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Advisor(s)
Abstract(s)
Abstract: Pears (Pyrus communis L. cv. ‘Rocha’) were exposed to air or controlled atmosphere (CA) containing various concentrations of CO2: 0, 0.5 and 5 kPa, all with 2 kPa O2. After 4months of storage
at 2 ◦C, the fruits were transferred to air at room temperature, and assessed in terms of soluble solids, titratable acidity, pH, incidence of brown heart and flesh browning, phenolic content, vitamin C content
and polyphenol oxidase activity. By 4months of storage, soluble solids and pH increased, and acidity decreased relative to harvest, but no differences were detected between pears stored under air or any of
the CA tested. Higher contents of hydroxycinnamic derivatives and flavan-3-ols in the peel than in the flesh were recorded. However, the content of arbutin was higher in the flesh than in the peel, whereas
flavonols were only detected in the peel. In general, hydroxycinnamic derivatives and flavonols were stable throughout storage, but flavan-3-ols decreased in concentration under air or CA. Arbutin was the only
phenolic compound that increased in concentration as time elapsed. No clear relation was found between
the storage conditions tested and the phenolic concentration in pears. Regarding ascorbic acid (AA) and dehydroascorbic acid (DHA), their concentrations were higher in the peel than in the flesh. Furthermore,
AA and DHA were strongly affected by storage: the former decreased, whereas the latter increased in content. A decrease in PPO activity was apparent after harvest and during storage, particularly under
higher levels of CO2. The combination 2 kPa O2 + 5kPa CO2 increased the incidence of internal disorders (viz. brown heart and flesh browning) after storage.
Description
Keywords
Controlled atmosphere Phenolics Vitamin C Disorders Quality
Citation
"Journal of the Science of Food and Agriculture". ISSN 0022–5142. 86 (2006) 509–517
Publisher
Society of Chemical Industry