Effect of Season and Harvesting Time on Quality of Organic Pak Choi (Brassica rapa var. chinensis)

Abstract

This research was aimed at study the effects of season and harvesting time on the quality of organic Pak choi (Brassica rapa var. chinensis). Pak choi was harvested from a farmer’s greenhouse at different times of the day: morning (05:00 am–08:00 am), afternoon (12:00 pm–2:00 pm) and evening(4:30 pm–6:30 pm) in the winter, summer and rainy season. Season affected on total sugar, glucosinolate, vitamin C and crude fiber content while harvesting time affected on glucosinolate, vitamin C content and leaf color. After 3–day storage at ambient temperature, it was revealed that season affected all parameters, whereas harvesting time only affected reducing and total sugar contents, glucosinolate, vitamin C and respiration rate. Nevertheless, the interaction of both factors affected sugar contents, glucosinolate and respiration rate. This study suggested that rescheduling planting dates depending on the season and selecting a suitable time in the day for harvest can positively affect the quality of organic Pak choi. For nutritional benefits, Pak choi has the highest glucosinolate content when it is harvested in the morning. On the other hand, the produce harvested in the evening has the highest vitamin C content. The summer season may affect the quality due to the highest respiration rate and weight loss at that time.