Effect of treatment with dimethyl dicarbonate on microorganisms and quality of Chinese cabbage

The effects of dimethyl dicarbonate (DMDC) (200 mg L-1) treatment on microorganisms and quality of Chinese cabbage were investigated. The results indicated that in the different tissues treated by DMDC, a significant reduction (P < 0.05) of total aerobic plate count (TAPC) of the leaf (ca. 4.49 log cfu g(-1)) and stalk (ca. 4.45 log cfu g(-1)), as well as the count of total yeasts and molds of the leaf (ca. 3.02 log cfu) and stalk (ca. 3.62 log cfu g-i), was obtained in comparison with the control (sterile water dip). However, in the flower bud and/or flower treated by DMDC, the reduction of TAPC (ca. 2.74 log cfu g(-1)) and counts of total yeasts and molds (ca. 2.26 log cfu g(-1)) were much lower. DMDC treatment affected appearance and texture early in storage, but an impact on the nutritional composition of Chinese cabbage during storage was not found. Additionally, DMDC treatment significantly (P < 0.05) inhibited the activity of polyphenol oxidase (PPO) and peroxidase (POD) late during storage. Therefore, DMDC is a new and effective alternative for sanitation of Chinese cabbage where a protective measure of appearance quality needs to be adopted. (C) 2012 Elsevier B.V. All rights reserved.