Involvement of peroxidase and polyphenol oxidase in mango sap-injury.
Saby John, K. and Bhat, S. G. and Prasada Rao, U. J. S. (2002) Involvement of peroxidase and polyphenol oxidase in mango sap-injury. Journal of Food Biochemistry, 26 (5). pp. 403-414.
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Abstract
Sap (latex) that oozes out from mangoes during harvest, upon contact with fruits, causes dark spots (sap injury) on the peel and reduces consumer acceptance and shelf-life of fruits. In this investigation different components responsible for sap-injury were identified. Sap from 4 Indian mango varieties was collected and separated into aqueous and nonaqueous phases. Whole sap, aqueous phase and non-aqueous phase were tested for their ability to cause sap injury (browning) on mangoes. The non-aqueous phase caused max. injury; the extent of injury caused by non-aqueous phases from different varieties varied. Limonene, ocimene and beta-myrcene, the major terpenoids identified in sap of Indian mango varieties, caused injury to fruits. A similar type of injury to mangoes was also caused by organic solvents. Damage to Totapuri mangoes was significantly lower compared to other varieties, whereas the non-aqueous phase from Totapuri mango sap caused injury to all other varieties. Peel from Totapuri mangoes had very low levels of polyphenol oxidase (catechol oxidase), peroxidase and polyphenols compared to other varieties. Thus, a clear relation was found between peel polyphenol oxidase content, peroxidase activities, polyphenol content in peel and the extent of injury. Application of non-aqueous phase to peels previously heat treated at 95C for 5 min caused no injury (no enzyme activity occurred in heat treated peels). Results indicated that both the terpenoid components of sap, and levels of polyphenol oxidase, peroxidase and polyphenols in peel are involved in sap injury in mangoes.
Item Type: | Article |
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Uncontrolled Keywords: | DAMAGE-; MANGOES-; PEEL-; PEROXIDASES-; PHENOLASES-; POLYPHENOLS-; CATECHOL-OXIDASES; INJURY- |
Subjects: | 600 Technology > 08 Food technology > 24 Fruits > 06 Mango |
Divisions: | Dept. of Biochemistry |
Depositing User: | Food Sci. & Technol. Information Services |
Date Deposited: | 09 Aug 2008 05:18 |
Last Modified: | 28 Dec 2011 09:59 |
URI: | http://ir.cftri.res.in/id/eprint/7591 |
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