Department of Food and Nutritional Sciences, University of Reading, Reading, RG66AH, UK.
Department of Food Technology, Faculty Food Science and Technology, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
J Food Sci. 2020 Nov;85(11):3745-3755. doi: 10.1111/1750-3841.15466. Epub 2020 Sep 29.
The aim of this study was to investigate the effects of different solvent and extraction temperatures on the free and bound phenolic compounds and antioxidant activity of dried blackcurrant skins (DBS). Apart from acetic acid buffer solution, different solvent systems, including water, methanol, and mixtures of methanol/water, were also employed and the effects of solvent and temperature (30 and 50 °C) on the free and bound forms of anthocyanins, hydroxycinnamic acids, and flavonols yield were assessed. The results showed that among all solvents, acetic acid buffer resulted in the highest free anthocyanin content (1,712.3 ± 56.1 mg/100 g) (P < 0.05) after 2 hr extraction at 50 °C from DBS, while lower amounts of bound anthocyanins and anthocyanidins were detected after acid hydrolysis. Acetic acid buffer extracts exhibited the highest free hydroxycinnamic acid content (268.0 ± 4.5 mg/100 g), total phenolic content (3702.2 ± 259.3 mg GAE/100 g), and DPPH activity (60.7 ± 2.0% of inhibition). However, their free flavonol content was slightly lower (60.2 ± 0.8 mg/100 g) compared to 100% methanol at 30 and 50 °C (71.4 ± 1.5 mg/100 g and 71.5 ± 6.2 mg/100 g, respectively). Two-way ANOVA indicated interactions between solvent and temperature (P < 0.05), which suggested that the relationship between solvent and phenolic compounds depends on the extraction temperature. PRACTICAL APPLICATION: Overall, acetic acid buffer is more environmental friendly, efficient, and cost effective than other solvents, thus, offering an improved extraction method for phytochemicals as valuable ingredients for nutraceutical applications, from underutilized dried blackcurrant skins (DBS).
本研究旨在探讨不同溶剂和提取温度对干黑加仑皮（DBS）中游离和结合酚类化合物及抗氧化活性的影响。除乙酸缓冲溶液外，还采用了水、甲醇和甲醇/水混合物等不同溶剂体系，并评估了溶剂和温度（30 和 50°C）对游离和结合形式的花色苷、羟基肉桂酸和类黄酮产率的影响。结果表明，在所有溶剂中，乙酸缓冲液在 50°C 下提取 2 小时后，DBS 中的游离花色苷含量最高（1712.3±56.1mg/100g）（P＜0.05），而酸水解后检测到的结合花色苷和花色苷元含量较低。乙酸缓冲液提取物表现出最高的游离羟基肉桂酸含量（268.0±4.5mg/100g）、总酚含量（3702.2±259.3mg GAE/100g）和 DPPH 活性（60.7±2.0%的抑制率）。然而，与 30 和 50°C 下的 100%甲醇相比，其游离类黄酮含量略低（60.2±0.8mg/100g）（分别为 71.4±1.5mg/100g 和 71.5±6.2mg/100g）。双因素方差分析表明溶剂和温度之间存在交互作用（P＜0.05），这表明溶剂和酚类化合物之间的关系取决于提取温度。实际应用：总体而言，乙酸缓冲液比其他溶剂更环保、高效且具有成本效益，因此为从利用率较低的干黑加仑皮（DBS）中提取具有营养保健品应用价值的植物化学物质提供了一种改进的提取方法。
