Journal of Taiwan Agricultural Research

Author:Pai-Chi Syue, Chia-Hui Tang, and Tan-Cha Lee*

Abstract:

    Although both hand-harvest and sickle-harvest methods are used for harvesting pineapple fruits in Taiwan, the hand-harvest method is more popular than the sickle-harvest method. However, unlike the smooth cutting surface of the fruit stem by sickle-harvesting, pineapple fruits harvested by hands often resulted in uneven breaks of the stem, creating large wounds with rough surface and, thereby, reduced storage or shelf-life of the harvested produce. Results of this study showed that all the hand-harvested pineapple fruits stored at cold room (12.5℃) for 2 weeks and then moved them onto shelf (25℃) for 4 days, developed severe internal browning of fruit tissues (browning intensity index of 5.8 or >51% of browning tissues) and of no market values; whereas the internal browning of the sickle-harvested fruits was mild (browning intensity index of 2.0 or 3-5% of browning tissues) for the same storage period and conditions. The phenylalanine ammonia lyase (PAL) in harvested pineapple fruits increased with time of storage but the level of PAL in hand-harvested fruits was significantly higher than sickle-harvested ones. The polyphenol oxidase (PPO) and peroxidase (POD) in pineapple fruits decreased with time of storage but there was no significant difference between hand-harvest and sickle-harvest treatments.

Key words:Hand-harvesting, Sickle-harvesting, Phenylalanine ammonia lyase, Polyphenol oxidase, Peroxidase, Internal browning

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