Postharvest quality evaluation on the hot water-dipped Zingiber officinale rhizomes stored at low-temperature storage

Abstract

Storing ginger at chilling temperature will reduce its postharvest quality as they are prone to chilling injury (CI). Therefore, a study on hot-water dip treatment in alleviating CI in 'Bentong' ginger rhizome on physical and chemical properties was conducted. Fresh ginger rhizomes were harvested in the 9th month after planting. The fresh and cleaned rhizomes were hot-water treated at 45°C for 0, 5, 10 and 15 mins before being packed in a box and stored at 5°C for 0, 8 and 16 days. There was a significant interaction effect between dipping and storage durations on the physical and chemical properties of the rhizome. Exposed rhizome for 5, 10 and 15 mins was observed to maintain the ho and L* of the rhizome after storage at 5°C. The decreases in h° from yellow to slightly brown also indicated rhizome browning. Rhizome held at 45°C for 5 mins managed to reduce browning as compared to other durations. In addition, dipping for 15 mins resulted in a significant increase in total phenolic content, total flavonoid content and 6-gingerols. While 6-shogaols was maintained at 45°C for 5 mins. Preconditioning by the hot-water treatment could induce chilling tolerance upon storage at chilling temperature.