Effects of Heat Treatment on Ascorbic Acid Content and Associated Enzymes in Broccoli During Chilling Storage
P. Yingsanga, S. Kanlayanarat and S. Noichinda
Book of Abstract. APEC Symposium on Assuring Quality and Safety of Fresh Produce, August 1-3, 2005, Bangkok, Thailand. 76 page.
2005
บทคัดย่อ
Broccoli (Brassica oleracea L. Italica Group) heads cv. Top Greens were dipped in 47°C water for 7 min and then stored at 20°C (non-chilling) or 4°C (chilling). Ascorbic acid content sharply decreased after 2 days of storage and remained almost unchanged thereafter. Storage at 4°C generally maintained higher ascorbic acid content than at 20°C. Heat treatment resulted to lower ascorbic acid content than the unheated control both at 20°C and 4°C. It increased ascorbate peroxidase (APX) activity, particularly at 4°C, and decreased dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDHAR) activities. DHAR and MDHAR decreased at a more rapid rate at 20°C than at 4°C.