Influence of environmental conditions on the quality attributes and shelf life of ‘Goldfinger’ bananas

‘Goldfinger’ bananas (Musa accuminata, FHIA-01) were harvested, held for 14–22 d at five temperatures and a constant relative humidity (RH) or at five RHs and a constant temperature and evaluated for quality attributes. The objectives of this work were to: (1) create quality curves for bananas stored at chilling and non-chilling temperatures; (2) create quality curves for bananas stored at a non-chilling temperatures and different RHs; (3) identify which sensory quality attribute limits the shelf life and marketability of bananas when stored at chilling and non-chilling temperatures or at different RHs; and (4) correlate subjective sensory attributes with quantitative quality measurements. Results from this study showed that temperature had a more significant impact on the quality of banana than RH. Bananas stored at temperatures higher than 10 °C were yellower and softer but had lower starch and higher soluble solids and total sugar content than those stored at lower temperatures. When stored at 2, 5 and 10 °C, bananas developed chilling injury (CI) and abnormal ripening when transferred to 20 °C. The most remarkable impact of RH on banana quality was on weight loss, which was significantly higher in fruit held below 80% RH than in fruit held in 87 or 92% RH. CI was the first sensory quality attribute to reach the limit of acceptability in fruit stored at 2, 5 and 10 °C, whereas color changes and softening limited the shelf life of bananas stored at 15 and 20 °C. Changes in color and/or softening were the two main sensory attributes that limited the shelf life of bananas stored at different RHs. Overall, for maximum quality and shelf life bananas should be stored at or above 15 °C and 92% RH. Finally, sensory attributes can be used to estimate peel color, pulp softening and sweetness, while SSC can be used as a reliable and simple method to estimate the total sugar content of bananas stored at different temperatures or different RHs.     

Postharvest conditioning of Satsuma mandarins for reduction of acidity and skin puffiness

Postharvest temperature and relative humidity (RH) treatments were tested for their capacity to increase the soluble solids content:titratable acidity ratio (SSC:TA ratio) and/or reduce skin puffiness of New Zealand grown ‘Miho’ Satsuma mandarin. Fruit of low SSC:TA (approximately 6.8:1) harvested in 2001 and 2002 were held at 18 or 30 °C at low (approximately 65%) or high (>95%) RH for 3 or 5 days, followed by 2 days at 10 °C (88–92% RH). In 2002, an additional treatment of high and low RH at 10 °C was examined. Treatments at 30 °C, irrespective of RH, resulted in increased SSC:TA ratios in the fruit as a result of a decrease in titratable acidity, largely a decrease in citric acid. There was little effect of temperature on SSC and the levels of individual sugars. There was no significant effect of RH on either TA or SSC. The altered metabolism was also seen in an elevated respiratory CO₂ output at 30 °C, but a decreased CO₂ output once these fruit were transferred to 10 °C, in comparison with fruit treated at lower temperatures.At 30 °C, weight loss was up to 8.5% after 5 days under low RH, but <4% under high RH. Fruit with >4% weight loss tended to have an unacceptable level of dehydration of the skin. After 5 days at 30 °C and low RH, skin puffiness, quantified from magnetic resonance images taken before and after treatment, was reduced, although fruit tended to have soft skin that could be more prone to damage.It is concluded that short high temperature treatments such as 3–5 days at 30 °C can significantly raise the SSC:TA ratio in Satsuma mandarin through a reduction in TA, and conducting these treatments under a RH >90% minimises the risk of excessive weight loss and softening of the skin.     

Influence of film wrapping and fludioxonil application on quality of pomegranate fruit

Pomegranates are sensitive to low temperatures. When fruit are exposed to temperatures below 5–6 °C chilling injury appears as pitting of the skin, browning of the white segments separating the arils and discoloration of the arils, and husk scald, which generally is more severe at temperatures of 6–10 °C. The main objective of this work was to assess the effectiveness of individual film packaging, applied as a stand alone treatment or in combination with fludioxonil, on reducing the occurrence of husk scald, weight loss and decay. Fruit were dipped in an aqueous mixture containing 600 mg L^?1 fludioxonil, wrapped or not wrapped with a polyolephinic heat-shrinkable film and stored at 8 °C and 90% RH for 6 or 12 weeks plus one additional week of simulated shelf-life at 20 °C and 65–70% RH. Respiration rate decreased both in cold storage and at 20 °C. Ethylene production was not detected during cold storage; its rate increased upon transfer to 20 °C, but results were inconsistent. Control fruit deteriorated at a very high rate, due to excessive weight loss, skin browning and decay. Film wrapping almost completely inhibited weight loss and husk scald and preserved fruit freshness for the whole storage time. There was no statistical difference in decay incidence between wrapped and control fruit after 6 or 12 weeks of storage and after the first shelf-life, while after the second shelf-life, wrapped fruit had significantly higher decay levels. By contrast, fludioxonil, both alone and in combination with wrapping, effectively controlled mold development, resulting in 50–67% less decay than control fruit after 12 weeks at 8 °C plus one week shelf-life. Control fruit showed minor changes in nutritional compounds as well as in total polyphenols, anthocyanins and antioxidant activity, while higher losses were detected in film-wrapped fruit during storage at 20 °C.     

Effectiveness of 1-MCP treatments on ‘Bartlett’ pears as influenced by the cooling method and the bin material

Wooden bin-stored ‘Bartlett’ pears (Pyrus communis L.) were hydrocooled (HC) or forced-air cooled (FAC) and immediately treated or not with 1-methylcyclopropene (1-MCP) for 24 h. 1-MCP gas concentrations used were 0, 0.3 or 0.6 μL L^?1 (called 0, 0.3 and 0.6, respectively). Fruit were subsequently kept at 20 °C for 20 d or stored at ?0.5 °C and 95% RH for 60, 90, 120 or 150 d. After cold storage, fruit were kept at 20 °C for up to 16 d for further ripening. In another experiment, pears stored in wooden bins (W) or plastic bins (P) were all hydrocooled, treated or not with 0.5 μL L^?1 1-MCP (called 0.5 and 0, respectively), stored at ?0.5 °C and 95% RH for 0, 30, 60, 90 or 120 d, and transferred to 20 °C for further ripening. In FAC pears, increasing 1-MCP concentrations usually resulted in delayed increases in ethylene production and lower ethylene production rates, as well as delayed softening. In contrast, HC-0.3 pear firmness did not differ from that of HC-0 fruit after cold storage. Generally, HC-0.3 pears displayed higher ethylene production and lower firmness values than FAC-0.3 pears after a 7-d exposure to 20 °C, regardless the length of cold storage. FAC-0.6 pears always showed lower ethylene production rates and higher flesh firmness values than HC-0.6 fruit. Soluble solids concentration was not consistently affected by 1-MCP. FAC-0.3 and HC-0.6 fruit showed higher titratable acidity values than HC-0 fruit after 0, 60, 120 and 150 d of cold storage plus 7 d at 20 °C. Effectiveness of 1-MCP treatments on HC pears was influenced by the bin material; P-0.5 pears were firmer than W-0.5 pears after 7 d at 20 °C, regardless the length of the cold storage. HC-0.5 fruit exposed to ?0.5 °C for 90 d reached eating quality (firmness ≤23 N) by day 7 if placed in W, and by day 21 when stored in P. Results and previous evidence suggest that wet wooden bin material may represent a major though unpredictable source of 1-MCP sorption that could bind a significant percentage of the 1-MCP applied. When used at relatively low doses 1-MCP partial removal by wet wooden bins can compromise the application effectiveness for controlling ethylene action.     

The susceptibility of kiwifruit to low temperature breakdown is associated with pre-harvest temperatures and at-harvest soluble solids content

At harvest, kiwifruit may be susceptible to a physiological storage disorder termed low temperature breakdown (LTB). The incidence and severity of LTB in ‘Tomua’ kiwifruit was quantified following storage at 0 °C. Fruit were harvested at weekly intervals across the period of fruit maturation in 2001 and 2002. The environmental temperatures during the two harvest seasons differed considerably. In 2001, the autumn was warm, and a period of cool (<7 °C) nights in the middle of the harvest period coincided with both a reduced incidence of LTB and an increased rate of soluble solids content (SSC) accumulation. In 2002, there was a more consistent increase in hours <7 °C through the harvest season, coincident with a more consistent reduction in the incidence of LTB and increase in SSC. The incidence of LTB was lower in fruit from later harvests that had a higher SSC at harvest. The combined 2001 and 2002 data for hours <7 °C and SSC at harvest relationships with LTB incidence after storage both fitted sigmoidal models. It is concluded that acclimation by low pre-harvest temperatures increases the rate of SSC accumulation and reduces the susceptibility of ‘Tomua’ kiwifruit to LTB.     

Postharvest nitric oxide fumigation delays fruit ripening and alleviates chilling injury during cold storage of Japanese plums (Prunus salicina Lindell)

We investigated the effects of nitric oxide (NO) fumigation on fruit ripening, chilling injury, and quality of Japanese plums cv. ‘Amber Jewel’. Commercially mature fruit were fumigated with 0, 5, 10, and 20 μL L⁻¹ NO gas at 20 °C for 2 h. Post-fumigation, fruit were either allowed to ripen at 21 ± 1 °C or were stored at 0 °C for 5, 6, and 7 weeks followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation, irrespective of concentration applied, significantly (P ≤ 0.5) suppressed respiration and ethylene production rates during ripening at 21 ± 1 °C. At 21 ± 1 °C, the delay in ripening caused by NO-fumigation was evident from the restricted skin colour changes and retarded softening in fumigated fruit. NO treatments (10 and 20 μL L⁻¹) delayed the decrease in titratable acidity (TA) without a significant (P ≤ 0.5) effect on soluble solids concentration (SSC) during ripening. During 5, 6, and 7 weeks of storage at 0 °C, NO-fumigation was effective towards restricting changes in the ripening related parameters, skin colour, firmness, and TA. The individual sugar (fructose, glucose, sucrose, and sorbitol) profiles of NO-fumigated fruit were significantly different from those of non-fumigated fruit after cold storage and ripening at 21 ± 1 °C. CI symptoms, manifest in the form of flesh browning and translucency, were significantly lower in NO-fumigated fruit than in non-fumigated fruit after 5, 6, and 7 weeks storage followed by ripening for 5 d at 21 ± 1 °C. NO-fumigation was effective in reducing decay incidence in plums during ripening without storage and after cold storage at 0 °C for 5, 6, and 7 weeks. In conclusion, the postharvest exposure of ‘Amber Jewel’ plums to NO gas (10 μL L⁻¹) delayed ripening by 3–4 d at 21 ± 1 °C, and also alleviated chilling injury symptoms during cold storage at 0 °C for 6 weeks.     

Opening of cut Iris x hollandica flowers as affected by temperature,dry storage,and light

Flower opening in Iris (Iris x hollandica) depends on elongation of the pedicel + ovary. This elongation lifts the bud above the point where the sheath leaves no longer mechanically inhibit lateral tepal movement. We here report on the effects on flower opening of storage at various temperatures, of holding the flowers dry rather than in water, and of a 12 h light/dark cycle instead of darkness, in cv. Blue Magic. During 3 d of storage in darkness at 11 °C or 6 °C the flowers placed in water opened. Flowers stored at 3.0 °C did not open during the storage period but did so during subsequent vase life at 20 °C. Flowers stored in water at 0.5 °C remained closed, even during subsequent vase life at 20 °C. None of the flowers that were stored dry for 3 d at 15 °C, 11 °C, 6 °C, 3 °C or 0.5 °C opened during vase life. Compared to flowers placed in continuous darkness, a rhythm of 12 h light and 12 h darkness inhibited opening during a 3 d storage period at 20 °C. It is concluded that cut Iris flowers (a) can be stored in water at 3 °C for more than a week, but cannot be stored for 3 d or more in water at 15 °C, 11 °C, 6 °C or 0.5 °C, and (b) cannot be stored dry for long (under the present conditions 3 d or longer) at any of these temperatures. Iris flowers were found to be chilling-sensitive, although only at temperatures of about 0.5 °C.     

Effect of hyperbaric pressure and temperature on respiration rates and quality attributes of tomato

Previous work with hyperbaric treatment of tomato focused on application at lower temperature (13 °C). In this work, hyperbaric treatment at varying pressure levels (i.e., 0.1, 0.3, 0.5, 0.7 and 0.9 MPa) at ambient temperature (20 °C) was tested as a potential alternative to conventional refrigerated storage (0.1 MPa at 13 °C) to preserve tomato quality. The experiments were divided into 3 phases: (1) 4 day of hyperbaric treatment, (2) 5 day of post-treatment ripening, and (3) 10 day of post-treatment ripening. Respiration rate (RR) of the tomatoes was continuously monitored during the course of the hyperbaric treatments. Quality attributes were assessed immediately after removal from the hyperbaric treatments and after 5 and 10 day ripening at 20 °C after removal from the treatments. Hyperbaric treatments at ≥0.3 MPa resulted in RR equal or higher than the RR in control fruit (0.1 MPa at 20 °C). The lowest RR was obtained from tomato stored at 0.1 MPa at 13 °C. Hyperbaric treatment at 0.5, 0.7 and 0.9 MPa significantly reduced weight loss, retained color, firmness, total soluble solid (TSS), titratable acidity (TA) and TSS:TA ratio at similar levels as the tomato treated at 13 °C and 0.1 MPa. Firmness after treatment was highest for fruit from 0.1 MPa at 13 °C and from 0.5, 0.7 and 0.9 MPa at 20 °C. The higher firmness advantage declined by 5 day of ripening after treatment, with higher firmness only being retained for fruit from the 0.9 MPa at 20 °C and the 0.1 MPa at 13 °C treatments. After 10 day ripening, firmness was similar for all treatments. Lightness (L*) and hue angle were greater for all treatments compared with the 0.1 MPa at 20 °C treatment. However, only the greater hue angle difference was maintained after 5 day of ripening. After 10 day ripening, no significant differences were found in color attributes. Only 0.1 MPa at 13 °C retained higher soluble solids, lower titratable acidity and higher TSS:TA ratios after treatment and after 5 day ripening. At 10 day of ripening none of the quality attribute differences noted were retained for any of the treatments. These results show that the only consistent effect of hyperbaric treatment at 0.5, 0.7 and 0.9 MPa was to reduce weight loss and enhance firmness retention up to 5 day ripening after treatment.     

Storage temperature and time influences sensory quality of mandarins by altering soluble solids,acidity and aroma volatile composition

Mandarins are very prone to losing flavor quality during storage and, as a result, often have a short shelf life. To better understand the basis of this flavor loss, two mandarin varieties (‘W. Murcott’ and ‘Owari’) were stored for 0, 3 and 6 weeks at either 0 °C, 4 °C, or 8 °C plus 1 week at 20 °C, and then evaluated for sensory attributes as well as quality parameters and aroma volatile profile. The experiment was conducted multiple times for each variety over two seasons, using three separate grower lots per experiment. Flavor quality was reduced in ‘Owari’ following 4 weeks of storage as off-flavor increased, while for ‘W. Murcott’ the hedonic score decreased after the fruit were stored for 7 weeks. Sensory panelists also noted a decline in tartness during storage for both varieties that was associated with an increase in the ratio of soluble solids concentration (SSC) to titratable acidity (TA). Large increases in alcohols and esters occurred during storage in both varieties, a number of which were present in concentrations in excess of their odor threshold values and are likely contributing to the loss in flavor quality. Thirteen aroma volatiles, consisting mainly of terpenes and aldehydes, declined during storage by up to 73% in ‘Owari’, only one of which significantly changed in ‘W. Murcott’. Although many of these volatiles had aromas characteristic of citrus, their involvement in flavor loss during storage is unclear. ‘W. Murcott’ stored at 8 °C had slightly superior flavor to fruit stored at either 0 °C or 4 °C, and the better flavor was associated with higher SSC/TA and lesser tartness. Aroma volatiles did not play a role in the temperature effect on flavor as there were no significant differences in volatile concentrations among the three temperatures. There was no effect of storage temperature on the flavor of ‘Owari’.     

Respiration rate,ethylene production and biochemical variations of ackee fruit arils (Blighia sapida Köenig) stored under three temperature regimes

The storage of fruit is characterized by many physiological and biochemical changes, and this study aimed to study respiration rate, ethylene production, and other biochemical variations of ackee fruit arils (Blighia sapida), cheese variety, stored at 5, 10 and 20 °C during eight days. During storage, respiration rate decreased but ethylene production increased. Glucose, fructose, sucrose, and short chain fructooligosaccharides – 1-kestose, nystose and DP-5 – and total phenolic compounds also decreased, however, the decrease was much higher at 20 °C. The L*, a*, b, C* and H* values showed that lower temperatures preserved much better colour and visual quality, and arils stored at 5 °C were rated excellent compared to those stored at 10 and 20 °C. The quality of arils stored at 10 °C also was more than satisfactory, while arils stored at 20 °C were completely spoiled after 8 days and showed high weight losses compared to arils stored at 5 and 10 °C, which did not show any spoilage and very low weight losses. In conclusion, the results demonstrated that ackee fruit arils can be stored in very good conditions for a minimum of eight days under low temperature regimes, although at 5 °C arils showed the best shelf-life.     

Variation of total FOS,total IOS,inulin and their related-metabolizing enzymes in burdock roots (Arctium lappa L.) stored under different temperatures

Burdock roots were stored for six weeks at three temperatures, 0, 15 and 20 °C, and activity of sucrose hydrolase (SH), 1-kestose hydrolase (1-KH), inulin hydrolase (InH), sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan:fructan 1-fructoslytransferase (1-FFT) were assessed. Simultaneously, total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin were also assessed during storage. During storage, SH showed an irregular variation at 15 and 20 °C, and was significantly higher at 0 °C showing a continuous increase during the storage period. 1-KH decreased progressively at 15 and 20 °C, but showed a sharp increase at 0 °C after two weeks and decreased afterwards. InH showed a different although more regular pattern by decreasing progressively at 0, 15 and 20 °C. However, the decrease was more significant at 15 and 20 °C during the first two weeks, while at 0 °C the decrease was significant after four weeks storage. 1-SST and 1-FFT activities decreased progressively in a pseudo-linear regression during storage, and showed similar patterns. At 15 and 20 °C, total FOS increased during the first three weeks then decreased, while at 0 °C FOS increased progressively during storage. Total IOS increased during storage, however, this increase was much higher at 0 °C than that observed at 15 and 20 °C. Inulin content decreased during storage and final content was lower at 20 °C. The inulin to total FOS plus total IOS ratio decreased sharply during the first two weeks of storage, then progressively during the last four weeks, while the ratio of hydrolyzing to synthesizing activities was quite stable at 15 and 20 °C, but showed a peak at 0 °C after two weeks. The results suggest that carbohydrate metabolism in stored burdock depends partly on temperature and other physiological factors.     

Ethylene synthesis,ripening capacity,and superficial scald inhibition in 1-MCP treated ‘d’Anjou’ pears are affected by storage temperature

A continuing challenge for commercializing 1-methylcyclopropene (1-MCP) to extend the storage life and control superficial scald of ‘d’Anjou’ pear (Pyrus communis L.) is how to initiate ripening in 1-MCP treated fruit. ‘D’Anjou’ pears harvested at commercial and late maturity were treated with 1-MCP at 0.15 μL L⁻¹ and stored either at the commercial storage temperature −1.1 °C (1-MCP@−1.1 °C), or at 1.1 °C (1-MCP@1.1 °C) or 2.2 °C (1-MCP@2.2 °C) for 8 months. Control fruit stored at −1.1 °C ripened and developed significant scald within 7 d at 20 °C following 3–5 months of storage. While 1-MCP@−1.1 °C fruit did not develop ripening capacity due to extremely low internal ethylene concentration (IEC) and ethylene production rate for 8 months, 1-MCP@1.1 °C fruit produced significant amounts of IEC during storage and developed ripening capacity with relatively low levels of scald within 7 d at 20 °C following 6–8 months of storage. 1-MCP@2.2 °C fruit lost quality quickly during storage. Compared to the control, the expression of ethylene synthesis (PcACS1, PcACO1) and signal (PcETR1, PcETR2) genes was stable at extremely low levels in 1-MCP@−1.1 °C fruit. In contrast, they increased expression after 4 or 5 months of storage in 1-MCP@1.1 °C fruit. Other genes (PcCTR1, PcACS2, PcACS4 and PcACS5) remained at very low expression regardless of fruit capacity to ripen. A storage temperature of 1.1 °C can facilitate initiation of ripening capacity in 1-MCP treated ‘d’Anjou’ pears with relatively low scald incidence following 6–8 months storage through recovering the expression of certain ethylene synthesis and signal genes.     

Response of climacteric-type guava (Psidium guajava L.) to postharvest treatment with 1-MCP

Guava (Psidium guajava L. cv. ‘Allahabad Safeda’) fruit harvested at the mature light-green stage were exposed to 300 and 600 nL L⁻¹ 1-methylcyclopropene (1-MCP) for 6, 12 and 24 h at 20 ± 1 °C, and held in either cold storage (10 °C) for 25 days or ambient conditions (25–29 °C) for 9 days. Most of the physiological and biochemical changes during storage and ripening were affected by 1-MCP in a dose dependent manner. Ethylene production and respiratory rates were significantly suppressed during storage as well as ripening under both the storage conditions depending upon 1-MCP concentration and exposure duration. 1-MCP treatment had a pronounced effect on fruit firmness changes during storage under both the conditions. The reduced changes in the soluble solids contents (SSC), titratable acidity (TA) and vitamin C content showed the effectiveness of 1-MCP in retarding fruit ripening. Vitamin C content in 1-MCP-treated fruit was significantly higher than in non-treated fruit, and those treated with 300 nL L⁻¹ 1-MCP for 6 h. The development of chilling injury symptoms was ameliorated to a greater extent in 1-MCP-treated fruit during cold storage and ripening. A significant reduction in the decay incidence of 1-MCP-treated fruit was observed under both the storage conditions. 1-MCP at 600 nL L⁻¹ for 12 h, in combination with cold storage (10 °C) seems a promising way to extend the storage life of guava cv. ‘Allahabad Safeda’ while 1-MCP at 300 nL L⁻¹ for 12 and 24 h or 600 nL L⁻¹ for 6 h, may be used to provide 4–5 days extended marketability of fruit under ambient conditions.     

High-pressure water washing and continuous high humidity during storage and shelf conditions prolongs quality of red capsicums (Capsicum annuum L.)

In order to develop practical sea freight and marketing options for high quality red capsicums, we have investigated washing treatments that can minimize deterioration when fruit are subsequently stored under high humidity packaging conditions, at cool (6–8 °C) and warm (20 °C) temperatures. In small-scale trials using vented plastic bags to provide high humidity, fruit washed with unheated high-pressure water (517 kPa) had reduced incidence of flesh rots and deterioration of the calyx and stem compared to controls (unwashed or passed through a commercial packing line) or hot water drenched fruit (55 °C for 30 s) following a high humidity storage regime of 2 weeks at 6–8 °C and a further 14 d at 20 °C. In a more extensive trial where 5 kg boxes of fruit were used as replicates, washing with high-pressure water, packing in unperforated plastic box-liners and storing at 6–8 °C for 2 weeks, then 21 d at 20 °C resulted in 84% acceptability. In contrast, acceptability of fruit treated in a commercial packing line stored under regular (uncontrolled humidity) conditions or inside box liners (high relative humidity) declined rapidly at 20 °C after 2 weeks cool storage, with final acceptabilities of 10% and 39% after 21 d, respectively. We conclude that high-pressure water washing is an effective cleaning step, permitting high humidity to be used to prevent shrivel during cool-storage and subsequent ambient conditions, while minimizing the incidence of flesh rots or calyx/stem deterioration. Extended capsicum quality in high humidity at room temperature suggests that (a) cool-storage during transport to some markets may not be necessary if fruit are cleaned to a high standard and (b) fruit could remain within a box liner right up until the product is displayed on the supermarket shelves.     

1-Methylcyclopropene (1-MCP) delays senescence,maintains quality and reduces browning of non-climacteric eggplant (Solanum melongena L.) fruit

Ethylene action can be counteracted by 1-methylcyclopropene (1-MCP), which has been used during postharvest storage to maintain quality. In this work, we evaluated the effect of 1-MCP treatments on eggplant quality and phenolic metabolism during refrigerated storage. Eggplants (cv. Lucía) were harvested at commercial maturity, treated with 1-MCP (1 μL/L, 12 h at 20 °C), stored at 10 °C for 21 d and subsequently held at 20 °C for 2 d. Corresponding controls were stored at 10 °C and then transferred to 20 °C for 2 d. During storage calyx color, damage and chlorophyll content, fruit weight loss and firmness, pulp sugar content, acidity, browning and total phenolics were measured. In addition, polyphenol oxidase (PPO), pyrogallol peroxidase (POD), and phenylalanine ammonia-lyase (PAL) activities were evaluated. Fruit calyxes showed reduced damage and remained greener in 1-MCP treated than in control fruit. 1-MCP treated eggplants showed lower weight loss. Pulp browning was clearly prevented as a consequence of 1-MCP exposure, and this was associated with delayed senescence, lower accumulation of total phenolics and reduced activity of PAL. The activity of the enzymes PPO and POD involved in the oxidation of phenolics compounds was also decreased in 1-MCP treated fruit. Results suggest that 1-MCP treatments delay senescence, prevent browning and are beneficial to complement low temperature storage and maintain quality of non-climacteric eggplant fruit.     

Effects of cold storage and shelf-life on sensory quality and consumer acceptance of ‘Abate Fetel’ pears

Fruit products certified by quality labels should guarantee high levels of consumer acceptance, despite the unavoidable variability arising from growing conditions and postharvest responses. The quality of ‘Abate Fetel’ pear (Pyrus communis L.) fruit was studied, after short or long cold storage, by analysis of physicochemical, texture and flavour traits, to investigate factors affecting consumer acceptance. Fruit from three orchards differing in location and design, monitored during 10 d of ripening at 20 °C, softened progressively to reach and exceed firmness adequate for consumption. Change in colour, in particular hue angle, paralleled softening. Sensory traits were investigated by evaluating fruit of three different firmness levels within the range of acceptable eating quality. Firmness differences were clearly perceived both by expert judges and by consumers, but did not influence the degree of liking. ‘Abate Fetel’ pear can maintain acceptable eating quality at 20 °C for 4–8 d after 13 weeks storage at ?1 °C, or 2–6 d after 23 weeks storage at ?1 °C. Changing texture parameters were perceived at eating, without compromising overall quality. Production system affected intrinsic quality parameters such as total soluble solids concentration, but did not influence consumer acceptance. In consumer tests conducted after 13 weeks of cold storage, high scores were recorded, with a 86% acceptance frequency and more than 40% of scores reflecting “like very much” or “like extremely”. After 23 weeks of cold storage a decrease in degree of liking was observed. The overall value of ‘Abate Fetel IGP Emilia-Romagna’ quality label was confirmed by consumer evaluations. However, the decrease in consumer acceptance after 23 weeks of cold storage indicates that caution should be used in using long storage durations.     

Effect of gum arabic as an edible coating on antioxidant capacity of tomato (Solanum lycopersicum L.) fruit during storage

Coating of tomato fruit with gum arabic has been found to delay the ripening process and maintain the antioxidant capacity. Gum arabic in aqueous solutions of 5, 10, 15 and 20% was applied as an edible coating to green-mature tomatoes which were stored at 20 °C and 80–90% RH for 20 days. Fruit coated with 10% gum arabic delayed the ripening process by slowing down the rate of respiration and ethylene production and also maintained total antioxidant capacity, lycopene content, total phenolics and total carotenoids during storage as compared to the uncoated control and fruit treated with 5% gum arabic concentration. The results suggest that by using 10% gum arabic as an edible coating, the ripening process of tomatoes can be delayed and the antioxidant can be preserved for up to 20 days during storage at 20 °C without any negative effects on postharvest quality.     

Preharvest application of methyl jasmonate (MeJA) in two plum cultivars. 2. Improvement of fruit quality and antioxidant systems during postharvest storage

‘Black Splendor’ (BS) and ‘Royal Rosa’ (RR) plums were treated preharvest with methyl jasmonate (MeJA) at three concentrations (0.5, 1.0 and 2.0 mM) along the on-tree fruit development: 63, 77 and 98 days after full blossom (DAFB). Both control and treated fruit were harvested at the commercial ripening stage and stored in two temperature conditions: 9 days at 20 °C or at 2 °C + 1 day at 20 °C for 50 days. Preharvest MeJA at 2.0 mM significantly accelerated whereas 0.5 mM delayed the postharvest ripening process for both cultivars, since ethylene production, respiration rate and softening were reduced significantly at the two storage conditions for 0.5 mM. In these fruit, total phenolics, total antioxidant activity (hydrophilic fraction, HTAA) and the antioxidant enzymes peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) were found at higher levels in treated than control plums during postharvest storage, which could account for the delay of the postharvest ripening process and the extension of shelf-life.