Control of Superficial Scald on 'ďAnjou' Pears by Ethoxyquin: Effect of Ethoxyquin Concentration, Time and Method of Application, and a Combined Effect with Controlled Atmosphere Storage

‘d'Anjou’ pears (Pyrus communis, L.) without ethoxyquin developed superficial scald upon ripening after 3 months of storage. Ethoxyquin at 1,000 ppm controlled scald for 4 months and did not cause phy-totoxicity to the fruit. Ethoxyquin at 2,700 ppm controlled scald for 5 months but caused phytotoxicity to the fruit. Fruit drenched with 1,000 ppm ethoxyquin within 2 days after harvest plus an additional line spray of 1,700 ppm ethoxyquin after 1 to 3 months of storage developed minimal scald incidence and did not suffer phytotoxicity after 5 months. Pre-storage drench of ethoxyquin at 500 ppm to ‘d'Anjou’ fruit was sufficient to control the scald disorder for up to 7 months in a controlled atmosphere (2% O₂+ 1% CO₂) storage.     

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.     

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.     

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.     

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.     

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     

Control of Superficial Scald On 'ďAnjou' Pears by Ethoxyquin: Oxidation of α-Farnesene and its Inhibition

α-Farnesene in the skin tissue of ‘?Anjou’ pears (Pyrus communis, L.) increased to a maximum after 3 months of storage in air at - 1°C and then declined. α-Farnesene was oxidized to conjugated trienes and its oxidation was inhibited by ethoxyquin. The split application by drenching fruit with 1,000 ppm ethoxyquin at harvest and then line-spraying 1,700 ppm after 1, 2 or 3 months of storage inhibited the oxidative activity of α-farnesene similar to the single application with 2,700 ppm ethoxyquin by drenching fruit at harvest. Incidence of superficial scald was highly correlated with the level of conjugated trienes. The control of scald by ethoxyquin was due to its antioxidant action and/or its inhibition of conjugated trienes biosynthesis.     

Effect of different levels of CO2 on the antioxidant content and the polyphenol oxidase activity of ‘Rocha’ pears during cold storage

Pears (Pyrus communis L. cv. ‘Rocha’) were exposed to air or controlled atmosphere (CA) containing various concentrations of CO₂: 0, 0.5 and 5 kPa, all with 2 kPa O₂. After 4 months of storage at 2 °C, the fruits were transferred to air at room temperature, and assessed in terms of soluble solids, titratable acidity, pH, incidence of brown heart and flesh browning, phenolic content, vitamin C content and polyphenol oxidase activity. By 4 months of storage, soluble solids and pH increased, and acidity decreased relative to harvest, but no differences were detected between pears stored under air or any of the CA tested. Higher contents of hydroxycinnamic derivatives and flavan‐3‐ols in the peel than in the flesh were recorded. However, the content of arbutin was higher in the flesh than in the peel, whereas flavonols were only detected in the peel. In general, hydroxycinnamic derivatives and flavonols were stable throughout storage, but flavan‐3‐ols decreased in concentration under air or CA. Arbutin was the only phenolic compound that increased in concentration as time elapsed. No clear relation was found between the storage conditions tested and the phenolic concentration in pears. Regarding ascorbic acid (AA) and dehydroascorbic acid (DHA), their concentrations were higher in the peel than in the flesh. Furthermore, AA and DHA were strongly affected by storage: the former decreased, whereas the latter increased in content. A decrease in PPO activity was apparent after harvest and during storage, particularly under higher levels of CO₂. The combination 2 kPa O₂ + 5 kPa CO₂ increased the incidence of internal disorders (viz. brown heart and flesh browning) after storage. Copyright © 2005 Society of Chemical Industry     

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.     

Production and Regeneration of Principal Volatiles in Apples Stored in Modified Atmospheres and Air

In a series of exploratory experiments, storage of McIntosh apples (Malus domestica Borkh.) in modified atmospheres (MA) (5% CO₂+ 3% O₂ at 2.8°C) suppressed the development of headspace ethanol and acetaldehyde from that in apples stored in air at 0°C (RA). Acetaldehyde, ethanol, ethyl butyrate and hexanal production from intact fruit was further suppressed when the apples were stored in 1.5% CO₂+ 1.5% O₂ or 1.5% CO₂+ 1.0% O₂ at 2.8°C. Placement of fruit in RA following MA storage initially regenerated ethyl butyrate and hexanal in preference to ethanol and acetaldehyde. However storage of fruit in 1.5% CO₂+ 1.0% O₂ for 320 days completely suppressed the principal headspace volatiles and blocked their subsequent regeneration in RA.     

INFLUENCE OF FLOAT MATERIALS ON THE QUALITY OF 'd'ANJOU' PEARS AFTER REGULAR AND CONTROLLED ATMOSPHERE STORAGE

Thirty bins of commercially harvested 'd'Anjou' pears from each of three growers were packed at a commercial packing facility, using either of two pear float materials and wrapping the pears in one of three paper wraps. Float materials used were potassium phosphate (XEDA-F, pH 11.3) or lignin sulfonate (lignosite), the industry standard. Paper wraps were impregnated with either Biox-A, 3% oil + copper and ethoxyquin (3% C&E), or 6% oil + copper and ethoxyquin (6%C&E). After packing, 36 boxes were placed in regular atmosphere (RA) storage at 1C. Seventy-two boxes were placed in controlled atmosphere (CA) storage (1.5% O₂ and 1.0% CO₂ at OC). After 50 days (RA) or 100 and 200 days (CA) storage, fruit was removed and quality evaluated. Float material (Lignosite or XEDA-F) did not influence either objective or subjective quality under either RA storage or up to 200 days CA storage. Type of paper wrap did have a strong influence on pear quality, particularly affecting scald rating and subjective ratings of pear quality. Paper wraps containing Biox A produced pears of reduced quality compared to papers with either 3 or 6% oil with C&E, which were comparable in quality.     

EFFECT OF HARVESTING SEASON AND POSTHARVEST TREATMENTS ON STORAGE LIFE OF MEXICAN LIMES (Citrus aurantifolia Swingle)

Changes in susceptibility to chilling of citrus fruits vary with the low temperature applied, storage period, growing area, season, time of harvest and postharvest treatments. The objective of this study was to determine the effect of low temperatures on the quality of Mexican limes coated with wax applied through spraying or dipping, and treated with thiabendazole (TBZ) at 500 ppm and gibberellic acid (GA3) at 250 ppm. Weight loss, % of juice, degrees Brix, titratable acidity, color development and severity of chilling injury were examined weekly during storage. The results, obtained from fruit collected in two harvest periods, demonstrated that limes during the maximum production period of harvest in July, in contrast to those harvested in September, retained 90.6% of their fruit marketability. The conditions under which the best quality was obtained were the following: waxing by dipping + TBZ at 500 ppm + GA₃ at 250 ppm and 10C storage temperature with RH at 85–90%.     

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     

BIOCHEMICAL RESPONSES OF ASPARAGUS TO CONTROLLED ATMOSPHERE STORAGE AT 20C

In seeking to understand the beneficial effects of controlled atmosphere (CA) storage at 20C on asparagus (Asparagus officinalis L.), biochemical responses of spear tips stored in air were compared with those of spears stored under CA (2% O₂, 10% CO₂). CA storage prevented the rapid loss of sucrose, increased acid invertase activity and asparagine accumulation observed in the tips of spears stored in air. CA storage also delayed changes in the levels of glutamine, malic, citric and fumaric acids, compared with those in tips of air-stored spears. Elongation observed in water-fed spears in air was reduced by CA. It is proposed that CA acted by depressing metabolism to such an extent that sucrose levels were maintained in the spear tip and this, in turn, prevented the cascade of metabolic events that contribute to spear deterioration in air.     

Assessment of Relationships between Sensory and Instrumental Quality of Controlled-atmosphere-stored 'Fuji' Apples by Multivariate Analysis

ABSTRACT: Physicochemical parameters, sensory attributes, and total aroma emission of ‘Fuji’ apples (Malus×domestica Borkh.) were studied in relation to storage conditions, storage duration, and shelf life period. Commercially ripe fruit were analyzed after 3, 5, and 7 mo of cold storage in normal atmosphere (AIR) (210 L/m³ O₂+ 0.3 L/m³ CO₂) or under 3 different controlled atmosphere (CA) treatments (10 L/m³ O₂+ 10 L/m³ CO₂, 20 L/m³ O₂+ 20 L/m³ CO₂, or 10 L/m³ O₂+ 30 L/m³ CO₂), after which apples were kept at 20 °C for 1, 5, and 10 d. Data were subjected to partial least square regression (PLSR) analysis. Physicochemical parameters were well preserved throughout storage, especially in CA‐stored apples; however, these apples showed lower total aroma emission. Sensory acceptability was also higher for CA‐stored fruit after 7 mo of storage, whereas no significant differences were found for shorter storage periods. Accordingly, greater scores in sensory firmness, sensory flavor, sensory acidity, and appearance were observed for fruit stored in 10 L/m³ O₂+ 10 L/m³ CO₂ after long storage. Two PLSR models were established, 1 for relating physicochemical parameters to overall acceptability, and another for assessing the correlation between sensory acidity and instrumentally measured titratable acidity. The 1st PLSR model indicated that soluble solids concentration, titratable acidity, flesh firmness, and background color of the shaded side have a positive influence on acceptability. The 2nd model indicated that sensory acidity also showed an excellent correlation to instrumentally measured titratable acidity.     

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.     

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.     

EFFECT OF DIFFERENT CA CONDITIONS ON AROMA AND QUALITY OF GOLDEN DELICIOUS APPLES

“Golden Delicious” apples were cold stored in semicommercial chambers in normal atmosphere and in different controlled atmospheres (CA) in which oxygen and carbon dioxide were held at 1%, 2% and 3% for three, five and seven months. Following storage, fruit was kept at 20C for 1, 5, and 10 days, after which volatile emission was collected and analyzed. The highest emission of volatile components was obtained after 5 months storage, in which the low CA conditions (2% O₂/CO₂) gave the highest aromatic production. Esters were the main compounds released during ripening at 20C after cold storage in all conditions. Ethyl 2-methyl butyrate, ethyl butyrate, hexyl acetate and ethyl hexanoate were the compounds that contributed most to the overall aroma of “Golden Delicious”.     

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.     

Pre‐harvest calcium treatments in relation to the respiration rate and ethylene production of ‘Golden Smoothee’ apples

Multivariate procedures were used to evaluate the effect of different pre‐harvest calcium treatments on the changes of respiratory rate and ethylene production in apples both at harvest and after extended cold storage. The study was carried out over two years on ‘Golden Smoothee’ apple trees from Lleida (Spain). Trees were sprayed with a calcium chloride based formulation (STOPIT) at a concentration of 1% (v/v). The first (6 applications) and second (12 applications) treatments began 60 days after full bloom (DAFB) and were repeated at intervals of 15 and 7 days respectively. After harvesting, the fruit was stored for 4 and 6 months under controlled ultra‐low oxygen atmosphere conditions (CA‐ULO). Each time fruit was withdrawn from storage, carbon dioxide and ethylene production were measured for 14 days at 20 °C. Independently of the calcium treatments, respiration rates fell from harvesting until 6 months of storage, while ethylene production was greater on withdrawal from storage than at harvest. Respiratory rate and ethylene production correlated negatively with calcium content. However, calcium apparently had a greater effect on the respiratory capacity (CO₂) of fruit than on ethylene production. Copyright © 2004 Society of Chemical Industry