Peroxidase and polyphenol oxidase in long-term frozen stored papaya slices. Differences among hermaphrodite and female papaya fruits
✍ Scribed by Cano, M P; Lobo, M G; De Ancos, B
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 199 KB
- Volume
- 76
- Category
- Article
- ISSN
- 0022-5142
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✦ Synopsis
The e †ects of freezing and frozen storage on hermaphrodite and female papayas (cv Sunrise, solo group) polyphenol oxidase (EC 1.10.3.1 ; PPO) and peroxidase (EC 1.11.1.7 ; POD) were evaluated. The freezing process produces a signiÐcant increase in both enzymatic activities (22È11%, PPO and 13%, POD) depending on the kind of papaya fruit. During frozen storage, the soluble PPO activity shows a continuous increase up to 9 months of storage only in hermaphrodite tissues. This same sample also showed a signiÐcant activation of soluble POD at 3 months of storage. Female frozen samples maintained a continuous decrease in soluble POD activity during storage, while PPO activity showed some increase up to 12 months. Isoenzyme pattern of PPO in freshly frozen papaya tissues showed an intensiÐcation of the most cationic forms, D and E and respectively) and a disappearance of band B (R
This band B was not regenerated during frozen storage. However, female 0É28). tissues only showed a continuous inactivation of bands D and E through storage. POD isoenzyme pattern showed di †erent changes depending on the kind of papaya fruit. In both frozen papayas a new isoenzyme form (R f \ 0É39) appeared at three months of storage. From this date, hermaphrodite frozen samples lost this isoenzyme together with original the most anionic POD form increasing the intensity of the only remaining form (R f \ 0É58), (R f \ 0É24). 1998 SCI.