Innovative approaches to enhancing kombucha through flavour additives: a phytochemical and antioxidant analysis†

Abstract

This study aimed to determine the phytochemical profile (flavonoids, phenolic acids, caffeine, vitamin C, and acetic acid), antioxidant potential (DPPH, ABTS, and FRAP method), total polyphenol (TPC) and flavonoid (TFC) content, as well as pH of eight commercial green tea-based kombuchas. The beverages were enriched with lemongrass; lavender; liquorice and mint; turmeric and lemon; mango; reishi and chaga; mint, rose, and pomegranate. The highest tested properties were found for kombucha with reishi and chaga (FRAP), with mint, rose, and pomegranate (ABTS), as well as with turmeric and lemon (DPPH, TPC, TFC). Among the identified phenolic acids, p-coumaric acid was found in the highest concentration (kombucha with reishi and chaga), while among the flavonoids – rutin (kombucha with liquorice and mint). Kombucha with reishi and chaga was the richest source of vitamin C, caffeine, and acetic acid. The addition of certain plant materials significantly affects the phytonutrient content of green tea-based kombucha.