Air-stored Fruit Research Articles

Antioxidant enzyme activities in strawberry fruit exposed to high carbon dioxide atmospheres during cold storage

The effects of storage, in air or a 20% CO 2 in air (16.8% O 2) atmosphere for 12 d at 2 °C, on antioxidant enzymes of strawberry fruit ( Fragaria x ananassa Duch. cv. ‘Jewel’) were investigated. The concentrations of acetaldehyde, ethanol and ethyl acetate associated with fermentation were measured, and the activities of peroxidase (POX), catalase (CAT) and superoxide dismutase (SOD) assayed. Ethanol, acetaldehyde and ethyl acetate concentrations increased in CO 2-treated fruit within a day of treatment, but more extensively after four days, while concentrations remained low in air-stored fruit. The total protein content extracted was not affected by CO 2 or storage time. Activities of POX were similar in air- and CO 2-treated fruit, with an increase occurring only in air-treated fruit on day-12. Neither CAT nor SOD activities were affected by CO 2 treatment. In summary, a 20% CO 2 storage treatment induced fermentation but did not significantly affect total antioxidant enzyme activities.

Combination of postharvest antifungal chemical treatments and controlled atmosphere storage to control gray mold and improve storability of ‘Wonderful’ pomegranates

Common food additives (sodium bicarbonate (SB), sodium carbonate (SC), and potassium sorbate (PS)) were compared to the fungicide fludioxonil for the control of gray mold on California-grown ‘Wonderful’ pomegranates artificially inoculated with Botrytis cinerea and stored at 7.2 °C in either air or controlled atmosphere (CA, 5 kPa O 2 + 15 kPa CO 2) conditions. Fludioxonil was superior to other treatments. PS was the most effective additive. Synergistic effects between antifungal treatments and CA storage were observed. After 15 weeks of storage at 7.2 °C, the combination of PS treatment (3 min dip in 3% solution at 21 °C) and CA storage was as effective as the combination of heated fludioxonil (30 s dip in 0.6 g L −1 of active ingredient at 49 °C) and air storage. Mixtures of PS with SB or SC did not improve the efficacy of either treatment alone. In tests conducted in commercial facilities, decay development and external and internal fruit quality were assessed on naturally infected pomegranates stored in either air or CA after application of a selected postharvest antifungal combined treatment (CTrt) integrating PS, SB + chlorine, and fludioxonil. CTrt was effective in controlling natural gray mold after 6 weeks of storage at 8.9 °C, but lacked persistence and it was not effective after 14 weeks. CA storage greatly enhanced decay control ability of CTrt. Skin red color was better maintained in CA-stored than in air-stored fruit. Juice color and properties (SSC, TA, and pH) were not practically affected by either postharvest treatment or storage condition. The integration of PS treatments with CA storage could provide an alternative to synthetic fungicides for the management of pomegranate postharvest decay.

Development and control of scald on wonderful pomegranates during long-term storage

Scald of the husk surface is an important factor limiting long-term storage of pomegranates and little information is available about its cause and methods of control. We evaluated the efficacy of prestorage treatment with diphenylamine and/or 1-methylcyclopropene and of atmospheric modification during storage on scald incidence and severity on Wonderful pomegranates. Scald incidence and severity were greater on pomegranates harvested during late season than on those harvested during mid season, indicating that this disorder may be associated with senescence. All pomegranates from both harvests that were kept in air exhibited some scald after 4–6 months at 7 °C. Neither diphenylamine, at 1100 or 2200 μL L −1, nor 1-methylcyclopropene at 1 μL L −1, alone or together reduced scald incidence and severity. In contrast, the three controlled atmosphere (CA) storage conditions tested (1 kPa O 2, 1 kPa O 2 + 15 kPa CO 2 and 5 kPa O 2 + 15 kPa CO 2) significantly reduced scald incidence and severity on pomegranates from both harvest dates for up to 6 months at 7 °C. However, the two CA treatments with 1 kPa O 2 resulted in greater accumulation of fermentative volatiles (acetaldehyde, ethanol, and ethyl acetate) than the CA treatment with 5 kPa O 2, especially in the mid-season-harvested pomegranates. In addition to its fungistatic effects, 15 kPa CO 2 appears to be critical for inhibition of scald development on pomegranates. These results confirm recommendation by Hess-Pierce and Kader (2003) of 5 kPa O 2 + 15 kPa CO 2 (balance N 2) as the optimal CA for pomegranates at 7 °C and 90–95% relative humidity. Since very little if any α-farnesene or its conjugated trienol oxidation products were found in the peel of pomegranates, it appears that the biochemical basis of scald in pomegranates is different from that in apples. CA storage (5 kPa O 2 + 15 kPa CO 2) decreased or prevented changes in carotenoid, acyl lipid, and phenylpropanoid metabolism that were associated with scald development in stem-end peel tissue of air-stored fruit and are indicative of stress and/or senescence.

Controlled atmosphere storage of ‘Delta R2E2’ mango fruit affects production of aroma volatile compounds

SummaryUniformly mature green ‘Delta R2E2’ mangoes were stored at 13° ± 1°C in normal air (control) or in controlled atmosphere (CA) chambers containing combinations of three concentrations of O2 (1.5%, 2% or 3%) and two levels of CO2 (6% or 8%) to investigate the effects of CA-storage on the biosynthesis of aroma volatile compounds in ripe fruit. Fruit were removed after 24 d and 38 d of storage and ripened at 21° ± 1°C. CA-storage of fruit for 24 d in 6% CO2 significantly reduced the total concentrations of aroma volatile compounds and monoterpenes. However, increased O2, in combination with 8% CO2 in CA-storage significantly increased most of the individual monoterpenes including -terpinolene (the most abundant terpene). All CA treatments significantly reduced total sesquiterpene levels compared to air-stored fruit irrespective of the storage period. Increased concentrations of O2 (1.5% to 3%), in combination with 6% and 8% CO2 in CA-storage, increased the production of sesquiterpenes in the pulp of ripe fruit and the trend was more pronounced in fruit stored for 24 d. Fruit stored in a CA of 1.5% O2 and 8% CO2 for 24 d resulted in significantly higher levels of -cymen-8-ol; however, after 38 d of storage, levels of this compound were significantly higher in fruit stored in 3% O2 and 6% CO2, compared to all other CA treatments. Levels of acetic acid and -ionone were high in ripe fruit stored under normal conditions for 24 d. After 38 d of storage, acetic acid was higher in fruit stored in a CA of 1.5% O2 and 8% CO2. Ethanol, acetaldehyde and esters were significantly higher in fruit stored in CAs of 1.5% O2 and 6% CO2, as well as in 1.5% or 2% O2 in combination with 8% CO2, compared to all other treatments. CA-storage for up to 38 d in 6% CO2 and 3% O2 appears promising for ‘Delta R2E2’ mango, without causing significant fermentation products, especially ethanol and acetaldehyde.

Changes in strawberry phenolics, anthocyanins, and antioxidant capacity in response to high oxygen treatments

Changes in fruit quality, decay, phenolic and anthocyanin content, and antioxidant capacity of strawberries ( Fragaria × ananassa Duch. cv. Allstar) stored under air and high oxygen atmospheres at 5 °C were investigated. Freshly harvested strawberries were placed in jars and ventilated continuously with air or with 40, 60, 80, or 100 kPa O 2 at 5 °C for up to 14 days. Samples were taken initially, and after 3, 7, 10 and 14 days of storage. While fruit quality parameters such as titratable acidity, total soluble solids and surface color were only slightly affected by differing levels of O 2, the higher oxygen concentration treatments significantly reduced decay. Oxygen concentrations higher than 60 kPa also promoted increases in ORAC values, total phenolics and total anthocyanins as well as individual phenolic compounds analysed by HPLC during the initial 7 days of storage. However, this effect diminished with prolonged storage. No significant differences in ORAC values, total phenolics, total anthocyanins, or the individual phenolic compounds were observed among the high O 2 and air-stored fruits after 14 days of storage. These results indicate that high oxygen treatments exert the most effects on fruit quality and antioxidant capacity of strawberry fruit in the first 7 days of storage.

(37) Metabolism of Apple Peel Constituents during Ripening is Differently Regulated by Ethylene

Metabolism of peel constituents was assessed during ripening of `Delicious' and `Golden Delicious' apples. The ethylene action inhibitor 1-methylcyclopropene (1-MCP) and/or controlled atmosphere storage (CA) were used to limit ethylene activity during and after storage at 1 °C. `Delicious' apples not exposed to 1-MCP developed a brownish discoloration (not superficial scald) during the initial 2 months of storage in air. LC/MS analyses of peel components indicated 1-MCP and/or CA inhibited the degradation of compounds responsible for red peel color (i.e., idaein) as well as other flavonoids. Ethylene regulation of metabolism of other phenolic and related constituents including (-)epicatechin and chlorogenic acid appears to be compound specific. The (-)epicatechin content is not impacted by 1-MCP or CA, while chlorogenic acid accumulation is reduced in fruit exposed to 1-MCP and/or stored in CA. β-carotene and lutein content in peel of `Delicious' fruit stored in air was lower compared with untreated controls. Chlorophyll degradation was enhanced in air-stored fruit previously exposed to 1-MCP; however, this result was not observed in 1-MCP exposed fruit from CA. Results for `Golden Delicious' apples also indicated that exposure to 1-MCP and CA, as well as storage duration, impacts metabolism of peel constituents. Chlorophyll degradation was delayed in fruit previously exposed to 1-MCP and then stored in CA. Impacts of 1-MCP and storage environment on concentrations of other `Golden Delicious' peel constituents increased with storage duration. The results indicate metabolism of apple fruit peel constituents during fruit ripening is differentially regulated by ethylene.

EFFECTS OF HIGH O2 PRETREATMENT AND HIGH O2 MAP ON QUALITY OF CUCUMBER FRUIT

The responses of cucumber fruit to high O 2 (100%) MAP (HO-MAP) and high O 2 pretreatment with 100% O 2 for 48 hours were investigated at 5°C. The fruit stored in HO-MAP observed no weight loss through the storage. The weight loss of air-stored fruit was 2 times higher than the fruit pretreated with 100% O 2 . The desiccation of cucumber fruit was concomitant with the reduction of fruit weight. The shrivel appearance was detected in control fruit and in fruit pretreated with 100% O 2 on day 4 and day 8, respectively. The onset on chilling injury was inhibited by HO-MAP. Fruit pretreated with 100% O 2 found to have less severity of chilling injury compared to air-stored fruit. The severity of chilling injury was related with the percentage of weight loss. The concentrations of CO 2 in HO-MAP increased to 20% while O 2 levels decreased to 50% at the end of storage. Fruit in the HO-MAP did not detect any abnormal visual quality throughout storage. On day 8, however, off-flavor was detected in fruit stored in HO-MAP, furthermore, the percentage of ion leakage from flesh tissues also increased over those receiving other treatments. The ion leakage of control and 100% O 2 pretreated fruit showed similar level during the first week of storage. The sharply increase of ion leakage from control fruit to a higher level than those of 100% O 2 pretreated fruit was observed after day 8 till the end of storage. Fungal decay was showed in control fruit and fruit pretreated with 100% O 2 on day 13 and dayl5, respectively. Pretreatment with 100% O 2 lowered the respiratory rate in cucumber fruit compared to control.

Changes in firmness, cell wall composition and cell wall hydrolases of grapes stored in high oxygen atmospheres

To investigate the effects of high oxygen (O 2) atmospheres on the firmness of ‘Kyoho’ grapes ( Vitis vinifera L. X V. labrusca L.), changes in cell wall constituents and hydrolase activities were examined during 60 days of controlled atmosphere storage in air (control), 40% O 2 + 30% CO 2 or 80% O 2 (high O 2) at 0 °C and 95% relative humidity. Grapes stored in high O 2 retained greater firmness than grapes stored in air. The cell wall contents of high O 2-stored fruits contained less water-soluble pectin (WSP), more Na 2CO 3 soluble pectin (SSP) and higher hemicelluloses than air-stored fruits. The levels of cellulose and CDTA-soluble pectin (CSP) did not significantly change. The effects of high O 2 on enzyme activity were dramatic for polygalacturonase and β-galactosidase, moderate for cellulase, and very low for pectinesterase. No pectate lyase was detected. Taken together, WSP, SSP and hemicelluloses appeared to have major structural roles in retaining the firmness and preventing the deterioration of fruits kept in high O 2.

Controlled atmosphere storage affects fruit ripening and quality of ‘Delta R2E2’ mango

SummaryUniformly mature, hard green ‘Delta R2E2’ mangoes were stored at 13° ± 1°C in either normal air (control) or in 90 l controlled atmosphere (CA) chambers with various combinations of three concentrations of oxygen (1.5%, 2% or 3%) and two levels of carbon dioxide (6% or 8%) to investigate the effects of CA storage on fruit ripening and quality. Fruit were removed after 24 d and 38 d of storage and ripened to the ‘eating soft’ stage at 21° ± 1°C. All CA treatments reduced respiration rate, and delayed de-greening of the skin and fruit softening. During ripening, all CA-stored fruit experienced post-storage respiratory suppression. The yellowness of the skin, total soluble solids (TSS), TSS/acid ratio, total sugars content, and taste of the ripe fruit were higher in fruit stored in a CA of 6% CO2 and 3% O2 compared to all other CA treatments. The respiration quotients and ethylene production levels of CA-stored fruit during ripening were higher than normal air-stored fruit, irrespective of storage period. CA storage in 6% CO2 and 3% O2 appears to be promising to extend the shelf-life of ‘Delta R2E2’ mangoes for up to 38 d, while still allowing the fruit to ripen normally with a yellow skin colour, good taste, high TSS and TSS/acid ratio, and a high total sugars content.

Carbon dioxide scrubbing systems alter the ripe fruit volatile profiles in controlled-atmosphere stored ‘Hayward’ kiwifruit

Abstract The method of CO 2 control used during controlled-atmosphere (CA) storage may affect the volatile composition of the room atmosphere, which in turn may affect the volatile production of ripe fruit. ‘Hayward’ kiwifruits were CA-stored (2 kPa O 2 /5 kPa CO 2 ) at 0 °C using one of three CO 2 scrubbing systems: activated carbon (AC) scrubber, hydrated lime scrubber or nitrogen purging. For further comparison, fruits were also stored in air. Fruit samples were removed from storage at intervals and allowed to soften in air at 20 °C until eating soft, whereupon they were sampled for volatiles with a headspace purge and trap system. Linear discriminant analysis (LDA) segregated the ripe fruits by their volatile profiles on the basis of both CO 2 scrubbing system and also time in storage. Ripe fruit volatile profiles differed between CA-stored and air-stored fruits, and also among fruits from the different CO 2 scrubbing systems. The work was repeated over two seasons with a large difference in alcohol and ester production of the fruit between the two seasons, despite storage under the same atmosphere of 2 kPa O 2 and 5 kPa CO 2 . It is suggested that alcohol metabolism contributed significantly to the ripe fruit volatile profile, particularly ester production. While the CO 2 scrubbing systems did result in measurable differences in ripe fruit volatile profiles, it remains to be determined whether the differences are significant to consumers.

Impact of 1-Methycyclopropene and Controlled Atmosphere Storage on Volatile Production in `Gala' Apples

`Gala' apples (Malus × domestica Borkh) were harvested at optimum maturity for long-term storage, precooled overnight at 0 °C, treated with 1 μL·L-1; 1-methylcyclopropene (1-MCP) for 24 hours at 0 °C, and then placed in controlled atmosphere (CA) to determine the storage regime that would have the least negative impact on post-storage aroma volatile production. Fruit were stored at 0° and 2.5° C in ultra low oxygen (0.6% O2 -0.6% CO2; ULOCA), low oxygen (1.2% O2 -1.2% CO2; LOCA) and standard (2.5% O2 -2.5% CO2; SCA) CA for 120 and 240 days, and in ambient air for 60, 90, 120 and 150 days. Post-storage fruit volatiles were quantified by headspace analysis using a solid-phase micro-extraction (SPME) probe and FID-GC, and key volatiles were identified by GC-MS. Fruit volatile production was greatest at harvest, and decreased thereafter for fruit held in air and CA for up to 150 or 240 days, respectively. 1-MCP treatment resulted in reduced rates of respiration, ethylene and volatile production, regardless of storage regime, and resulted in a reduced production rate of all the major volatile compounds, including esters, alcohols, acids, aldehydes and ketones. Post-storage volatile production was the least in fruits removed from 0 °C in ULO, followed by LO, SCA, and then air. 1-MCP treatment inhibited post-storage volatile production in CA- and air-stored fruit by as much as 95 percent. However, recovery of aroma was delayed significantly in fruit which had been held at 0 °C vs. 2.5 ° C, suggesting aroma volatile synthesis in `Gala' is chilling sensitive.

Incidence of water-soaking and phospholipid catabolism in ripe watermelon (Citrullus lanatus) fruit: induction by ethylene and prophylactic effects of 1-methylcyclopropene

Abstract Watermelon (Citrullus lanatus Thunb. Matsum and Nakai) fruits were held in 50 μl l−1 ethylene at 20 °C following an 18-h exposure to 5 μl l−1 1-methylcyclopropene (1-MCP) to investigate the involvement of ethylene perception in the regulation of placental tissue water-soaking through phospholipase-mediated phospholipid (PL) degradation. Water-soaking was accompanied by increase in phospholipases C (PLC, EC 3.1.4.3) and D (PLD, EC 3.1.4.4), and lipoxygenase (LOX, EC 1.13.11.12) activities, decreases in phosphatidylcholine (PC) and phosphatidylinositol (PI), and increases in phosphatidic acid (PA). These changes were evident within 2 days of ethylene exposure, coincident with accelerated softening, increased electrolyte leakage and extractable juice, and appearance of water-soaking. Air-stored fruits did not exhibit water-soaking, and the activities of lipid-degrading enzymes and PL levels remained constant throughout the 8-day storage period. Treatment of fruit with 5 μl l−1 1-MCP prior to ethylene exposure reduced ethylene-induced increases in the activities of lipid-degrading enzymes, and PL degradation, and completely prevented water-soaking and the attendant increases in electrolyte leakage and extractable juice. The results demonstrated that water-soaking in watermelon fruit requires competent ethylene responsiveness and is associated with ethylene-inducible PL degradation. This represents the first report wherein 1-MCP imparts to a fully ripe fruit complete protection against deleterious effects of exogenous ethylene. Watermelon fruit maintained under simulated commercial storage conditions (up to 3 weeks at 13 °C ) without exposure to exogenously provided ethylene also benefited significantly from prior exposure to 1-MCP.

PYRUVATE DECARBOXYLASE IS A RELIABLE BIOCHEMICAL MARKER FOR FORECASTING PHYSIOLOGICAL DISORDERS OF 'D' ANJOU' PEARS IN CONTROLLED ATMOSPHERE STORAGE

ISHS VIII International Controlled Atmosphere Research Conference PYRUVATE DECARBOXYLASE IS A RELIABLE BIOCHEMICAL MARKER FOR FORECASTING PHYSIOLOGICAL DISORDERS OF 'D' ANJOU' PEARS IN CONTROLLED ATMOSPHERE STORAGE

Impaired aroma production of CA-stored ‘Jonagold‘ apples as affected by adenine and pyridine nucleotide levels and fatty acid concentrations

SummaryPreclimacteric ‘Jonagold’ apples were stored for up to six months following two fruiting seasons. Storage was at 0°C in air (control) and various controlled atmosphere (CA) conditions. Fruits kept under CA-storage produced less aroma volatiles than air-stored fruits. This suppression of aroma volatiles was accentuated with increasing storage duration. Greatest impairment was caused by very low oxygen (0.5% O2) combined with high CO2 (6%) concentrations. Respiration rate was inhibited to a similar degree as the emission of aroma volatiles. There were lower ATP concentrations in fruits kept under CA-storage, thereby decreasing the ATP:ADP ratio and energy charge of tissues. On the other hand, concentrations of NADPH and NADH increased in CA as well as in air stored fruits. However, there were no significant differences between CA-treatments. Moreover, no correlations between NADPH or NADH concentrations and volatile aroma or fatty acid production were found. For that reason pyridine nucleotides are not considered to be of regulatory significance. CA storage caused an overall decrease in the concentrations of free- and esterified fatty acids. These acids are considered the dominant precursors of volatile aroma substances in apples. Suppressed aroma production appeared to be highly correlated with the concentration of free linoleic acid. Impaired aroma production of ‘Jonagold’ apples was apparently related to lower ATP concentrations and decreased fatty acid biosynthesis under CA-storage.

Impact of controlled atmosphere storage conditions on storability and consumer acceptability of sweet cherries ‘Regina’

SummarySweet cherries obtained from a rain-protected orchard were subjected to various controlled atmosphere storage conditions for up to seven weeks. Quality parameters responded differentially to various CA-conditions: changes in fruit firmness, sugar content and colour were mostly not significant. However, the storage conditions exerted significant impact on other parameters such as respiration rate, RQ, ATP- and ADP-concentrations. Air-stored fruits respired at significant higher rates than CA or ultra low oxygen-stored fruits. Moreover, the impact of CA-storage conditions persisted even after a conditioning period of 36 h at room temperature. The ATP and ADP concentrations of sweet cherries behaved similarly, where a combination of reduced O2 and very high CO2 concentration (12% or above) resulted in highly reduced ATP-concentration in the fruit tissue. A taste panel considered fruits stored under 6% CO2 + 2% O2 as good, although there was a strong indication that it is better to store sweet cherries for a limited time (up to five weeks) under a low O2 concentration combined with a high CO2 concentration (12%) or under a high O2 concentration combined with a very high CO2 (18%).

Oxygen action on respiratory processes in cucumber fruit (Cucumis sativus) stored at low temperature

SummaryRespiratory processes in cucumber fruit stored in 5%, 21% (air control) and 100% O2 at 5°C were studied. Storage in 100% O2 at 5°C was most effective for suppressing the respiratory rate in cucumber fruit, the rate being lower than in fruit stored in either 5% O2 or air. Succinate dehydrogenase (SDH) activity in cucumber fruit stored in 100% O2 was lower than in other storage conditions. Only slightly different SDH activity was recorded between the control and 5% O2-treated fruit. Cucumber flesh pH in all three atmospheres increased during storage. pH showed similar increasing trends and more than one pH unit change from the initial value was recorded in control and 5% O2-treated fruit. Fruit kept in 100% O2 had a lower pH than fruit stored in 5% O2 and air. Pyruvate concentration in all three storage atmospheres increased during storage. The pyruvate concentration in 100% O2 was higher than in other storage atmospheres. The increase in pyruvate concentration in control fruit was similar to that in 5% O2 stored fruit. However, the pyruvate concentration in air-stored fruit increased sharply after day 11 and finally reached a higher level than that in 100% O2-treated fruit. Thus, the elevated O2 concentration suppressed SDH activity. This effect may be due to a reduction in fruit pH change. Consequently, reduced SDH activity in the 100% O2 treatment resulted in pyruvate accumulation which was not associated to any off-flavours. High O2 treatment has the potential to help maintain the quality of cucumber fruit. This is discussed.

Storage disorder and ripening behavior of ‘Doyenne du Comice’ pears in relation to storage conditions

‘Doyenne du Comice’ pears (Pyrus communis, L.) harvested at commercial maturity with flesh firmness (FF) of 55.1 N (±2.78 N) were stored in air and different controlled atmosphere (CA) conditions at −1 °C to evaluate storage disorder, ripening behavior and dessert quality after different storage intervals. Fruit stored in air developed both flesh breakdown (FB) and senescent scald (SCALD) disorders alter 4 months of storage. Incidence of FB and SCALD increased after 5 and 6 months of storage. Development of FB disorder in air-stored fruit was not associated with the activity of pyruvate decarboxylase (PDC) or alcohol dehydrogenase. Changes in α-farnesene and conjugated trienes in the peel tissue were highly associated with the development of SCALD. CA-stored fruit were free from SCALD disorder regardless of CA regime and storage time but developed internal browning (IB) disorder after 4 months of storage. Incidence of IB increased after 5 and 6 months of CA storage. Fruit stored in 0.5 and 1% O2 suffered higher incidence of IB than those stored in 1.5 and 2.0% O2. Symptoms of CA-induced IB are different from those of FB disorder, which resulted from prolonged air storage. The development of IB disorder was closely associated with an increase in PDC activity. Changes in ethylene production and FF during post-storage ripening at 20 °C were found to be the best objective measurements of storage life of ‘Doyenne du Comice’ fruit. Fruit stored in refrigerated air for 1–3 months exhibited typical climacteric-like patterns of ethylene production during 15 days at 20 °C and softened to proper ripeness with desirable eating quality on day 5 at 20 °C. The magnitude of ethylene production increased with storage time when initially transferred to temperature at 20 °C. Fruit stored in air for 4 months or longer did not exhibit climacteric-like patterns of ethylene production during ripening and softened improperly with coarse and dry texture. Fruit stored in either 1% O2/<0.1% CO2 or 2% O2/1% CO2 for 3 months (short-term CA storage) followed by holding in air at −1 °C for 1, 2, and 3 months were capable of ripening normally with desirable dessert quality without developing any physiological disorders. Short-term CA storage 4 of ‘Comice’ fruits maintained green skin color during 3 months of holding in air at −1 °C.

Integrated control of brown rot of sweet cherry fruit with a preharvest fungicide, a postharvest yeast, modified atmosphere packaging, and cold storage temperature

Abstract An integrated approach was studied for control of postharvest brown rot of sweet cherry fruit. System components included a preharvest application of propiconazole, a postharvest application of a wettable dispersible granular formulation of the yeast Cryptococcus infirmo-miniatus (CIM) Pfaff and Fell, storage in modified atmosphere, and storage at 2.8 °C for 20 days or −0.5 °C for 42 days. Preharvest propiconazole and postharvest CIM were similarly effective for control of brown rot. A significant propiconazole–CIM synergism was observed. Modified atmosphere significantly reduced brown rot compared to air-stored fruit. The storage temperature regime effect was inconsistent. This integrated decay control approach was effective and is especially relevant since postharvest fungicide options for cherry are limited.

Aroma Volatiles of Mature-green and Tree-ripe `Tommy Atkins' Mangoes after Controlled Atmosphere vs. Air Storage

To determine the effects of fruit maturity, storage temperature, and controlled atmosphere (CA) on aroma volatiles, mature-green (MG) and tree-ripe (TR) `Tommy Atkins' mangoes (Mangifera indica L.) were stored for 21 days in air or in CA (5% O2 plus 10% or 25% CO2). The MG fruit were stored at 12 °C and the TR fruit at either 8 or 12 °C. Homogenized mesocarp tissue from fruit that had ripened for 2 days in air at 20 °C after the 21-day storage period was used for aroma volatile analysis. The TR mangoes produced much higher levels of all aroma volatiles except hexanal than did MG fruit. Both MG and TR mangoes stored in 25% CO2 tended to have lower terpene (especially p-cymene) and hexanal concentrations than did those stored in 10% CO2 and air-stored fruit. Acetaldehyde and ethanol levels tended to be higher in TR mangoes from 25% CO2 than in those from 10% CO2 or air storage, especially at 8 °C. Inhibition of volatile production by 25% CO2 was greater in MG than in TR mangoes, and at 8 °C compared to 12 °C for TR fruit. However, aroma volatile levels in TR mangoes from the 25% CO2 treatment were in all cases equal to or greater than those in MG fruit treatments. The results suggest that properly selected atmospheres, which prolong mango shelf life by slowing ripening processes, can allow TR mangoes to be stored or shipped without sacrificing their superior aroma quality.

129 Postharvest Life, Quality and Flavor Characterization of Three Strawberry Cultivars Kept in Air or CO2-enriched Atmospheres

Elevated CO2 atmospheres reduce decay and extend postharvest life based on appearance of strawberries but flavor quality may be lost faster than appearance quality. California-grown `Aromas', `Diamante,' and `Selva' strawberries were stored at 5 °C in air or 20 kPa CO2 + air for 15 days and evaluated for quality attributes, chemical changes, and flavor. In a “Preference Test”, `Selva” and `Diamante' were more preferred than `Aromas'. This may be related to their higher titratable acidity (TA), total soluble solids (TSS), the concentration of total aroma compounds, a different methyl/ethyl esters ratio, and the presence of C6 aldehydes. The postharvest life in air was 7, 9, and 9 days for `Aromas', `Diamante' and `Selva', respectively and these periods were extended by 30%, 20%, and 45% in the CO2-enriched atmosphere. There were no significant differences in TA or TSS between fruits kept in air or in air + CO2 and panelists could not detect differences in sourness and sweetness after 9 days of storage. In contrast, there was a trend for CO2-stored fruits of the three cultivars to be categorized as more aromatic, and for `Aromas' and `Selva' fruits to be described as more “strawberry like” in flavor compared to the corresponding air-stored fruits. The total aroma concentration decreased to a lesser extent in `Aromas' and `Selva' strawberries kept in air + CO2 than in those stored in air. The CO2-enriched atmosphere stimulated fermentative metabolism only in `Aromas' and `Selva'; the higher concentration of ethanol in these two cultivars favored the synthesis of ethyl esters. The total content of aroma compounds and the methyl/ethyl esters ratio may be two of the multiple factors determining the overall fruit flavor.