Qualitative and Quantitative Analysis of Phytochemicals and Antioxidant Activity in Stem Lettuce Peel Byproducts
10.14373/JKDA.2026.32.1.1
- Author:
Sun Young HAN
1
;
Nami JOO
Author Information
1. Dept. of Food and Nutrition, College of Human Ecology, Sookmyung Women’s University, Seoul 04310, Korea
- Publication Type:Original Article
- From:Journal of the Korean Dietetic Association
2026;32(1):1-9
- CountryRepublic of Korea
- Language:English
-
Abstract:
This study examined the phytochemical composition and antioxidant potential of the peel of stem lettuce (Lactuca sativa var. angustana), an agricultural byproduct that is typically discarded despite its potential as a functional material. The peel powder was prepared by freeze-drying and ethanol extraction, and ultra-high performance liquid chromatography–triple time of flight electrospray ionization mass spectrometry/ mass spectrometry was used for phytochemical profiling. The qualitative and quantitative analyses showed that the peel contained a wide range of phytochemicals, including phenolic acids, lignans, flavonoids, and sesquiterpene lactones. Among these, phenolic acids and sesquiterpene lactones were identified as the dominant groups contributing to the characteristic phytochemical composition of the peel. The antioxidant activity of the peel extract was evaluated using various in vitro assays, including radical scavenging and reducing power tests. The results revealed strong antioxidant capacity, suggesting that phenolic and flavonoid phytochemicals in the outer tissues of stem lettuce play a crucial role in protecting against oxidative stress. These findings confirm that the peel serves as a natural reservoir of functional phytochemicals with significant antioxidant potential. Collectively, these results highlight the potential of stem lettuce peel as a natural antioxidant source and functional food ingredient. The utilization of this plant byproduct aligns with sustainable food production and circular economy principles by promoting resource efficiency and reducing agricultural waste. Nevertheless, further research is needed to evaluate the bioavailability, stability, and practical applicability of peel-derived phytochemicals in food systems for their industrial application as natural functional materials.
