Evaluation of Volatile Profile and In Vitro Antioxidant Activity of Fermented Green Tea Infusion With Pleurotus sajor-caju (Oyster Mushroom)

Abstract

Green tea has distinct astringency, bitter taste, and typical green flavor because of its post-harvest treatment without withering and enzymatic oxidation. Microbial fermentation has been identified as a promising strategy that could give green tea infusion a special taste flavor. This might be linked to the metabolic transformation ability of microorganisms. In this study, starter culture of edible mushroom Pleurotus sajor-caju (oyster mushroom) was used for submerged fermentation of green tea infusion in order to improve its flavor and taste quality. The volatile profile determined by headspace solid-phase microextraction, coupled with gas chromatography mass spectrometry, showed that the contents of (Z)-2-penten-1-ol and methyl heptadienone in green tea infusion were decreased significantly by the fermentation with the basidiomycete P. sajor-caju (p < 0.01), which would alleviate the herbal and grass flavor of green tea infusion to a certain extent. Meanwhile, the contents of linalool and geraniol were increased 9.3 and 11.3 times, respectively, whereas methyl salicylate was newly produced after fermentation by P. sajor-caju, endowing the fermented tea infusion with a pleasant flower and fruit aroma. In addition, the polyphenol profile was determined using high-performance liquid chromatography equipped with ion trap mass spectrometry, and the results indicated that the contents of most polyphenols in green tea infusion decreased significantly after fermentation by P. sajor-caju. The reduction of catechins and anthocyanins in fermented green tea infusion alleviated the astringency and bitterness. Moreover, the antioxidant activity of fermented green tea infusion was obviously decreased, especially the DPPH-free radical-scavenging ability and the ferric-reducing power. However, it is noteworthy that the ABTS-free radical scavenging ability was improved compared with the unfermented one, indicating that the increased tea pigments and volatile metabolites (such as linalool and geraniol) after fermentation with P. sajor-caju may also contribute to the antioxidant capacity of fermented green tea infusion. Overall, the innovative approach driven by P. sajor-caju fermentation has achieved promising potential to manipulate the green tea flavor.

Reconstruction of Simplified Microbial Consortia to Modulate Sensory Quality of Kombucha Tea

“…bruxellensis, in monoculture, produced the highest concentrations of the benzenoids 4-ethylphenol and methyl salicylate, while single Z. parabailii was the biggest producer of the sulfur-containing compounds dimethyl sulfide and methionol, and benzaldehyde. Methyl salicylate (spicy, wintergreen) and benzaldehyde (cherry, almond), as linalool and β-citronellol, are mainly released from bound glycosides in fermented beverages by yeast-derived glycosidase enzymes, and they are all important contributors to the flavor of tea [56,57]. Brettanomyces spp.…”

Characterization of Key Odorants in Lushan Yunwu Tea in Response to Intercropping with Flowering Cherry

“…Linalool has a citrus-like and flowery aroma [27,41]. Su et al [42] showed that linalool is the key volatile compound of green tea and that it plays an important role in the aroma of green tea. Nonanal is widely found in green tea and has a sweet, fruity flavor [37].…”

Metabolomic and transcriptomic analyses reveal the biosynthetic mechanisms of pigments and main taste compounds in an albino tea cultivar

“…Anthocyanins and catechins are important flavonoid compounds in fresh tea leaves. The purple shoots of tea plants contain too many anthocyanins, resulting in greater bitterness and astringency (Lai et al, 2016; Su et al, 2022). Anthocyanins and catechins are derived from the phenylpropanoid and flavonoid biosynthetic pathways involving complex enzyme‐catalysed reactions primarily regulated by the phenylalanine metabolic pathway (Mei et al, 2021; Wang et al, 2018).…”