EFFECT OF COLD STORAGE ON THE QUALITY CHARACTERISTICS OF ‘AU-RUBRUM’ PLUMS1

The effect of cold storage (0°C) and maturity on the physical, chemical and sensory characteristics of plums (cv. ‘AU-Rubrum’) was determined. The size, weight, soluble solids and total sugar contents of the more mature fruit were significantly higher (P<0.05) and the “L” and hue angle were significantly lower (P<0.05) than plums in the less mature class. ‘AU-Rubrum’ fruit contained glucose, fructose and sorbitol but had no sucrose. Artificially ripening fruit at 20°C had a significant effect (P<0.01) on all color values for both maturity 1 and 2 fruit. The titratable acidity and sugar contents of the fruit ripened at 20°C were lower for ripened than for unripened fruit. Storage of the plums at 0°C for 5 weeks followed by subsequent ripening at 20°C had no significant effect on physical, chemical or sensory characteristics. Data indicate that ‘A U-Rubrum’ plums which have one-half red ground color (maturity 1) will develop full color and complete the normal ripening process. Data also indicate that the plums can be stored for at least 5 weeks at O°C without loss of quality and that the cultivar has potential for shipping to distant markets.     

Variations in proanthocyanidins of japanese-type plums during maturation and storage

Proanthocyanidins in epicarp and mesocarp tissue of dark-red-fleshed (Rubysweet) and yellow-fleshed (Byrongold) plums remained unchanged during the third stage of fruit development and storage of green and midripe fruit for 6 days at 18 °C, 80% RH. Differences were significant by cultivar and tissue type. Red-fleshed plums and epicarps of both cultivars contained greater quantities of proanthocyanidins. Degree of polymerization, indicated by vanillin/proanthocyanidin ratios, did not increase in either cultivar with maturity or storage time.     

QUALITY OF ‘GALA’ APPLES AS INFLUENCED BY HARVEST MATURITY,STORAGE ATMOSPHERE AND CONCOMITANT STORAGE WITH ‘BARTLETT’ PEARS1

Controlled atmosphere (CA) storage for 45 or 90 days following harvest reduced quality losses for both ‘Gala’apples and ‘Bartlett’pears compared with fruit from regular atmosphere (RA) storage. Fruit stored in CA were firmer, had higher acidity and less color change than fruit from RA storage. Apples and pears stored together in CA maintained good quality and compared favorably with apples or pears stored separately. There was no difference in fruit quality between fruit stored at 1% O₂ and 1% CO₂ compared with fruit stored in 2% O₂ and 3% CO₂. Fruit harvested at a more advanced stage of maturity deteriorated more quickly in storage than earlier harvested fruit. A combination of 45 days in CA followed by 30 days RA resulted in apples that were superior in quality to apples stored for 75 days in RA alone.     

Preconditioning treatment maintains taste characteristic perception of ripe ‘September Sun’ peach following cold storage

Preconditioning is a thermal treatment that consists in maintaining stone fruits immediately after harvest and prior to cold storage at 20 °C for 24–48 h in special chambers aimed to extend fruit market life reducing chilling injury symptoms. This work investigates whether preconditioned ‘September Sun’ peaches had better eating quality than control fruit. Commercially harvested peaches were preconditioned and transferred to cold storage for 12, 26 and 40 days and evaluated for sensory characteristic perception after a ripening period at 20 °C. Acceptability of preconditioned fruit was higher than control fruit during this 40‐day cold‐storage period. Preconditioned and control fruit were also segregated into two clusters by PCA analysis; preconditioned fruit clustered together and show association to acceptability, sweetness and juiciness, while the second cluster was associated with flesh texture, acidity and aroma, suggesting the positive effect of preconditioning on final fruit quality. Preconditioned fruit maintained their sensory characteristics longer than control fruit during this 40‐day cold‐storage period.     

SHELF-LIFE AND QUALITY OF‘NAVAHO’ AND ‘SHAWNEE’ BLACKBERRY FRUIT STORED UNDER RETAIL STORAGE CONDITIONS1

The quality of soft-fruited (‘Shawnee’) and firm-fruited (‘Navaho’) blackberry cultivars held under simulated retail conditions was determined. Leakage and decay increased during storage and exceeded 20% in 'Shawnee’ fruit after 14 days at 2C or 7 days at 5C, while ‘Navaho’ held under similar conditions was still marketable (<10% decay). Transferring fruit to 20C for 2 days after low temperature storage intervals was detrimental to fruit quality, resulting in increased weight loss, leakage, decay and softening in both cultivars. After retail warming, ‘Shawnee’ fruit lost 25% of marketable fruit while‘Navaho’ had a 10% loss. Soluble solids concentration did not change significantly during storage, but titratable acidity declined 40–50%. Anthocyanin content increased from 20–100% depending on cultivar, storage temperature and storage intervals. The sugar composition of blackberries before storage was about 10, 260 and 260 mg/g dry weight, glucose, and fructose, respectively. Sucrose and glucose decreased and fructose increased slightly during storage. Warming fruit after low temperature storage did not accelerate loss of total sugars. If held constantly at 2C, ‘Navaho’ could be held 21 days.     

Multivariate analysis of maturity stages,including quality and aroma,in ‘Royal Glory’ peaches and ‘Big Top’ nectarines

Ethylene production, quality attributes and aroma compounds were analysed to determine the maturity evolution of ‘Big Top’ nectarines and ‘Royal Glory’ peaches at harvest dates ranging from 89 to 116 days after full bloom (DAFB) for nectarines and from 85 to 112 DAFB for peaches. These cultivars are highly coloured even in the early stages of maturity. However, the two cultivars had different patterns of ethylene production, this being slower in nectarines than in peaches. Principal component analysis (PCA) was used to provide partial visualisation of the complete data set in a reduced dimension plot. Separation of the two cultivars can be shown by means of a two‐dimensional plot of the samples. Although only some aroma compounds are slightly correlated with quality parameters, when aroma volatiles were included in the PCA, the aroma compound set allowed both cultivars to be classified into three stages of maturity: immature, intermediate and fully mature. Compounds such as propanol, hexyl acetate, 2‐methylpropyl acetate, limonene, butanol, (Z)‐3‐hexenyl acetate, buthyl acetate, linalool, ethanol, propyl acetate and ethyl acetate are the most important volatiles for ‘Big Top’ nectarines. It is suggested that the presence of these compounds can be used to indicate when the fruit should be harvested. The presence of γ‐decalactone, δ‐octalactone, γ‐octalactone, ethyl butyrate, hexanal and (E)‐2‐hexenol can be used to indicate the harvesting maturity stage for ‘Royal Glory’ peaches. The optimum maturity date for harvest would be 105–107 DAFB for ‘Big Top’ nectarines and 93–95 DAFB for ‘Royal Glory’ peaches. © 2002 Society of Chemical Industry     

Abscisic Acid in the Response of ‘Fortune’ Mandarins to Chilling. Effect of Maturity and High-Temperature Conditioning

The possible role of abscisic acid (ABA) and peel colour in chilling tolerance of ‘Fortune’ mandarins has been examined. Fruit stored at 2·5°C, but not at 12°C, showed pitting damage. The degree of damage changed considerably during development and maturity from November until May. Green fruit were more tolerant to chilling injury (CI). After colour break, chilling susceptibility increased from the beginning of December until January and February (the coolest season during the growing period) and declined towards May. This trend did not parallel changes in fruit colour index or free and bound ABA levels, which increased from November until May. At the time of chloroplast transformation to chromoplast a noticeable shift in free but not in bound ABA occurred. During storage, free ABA levels increased in fruits stored at 12°C, but not at 2·5°C. Changes in ABA with storage temperature depended on the stage of maturity of the fruits, but not on their susceptibility to CI. It has also been shown that there was no relationship between ABA content following exposure to 37°C and chilling tolerance. At all stages of maturity, the susceptibility of the fruits to CI and the free ABA levels of the flavedo decreased after conditioning the fruits for 3 days at 37°C. After storage at 2·5°C, the ABA levels of the conditioned fruit were similar or even lower than those of non-conditioned fruit. Treatment of fruit for 3 days with 10 μl litre^-1 ethylene increased free ABA about four times, whereas bound ABA remained nearly constant. This treatment enhanced cold-induced peel damage after prolonged storage. Thus, the ethylene-induced changes in free ABA appear not to be related to the induced changes in chilling susceptibility. The results obtained indicated, therefore, that free and bound ABA appear not to be involved on the adaptative mechanism developed in ‘Fortune’ mandarins to cope with chilling stress. © 1997 SCI.     

Delayed harvest and cold storage period influence ethylene production,fruit firmness and quality of ‘Cripps Pink’ apple

The effects of harvest date and cold storage period on ethylene production, fruit firmness and quality of ‘Cripps Pink’ apple were investigated. Fruit were harvested from Perth Hills and Donnybrook (Western Australia) at commercial maturity (CM), 2, 4 and 6 weeks after CM prior to 0, 45, 90 and 135 days cold storage in 2003 and 2004. Delayed harvest significantly increased ethylene production, CIE values a* and C* at both locations in 2 years. Delayed harvest and extended cold storage period increased the internal ethylene production and reduced fruit firmness, soluble solids concentration: titratable acidity (SSC:TA) ratio and reduced CIE values L*, b*, h° during both years and locations. Fruit harvested 2 weeks after CM can be cold‐stored for 90 days with acceptable fruit quality. If the fruit is intended to be sold fresh immediately in local markets, the harvest can be delayed up to 6 weeks after CM to harness substantially improved fruit colour with acceptable fruit quality.     

STORAGE OF ‘SWEETHEART’ CHERRIES IN SEALED PLASTIC FILM1

‘Sweetheart’ cherries were sealed in perforated or nonperforated polyethylene bags and stored for 6 weeks in air at 0C. Samples were removed after 1, 2, 4 and 6 weeks of storage and evaluated for fruit and sensory quality. Volatile analyses were done on samples kept in storage for 2, 4, 6, 8 and 9 weeks. Atmospheres after 6 weeks of storage were approximately 4.6% O₂ and 10% CO₂ for the perforated bags (1993) and 6.6% O₂ and 3.5% CO₂ for the non-perforated bags (1994). Fruit brightness (L* value), firmness and titratable acidity declined during storage. Skin color (hue angle) decreased slightly in redness over the 6-week storage period. Sensory evaluation in 1993 showed a decline in fruit appearance and flavor with storage duration. Texture and juiciness did not change. Acceptability remained high for the first 4 weeks of storage. Twenty-seven volatiles were identified by head-space analysis (1993). Little change occurred in volatile production except for acetaldehyde which increased sharply from week 2 to 4 and ethanol which increased sharply between week 8 and week 9. Butyl acetate behaved much like acetaldehyde. Modified atmosphere packaging maintained high fruit luster and green stems. No differences in fruit quality were observed with bag type, but storage appears to be limited to 4 weeks for ‘Sweetheart’ cherries because of flavor loss.     

Antioxidant activity determines on‐tree maturation in ‘Golden Smoothee’ apples

BACKGROUND: Harvest date clearly determines the postharvest storage behaviour and sensitivity of fruit to physiological disorders. Generally fruit are picked following their maturity indexes but often these indexes poorly represent the physiological state of the fruit. With this in mind, this work aimed to determine a biochemical marker capable of predicting on‐tree maturation in ‘Golden Smoothee’ apples. Changes in the non‐enzymatic and in enzymatic antioxidant potential of fruit were assessed for different harvest dates. RESULTS: Significant differences in antioxidant levels, especially ascorbate and catalase, were found. These changes were related to climatic variations, especially relating to temperature, that appeared to determine the capability of the fruit to produce ethylene. Fruit exposed to higher temperature produced less ethylene and exhibited a significant delay in the induction of their climacteric. In both seasons, changes in quality parameters during on‐tree ripening were not related to the capability of the fruit to produce ethylene, but rather to endogenous levels of antioxidants, especially catalase and ascorbate, at the earliest picking date. CONCLUSION: We hypothesize that ascorbate and antioxidant activity play a role in changes in maturity patterns exhibited by apples in orchards. Both parameters appear to be interesting markers to follow these changes. Copyright © 2009 Society of Chemical Industry     

CHANGES IN QUALITY CHARACTERISTICS DURING PEACH (CV. ‘MAJESTIC’) MATURATION1

Changes in the physical, chemical and sensory characteristics of peaches (cv. ‘Majestic’) were determined. Size, weight, ground color “a” values and SS/TA ratio increased significantly with increased degree of maturity; whereas, firmness, DLE, hue angle, titratable acidity, quinic acid, and citric acid decreased significantly. Malic acid increased significantly with maturity up to grade 5 then significantly decreased. In general sucrose content and total sugars increased through grade 6 and then decreased for tree ripe fruit. Sensory evaluation results showed no significant differences among maturity grades for sweet, sour, juice and overall peach flavor attributes. However, grade 1 and 2 fruit had lower scores for sweet and overall peach flavor attributes and tended to be more sour than grades 3–6 and tree ripe fruit. Correlation coefficients between maturity grade and all the selected quality parameters, except for the sour flavor attribute, were significant at the 1% level. DLE had the highest correlation with maturity grade followed by ground color “a” value, SS/TA ratio and firmness.     

Antioxidative enzyme activity and internal browning of 1‐methylcyclopropene‐treated European pear fruits (cv. ‘Shahmiveh’ and ‘Sebri’)

The effects of 1‐methylcyclopropene (1‐MCP) on antioxidative enzyme and internal browning (IB) incidence of two European pear cultivars ‘Shahmiveh’ and ‘Sebri’ stored at 0.5 °C were investigated. Ethylene production of ‘Sebri’ was delayed by 1‐MCP but suppressed in ‘Shahmiveh’. IB increased in both cultivars, with a higher level of the incidence in ‘Shahmiveh’, and was reduced by 1‐MCP. Activities of catalase (CAT) and peroxidase, but not superoxide dismutase (SOD), decreased in untreated fruit during the first 40 days. 1‐MCP had little effect on SOD activity or on total phenolics. Polyphenoloxidase activity did not increase over time in 1‐MCP‐treated fruit of the IB sensitive ‘Shahmiveh’, and the effect was inconsistent for ‘Sebri’. Ascorbic acid (AA) levels in 1‐MCP‐treated fruit of both cultivars declined at a lower rate compared with untreated fruit during storage, but the reduction in AA levels was faster in ‘Shahmiveh’ compared with ‘Sebri’. Also, the effects of 1‐MCP on antioxidative systems may be related to IB development.     

ETHYLENE CAPSULE PROMOTES EARLY RIPENING OF 'd'ANJOU' PEARS PACKED IN MODIFIED ATMOSPHERE BAGS

‘d'Anjou’ pears (Pyrus communis, L.) harvested commercially with flesh firmness of 64.5 N were incapable of ripening normally at 20C within 60 days of air storage at ‐1C (denoted as “under‐chilled” fruits). When under‐chilled ‘d'Anjou’ fruits (8 fruits, total fruit weight of 1.8 kg) were packed in a 3.8‐liter perforated bag inserted with an ethylene capsule, fruit would ripen normally at 20C. The ethylene concentration in the packed bag maintained no less than 100 ppm after 4 days at 20C, and declined to about 25 ppm on day 7. Regardless of the storage length, ripened fruit induced by the ethylene capsule developed high buttery and juicy texture. If ‘d’ Anjou’ fruit had been stored at ‐1C for less than 30 days, ripened fruit lacked high flavor quality. Flavor quality of ripened fruit improved rapidly when the fruit had been stored for longer than 30 days.     

The effects of fruit maturation,delayed storage and ethylene treatment on the incidence of low‐temperature breakdown of ‘Hayward’ kiwifruit

BACKGROUND: Low‐temperature breakdown (LTB), a disorder inducing quality loss, during and after cold storage of ‘Hayward’ kiwifruit was investigated. Harvested kiwifruits during fruit maturation or after delayed storage (DS) at 20 °C for 0, 1, 2, 3 and 4 weeks and 1 µL L^?1 ethylene treatment for 24 h were stored at ? 0.5 °C for 24 weeks and additional ripening at 20 °C for 5 days. Fruit quality indices and LTB incidence and severity were determined before and after treatments. RESULTS: Harvested fruits ripened during maturation, DS and after ethylene treatment. After storage and shelf life, fruits of all treatments were at complete ripening stage. LTB incidence of early harvested fruits was high, while that of fruits of the mid (third) and late harvests was low. Fruits of the third harvest date showed progressively increased LTB incidence with increasing duration of DS to as high as 95–100% after 4 weeks. Ethylene‐treated fruits showed a comparable increase in LTB to that corresponding to 2–3 weeks of DS. CONCLUSION: In contrast to fruit maturation, postharvest (after harvest and before storage) DS at non‐chilling temperature and ethylene treatment advanced the ripening of ‘Hayward’ kiwifruit and resulted in increased LTB incidence. Copyright © 2012 Society of Chemical Industry     

Quality of Retail Florida-Packed Frozen Concentrated Orange Juice as Determined by Consumers and Physical and Chemical Analyses

Six commercial Florida-packed frozen concentrated orange juice samples drawn from the U.S. retail market on a monthly basis for 1 yr were evaluated for sensory attributes, color (by colorimeter), Brix, acid, and bottom pulp. Consumers rated flavor “like moderately” on a 9-point hedonic scale for every sample. The degree of sweetness and tartness of samples was “just right;” bitterness was somewhat excessive and color was somewhat too light (P < 0.05). Generally, as the °Brix to % acid ratio increased, the flavor improved, and the closer to “just right” was the degree of sweetness, tartness, and bitterness. A significant amount of bitterness was perceived as tartness or lack of sweetness (P < 0.01). Plant-to-plant variation was found in ratings of flavor and colorimeter color and °Brix to % acid ratios.     

高寒荒漠区延后栽培葡萄品质分析

为评价鲜食葡萄在高寒荒漠区延后栽培条件下的品质表现,以适应性较好的8个品种为研究对象,测定葡萄感官品质、内在品质、功效成分和糖酸品质,采用主成分分析法对果实品质进行综合分析和评价。结果表明,‘红地球’和‘紫地球’单果质量10 g以上,果粒大,能够保持原有的大果特征;无核品种较有核品种果粒小;8个品种果实果形指数均> 1,呈长椭圆形,除绿色品种外,果实着色较深;果皮颜色越深的品种,果皮花青素、类黄酮、总酚含量越高。2个无核品种(‘红宝石无核’和‘紫甜无核’)和‘红地球’可溶性固形物含量较高,在21%以上;糖酸组分及含量方面,果实中的糖分主要是果糖和葡萄糖,蔗糖未检出;酒石酸和苹果酸是主要有机酸,柠檬酸和草酸含量极微。酸甜风味方面,‘红宝石无核’口感最甜,其次为‘红地球’,‘瑞都香玉’和‘紫地球’口感较淡,‘摩尔多瓦’口感偏酸。通过主成分分析法提取了5个独立的主成分,累计贡献率87. 396%,以主成分为评价指标,对浆果品质进行综合评价,‘红宝石无核’、‘红地球’和‘玫瑰香’果实综合品质最好。     

Effects of various coatings and antioxidants on peel browning of ‘Bartlett’ pears

Peel browning of ‘Bartlett’ pears (Pyrus communis L) caused by various mechanical injuries during postharvest handling results in a reduction in visual quality. Various commercial and experimental coatings and antioxidants with potential to reduce peel browning of pears have been evaluated. Treatment with 0.2% diphenylamine (DPA) or 0.3% ethoxyquin (Eth) reduced peel browning on ‘Bartlett’ pears induced by vibration, rolling or scuffing. However, this effect only lasted for about 5 days when treated pears were stored at 0 °C. For the consideration of practical use, pears would have to be treated and packed shortly before transport to achieve a reduction in peel browning. DPA and Eth did not reduce peel browning on pears induced by handling at 20 °C after treatment. It is suggested that tight‐fill packaging and use of DPA or Eth would best reduce peel browning. Copyright © 2004 Society of Chemical Industry     

EFFECTS OF THE RATE OF HEATING ON APPLE AND PEAR FRUIT QUALITY

There is evidence that the rate of heating to meet quarantine security impacts fruit quality as well as insect mortality. Linear heating rates, of 4, 6, 8, 10, and 12C/h to treatment temperatures of 44 and 46C were used to treat 8 cultivars of apples (‘Delicious’, ‘Golden Delicious’, ‘Granny Smith’, ‘Fuji’, ‘Gala’, ‘Jonagold’, ‘Braeburn’, and ‘Cameo’) and two cultivars of winter pear (‘d'Anjou’ and ‘Bosc’). Fruit were stored, ripened, and tested for various quality parameters. Scald was controlled, firmness was higher in heat treated fruit, ripening was delayed but uniform in pears, decay organisms were suppressed, red fruit became redder and green fruit remained green, the Brix‐acid ratio (SS/TA) was either unchanged (‘Granny Smith’) or increased. Physiological disorders such as bitter pit were exacerbated by the heat treatment, requiring culling after treatment to avoid storage of fruit so affected.     

Effect of controlled atmospheres and shelf life period on concentrations of volatile substances released by ‘Pink Lady®’ apples and on consumer acceptance

BACKGROUND: ‘Pink Lady^®’ (Malus × domestica Borkh.) apples were harvested at commercial maturity and stored at 1 °C under either air or controlled atmosphere (CA) conditions (2.5 kPa O₂: 3 kPa CO₂ and 1 kPa O₂: 2 kPa CO₂) for 15 or 28 weeks. Standard quality parameters, consumer acceptance and volatile compound emission were evaluated after cold storage plus shelf life period at 20 °C. RESULTS: A shelf life period of 17 days after long‐term storage in controlled atmosphere allowed the regeneration of the characteristic esters associated to the aroma of this variety. Sixty‐five per cent of consumers preferred apples with higher emissions of aroma‐active volatile compounds, despite the fact that these apples displayed lower values for standard quality attributes. The most accepted samples corresponded to fruit stored in air for 15 weeks regardless of post‐storage period, in air for 28 weeks plus 1 day at 20 °C, and in 2.5 kPa O₂: 3 kPa CO₂ for 15 weeks plus 7 days at 20 °C. CONCLUSIONS: Concentrations of specific aroma volatile compounds are suggested to be more important than total aroma emission for consumer acceptance of ‘Pink Lady^®’ apples. Copyright © 2009 Society of Chemical Industry