Variation in fruit chilling injury among mango cultivars

Mango(Mangifera indica L.) fruit of six cultivars ('Kaew', 'Rad', 'Okrong', 'Tongdum', 'Nam Dok Mai' and 'Nungklangwun') were stored at 4, 8 and 12degreesC (85-90% RH) and randomly sampled every 5 days. Chilling injury was manifested initially as a gray to brown discoloration of the peel, followed by a color change in the pulp and the endocarp (seed coat). The seed tissue of most cultivars became brittle during storage at 4 and 8degreesC for as little as 5 days, and the seeds did not germinate. In all cultivars Studied, storage life was limited by skin discoloration. If acceptable skin color (no discoloration of more than 10% of the skin surface) after 5 days of shelf life at room temperature (about 30degreesC) was taken as a criterion, fruit of all cultivars, except 'Rad' and 'Okrong', could be not be stored for more than 5 days. According to this criterion, 'Rad' fruit Could be stored at 12degreesC for 15 days and 'Okrong' fruit for as long as 25 days. This variation in chilling injury (CI) sensitivity may be useful in breeding cultivars with improved storage life at low temperatures. (C) 2003 Elsevier B.V. All rights reserved

Variation in fruit chilling injury among mango cultivars

Mango(Mangifera indica L.) fruit of six cultivars ('Kaew', 'Rad', 'Okrong', 'Tongdum', 'Nam Dok Mai' and 'Nungklangwun') were stored at 4, 8 and 12degreesC (85-90% RH) and randomly sampled every 5 days. Chilling injury was manifested initially as a gray to brown discoloration of the peel, followed by a color change in the pulp and the endocarp (seed coat). The seed tissue of most cultivars became brittle during storage at 4 and 8degreesC for as little as 5 days, and the seeds did not germinate. In all cultivars Studied, storage life was limited by skin discoloration. If acceptable skin color (no discoloration of more than 10% of the skin surface) after 5 days of shelf life at room temperature (about 30degreesC) was taken as a criterion, fruit of all cultivars, except 'Rad' and 'Okrong', could be not be stored for more than 5 days. According to this criterion, 'Rad' fruit Could be stored at 12degreesC for 15 days and 'Okrong' fruit for as long as 25 days. This variation in chilling injury (CI) sensitivity may be useful in breeding cultivars with improved storage life at low temperatures. (C) 2003 Elsevier B.V. All rights reserved

Injúria pelo frio na qualidade pós-colheita de mangas cv. Palmer

Este trabalho objetivou estabelecer os binômios temperatura x tempo, que podem ocasionar injúria pelo frio em mangas 'Palmer'. Frutos colhidos no estádio "de vez" foram cuidadosamente transportados para laboratório, onde foram selecionados, padronizados quanto à coloração, ao tamanho e à ausência de injúrias, e tratados com fungicida antes de serem armazenados a 2 ºC, 5 ºC e 12 ºC, por até 28 dias. Os frutos foram avaliados semanalmente quanto à ocorrência de podridões, danos pelo frio, atividade respiratória, coloração da casca e da polpa, massa fresca, firmeza da polpa, teores de sólidos solúveis (SS) e de acidez titulável (AT), e relação SS/AT. Os resultados indicaram que os sintomas de injúrias pelo frio foram exteriorizados após 7 dias do armazenamento refrigerado a 2 ºC ou 5 ºC, com os frutos não diferindo quanto à gravidade dos danos. A presença dos danos não impediu o desenvolvimento da coloração característica da polpa, porém levou ao escurecimento da casca e afetou o amadurecimento normal dos frutos. Frutos armazenados a 12 ºC não apresentaram sinais de danos pelo frio ou prejuízos aos seus processos metabólicos normais

Postharvest internal browning of pineapple fruit originates at the phloem.

A typical symptom of postharvest chilling injury (PCI) in pineapple fruit (Ananas comosus (L.) Merr.) is internal browning (IB) near the fruit core. Since vascular bundles (VBs) are localized to this region, it was hypothesized that the VBs might be the site of IB. To test this, the anatomy and histochemistry of VBs during chilling stress in four pineapple cultivars with different levels of sensitivity to PCI were examined. Fruit were stored at 10°C for up to three weeks to stimulate translucency symptoms (TS; the initiation of IB). After three weeks of chilling exposure, the cultivars 'MD2' showed 0%, 'Pattavia' and 'Savee' showed 10-16%, and 'Trad Sri Thong' showed 100% TS and IB symptom. Scanning electron microscopy and in situ histochemical staining techniques that detect enzymes and substrates commonly associated with IB initiation were used in parallel. The TS of pineapple fruit coincided with the collapse of the phloem tissue. The VBs in the tissue where IB was initiated (i.e., the flesh adjacent to the core or F/C) had the highest activity of polyphenol oxidase, hydrogen peroxide, and phenolic compounds. The IB-resistant 'MD2' genotype had fewer VBs, but a greater proportion of sclerenchyma fibers (P<0.05) than did the susceptible 'Trad Sri Thong'. Based on these data, the first report of pineapple IB occurrence in the phloem was proposed