ASHS 2024 Conference

In an effort to improve the shelf life of water spinach (Ipomoea aquatica Forsk.) and amaranth (Amaranthus tricolor L.) during summer in humid subtropical regions like northern Taiwan, the study investigated the effectiveness of modified hydrocooling and optimized postharvest handling practices. Most farmers in Taiwan often compromised postharvest vegetable quality due to uneven cooling. The first trial implemented a modified hydrocooling system using a 10-minute 5°C shower with a multi-hole perforated pipe and smaller baskets for precooling to substitute the conventional method. The results showed that the modified hydrocooling improved cooling uniformity and reduced vegetable loss rates. Meanwhile, for some farmers needed to meet the specialized market requirement which extend vegetable shelf life, the second trial conducted optimized postharvest handling practices including storage vegetables at 11°C, consistently clean 10°C water for washing/hydrocooling, and wrapping vegetables in plastic film. These practices revealed significantly decreased the water spinach quality loss for longer duration but less effective for amaranth. Even with the addition of hypochlorous acid in washing/hydrocooling water, the shelf life of amaranth was difficult to extend due to severe pre-harvest leaf disease. In conclusion, the study showed that modified hydrocooling offers benefits for most conventional farmers by reducing vegetable loss rates. On the other hands, for farmers needed to meet the specialized market requirement, optimized postharvest handling practices significantly improves the quality of water spinach in longer shelf life. Also, the research emphasized the importance of disease management in amaranth cultivation for postharvest quality.