Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan 430062, China.
Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Key Laboratory of Oil Seed Processing of Ministry of Agriculture, Oil Crops and Lipids Process Technology National and Local Joint Engineering Laboratory, Wuhan 430062, China.
Food Chem. 2024 Aug 1;448:139124. doi: 10.1016/j.foodchem.2024.139124. Epub 2024 Mar 26.
In this study, we applied various thermal pretreatment methods (e.g., hot-air, microwave, and stir-frying) to process walnut kernels, and conducted comparative analysis of the physicochemical properties, nutritional components, in vitro antioxidant activity, and flavor substances of the extracted walnut oil (WO). The results indicated that, thermal pretreatment significantly increased the extraction of total trace nutrients (e.g., total phenols, tocopherols, and phytosterols) in WO. The WO produced using microwave had 2316.71 mg/kg of total trace nutrients, closely followed by the stir-frying method, which yielded an 11.22% increase compared to the untreated method. The WO obtained by the microwave method had a higher Oxidative inductance period (4.05 h) and oil yield (2.48%). After analyzing the flavor in WO, we found that aldehydes accounted for 28.77% of the 73 of volatile compounds and 58.12% of the total flavor compound content in microwave-pretreated WO, these percentages were higher than those recorded by using other methods. Based on the comprehensive score obtained by the PCA, microwave-pretreatment might be a promising strategy to improve the quality of WO based on aromatic characteristics.
在这项研究中，我们应用了各种热预处理方法（如热空气、微波和炒制）来处理核桃仁，并对提取的核桃油（WO）的理化性质、营养成分、体外抗氧化活性和风味物质进行了比较分析。结果表明，热预处理显著提高了 WO 中总微量营养素（如总酚类、生育酚和植物甾醇）的提取率。微波处理的 WO 中总微量营养素含量最高，达到 2316.71mg/kg，其次是炒制方法，与未处理方法相比，增加了 11.22%。微波法制备的 WO 具有更高的氧化诱导期（4.05 小时）和出油率（2.48%）。在分析 WO 的风味后，我们发现，在 73 种挥发性化合物中，醛类占 28.77%，在微波预处理 WO 中的总风味化合物含量中占 58.12%，这些百分比均高于其他方法。基于 PCA 获得的综合得分，微波预处理可能是一种有前途的策略，可以根据芳香特性来提高 WO 的质量。
