Lucas-González Raquel, Pateiro Mirian, Domínguez-Valencia Rubén, Carrillo Celia, Lorenzo José M
Institute for Agri-Food and Agri-Environmental Research and Innovation, Miguel Hernández University (CIAGRO-UMH), Ctra. Beniel km 3.2, 03312 Orihuela, Alicante, Spain.
Centro Tecnológico de la Carne de Galicia, Avd. Galicia N° 4, Parque Tecnológico de Galicia, 32900 San Cibrao das Viñas, Ourense, Spain.
Foods. 2025 Jul 30;14(15):2686. doi: 10.3390/foods14152686.
Sweet potato is a valuable root due to its nutritional benefits, health-promoting properties, and technological applications. The peel, often discarded during food processing, can be employed in the food industry, supporting a circular economy. Purple sweet potato peel (PSPP) is rich in anthocyanins, which can be used as natural colourants and antioxidants. Optimising their extraction can enhance yield and reduce costs. The current work aimed to optimize anthocyanin and antioxidant recovery from PSPP using a Box-Behnken design and sonotrode ultrasound-assisted extraction (sonotrode-UAE). Three independent variables were analysed: extraction time (2-6 min), ethanol concentration (35-85%), and liquid-to-solid ratio (10-30 mL/g). The dependent variables included total monomeric anthocyanin content (TMAC), individual anthocyanins, and antioxidant activity. TMAC in 15 extracts ranged from 0.16 to 2.66 mg/g PSPP. Peonidin-3-caffeoyl-p-hydroxybenzoyl sophoroside-5-glucoside was the predominant anthocyanin. Among four antioxidant assays, Ferric-reducing antioxidant power (FRAP) showed the highest value. Ethanol concentration significantly influenced anthocyanin and antioxidant recovery ( < 0.05). The model demonstrated adequacy based on the coefficient of determination and variation. Optimal extraction conditions were 6 min with 60% ethanol at a 30 mL/g ratio. Predicted values were validated experimentally (coefficient of variation <10%). In conclusion, PSPP is a promising matrix for obtaining anthocyanin-rich extracts with antioxidant activity, offering potential applications in the food industry.
红薯因其营养价值、促进健康的特性和技术应用而成为一种有价值的根茎类作物。在食品加工过程中通常被丢弃的红薯皮，可应用于食品工业，以支持循环经济。紫红薯皮（PSPP）富含花青素，可用作天然色素和抗氧化剂。优化其提取工艺可提高产量并降低成本。当前的研究旨在使用Box-Behnken设计和超声探头超声辅助提取（超声探头-UAE）优化从PSPP中提取花青素和抗氧化剂。分析了三个自变量：提取时间（2-6分钟）、乙醇浓度（35-85%）和液固比（10-30毫升/克）。因变量包括总单体花青素含量（TMAC）、单个花青素和抗氧化活性。15种提取物中的TMAC范围为0.16至2.66毫克/克PSPP。芍药素-3-咖啡酰-对羟基苯甲酰槐糖苷-5-葡萄糖苷是主要的花青素。在四种抗氧化剂测定中，铁还原抗氧化能力（FRAP）显示出最高值。乙醇浓度对花青素和抗氧化剂的提取有显著影响（<0.05）。基于决定系数和变异系数，该模型显示出充分性。最佳提取条件为6分钟、60%乙醇、30毫升/克的比例。预测值通过实验得到验证（变异系数<10%）。总之，PSPP是一种有前景的基质，可用于获得具有抗氧化活性的富含花青素的提取物，在食品工业中具有潜在应用价值。
