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  • Author or Editor: Donald H. Spalding x
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Abstract

‘Waldin’, ‘Booth 8’, and ‘Lula’ avocados (Persea americana Miller) were not acceptable when softened at 21.1 °C in air under normal pressure, if they had been stored for 4–6 weeks at 7.2-10.0°, 98-100% relative humidity, and an atmospheric pressure of 76, 152, or 760 mm Hg. ‘Waldin’ avocados were acceptable when softened after 25 days at 7.2°C and 91 mm Hg provided that storage was in 2% O2 and 10% CO2. The results suggest that atmospheres both low in O2 and high in CO2 are necessary for the successful storage of avocados under low pressure. Under these conditions the low pressure system is comparable to the standard controlled atmosphere system in which avocados are stored in 2% O2 and 10% CO2 at normal atmospheric pressure.

Open Access

Abstract

‘Irwin’, ‘Tommy Atkins’, and ‘Kent’ mangos (Mangifera indica L.) softened (ripened) with less decay at 21°C in air under normal pressure, and had a higher percentage of acceptable fruits, if they had been stored for 3 weeks at 13°, 98-100% relative humidity, and an atmospheric pressure of 76 or 152 mm Hg rather than at normal atmospheric pressure. ‘Keitt’ mangos softened similarly whether stored at low or normal pressure. Low pressure storage extended shelf life: mangos stored at 152 mm Hg required 3-5 days longer to soften after storage than similar fruits stored at 760 mm Hg. Softening times were similar for mangos of the same cultivar stored at 76 and 152 mm Hg.

Open Access

Abstract

Mangos (Mangifera indica L. cvs. Tommy Atkins and Keitt) irradiated with γ-rays from 60Co at dosages of 150 to 1500 Gy, then held for 3 days at 13°C followed by ripening at 24°, developed less ripe peel color than unirradiated mangos. Ripening of ‘Tommy Atkins’ mangos was delayed for 2 to 3 days by 150 and 250 Gy, unaffected by 500 and 750 Gy, and accelerated by 1500 Gy. The pH of juice from ‘Tommy Atkins’ mangos decreased and titratable acidity increased as irradiation dosage increased; soluble solids content was not affected by irradiation. Scald-like peel injury increased with dosage, especially at 500 Gy or higher. Internal breakdown was localized and slight, but its incidence in ‘Tommy Atkins’ mangos was increased at 250 Gy or higher. Hollow pockets in the flesh and flesh darkening were significantly increased by irradiation at 1500 Gy, but not 750 Gy. Severity of anthracnose, caused by Colletotrichum gloeosporioides Penz., was reduced in ‘Keitt’ mangos at 500 Gy and higher. The severity of stem-end rot, caused by Diplodia natalensis P. Evans or Phomopsis citri Fawc., was reduced in ‘Tommy Atkins’ mongos at 1500 Gy, but not 750 Gy. The overall percentage of decayed fruit was reduced by irradiation at 750 Gy or higher. The results suggest that if irradiation is used for insect control on mangos, dosages of 250 Gy and above should be avoided to minimize injury.

Open Access

Abstract

‘Tahiti’ (‘Persian’) limes (Citrus latifolia Tanaka) retained green color, juice content, and flavor acceptable for marketing and had a low incidence of decay during storage at a low atmospheric pressure of 170 mm Hg for up to 6 weeks at 10.0°C or 15.6° and a relative humidity (RH) of 98—100%. Check fruits turned yellow within 3 weeks at normal atmospheric pressure (760 mm Hg). Limes stored for 4 weeks at 170 mm Hg at 2.2°C and 98—100% RH developed as much chilling injury as comparable limes stored at normal atmospheric pressure. Limes coated with wax containing 0.1% of either thiabendazole or benomyl remained green and suitable for marketing after 3—4 weeks at 170 mm Hg at 21.1°C.

Open Access

Abstract

Preharvest development of external red color of ‘Irwin’ and ‘Keitt’ mango (Mangifera indica L.) was enhanced with an application of the antitranspirant poly-l-p-menthen-8-9 diyl (Vapor Gard) prior to commercial fruit maturity. Both the percentage of fruit surface area showing red color and intensity of the red color was increased. Red color development in storage at 21°C was not affected by Vapor Gard. This effect was specific for the anthocyanin pigment(s). Colorimetric measurements in both yellow and green areas indicated that Vapor Gard did not affect disappearance of chlorophyll and development of yellow color at time of or following harvest.

Open Access

Abstract

Tobelle’ sweet corn (Zea mays var. saccharata (Sturtev.) Bailey) stored for 3 weeks at 1.7°C and 98100% relative humidity in controlled atmospheres (2 or 21% 02 with 0, 15, or 25% CO2) or at low atmospheric pressure (50 mm Hg) did not differ significantly in appearance or flavor. Sucrose content of stored corn remained higher in 2% O2 at normal or low atmospheric pressure (76 mm Hg) than in other atmospheres. Ethanol content increased during storage, except in 21% O2 without added CO2, and was highest in corn stored in atmospheres containing 25% CO2. The high sucrose content of ‘Florida Sweet’ even after 3-weeks-storage suggests that for maintenance of high market quality, breeding cultivars that retain quality in combination with prompt precooling offers more chance of success than modified atmospheres.

Open Access