Simoes Grilo Filipa, Srisaard Yanisa, Wang Selina C
Department of Food Science and Technology, University of California, Davis, CA 95616, USA.
Olive Center, Robert Mondavi Institute for Wine and Food Science, University of California, Davis, CA 95616, USA.
Foods. 2020 Sep 1;9(9):1207. doi: 10.3390/foods9091207.
Monitoring walnut oxidation is essential to control walnut quality during storage. An accelerated oxidation method for differentiating the oxidative stability index (OSI) of walnut kernels was examined and the effects of instrument operational parameters such as temperature and airflow were evaluated. Four cultivars, Chandler, Solano, Durham, and Howard were analyzed at 110, 120, and 130 °C with 15, 20, and 25 L h airflow. Analysis using 110 °C with 25 L h yielded the lowest coefficients of variance (4.4) than other operational parameters; analysis using the same temperature at lower airflow, 15 L h, yield the highest coefficient of variance (10.5). Kernel OSI values were independent of airflow, however, dependence of temperature coefficient and Q were demonstrated. The results from selected parameters were correlated with fat and moisture content, peroxide value, UV absorbances, oil oxidative stability, hexanal, and rancidity to establish the relationships between OSI values and quality changes during storage. Using 0.5 g of ground kernels, at 110 °C with 25 L h airflow gave a lower coefficient of variance and higher correlation with kernel quality and oxidative markers comparing to other combinations of operating parameters.
监测核桃氧化对于控制核桃储存期间的品质至关重要。研究了一种用于区分核桃仁氧化稳定性指数（OSI）的加速氧化方法，并评估了温度和气流等仪器操作参数的影响。对四个品种，即钱德勒、索拉诺、达勒姆和霍华德，在110、120和130°C以及15、20和25 L/h的气流条件下进行了分析。与其他操作参数相比，在110°C和25 L/h条件下进行分析得到的变异系数最低（4.4）；在相同温度下较低气流（15 L/h）条件下进行分析得到的变异系数最高（10.5）。然而，仁的OSI值与气流无关，但显示出对温度系数和Q的依赖性。所选参数的结果与脂肪和水分含量、过氧化值、紫外线吸光度、油脂氧化稳定性、己醛和酸败相关，以建立OSI值与储存期间品质变化之间的关系。与其他操作参数组合相比，使用0.5 g磨碎的果仁，在110°C和25 L/h气流条件下变异系数较低，且与果仁品质和氧化指标的相关性较高。
