ScholarWorks@숙명여자대학교

초록

Onion (Allium cepa L.) is a vegetable widely used in the culinary world. It is also remarkable as a source of nutrition and bioactive compounds. Onion leaves, which are inevitable byproducts of onion production, are morphologically similar to green onion leaves with similar taste profiles. Although they have potential as new sources of food, they are largely considered waste products. This study was conducted to investigate phytochemical compositions, quantities of phytochemicals, and antioxidant activities of onion (Allium cepa L.) leaves. Onion bulbs and green onion (Allium fistulosum L.) leaves were included for comparisons. A total of 27 phenolic compounds, predominantly flavonols, were identified from extracts of three samples, with quercetin-4'-O-glucoside and quercetin 3,7-O-diglucoside being the most significant. Hierarchical clustering analysis showed that onion leaves and green onion leaves shared distribution of bioactive compound compositions, indicating their potential as alternative food sources. Quantification results showed that: 1) onion leaves were exceptionally abundant in quercetin 4'-O-glucoside; 2) green onion leaves were more abundant in hydroxycinnamic acids, and 3) onion bulbs had relatively lower contents of analytes. Antioxidant activities of samples measured by DPPH and FRAP assays reflected quantification data, with onion leaves showing the most potent antioxidant activities. Hence, onion leaves are not only great substitutes for green onions but also have potential to provide more powerful health benefits.

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