For Abstracts

Hetong Lin (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China); Yifen Lin (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China); Yen-Con Hung (Department of Food Science and Technology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223, USA); Yihui Chen (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China); Meirong Fan (College of Food Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China)

Nisin has been widely used in the food industry as a safe and natural preservative to increase the shelf-life of many foods. In order to evaluate the possibility of nisin for anti-microorganism development and maintaining quality of fresh-cut Chinese yam, fresh tubers of harvested Chinese yam (Dioscorea opposita Thunb.) cv. Shangehuaishan No.1 were washed, peeled and cut into approximate 30-mm blocks. The cut tubers were dipped with 0% (control), 0.01%, 0.02%, or 0.03% nisin solution for 10 min, respectively, then air-dried and packed into sealed polyethylene bags (0.015 mm thickness) and stored at 4 degrees C for 10 days. At 2-day intervals during storage, aerobic plate count (APC), CIE (Commission Internationale de L'Eclairage) parameter of L, browning index, value of browning degree, polyphenol oxidase (PPO) activity and weight loss were determined. The results showed that compared to the control yam samples, different doses (0.01%, 0.02%, or 0.03%) of nisin treated-fresh-cut Chinese yam exhibited lower APC, higher value of CIE L, lower browning index, lower value of browning degree and lower PPO activity, as well as lower weight loss. Among the nisin-treated yam samples, the yam treated with 0.03% nisin for 10 min was the most effective in antimicrobial activity, reducing the development of browning and weight loss. From the results it could be concluded that the postharvest treatment with .03% nisin for 10 min might be a feasible and safe technique for suppressing the growth of microorganism and maintaining quality of fresh-cut Chinese yam during storage at 4 degrees C.