Department of Food Technology, Kalasalingam Academy of Research and Education, Krishnankoil, Tamilnadu, India.
Laboratory of Computational Modeling of Drugs, Higher Medical and Biological School, South Ural State University, Chelyabinsk, Russia.
Crit Rev Food Sci Nutr. 2022;62(9):2560-2567. doi: 10.1080/10408398.2020.1856772. Epub 2020 Dec 4.
A large amount of onion waste is produced by the food industries. This onion waste contains high-value functional ingredients, since several compounds and nutrients are present in onion peel. The objective of this work is to extract and stabilize the anthocyanin from onion peel waste in various forms. The major component present in onion peel is anthocyanin. The anthocyanin was extracted from onion peel by the microwave-assisted extraction process. A fractional factorial experiment was used to carry out 16 possible extractions instead of 64 possible extractions. The highest yield of total anthocyanin content such as 21.99 attains when using 2 g of onion peel with the extraction time 5 minutes, power as 700 W, ethanol concentration as 75 mL, and solvent feed ratio as 20 g/mL. The anthocyanin was stabilized in three ways such as co-pigmentation, a combination of buffer and hardpan coating. The most stable and colorless anthocyanin was observed by the co-pigmentation method. Stable and red color anthocyanin is obtained using a combination of buffer and dark brown color stable anthocyanin is perceived using hard pan coating. The antioxidant activity of each sample was studied during 3 weeks of storage. Sample A (co-pigmented sample) showed 75% of antioxidant activity, sample B (hardpan coating) exhibited 60% of antioxidant activity and sample C (buffer combination) confirmed 81% of antioxidant activity. This anthocyanin study can be used in future studies for various applications such as the preservation of meat and natural colorant.
大量洋葱废料是食品工业产生的。这种洋葱废料含有高价值的功能性成分，因为洋葱皮中存在几种化合物和营养物质。本工作的目的是从不同形式的洋葱皮废料中提取和稳定花色苷。洋葱皮中的主要成分是花色苷。花色苷是通过微波辅助提取工艺从洋葱皮中提取的。采用部分因子实验进行了 16 次可能的提取，而不是 64 次可能的提取。当使用 2g 的洋葱皮，提取时间 5 分钟，功率为 700W，乙醇浓度为 75ml，溶剂进料比为 20g/ml 时，总花色苷含量的收率最高可达 21.99。花色苷通过共显色、缓冲液和硬涂层的组合三种方式稳定下来。通过共显色法观察到最稳定和无色的花色苷。通过缓冲液和深棕色稳定的花色苷组合获得稳定和红色的花色苷，通过硬涂层获得稳定的深褐色花色苷。在 3 周的储存期间研究了每个样品的抗氧化活性。样品 A（共显色样品）表现出 75%的抗氧化活性，样品 B（硬涂层）表现出 60%的抗氧化活性，样品 C（缓冲液组合）证实了 81%的抗氧化活性。这项花色苷研究可用于未来的各种应用研究，例如肉类的保存和天然着色剂。
