Citation
Seow C. C., . and Lee S. K., . (1996) Enhancing the firmness of processed tropical fruits by low-temperature blanching and calcium infiltration. [Proceedings Paper]
Abstract
An attempt was made to enhance the firmness of canned and frozen papaya Carica papaya L. as well as minimally processed papaya mango Mangifera indica L. and jackfruit Artocarpus heferophyllus Lam. through low-temperature blanching and calcium infiltration applied prior to processing. Low-temperature blanching was carried out at 55C and at pH 8.0 for 25 min. The temperature and pH conditions employed were considered optimal for in-situ pectin deesterification by endogenous pectin methylesterase in most fruits. Pectin demethylation is known to promote saltbridge formation between endogenous divalent cations and free carboxyl groups of adjacent polygalacturonide chains. As a result the strengthened middle lamellae and cell walls of the parenchyma tissues are protected against the disruptive effects of subsequent processing. Infiltration of calcium by soaking fruit pieces in a 60 mM Ca brine at 10C for 18 h into the fruit tissues was conducted after low-temperature blanching in order to augment the firming effect. In all cases pretreated processed products were found to be significantly firmer P0.01 than the corresponding untreated control processed samples. Pretreated canned and frozen/thawed papayas were 4.0-4.5 times firmer than the control samples. The enhancement in firmness of minimally processed fruits resulting from the pretreatment applied was 1.9-2.9 times.
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Abstract
An attempt was made to enhance the firmness of canned and frozen papaya Carica papaya L. as well as minimally processed papaya mango Mangifera indica L. and jackfruit Artocarpus heferophyllus Lam. through low-temperature blanching and calcium infiltration applied prior to processing. Low-temperature blanching was carried out at 55C and at pH 8.0 for 25 min. The temperature and pH conditions employed were considered optimal for in-situ pectin deesterification by endogenous pectin methylesterase in most fruits. Pectin demethylation is known to promote saltbridge formation between endogenous divalent cations and free carboxyl groups of adjacent polygalacturonide chains. As a result the strengthened middle lamellae and cell walls of the parenchyma tissues are protected against the disruptive effects of subsequent processing. Infiltration of calcium by soaking fruit pieces in a 60 mM Ca brine at 10C for 18 h into the fruit tissues was conducted after low-temperature blanching in order to augment the firming effect. In all cases pretreated processed products were found to be significantly firmer P0.01 than the corresponding untreated control processed samples. Pretreated canned and frozen/thawed papayas were 4.0-4.5 times firmer than the control samples. The enhancement in firmness of minimally processed fruits resulting from the pretreatment applied was 1.9-2.9 times.
Additional Metadata
| Item Type: | Proceedings Paper |
|---|---|
| Additional Information: | Available at Perpustakaan Sultan Abdul Samad Universiti Putra Malaysia 43400 UPM Serdang Selangor Malaysia. mal SB 359 I61 1996 Vol. 2 Call Number |
| AGROVOC Term: | Firmness |
| AGROVOC Term: | Tropical fruits |
| AGROVOC Term: | Canned fruits |
| AGROVOC Term: | Frozen fruits |
| AGROVOC Term: | Low temperature |
| AGROVOC Term: | Blanching |
| AGROVOC Term: | Calcium |
| AGROVOC Term: | Infiltration |
| AGROVOC Term: | Papayas |
| AGROVOC Term: | Carica papaya |
| Geographical Term: | MALAYSIA |
| Depositing User: | Ms. Suzila Mohamad Kasim |
| Last Modified: | 24 Apr 2025 05:14 |
| URI: | http://webagris.upm.edu.my/id/eprint/12004 |
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