Liu Fengjuan, Lei Jing, Shao Xupeng, Fan Yingying, Huang Wei, Lian Weijia, Sun Tao, Chen Ya, Wang Cheng
Laboratory of Quality and Safety Risk Assessment for Agri-Products (Urumqi), Key Laboratory of Functional Nutrition and Health of Characteristic Agricultural Products in Desert Oasis Ecological Region (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Institute of Quality Standards & Testing Technology for Agri-Products, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China.
Turpan Institute of Agricultural Science, Xinjiang Academy of Agricultural Science, Turpan 838000, China.
Foods. 2024 Apr 9;13(8):1138. doi: 10.3390/foods13081138.
Raisins, known for their delicious taste and high nutritional value, are among the most widely consumed dried fruits globally. The natural waxy layer on the surface of grapes impedes water migration, making pretreatment necessary before drying. This study evaluated the effects of various pretreatment methods on the nutritional and functional quality of seedless purple raisins. By using non-pretreated dry seedless purple raisins as a control, the impact of physical and chemical pretreatment methods on the nutritional and functional qualities of seedless purple raisins was assessed through the analysis of nutrient content, phenolic compounds, and antioxidant activity. Our results demonstrate that physical pretreatment significantly increases the levels of vitamin C, fructose, glucose, total acid, total phenolics, total flavonoids, total anthocyanins, and antioxidant activity compared to chemical pretreatment and the control group. The correlation analysis revealed that phenolic substances were closely linked to antioxidant capacity. Additionally, phenolic compounds, including resveratrol, ferulic acid, chlorogenic acid, ethyl coumarate, and cinnamic acid, were more abundant following physical pretreatment. The OPLS-DA model effectively differentiated the three groups of processed samples, showing that different pretreatments significantly affect the nutritional and functional quality of seedless purple raisins. These findings suggest that physical pretreatment offers considerable potential for improving the drying quality of seedless purple raisins.
葡萄干以其美味的口感和高营养价值而闻名，是全球消费最广泛的干果之一。葡萄表面的天然蜡质层阻碍了水分迁移，因此在干燥前需要进行预处理。本研究评估了各种预处理方法对无核紫葡萄干营养和功能品质的影响。以未经预处理的干制无核紫葡萄干作为对照，通过分析营养成分、酚类化合物和抗氧化活性，评估了物理和化学预处理方法对无核紫葡萄干营养和功能品质的影响。我们的结果表明，与化学预处理和对照组相比，物理预处理显著提高了维生素C、果糖、葡萄糖、总酸、总酚、总黄酮、总花青素的含量以及抗氧化活性。相关性分析表明，酚类物质与抗氧化能力密切相关。此外，经过物理预处理后，包括白藜芦醇、阿魏酸、绿原酸、乙基香豆酸和肉桂酸在内的酚类化合物含量更为丰富。OPLS-DA模型有效地区分了三组加工样品，表明不同的预处理对无核紫葡萄干的营养和功能品质有显著影响。这些发现表明，物理预处理在改善无核紫葡萄干干燥品质方面具有巨大潜力。
