine while retaining 94% of the catechins. The optimal spray drying conditions, which gave the highest yield of green tea powder and the highest concentrations of the naturally occurring epistructured catechins were found to be 180. °C for the inlet temperature and 115. °C for the outlet temperature. Using these optimal conditions, a decaffeinated green tea powder (7 mg/g caffeine) and a high caffeine powder (95. mg/g) were produced. These two green tea powders had excellent physical properties and could be used as instant teas by consumers or utilized in the food, cosmetic and nutraceutical industries. © 2012 Elsevier B.V.

The pH of the aqueous brewing solution was maintained at values ranging from 1 to 9 during the green tea extraction and the effects on the tea's extracted constituents were studied. The epistructured catechins were stable under acidic conditions but epimerized or degraded at pH. =. 6. The extractable solids contained more epistructured catechins at pHs 3-5 but more non-epistructured catechins at pHs 6-7. More tea cream was obtained at pH 1 but the concentration of catechins, caffeine and theanine was low in this fraction. Therefore, to maximize the extraction of the epistructured catechins and to minimize their epimerization and degradation and to maximize the extraction of caffeine and theanine, the results suggest that the pH should be maintained between 3 and 5.3 during the aqueous brewing process. © 2012 Elsevier Ltd.

Cold storage is essential for the successful distribution of stonefruit to distant markets; however most cultivars suffer chilling injury (CI), commonly referred to as low temperature breakdown (LTB). LTB is a significant problem for industry and the genetic factors responsible for its onset are not understood. Treatment of stonefruit with the ethylene antagonist, 1-methylcyclopropene (1-MCP) before cold storage has been shown to differentially affect the development of CI in peaches and plums. 1-MCP treatment increases the incidence of LTB in peaches but reduces it in plums (Fernández-Trujillo and Artés, 1997; Fan et al., 2002). These observations were confirmed and preliminary research into the effects of 1-MCP and cold storage on gene expression is reported herein. © ISHS 2012.

This study investigated the effect of a postharvest 1-methylcyclopropene (1-MCP) treatment, controlled atmosphere and storage time on the total antioxidant activity (TAA) and phenolic compounds in the peel and flesh of 'Cripps Pink' apples (Malus domestica Borkh.). Preclimacteric apples were harvested and treated with 1-MCP then stored in normal atmosphere (NA) or controlled atmosphere (CA) at 0 °C for up to 160 days. In general, the level of phenolics decreased by 9% in the peel and significantly increased twofold in the flesh during cold storage, regardless of storage atmosphere or 1-MCP treatment. However, treatment with 1-MCP resulted in significantly lower concentrations of chlorogenic acid and procyanidin B2 in apple flesh, and catechin and epicatechin in the peel compared to the control fruits. There was no significant effect of CA on the phenolic compounds during long-term storage, except for quercetin 3-galactoside and quercetin 3-glucoside, which both significantly increased under CA storage. Total antioxidant activity (TAA) is an important nutritional attribute of apples in the human diet. The results showed that TAA in the peel tissue was about eight times higher than that of the flesh, with mean values of 4.75 g TE/kg FW and 0.56 TE/kg FW, respectively. The TAA in both the peel and flesh tissue increased significantly during storage by 40% and 70%, respectively. The storage atmosphere did not significantly affect TAA in either the peel or flesh, whilst the 1-MCP treatment significantly reduced the TAA in the peel tissue only. These results show the beneficial combined effects of pre-storage 1-MCP treatment and CA on 'Cripps Pink' apple phenolic composition and antioxidant capacity during long term storage. © 2011 Elsevier Ltd. All rights reserved.

Bruising is the major cause of down grading of apple fruit quality. It is a serious commercial problem in apple handling and marketing, as small bruises in the flesh can often be masked by highly coloured and dark peel. Although much of this damage is preventable (careful handling and grading), bruising still remains a significant commercial problem for the apple industry. While a number of factors affect bruise susceptibility or the potential of apples to bruise, this study specifically examined the effect of time of harvest through the day and storage temperature on bruise development of 'Cripps Pink' and 'Granny Smith' apples. Bruises were created using a standardised impact, and bruise volume was related to impact energy. Fruit harvested later in the day were more tolerant of bruising than those harvested in the morning suggesting that bruise susceptibility is related to cell turgor. Bruise susceptibility of 'Granny Smith' apples was greater at 5°C than at higher or lower temperatures, whilst susceptibility of 'Cripps Pink' tended to be greater at higher temperatures used (12 and 20°C), thus the interactions between bruise susceptibility and temperature appear to be variety-specific. These preliminary results show a need to understand how bruise susceptibility changes during postharvest handling and storage for each variety. Further exploration and adoption of this information during harvest and packing will be of great assistance to minimise apple bruising.

Mature green bananas (Musa sp., AAA group, Cavendish subgroup, cultivar 'Williams') were used to examine the uneven de-greening of banana peel treated with 1-methylcyclopropene (1-MCP). After ethylene treatment (200 µl litre-1 for 24h at 20°C) bananas were allocated different treatment units: 1-MCP treatment (200 nl litre-1, 20°C, 24h); nitrogen treatment (O2<0.1%, 20°C, 24h); ethanol treatment (0.3 ml litre-1, 20°C, 24h); chilling treatment (1±1°C, 24h); and untreated control (20°C). After these post-ripening treatments (24h), fruit were stored in perforated plastic bags at 20°C. Ethylene, respiration, ethanol and acetaldehyde production, skin colour, chlorophyll fluorescence, chlorophyll content, and flesh firmness were assessed at regular intervals. The post-ripening nitrogen atmosphere and chilling treatment (24h) led to a transient delay of ripening compared to ethanol -treated fruit and untreated control fruit. However by 1 week of shelf life at 20°C, there were no differences between non-1-MCP treated fruit. No differences in the accumulation of acetaldehyde and ethanol were detected during storage. Ethylene production was not affected by the 1-MCP treatment 24h after initiating ripening. However peel de-greening, the decrease in chlorophyll content and chlorophyll fluorescence were delayed with 1-MCP treatment. There was some general browning throughout the 1-MCP treated peel in both the green and yellow areas of the ripening peel. It appears the 1-MCP treated peel 24h after ethylene treatment may still undertake some normal senescence that occurs during banana ripening. © 2007 Taylor & Francis Group, LLC.

The date plum persimmon fruit (Diospyros lotus L., fam: Ebenaceae) is cultivated throughout northern of Turkey for its edible fruits. Sugars and organic acids were measured during fruit maturation and ripening using HPLC. The analyses showed that fructose and glucose were the main sugars accumulated in the fruit pulp. Fructose and glucose increased up to 43,552.8 mg.100 g -1 fw and 35,450.8 mg.100 g-1 fw respectively during fruit ripening. Sucrose content remained relatively low and decreased during ripening. The major organic acids found in date plum fruit were citric and malic acids, which increased through the immature and midripe maturity, and then the levels decreased in the overripe fruit. Palmitic acid (16:0), palmitoleic acid (16:1), stearic acid (18:0), oleic acid (18:1) and linolenic acid (18:3) were among the major fatty acids determined by GC throughout the maturation and ripening of the fruits. The levels of these fatty acids were found to be significantly different (P=0.05) between the three maturity stages. The fruits displayed the level of linoleic acid (0.7%) in low and a-linolenic acid (17.8%) in higher quantities, and the combined levels of linoleic and a-linolenic acid comprised ~19% (120.1 µg.g-1 dw) of the total fatty acid content in the over ripened fruit. These results show that naturally parthenocarpic date plum fruits have high levels of sugars and organic acids and moderate levels of fatty acids that significantly changed during maturation and ripening. This information can be used by nutritionalists and food technologists to improve the nutrition of local people and develop food products that would be beneficial to human health. © Springer-Verlag 2005.

Consumption of certain phenolics in the diet is considered beneficial to human health. In this study, individual phenolics were measured by diode-array HPLC at monthly intervals in the peel of Granny Smith, Lady Williams, and Crofton apple cultivars stored in air at 0 °C for 9 months. The concentrations of total phenolics significantly differed among the cultivars examined, with Lady Williams peel having significantly more phenolics (over 4000 µg·g-1 peel fresh weight) than Crofton (2668 µg·g-1 peel fresh weight) and Granny Smith, which had the lowest concentration of total phenolics (1275 µg·g-1 peel fresh weight). There were also significant differences in individual phenolics among cultivars and during storage. Quercetin glycosides were the only flavonols identified, with quercetin rhamnoglucoside being the most abundant phenolic in the peel. Chlorogenic acid was the major cinnamic acid derivative, with high concentrations, up to 412 µg·g-1 peel fresh weight, in Crofton peel. A pre-storage diphenylamine (DPA)-treatment had few significant effects on peel phenolic metabolism. Where differences did occur, fruit treated with DPA retained higher concentrations of total peel phenolics during storage than fruit not treated with DPA. Storage of all cultivars for up to 9 months in air at 0 °C induced few significant changes in the peel phenolic concentrations. This indicates that phenolic metabolism in apple peel is relatively stable, and the health benefits of phenolics in apple peel should be maintained during long-term storage.

The relationship between ethylene and peel a-farnesene concentrations was examined by applying diphenylamine (DPA) and the ethylene analogue, propylene at varying times after harvest to superficial scald (scald) susceptible 'Granny Smith' apples (Malus domestica Borkh.) stored at 10°C. Delaying DPA application after harvest had no large effect on ethylene or on peel a-farnesene production. Propylene advanced fruit ripening and promoted an increase in peel a-farnesene concentration before endogenous internal ethylene production, suggesting that ethylene has an important regulatory role in a-farnesene production, but their biosynthetic pathways are controlled independently. The effect of delayed DPA application (4 and 7 days after harvest) on the relationship between ethylene and peel a-farnesene was further examined at both a scald-inducing temperature (0°C) and a non-scald-inducing temperature (10°C) with 'Granny Smith' and the scald resistant 'Crofton' cultivar. Similarly a delayed DPA application had only minor effects on internal ethylene and peel a-farnesene concentrations. The relationship between internal ethylene and peel a-farnesene concentration was dependent on storage temperature, and the type of relationship was independent of cultivar. However, the magnitude of the relationship between cultivars was significantly different ('Granny Smith' produced significantly more a-farnesene than 'Crofton') and may be related to scald development. © 2001 Elsevier Science B.V.

Mature green bananas were treated with the ethylene antagonist 1- methylcyclopropene (1-MCP) at intervals during the 24 h period after initiation of ripening with propylene. Following 1-MCP treatment, the fruits were ripened in either air or propylene while ethylene, carbon dioxide, and volatile production and composition were monitored at regular intervals. The application of 1-MCP significantly delayed and suppressed the onset and magnitude of fruit respiration and volatile production. The 1-MCP treatments also caused a quantitative change in the composition of the aroma volatiles, resulting in a substantial increase in the concentration of alcohols and a decrease in their related esters. The results showed that ethylene has a continuing role in integrating many of the biochemical processes that take place during the ripening of bananas.

This work discusses the influence of the ethylene antagonist 1-methyl-cyclopropene (1-MCP) and the timing of its application on the ripening related parameters in bananas such as ethylene, CO2 and volatiles production, volatiles composition and skin color. The preclimacteric application of 1-MCP to banana fruit delayed the onset of the common parameters associated with ripening, namely ethylene and aroma volatiles production, respiration and skin color changes. The extent of these delays depended on the developmental stage of the fruit at application and on whether the fruit was subsequently challenged with the ethylene analogue, propylene. The application of 1-MCP to bananas continuously challenged with propylene delayed the onset of ripening and volatiles production by two days. When preclimacteric mature green bananas were allowed to naturally ripen in the absence of propylene, 1-MCP delayed the onset of ripening by nine days. Hence 1-MCP application offers a convenient means of examining the role of ethylene in ripening and offers an excellent opportunity to differentiate and clearly study the biochemical and physiological interactions occurring in ripening fruit. © 1998 Elsevier B.V. All rights reserved.

Mature green bananas (Musa sp., AAA group, Cavendish subgroup, cultivar 'Williams') were treated with 1-methylcyclopropene (1-MCP) at a preclimacteric stage and at intervals of 6, 12 and 24 h after propylene treatment (HAPT) to initiate ripening. The fruit were then allowed to ripen in air or propylene. Ethylene production, respiration rates, peel colour and total volatiles production were monitored during ripening. 1-MCP significantly delayed the onset and affected the rate and magnitude of several physiological responses. Application of 1-MCP at a preclimacteric stage or 6 and 12 HAPT delayed onset of the ethylene and respiratory climacterics, peel degreening and total volatiles production. Application of 1-MCP 24 HAPT after autocatalytic ethylene had commenced did not inhibit development of the ethylene and respiratory climacterics, but delayed colour development and total volatiles production. In all cases, when 1-MCP treated fruit did produce ethylene, rates of production were significantly enhanced, whilst rates of respiration were always lower. Onset of total volatiles production was delayed and the rates were lower in all 1-MCP treated fruit. Degreening of the peel was significantly delayed and disrupted by 1-MCP. The results show that these ripening related processes, once engaged with autocatalytic ethylene production, become partially independent of further ethylene action. Some possible reasons for the failure of 1-MCP treated fruit to ripen normally are discussed.