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  • Author or Editor: R. H. Cubbedge x
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Abstract

Reduction of chilling injury (CI) during 1°C storage by conditioning treatments was determined on early (1975–76 test), midseason and late (1977–78 and 1978–79 tests) ‘Marsh’ and ‘Ruby Red’ grapefruit (Citrus paradisi Macf.). Constant storage at 1° for 28 days resulted in excessive CI; however, conditioning the fruit for 7 days at 10°, 16°, or 21° significantly reduced CI during 21 days of storage at 1°. Conditioning for fewer than 7 days resulted in significantly more CI. Treatment with 40% CO2 during 3 days of conditioning at 21° also reduced CI during low-temperature storage. Conditioning for 7 days at 10°, 16°, or 21° followed by a gradual lowering of the temperature to 1° was also effective. Placing the fruit at 10° for 14 days after 21 days of storage at 1° had no adverse effects; neither did an additional holding period of 7 days at 21°. Decay, mostly green mold rot caused by Penicillium digitatum Sacc., was negligible during storage but increased at 21°. At 21°, decay was sometimes related to the extent of CI during storage.

Open Access

Abstract

Late-season ‘Marsh’ grapefruit was stored for 4, 8, and 12 weeks at 10°C in air containing 0, 2, 20, and 200 ppm ethylene. Rind stickiness was noted on all fruit exposed to ethylene for 8 and 12 weeks, while that unexposed to ethylene was not sticky. After 4 weeks storage, only fruit exposed to 200 ppm ethylene was sticky. After 8 weeks storage, and especially after 12 weeks, the rind of fruit exposed to ethylene was significantly more orange-yellow than that of fruit not exposed to ethylene. After 12 weeks storage, rind injury, presumably caused by ethylene, was observed only on fruit exposed to 20 and 200 ppm ethylene. Ethylene had no significant effects on aging and decay. Pitting was never observed throughout the investigation. Ethylene during storage had no significant effects after storage on fruit held for 2 weeks at 21°. Palatability of fruit was acceptable, and no significant treatment differences could be detected.

Open Access

Abstract

Early Florida ‘Marsh’ grapefruit (Citrus paradisi Macf.) can be safely degreened with 5 ppm C2H4 up to 72 hours and then stored for 17 days at 1°C, providing the fruit are conditioned for 7 days at 16° prior to storage.

Open Access

Abstract

Prestorage treatments of 10, 20, and 40% CO2 for 3 and 7 days at 21°C significantly reduced stem-end rind breakdown in grapefruit (Citrus paradisi Macf.) held at 4.5° for 8 and 12 weeks. Three days’ exposure to CO2 was as effective as 7 days’ exposure; however, 20 and 40% concentrations of CO2 were significantly more effective in reducing stem-end rind breakdown than was 10% CO2. Fruit stored continuously at 4.5° in air or that exposed to 21° in an air prior to storage at 4.5° had significantly more stem-end rind breakdown than that exposed to CO2.

Open Access

Abstract

Prestorage conditioning of grapefruit (Citrus paradisi Macf.) at 16°C was better than at 21° and 27° in minimizing chilling injury (Cl) to grapefruit stored at 1°. Fruit preconditioned for 7 days at 16° did not develop Cl during 21 days at 1°. Fruit stored for 28 days at 1° without preconditioning sustained 23% CL Fruit stored for 21 days at 1° after 7 days of preconditioning at either 21° or 27° sustained 11% CI.

Open Access

Abstract

‘Bearss’ lemons (Citrus limon Burm f.) stored 21 days at 1°C and held 14 days at 21° sustained 15% chilling injury (Cl) compared to 1% after 10° storage and 21° holding period. Decay, predominantly caused by Penicillium digitatum Sacc., was negligible during storage at either 1° or 10°, but developed during the holding period at 21°. After storage at 1° or 10° plus 2 weeks at 21°, decay averaged 7.4% and 0.7%, respectively. Fruit size, method of curing, and presence of oleocellosis were not related to Cl or decay development.

Open Access

Abstract

Seven irradiation tests (with exposures of 0, 7.5, 15, 30, 60 and 90 krad) were conducted on 26 lots of grapefruit throughout the 1981–82 and early 1982–83 citrus seasons. Fruit treated with 60 and 90 krad showed rind breakdown and scald after storage for 28 days at optimum temperatures. Scald was the dominant injury in early-season fruit in tests conducted during Oct. and Dec. 1981 and Sept, and Oct. 1982. Rind breakdown, especially pitting, was the dominant injury in all other tests with midseason and late-season fruit. At the 7.5-, and 15-, and 30-krad exposures, injury was minimal, and fruit exposed to these dosages were acceptable. Although some 60- and 90-krad exposures resulted in excessive injury, 2 tests at 60 and 90 krad were acceptable with early fruit. In some instances, injured areas developed decay after storage and marketing conditions at 21°C.

Open Access