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Yair Aharoni, Azica Copel, and Elazar Fallik

The quality of `Galia' melons (Cucumis melo pv. reticulates) stored in a controlled atmosphere (CA) of 10% CO2 plus 10% O2 with ethylene absorbent (EA) for 14 days at 6C and an additional 6 days at 20C was significantly better than that of control fruit or fruit stored in CA only. Fruit stored in CA plus EA were firmer and exhibited less decay than fruit from the other two treatments.

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Susan S. Han and Jennifer Konieczny

Eggs, larvae, pupae, and adult stages of greenhouse whitefly (Trialeurodes vaporarium Westwood) and silverleaf whitefly (Bemisia argentifolii Bellows & Perring) were exposed to insecticidal controlled atmospheres at 20 °C or 30 °C. Mortality data were calculated for each stage and results demonstrated that reduced-O2 atmospheres (an O2 level of <2 μL·L-1 balance in N2) resulted in faster and higher mortality than elevated-CO2 atmospheres (25% or 50% CO2). Responses, from the least to most tolerant stage was adult < larvae < eggs = pupae, regardless of the species of whitefly and treatment temperature. At 20 °C, treatment time required to kill >90% of adults, larvae, and eggs and pupae was 2, 4, and 8 hours, respectively. Increasing the treatment temperature from 20 to 30 °C reduced the treatment time to one-half that of 20 °C. Treatment time required to achieve complete elimination of the insects also caused phytotoxicity symptoms on poinsettias (Euphorbia pulcherrima Willd. ex Klotzsch), thus, limiting use of insecticidal controlled atmospheres as the sole means for managing whitefly.

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S.R. Drake, T.A. Eisle, and H. Waelti

`Delicious' apples were held in controlled atmosphere (CA) storage at various carbon dioxide (CO2) levels for 9 months. CO2 levels were either 1, 3, or 5% with an additional treatment that was increased by 1% every 6 weeks to a maximum of 5%. For each treatment oxygen was 1%, and storage temperature was 1°C. Little quality difference was noted for the `Delicious' apples immediately after storage or after an 8 day ripening period. Firmness, external or internal color, titratable acidity and amount of scald showed no difference among the different storage treatments. Total carbohydrates and fructose were higher in apples stored at CO2 levels above 1 %. Sensory panelists found no flavor difference in `Delicious' apples regardless of CO2 storage level atmospheres. If one considers the substantial cost savings that are possible with increased CO2 in the storage system, there is good reason to increase the CO2 storage level in long term storage.

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Arturo Martínez-Morales, Iran Alia-Tejacal*, María-Teresa Colinas-León, and María-Teresa Martínez-Damián

Zapote mamey fruit (Pouteria sapota) has a great potential for exportation, due to its organoleptic characteristics, however, very little is known about harvest technologies to increase its shelf life. So in this research, zapote mamey fruit from two harvest dates in the same year, were stored at 12 °C [95% relative humidity (RH)] for 14, 21, and 28 days under controlled atmospheres (10% or 5% CO2 + 5% O2 with balance of nitrogen), in addition, two groups of fruit were stored at the same temperature and time intervals, but with no controlled atmosphere (CA). Variables considered were: CO2 and ethylene production inmediately after transfer to ambient conditions (29 °C ± 2 °C; 85% RH). Control fruit from both harvest dates had a typical climacteric behaviour, ripening 2 to 3 days after transfer to ambient temperature. Fruit from the first harvest date, stored for 14 and 21 days under CA had a ripening process similar to the control, however fruit stored for 28 days fail to ripen even after 6 days at ambient temperature. Fruit from the second harvest date did not show this ripening problem.

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Ahmad Shirazi and Arthur C. Cameron

The feasibility of controlling relative humidity in modified atmosphere packages using compounds possessing Type III sorption isotherm behavior was studied. Ten grams each of dry sorbitol, xylitol, NaCl, KCl, or CaCl2 sealed with one maturegreen tomato (Lycopersicon esculentum L.) fruit at 20C in simulated packages for 48 days resulted in stable relative humidities of ≈75%, 80%, 75%, 85%, and 35%, respectively. Relative humidity was a function of the ratio of chemical to fruit mass. Relative humidities within control packages were in the range of 96% to 100% throughout the experiments. A simple system that uses spunbonded polyethylene pouches for the application of this humidity control method to packages is described. The storage life of packaged red-ripe tomato fruit at 20C was extended from 5 days using no pouch to 15 to 17 days with a pouch containing NaCl, mainly by retardation of surface mold development.

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R.J. Bender, J.K. Brecht, S.A. Sargent, and D.J. Huber

Exposure to hypoxic O2 levels has been reported to result in better epidermal color, higher titratable acidity and soluble solids levels, delayed softening and reduced ethylene production and respiratory activity in many fruit species. Mangoes have been shown to tolerate short term (4 days) exposures to O2 concentrations below 0.5% with beneficial effects on firmness retention and maintenance of ground color. In the present work, `Haden' mangoes were stored for 14 days at 15°C with O2 levels ranging from 2% to 5% and compared to an air control and an atmosphere of 25% CO2 in air. `Tommy Atkins' mangoes were stored under the same treatments at 12°C for 21 days. After storage at 12 or 15°C the mangoes were transferred to air at 20°C for 5 days. Ethanol production rates during controlled atmosphere (CA) storage were significantly higher at O2 levels of 4% and below. Respiration (CO2 production) rates were reduced during CA storage but did not differ from the control after transfer to air. There were no differences in ethylene production as well as in flesh firmness, titratable acidity and total sugars. The ground color of mangoes kept under the lowest O2 concentration and under 25% CO2 was greener, as indicated by higher hue angles, than in the other treatments upon transfer to air at 20°C. However, only the mangoes stored under high CO2 maintained higher hue angles during the subsequent 5 days at 20°C.

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James W. Rushing

Mature-green fresh-market tomatoes (Lycopersicon esculentum Mill.) were held at 11 °C under controlled atmosphere (CA) at 4% O2 and 4% CO2 in a commercial intermodal shipping container equipped with a membrane-based nitrogen-generating CA system. After 4 weeks, tomatoes in CA had 11.9% decay compared to 46.4% decay in control samples held at the same temperature under normal atmosphere. During storage, color development in controls progressed from green to the light red stage in more than 50% of the fruit and only 4.5% remained green after 4 weeks. In contrast, CA stored samples had 25.7% of the fruit in green condition and only 3.9% had progressed to the light red stage. Following CA exposure tomatoes were held at 20 °C with or without 250 ppm C2H4 treatment to observe ripening. All samples ripened normally without symptoms of chilling injury. Results suggest that CA is a useful method for reducing decay and delaying ripening during international transport.

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Lawford Baxter and Luther Waters Jr.

Okra (Abelmoschus esculentus L. Moench) pods stored In a controlled atmosphere (CA) of 5% O2 and 10% CO2 at 11 ± 1C and in air at the same temperature (RA) were compared to determine the effects of the two storage environments on changes in sugars, organic acids, proteins and amino acids, and ascorbic acid contents within the tissue. Pods were sampled at 3-day intervals for 12 days. CA-stored pods generally had greater retention of sugars, soluble proteins, and amino acids than RA-stored pods. Citric, malic, and ascorbic acids contents of CA pods also declined more slowly than those of RA pods.

Open access

James Mattheis and David R. Rudell

air-stored fruit in both years (controls in year two). Ethylene production was influenced by an atmosphere × 1-MCP interaction in year two at both 4 and 8 months. Discussion As ‘Honeycrisp’ loses little if any firmness during storage ( Tong et al

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Fairuz. El-Wazir, Dangyang Ke, and Adel A. Kader

The tolerances (based on time before detection of off-flavor) of nectarine and peach cultivars to an insecticidal controlled atmosphere of 0.25% O2 (balance N2) at 20C were 2.8, 4.0, 4.0, 4.4, 5.1, and 5.3 days for `John Henry' peaches, `Fantasia' nectarines, `Five Red' peaches, `O'Henry' peaches, `Royal Giant' nectarines, and `Flamekist' nectarines, respectively. The greater sensitivity of `John Henry' peaches to low O2 stress was associated with a higher respiration rate; faster accumulation rates of acetaldehyde, ethanol, and ethyl acetate; and a more mature and larger fruit. The tolerances of `Fairtime' peaches to 0.21% O2 + 99% CO2 at 20C, 0.21 O2 + 99% CO2 at 0C, and 0.21% O2 at 20C were 3.8, 5.0, and 6.0 days respectively. There was a good correlation between tolerance of nectarines and peaches to insecticidal atmospheres and the accumulation rates of acetaldehyde (r=-0.94, p<0.01) and ethanol (r=-0.88, p,0.01).