基于抗氧化活性分析的枇杷干制工艺优化

为研究枇杷果干加工过程抗氧化性能的变化规律及优化工艺参数,以枇杷果为原料,测定在不同温度干制条件下抗氧化成分及活性指标,并进行Arrhenius一级动力学及差分模型拟合。结果表明:在枇杷果干干制过程中随着水分的散失,黄酮、总酚含量以及抗氧化活性呈缓慢上升趋势。建立了黄酮含量、总酚含量和2,2’-连氮-双(3-乙基苯并噻唑-6-磺酸)自由基清除率随时间和温度变化的Arrhenius一级动力学及差分预测模型,差分模型的决定系数分别为0.92、0.90和0.93。模型检验平均误差、平均绝对误差和均方根误差平均值分别介于0.07~0.80、0.18~1.53和0.07~0.59之间,符合模型精度要求;优化出最佳工艺参数为温度(65±1)℃、时间(183±1)min。该工艺参数和模型可用于枇杷果干的加工生产和预测。

Drying Optimization of Loquat Fruit Based on Analysis of Antioxidant Activity

Correlation analyses of antioxidant properties were used for selecting an appropriate method for quality evaluation of dried loquat. Arrhenius first order kinetics and difference models were established with drying time and temperature as independent variables versus the contents of flavonoids and total phenols and 2,2’-azino-bis(3-ethylbenzothiazoline-6- sulphonic acid) (ABTS) free radical scavenging capacity. The models were tested by mean error, mean absolute error and root mean square error. Nonlinear programming and evolutionary algorithms were used to minimize the energy consumption. Results showed that flaovonoids, total phenols and antioxidant activity demonstrated a slow upward trend with the loss of water during the drying process of loquat. The Arrhenius difference models improved the accuracy of predictions compared with the first order kinetics models, with determination coefficients of 0.92, 0.90 and 0.93 for flavonoids, total phenols and ABTS free radical scavenging capacity, respectively. Mean error, mean absolute error and root mean square error of validation were between 0.07–0.80, 0.18–1.53 and 0.07–0.59, respectively. The models were found to be valid in terms of precision. Optimal drying time and temperature were (183 ± 1) min and (65 ± 1) ℃, respectively.