Effect of Characterized Green Tea Extraction Methods and Formulations on Enzymatic Starch Hydrolysis and Intestinal Glucose Transport

Abstract

The purpose of the current study was to investigate the effect of various characterized green tea extracts (GTEs) according to extraction methods on enzymatic starch hydrolysis and intestinal glucose transport. Codigestion of wheat starch with water extract (WGT) or ethanol extract formulated with green tea polysaccharides and flavonols (CATEPLUS) produced 3.4–3.5 times higher resistant starch (RS) than wheat starch only. Its microstructures were changed to spherical shapes and smooth surfaces as shown by scanning electron microscopy (SEM) results. According to Fourier transform infrared (FT-IR) spectra, the absorption peak of O–H stretching was red-shifted in WGT or CATEPLUS. The results confirmed that hydrogen bonds were formed between starch granules and polysaccharides in WGT or CATEPLUS. Intestinal glucose transport subsequently measured after in vitro digestion was mostly suppressed in CATEPLUS. Gene expression of the glucose transporter protein, particularly SGLT1, was significantly inhibited by addition of CATEPLUS (p < 0.05). Results from the current study suggest that co-intake of green tea extracts formulated with green tea polysaccharides and flavonols could be a potentially useful means to delay blood glucose absorption when consuming starchy foods.

Kinetic conversion of BIOGF1K enriched in compound K from in vitro 3-D human tissue model

“…3 A). The result corresponds with a previous finding in which a broad band between 3200 and 3600 cm −1 was ascribed to O–H stretching, which is related to intramolecular and intermolecular hydrogen bonds ( Oh et al, 2021 ). After 24 h topical treatment of BIOGF1K and CY single component in the 3-D human tissue model, the absorption peak of O–H stretching was red-shifted from 3314 to 3321 cm −1 to 3274 and 3308 cm −1 respectively ( Fig.…”