Khalfi Asma, Garrigós María Carmen, Ramos Marina, Jiménez Alfonso
Department of Analytical Chemistry, Nutrition & Food Sciences, University of Alicante, ES-03690 San Vicente del Raspeig, Alicante, Spain.
Foods. 2024 Nov 25;13(23):3771. doi: 10.3390/foods13233771.
Date seeds, often discarded during industrial processing, are an underexploited by-product rich in polyphenols with significant antioxidant potential. This study explores the extraction of polyphenols from date seeds using microwave-assisted extraction (MAE) with an organic solvent. The extraction process was optimized using response surface methodology (RSM), focusing on extraction time, ethanol concentration, and temperature. The optimal extraction conditions were 46% (/) of ethanol, at 62 °C and for 27.3 min. Under these optimized conditions, the extraction yield and total phenolic content of the extract are 12.5% and 59 mg gallic acid equivalent g of date seed, respectively, as confirmed by the experimental tests. The extract's antioxidant activity was confirmed through DPPH, ABTS, and FRAP assays. High-performance liquid chromatography with diode-array detection (HPLC-DAD) identified major phenolic compounds, including procyanidin B1, catechin, quercetin-3,5'-di--glucoside, epicatechin, procyanidin B, and syringic acid, alongside eight other tentatively identified compounds. These findings underscore the potential of MAE as an environmentally friendly technique for producing polyphenol-rich extracts from date seeds, adding value to this by-product and opening avenues for its application in food and nutritional products.
海枣种子在工业加工过程中常被丢弃，是一种未得到充分利用的副产品，富含具有显著抗氧化潜力的多酚。本研究探索了使用有机溶剂通过微波辅助萃取（MAE）从海枣种子中提取多酚的方法。采用响应面法（RSM）对萃取过程进行优化，重点关注萃取时间、乙醇浓度和温度。最佳萃取条件为乙醇浓度46%（/）、温度62℃、时间27.3分钟。实验测试证实，在这些优化条件下，提取物的萃取产率和总酚含量分别为12.5%和59毫克没食子酸当量/克海枣种子。通过DPPH、ABTS和FRAP测定法证实了提取物的抗氧化活性。采用二极管阵列检测的高效液相色谱法（HPLC-DAD）鉴定出主要酚类化合物，包括原花青素B1、儿茶素、槲皮素-3,5'-二-O-葡萄糖苷、表儿茶素、原花青素B和丁香酸，以及其他8种初步鉴定的化合物。这些发现强调了微波辅助萃取作为一种环保技术从海枣种子中生产富含多酚提取物的潜力，为这种副产品增加了价值，并为其在食品和营养产品中的应用开辟了道路。
