QUALITY OF 'ANJOU' PEARS AFTER DIFFERENT TYPES OF CONTROLLED ATMOSPHERE STORAGE

‘Anjou’ pears (Pyrus communis, L) were subjected to seven different controlled atmosphere (CA) storage practices and stored at 1C, for 90, 150 or 210 days plus 30 days at regular air atmosphere (RA). CA storage treatment conserved pear qualities to a certain extent regardless of storage treatment. Establishment of CA conditions (2% O₂ and < 1 % CO₂ on warm pears (20C), prior to cooling, resulted in reduced firmness, finish and color and increased amount of scald, shrivel and physiological disorders. Pears held in CA storage (2% O₂ and < 1 % CO₂) for 90 days and an additional 30 days in RA storage maintained good quality. When held for longer storage periods, firmness, finish and color decreased, and scald, shrivel and physiological disorders increased.     

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     

Control of internal browning and quality improvement of ‘Fuji’ apples by stepwise increase of CO2 level during controlled atmosphere storage

To control internal browning injury and to reduce quality loss in ‘Fuji’ apples during storage, a stepwise controlled atmosphere (CA) method was applied in this study. Both non‐bagged and bagged apples during maturation were stored at 0 °C under 1% O₂ + 1% CO₂, 1% O₂ + 3% CO₂ or air for 10 months, and 1% O₂ + 1% CO₂ for 2 months followed by 1% O₂ + 3% CO₂ for 8 months (stepwise CA). The concentrations of internal ethylene and carbon dioxide in apples kept for 24 h at 20 °C after storage under CA conditions were maintained at low level, but there was no effect of stepwise CO₂ increase on internal gas concentrations. The non‐bagged and bagged apples stored under stepwise CA were not significantly different from those stored under 1% O₂ + 3% CO₂ continuously for 10 months in term of flesh firmness, titratable acidity and yellowing index. However, the apples stored under stepwise CA were firmer, more acid and greener than those stored under 1% O₂ + 1% CO₂ continuously for 10 months. Internal browning injury occurred in apples stored under 1% O₂ + 3% CO₂ continuously for 10 months, but it was suppressed completely by stepwise CA storage. The stepwise CA, increasing of CO₂ level after holding at 1% CO₂ for the first 2 months of storage, was effective in maintaining the quality and controlling the internal browning injury in non‐bagged and bagged ‘Fuji’ apples. Copyright © 2005 Society of Chemical Industry     

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.     

QUALITY OF PACKED AND BIN STORED 'ANJOU' PEARS AS INFLUENCED BY STORAGE ATMOSPHERE AND TEMPERATURE

Packed pears (Pyrus communis‘d’‘Anjou’) were stored under four individual controlled atmosphere (CA) storage conditions (#1: CA of 1.5% O₂ and < 1% CO₂ at −1.5C; #2: CA of 1.5% O₂ and < 1% CO₂ at + 1.5C; #3: CA of 1.5% O₂ and 3.0% CO₂ at −1.5C; #4: CA of 1.5% O₂ and 3.0% CO₂ at + 1.5C). Loose pears in bins were stored under three CA storage conditions (#1: CA of 1.5% O₂ and <1% CO₂ at −1.5C; #2: CA of 1.5% O₂ and 3.0% CO₂ at −1.5C; #3: CA of 1.5% O₂ and 3.0% CO₂ at +1.5C). For packed pears, increased CO₂ in the storage atmosphere resulted in retention of peel color, reduced firmness loss and enhanced subjective scores, particularly for finish and stem condition. Pears stored loose in bins, prior to packing in late January in an atmosphere containing 3.0% CO₂ aided firmness retention, reduced scald and greatly enhanced subjective quality scores for appearance, finish and scuffing. Storing ‘Anjou’pears in a 3.0% CO₂ atmosphere allows for storing pears loose in bin and packing in late January with little or no quality losses compared with using the standard 1.0% CO₂ in the storage atmosphere.     

SENSORY CHARACTERISTICS OF CONTROLLED ATMOSPHERE- AND AIR-STORED ‘GALA’ APPLES1

‘Gala’ apples from two Summerland sites were harvested at two harvest dates for two growing seasons (1994, 1995) and stored for 6 months in air and controlled atmosphere (CA). At harvest maturity indices were recorded. After storage, flesh firmness, titratable acidity and soluble solids were determined and sensory attributes were evaluated by a trained sensory panel. In both years, analyses of variance showed apples picked at commercial harvest were significantly more crisp, firm, and sour and less fruity and sweet than apples harvested two weeks later. Apples stored for 6 months in CA were more crisp, firm, juicy and sour, had fewer off-flavors, and had greater overall acceptability than apples stored in air. Apples held at 1.2% O₂for 6 months were more crisp than apples stored at either 2.5% O₂ or 5% Q, while apples stored at 5.0% O were significantly less firm, juicy, and sour than apples stored using the other O₂ concentrations. Apples stored at either 1.2% and 2.5% O₂ had significantly more fruity flavor than apples stored at either 5.0% O₂ or in air.     

QUALITY OF 'ANJOU' PEARS FROM VARIABLE OXYGEN AND HIGH CARBON DIOXIDE CONTROLLED ATMOSPHERE STORAGE

Loss of ‘Anjou’ pear quality after 90 days of storage (60 days at 1.5% O₂ and <1.0% CO₂ then 30 days at 4% O₂) wasapparent in this study. Distinct color changes from green to yellow in the peel and a more yellow flesh, coupled with a loss of firmness, for ‘Anjou’ pears even afteronly a short period (30 days) in elevated O₂ was evident. Use of elevated CO₂ (3%), in CA storage, resulted in a greener peel and firmer pears with less change in flesh color, and superior stem condition after 150, or 210, days of storage compared with pears from 1.5% O₂ and <1% CO₂. After controlled atmosphere and an addition 30 days of storage in regular atmosphere, quality differences in ‘Anjou’ pears from the different atmospheres (1.5% O₂ and 1.0% CO₂; variable O₂;1.5% O₂ and 3.0% CO₂) was even more manifest. Pears in elevated O₂, displayed reduced firmness, finish and stem condition and enhanced shrivel. Pears in 3.0% CO₂, compared favorably in all quality considerations with pears from a normal (1.5% O₂ and <1.0% CO₂) atmosphere. No pithy brown core was evident in ‘Anjou’ pears regardless of storage atmosphere.     

SHORT‐TERM CONTROLLED ATMOSPHERE STORAGE FOR STORAGE‐LIFE EXTENSION OF WHITE‐FLESHED PEACHES AND NECTARINES1

Abstract Response of white‐fleshed peaches (‘Sugar Lady’, ‘Snow Giant’, ‘White Lady’and ‘Snow King’) and nectarines (‘Arctic Queen’and ‘Arctic Rose’) to controlled‐atmosphere (CA) storage is cultivar dependent. Samples of fruit of these six cultivars were collected just prior to commercial harvest and held in either regular‐atmosphere (RA) storage at 1C or controlled‐atmosphere (CA) storage at 2% O₂ and 6, 12 or 18% CO₂, all at 1C. Four of the six cultivars (‘Snow Giant’, ‘White Lady’, ‘Snow King’and ‘Arctic Queen’) displayed excessive internal browning and poor flesh color after only 30 days of storage and should not be considered for long storage (+30 days). While ‘Sugar Lady’and ‘Arctic Rose’performed better and are possible candidates for CA storage, they should not be stored more than 45 days after harvest. The value of CA storage to extend the marketing of white‐fleshed peaches and nectarines is questionable at best. If CA storage is to be used for storage‐life extension of white‐fleshed peaches and nectarines, O₂ level should be maintained at 2% or less and CO₂ level maintained at 12% or higher.     

Effects of controlled atmosphere (CA) storage on pectinmethylesterase (PME) activity and texture of ‘Rocha’ pears

Firmness and pectinmethylesterase (PME) activity were evaluated in pears (cv Rocha) after 9 months of storage in controlled atmosphere (CA) followed by various periods of exposure to air at room temperature. The free calcium content was also evaluated in tissues. Fruit firmness decreased with increasing time of air exposure for all four different CA storage conditions tested. After 9 days of air exposure, fruits stored in 2% O₂ + 1.5% CO₂ were less firm than control fruits (stored in air) and showed higher PME activity. In spite of normal textural changes being observed with increasing time of exposure to air at room temperature, the underlying metabolism might have been affected by CA storage. © 2001 Society of Chemical Industry     

STORAGE QUALITY of ETHYLENE TREATED 'ANJOU' and 'BOSC WINTER PEARS

'Anjou' and 'Bosc' pears (Pyrus communis, L.) were harvested one to two days prior to commercial harvest from three orchards in the Wenatchee growing district of Washington. Harvested fruit were treated with 300 ppm ethylene for three days at 20C. Ethylene treatment enhanced yellow color on fruit peel and the reduction of flesh firmness, and increased spoilage after 90 days in either regular atmosphere (RA) storage or controlled atmosphere (CA) storage regardless of cultivar. Ethylene-treated fruit, of both cultivars, stored in CA had a longer storage life than fruit stored in RA. the safe storage period of ethylene-treated 'Anjou'and 'Bosc' pears was 90 and 45 days, respectively, in RA and 120 and 90 days, respectively, in CA.     

QUALITY OF 'BOSC' PEARS AS INFLUENCED BY ELEVATED CARBON DIOXIDE STORAGE

‘Bosc’pears (Pyrus communis L.) were placed in a purge-type controlled–atmosphere (CA) storage immediately after harvest (>24 h) and held for 180 days at 1C. Oxygen in all atmospheres was 1.5% and CO₂ was 1%, 3% or 5%. Pears were evaluated immediately after removal from CA storage and after ripening for an additional 7 days at 21 C. Pears stored in 3% CO₂ were firmer, had a superior finish, with significantly reduced decay and internal breakdown than pears stored in 1% CO₂. In 3% CO₂, pears retained the ability to ripen after long-term storage. A 10 day delay in atmosphere establishment had little or no influence on the long-term keeping quality or ripening ability of ‘Bosc’pears. Firmness, soluble solids content and starch either alone or together were good indices of maturity for ‘Bosc’ pears.     

QUALITY OF MODIFIED ATMOSPHERE PACKAGED "BARTLETT" PEARS AS INFLUENCED BY TIME AND TYPE OF STORAGE

Commercially mature “Bartlett” pears for this study were obtained from local commercial packing facilities. In the first year, pears were packed in modified atmosphere bags and placed in boxes or packed normally (control) with an individual paper wrap around each pear plus a polyethylene liner in the box. Boxed pears from both types of packaging were stored in regular atmosphere (RA) storage at 1C for 30 or 90 days. In the second year, pears were packed normally and stored in both RA or controlled atmosphere (CA) storage for 45 or 90 days, or packed in modified atmosphere bags and stored in RA at 1C. After 45 days, normally packed pears from both RA and CA were removed from their initial storage, placed in modified atmosphere bags and returned to RA storage for an additional 45 days. Pears stored in modified atmosphere bags were superior in quality to normally packed pears stored only in RA storage and equal in quality to pears stored in CA for periods of 90 days. The quality of pears held in modified atmosphere bags under CA conditions deteriorated after only short periods of time (<45 days). Pears in modified atmosphere bags should be stored only in RA. Little or no quality advantage was evident if use of modified atmosphere bags was delayed regardless of prior storage type.     

SHORT-TERM CONTROLLED ATMOSPHERE STORAGE FOR SHELF-LIFE EXTENSION of APRICOTS1

Shelf-life of ‘Perfection’ and ‘Rival’ apricots can be enhanced with the use of controlled atmosphere (CA) storage. Apricots were harvested at commercial maturity and immediately stored in CA at 1 or 2% 0₂ and 3, 6, 9, 12 or 15% C0₂ for 30, 45 and 60 days. No differences in fruit quality were evident between 02 atmospheres of 1 and 2%, except that fruit stored in 1 % 02 displayed less rot development and higher acid content. Apricots stored in 9% or less C0₂ displayed reduced external and internal color, inadequate finish, increased internal breakdown and more rot development with unacceptable firmness retention for additional handling. Apricots stored in 12 or 15% CO₂ retained firmness and displayed enhanced finish with reduced rots and very little internal breakdown with storage duration of 60 days. Color was much slower to develop in apricots stored in 12 or 15% CO₂ for all storage periods.     

Low oxygen treatment prior to cold storage decreases the incidence of bitter pit in ‘Golden Reinders’ apples

BACKGROUND: The effect of subjecting ‘Golden Reinders’ apples to a low O₂ pre‐treatment (LOT; 1–2% O₂) was evaluated as a strategy to decrease the rate of bitter pit (BP) incidence after standard cold storage (ST). Immediately after harvest, apples were stored for 10 days at 20 °C under low O₂. Thereafter, apples were cold‐stored (0–4 °C) for 4 months and changes were monitored in terms of BP incidence, fruit quality traits and mineral element concentrations. RESULTS: After 4 months cold storage, LOT apples presented a 2.6‐fold decrease in the rate of BP incidence (14%) versus the values obtained for standard cold‐stored fruits (37% BP incidence). LOT increased flesh firmness, total soluble solids and titratable acidity as compared to the quality traits determined for cold‐stored fruits. Lower cortex Ca and Mg concentrations as compared to ST apples were determined in association with LOT, 2 months after cold storage. CONCLUSION: Application of a LOT prior to cold storage may be a promising strategy to reduce the incidence of BP and preserve fruit quality, which should be further investigated. Copyright © 2009 Society of Chemical Industry     

CONTROL OF STORAGE‐RELATED PHYSIOLOGICAL DISORDERS OF “D’ANJOU” PEARS BY INTEGRATED REDUCED DOSAGE OF ETHOXYQUIN AND LOW OXYGEN TREATMENTS1

A 1000‐p.p.m. ethoxyquin drench containing 528 p.p.m. thiobendazol (TBZ) fungicide prior to controlled atmosphere (CA) storage effectively controlled the development of superficial scald (SS) for 1 month regular air (RA) storage following 5 months CA storage. The preharvest drench was not effective in controlling the development of SS in fruit returned to RA storage following 7 months CA storage. Application of a 1750‐p.p.m. ethoxyquin line spray (without TBZ) following 5 months CA storage effectively extended the control of SS to 2 months under RA conditions. The 1750 p.p.m. ethoxyquin line spray was effective in controlling SS for 1 month RA storage following an additional 2 months CA storage period. This represents a 36% reduction in the amount of ethoxyquin currently used on fruit stored for short periods of time. Minor, noncommercial amounts of pithy brown core (PBC) developed during storage, demonstrating that 1% O ₂ and 1% CO ₂ in a flow‐through system can be safely utilized for the storage of pears. Growing location (Oregon vs. Washington) made no difference in the sensitivity to CO ₂ injury and packing and handling damage.     

EATING QUALITY OF “FUJI” APPLES AFFECTED BY A PERIOD OF COLD AIR AFTER ULO STORAGE

ABSTRACT

Over two subsequent seasons, emission of volatile compounds, consumer acceptability and quality parameters were analyzed in “Fuji” apples. In both seasons, apples were harvested at the same maturity stage and stored for 19 or 30 weeks at 1C and 92% relative humidity under an ultralow oxygen (ULO) atmosphere (1% O₂ + 1% CO₂) or under an ULO atmosphere followed by different periods (2 or 4 weeks) in cold air. The results revealed, for both seasons, that 4 weeks of cold air storage after ULO storage helped to increase the emission of some volatile compounds for both storage period, including characteristic volatile compounds for the variety, and did not have a negative effect on quality parameters. Additionally, the consumer acceptability was superior for those fruits.

PRACTICAL APPLICATIONS

It is well known for various apple varieties that long‐term storage under ULO conditions reduces volatile production resulting in poor flavor and aroma compared with fruits stored in air. Consequently, there is often dissatisfaction among consumers with the flavor of fruits which have been subjected to cold storage. The strategy that is proposed in the present work could be recommended to enhance the aromatic quality of fruit provided by the apple industry and, in consequence, increase its acceptability by consumers.     

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.     

EXTENDED STORAGE LIFE OF LITCHI FRUIT USING CONTROLLED ATMOSPHERE AND LOW TEMPERATURE

The postharvest quality of litchi (Litchi chinensis Sonn.) cv. Bombay stored under controlled atmosphere (CA) at 3.5% O₂and 3.5% CO₂, 2C temperature and 92–95% relative humidity was studied. Fruits were also held in regular atmosphere (RA) maintained at 2C temperature and 92–95% relative humidity. Fruits kept at normal ambient conditions were used as controls. Various quality attributes measured revealed that fruits stored in CA exhibited Hunter “a” values of 11.2 after 56 days of storage, indicating the beneficial effect of CA on retaining the red color of litchi fruits. Fruits held in RA exhibited Hunter “a” values (7.9) lower than that of CA‐stored litchi, showing that browning of litchi was noticeable in RA. Loss of weight was lowest (4.9%) for the fruits stored in CA compared to those stored in RA (11.0%) and control (33.1%). Loss of acidity and ascorbic acid content of fruits stored in CA were less than that of RA. The smallest increase of litchi firmness and pericarp puncture strength of 2.2 and 3.9 times of initial level, respectively, were observed even after 56 days of storage in CA. Total soluble solid of litchi increased from 19.3° Brix at harvest to 23.0° Brix until 48 days of storage in CA after which it declined to 22.8 °Brix. The sensory evaluation of aril color and taste showed that the fruits held in CA were rated good throughout 56 days of storage.     

EFFECT OF SOME GAS MIXTURES ON STORAGE QUALITY OF PLUMS1

Plums were stored in controlled atmospheres (CA) with five gas mixtures of the following O₂:CO₂ percentages; 1:1, 1:4, 4:4, 2:2 and 4:1, for 37 days at 2.5–3C. Fruit treated with CA displayed very low decay incidence at the end of the storage period plus 2 days ripening at 22C in air, in comparison with a very high decay incidence (88%) for control fruits. CA-treated fruit ripened normally, but slowly, after 2 days in ambient conditions. There were no clear differences among CA treatments in the quality attributes of total soluble solids, acidity, firmness or color. Treatment with 1% O₂ nd 4% CO₂, however, resulted in slightly firmer fruit, with higher acidity than the untreated checks.     

Controlled and modified atmospheres influence chilling injury,fruit quality and antioxidative system of Japanese plums (Prunus salicina Lindell)

Our objective was to compare the effects of controlled atmosphere (CA) and modified atmosphere packaging (MAP) on fruit quality, chilling injury (CI) and pro‐ and antioxidative systems in ‘Blackamber’ Japanese plums. Matured fruit were stored for 5 and 8 weeks at 0–1 °C in normal air, CA‐1 (1% O₂ + 3% CO₂), CA‐2 (2.5% O₂ + 3% CO₂) and MAP (~10% O₂ and 3.8% CO₂). CA was more effective than MAP in retention of flesh firmness and titratable acidity during cold storage. Fruit stored in CA‐1 showed reduced CI and membrane lipid peroxidation after 5 and 8 weeks of cold storage. Low O₂ atmospheres appeared to limit the generation of reactive oxygen species (ROS) and their efficient scavenging through the concerted action of superoxide dismutase and peroxidase. The role of ascorbate–glutathione (AsA–GSH) cycle in the regulation of oxidative stress was also studied during and after storage in different atmospheres. In conclusion, optimum CA conditions delayed fruit ripening and CI through augmentation of antioxidative metabolism and suppression of oxidative processes.