Ripe and Raw Pu-Erh Tea: LC-MS Profiling, Antioxidant Capacity and Enzyme Inhibition Activities of Aqueous and Hydro-Alcoholic Extracts

Abstract

Herein, we reported a detailed profiling of soluble components of two fermented varieties of Chinese green tea, namely raw and ripe pu-erh. The identification and quantification of the main components was carried out by means of mass spectrometry and UV spectroscopy, after chromatographic separation. The antioxidant capacity towards different radical species, the anti-microbial and the enzyme inhibition activities of the extracts were then correlated to their main constituents. Despite a superimposable qualitative composition, a similar caffeine content, and similar enzyme inhibition and antimicrobial activities, raw pu-erh tea extract had a better antioxidant capacity owing to its higher polyphenol content. However, the activity of raw pu-erh tea seems not to justify its higher production costs and ripe variety appears to be a valid and low-cost alternative for the preparation of products with antioxidant or antimicrobial properties.

Phenolic Compounds from Leaves and Flowers of Hibiscus roseus: Potential Skin Cosmetic Applications of an Under-Investigated Species

“…The collagenase enzyme inhibits the retention of skin elasticity and tensile strength [ 82 ]. Indeed, different studies have shown the importance of natural antioxidants due to their efficacy in delaying the premature aging through the inhibition of collagenase activity [ 78 , 83 ].…”

“…The collagenase inhibitory assay was performed similarly to those described by Roda et al [ 83 ], using a Collagenase Activity Assay Kit (Sigma-Aldrich ® ). This kit measures the collagenase activity with a synthetic peptide (i.e., FALGPA; N-(3-[2-Furyl]acryloyl)-Leu-Gly-Pro-Ala) that mimics the collagen structure.…”

Optimal fermentation time for Nigrospora‐fermented tea rich in bostrycin

“…The decreased soluble sugar content may be a result of the proliferation of microorganisms, which leads to the decomposition of soluble carbohydrates. It is also possible that soluble sugars react with amino acids in the Maillard reaction as described previously 37 …”

Differentiating Pu‐erh raw tea from different geographical origins by1H‐NMR and U‐HPLC/Q‐TOF‐MS combined with chemometrics

“…Recently, Pu‐erh ripe tea has been become the main research object of tea (Chen et al., 2016; Roda et al., 2019; Valentino et al., 2020; Zhang et al., 2019b). As to Pu‐erh raw tea, the researchers are rarely and mainly focus on its pharmacological activities or performances.…”

“…assamica Kitamura, which is planted in southwestern China (Liu et al., 2018). It is generally divided into Pu‐erh raw tea, Pu‐erh aging tea, and Pu‐erh ripe tea deriving from the manufactured process techniques and time‐consumption (Roda et al., 2019). Pu‐erh raw tea is produced by “fixation” after being picked, and it is fermented for several months to produce Pu‐erh ripe tea on the condition of microorganisms.…”