The Effect of In Vitro Digestion on Matcha Tea (Camellia sinensis) Active Components and Antioxidant Activity

Abstract

This study investigates the effects of in vitro digestion on the antioxidant activity and release of phenolics, xanthine alkaloids, and L-theanine contents of matcha. It establishes digestibility values between 61.2–65.8%. Considering native matcha, the rutin content (303–479 µg/g) reached higher values than catechin (10.2–23.1 µg/g). Chlorogenic acid (2090–2460 µg/g) was determined as predominant. Rutin, quercetin, ferulic, ellagic, and caffeic acid were the least-released phenolics, and their remaining residues reached 76–84%. Protocatechuic, hydroxybenzoic acid, epigallocatechin, and epigallocatechin-3-gallate were the best-released phenolics, with the remaining residues under 1%. Caffeine, L-theanine, and theobromine contents in native matcha reached 16.1, 9.85, and 0.27 mg/g, respectively. Only caffeine (3.66–5.26 mg/g) and L-theanine (0.09–0.15 mg/g) were monitored in the undigested residue, representing 13 and 0.1% of the remaining part, respectively. A chemiluminescence assay showed that water-soluble antioxidants showed significant antioxidant activity in native matcha, while lipid-soluble compounds showed higher antioxidant activity in the undigested samples. Cinnamic and neochlorogenic acids were determined as the main contributors to the ACW values in the undigested matcha, epicatechin, and quercetin in the ACL fraction. The application of the digestion process reduced the antioxidant activity by more than 94%. SEM has proved specific digestion patterns of in vitro digestibility of matcha.

The Effect of Flake Production and In Vitro Digestion on Releasing Minerals and Trace Elements from Wheat Flakes: The Extended Study of Dietary Intakes for Individual Life Stage Groups

“…The in vitro digestion process, including gastric and intestinal digestion, was performed according to [13] with a slight modification. Dry matter and ash content were determined following [15].…”

“…where RF is the retention factor of the appropriate analyte in the undigested part of the sample (%), CUWF is the analyte concentration in the undigested part of the wheat flakes (ng or µg/g), DMD is the dry matter digestibility value of the flakes (%), and CNWF is the analyte concentration in the native form of the flakes (ng or µg/g) [13].…”

“…The higher RF value, the higher amount of the analyte remaining in the matrix of the undigested part of the sample and thus not available for absorption in the digestive tract. Conversely, analytes with low RF values could be potentially more accessible for absorption in the tract [13].…”

“…Throughout time, in vitro digestion models have been gaining importance and are employed to monitor changes in the element profiles during the digestion processes and to predict bioaccessibility [6,11]. Furthermore, an innovative study has analysed solid undigested proportions of food of plant origin to calculate the remaining amounts of bioactive compounds after in vitro digestion simulation [13]. This remaining factor represents the percentage of analytes that are retained in the undigested matrix.…”

HPLC–MS2 Analysis of Chlorophylls in Green Teas Establishes Differences among Varieties

“…Because of the processing of Matcha, its consumption results in the ingestion of a higher amount of several bioactive compounds normally present in tea, such as catechins, amino acids, polyphenols, theanine, caffeine, and obviously, chlorophylls [ 3 ]. Interestingly, most of the named compounds have been shown to exert a positive effect on human health, including anti-inflammatory, antibacterial, cholesterol-lowering, antioxidant capacity, and antimutagenic effects [ 4 ]. This has caused an increase in interest in Matcha tea production as a potential food to help in the maintenance of health and the prevention of diseases, and it is now the most expensive green tea in the world [ 5 , 6 ].…”