热激-保鲜剂-冰温对鄂莲5号贮藏品质的影响

Effect of heat treatment-antistaling agent-freezing-point storage on storage quality of Elian No.5

目的:嘉兴市莲藕种植品种多、面积大。鄂莲5号采收时间跨度长,莲藕老熟程度不一致,且现有人工采收易损伤莲藕表皮,导致失水腐烂。使用符合国家标准的保鲜剂,联合热激-冰温贮藏方法,协同抑制鄂莲5号在贮藏期内发生褐变与腐烂,降低莲藕冷害发生,延长贮藏期及维持莲藕食用品质与商品性。方法:经65℃热激处理5 min后,选择不同浓度柠檬酸、Vc、CaCl_2 3种保鲜试剂浸泡莲藕30 min,于冰温贮藏35 d后测定色差、可溶性糖、多酚氧化酶活性与感官评价等指标。结论:通过分析单因素与正交试验的结果,得出其最优工艺条件为65℃热激处理5 min,保鲜剂比例为0.3%氯化钙、0.25%Vc和0.3%柠檬酸,浸泡30 min后,于-0.7℃至0℃贮藏,对鄂莲5号褐变与多酚氧化酶活抑制效果较明显,硬度保持有较好作用,腐烂率小于5%,贮藏期内可溶性糖含量下降幅度较小,可取得较好的保鲜效果。

Objective： The lotus root is planted in large area of many varieties in Jiaxing of Zhejiang province. Elian No.5 was uneven maturity because of the long harvest time. Artificial harvesting is easy to damage lotus root surface, and easy to lose moisture and decay. The antistaling agent conforming to the national standard, combined heat treatment and freezing-point storage method, were used to inhibition synergistically the browning, decay and avoid cold injury of Elian No.5 in the storage period. This method prolongs the storage period of lotus root, maintain the quality and commodity value. Method： After the first step 65 ℃ of heat treatment for 5 min. The second step choosed different concentrations three kinds of preservative reagent of citric acid, Vc, CaCl_2. to soak lotus root with preservative reagent for 30 min. After freezing-point storage 35 days, the color, total sugar, polyphenol oxidase activity and sensory evaluation of lotus root were determined. Result： Through the analysis of single factor and orthogonal test results, the optimum technological condition was 65 ℃ of heat treatment for 5 min, after soaking 30 min in the proportion of antistaling agent was CaCl_2 0.3%, Vc 0.25% and citric acid 0.3%, storage at（-0.7~0）℃degrees. The browning of lotus root and the activity of PPO enzyme was obvious restrain by this methoded. the good hardness of lotus root was maintained. During the storage period, the sugar content was decreased less, and decay rate is less than 5%.