Emerging techniques for catechin extraction from green tea ( <i>Camellia sinensis</i> ): extraction technologies, functional potential, Toxicology, and food-industry applications: a systematic review

Prominent polyphenolic compounds called catechins are mostly found in green tea (Camellia sinensis). Their potent anti-inflammatory qualities encourage increasing interest in using them in food, nutraceuticals, cosmetics and biomedical applications. Despite these advantages, plant matrices’ variability, intricate molecular structures, and sensitivity to processing conditions make it difficult to extract and purify catechins efficiently. The functional potential, toxicological considerations and present and future uses of catechins in the food industry are all examined in this systematic review, which also assesses new extraction techniques. Using Camellia sinensis, catechins, extraction technologies, microwave-assisted extraction, ultrasound-assisted extraction, enzymatic extraction, deep eutectic solvents, toxicology and food applications, a systematic literature search was conducted using Scopus, Web of Science, PubMed, and Google Scholar with an emphasis on original articles published within the last recent years. In comparison to traditional solvent extraction, the results show that advanced extraction techniques, in particular pressurized liquid extraction, deep eutectic solvent-based extraction, microwave-assisted extraction, ultrasound-assisted extraction and enzymatic extraction, exhibit improved catechin yield, increased stability and greater environmental sustainability. Catechins have significant anti-inflammatory properties related to inflammatory stress in food and biological systems, according to functional evaluations. Their safety is generally supported by toxicological evidence, but bioavailability and dose-dependent physiological responses need to be carefully taken into account. Overall, improving catechin recovery through continuous innovation in green extraction techniques is crucial for their efficient use in functional foods, dietary supplements and bioactive packaging systems, which advances sustainable and health-conscious food industry practices.