Unveiling the potential of selenium-enriched tea: Compositional profiles, physiological activities, and health benefits

Selenium is an essential trace element for human health and its deficiency leads to increased risk of many diseases worldwide. Tea (Camellia sinensis (L.) O. Kuntze) is a plant with selenium accumulation ability. Selenium-enriched tea combines the flavor and health benefits of tea with the additional wellness advantages of selenium, holding promising market potential. This article reviews the latest research advances on selenium-enriched tea. The ability and mechanism of selenium accumulation in tea plants, as well as the existence forms of selenium in tea leaves, have been summarized. In addition, we examined the effects of selenium on tea physiological activities, including metabolic and quality regulation, and provided a summary of the associated health benefits. Tea plants possess a strong ability to accumulate selenium in selenium-rich area or under selenium fertilizer application. Over 80% of the selenium in selenium-enriched tea leaves exists in organic forms, including selenoamino acids, selenoproteins, selenium-polysaccharides, and selenium-polyphenols. Selenium can promote tea growth and optimize the proportion of quality compounds (e.g., polyphenols, amino acids, and alkaloids). The levels of stress-related antioxidant enzymes and phytohormones are increased to promote environmental stress resistance and selenium tolerance. Selenium-enriched tea demonstrates superior health benefits compared to regular tea due to the synergistic effects of tea active ingredients and selenium element. This review aims to inspire innovative ideas for the development of selenium-enriched tea with thriving growth conditions, high selenium bioaccessibility, delightful flavor, and broad applications in the food and health industries.