Gao Shiwei

Bio: Gao Shiwei is an academic researcher. The author has contributed to research in topics: Brick & Barrel (horology). The author has an hindex of 6, co-authored 61 publications receiving 158 citations.

Chemical profile changes during pile fermentation of Qingzhuan tea affect inhibition of α-amylase and lipase.

Abstract: Qingzhuan tea (QZT), a post-fermented tea, has been reported to have anti-obesity and anti-hyperglycemic effects, perhaps due to bioactive compounds that inhibit lipase and α-amylase. It is unknown what chemical constituents' changes and what bioactive compounds occur during the manufacture of QZT. The aim of this study was to determine the secondary metabolites changes that occur during post-fermentation and how these changes affect the ability of QZT to inhibit the activities of lipase and α-amylase. During the processing steps, metabolites levels and their inhibitory effects on lipase and α-amylase were assessed. Changes in content and activities suggested that the first turn over or the second turn over was critical for the formation and conversion of bioactive compounds responsible for the anti-obesity and hypoglycemic effects. The relationship between constituents and activities was further evaluated by correlation analysis, which showed that amino acids and flavonoids might be responsible for the anti-obesity and anti-hyperglycemic effects of QZT. This study clarified that compounds were altered during pile fermentation of QZT and tentatively identified the bioactive compounds formed during QZT manufacture.

Comparing characteristic aroma components of bead-shaped green teas from different regions using headspace solid-phase microextraction and gas chromatography–mass spectrometry/olfactometry combined with chemometrics

Abstract: In this study, the aroma components of bead-shaped green teas were compared through headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry/olfactometry (GC–MS/O) coupled with chemometrics A total of 62 volatile compounds were identified in 16 green tea samples Notably, comparison of GC–MS/O and odour activity values (OAV) results revealed that nonanal, decanal, (E)-2-nonenal, β-ionone, and 1-octen-3-one were the most powerful aroma-active compounds that contributed to the aroma profile of the bead-shaped green teas Furthermore, multivariate statistical techniques (such as principal component analysis, partial least squares-discriminant analysis, and hierarchical cluster analysis) were used to characterise the bead-shaped green teas according to their geographical origin and the flavour characteristics of their volatile compounds Additionally, the variable importance in the projection method was used to identify 20 volatile markers that could successfully distinguish bead-shaped green teas on the basis of three flavour characteristics The results of the analysis revealed that HS-SPME and GC–MS/O coupled with chemometrics can provide an effective method for characterising and classifying bead-shaped green teas

Method for predicting water content of spread green leaves of green tea based on near infrared spectrum technology

Abstract: The invention provides a method for predicting the water content of spread green leaves of green tea based on the near infrared spectrum technology. A near infrared spectroscopy is applied, and an integrating sphere is used as an optical platform for conducting scanning. The method comprises the following steps that the spread fresh leaves are selected, the water content of the spread fresh leaf sample is measured, the spread fresh leaf sample is subjected to near infrared spectrum scanning, a spread fresh leave sample near infrared spectrum predicting model is established, a water content predicting model is established by converting all fresh leaf sample near infrared spectra into paired data points and utilizing a partial least squares method in a union section, and the water content of the spread green leaves of the green tea is quickly predicated through model stability checking; thus, a quick, accurate and lossless quantitative predicting method is provided for prediction of the water content of the spread green leaves of the green tea.

Protective Effects of Microbiome-Derived Inosine on Lipopolysaccharide-Induced Acute Liver Damage and Inflammation in Mice via Mediating the TLR4/NF-κB Pathway.

Abstract: This research assessed the anti-inflammatory and hepatoprotective properties of inosine and the associated mechanism. Inosine pretreatment significantly reduced the secretion of several inflammatory factors and serum alanine transaminase (ALT) and aspartate amino transferase (AST) levels in a dose-dependent manner compared with the lipopolysaccharide (LPS) group. In LPS-treated mice, inosine pretreatment significantly reduced the ALT and malondialdehyde (MDA) concentration and significantly elevated the antioxidant enzyme activity. Furthermore, inosine pretreatment significantly altered the relative abundance of the genera, Bifidobacterium, Lachnospiraceae UCG-006, and Muribaculum. Correlation analysis showed that Bifidobacterium and Lachnospiraceae UCG-006 were positively related to the cecal short-chain fatty acids but negatively related to the serum IL-6 and hepatic AST and ALT levels. Notably, inosine pretreatment significantly modulated the hepatic TLR4, MYD88, NF-κB, iNOS, COX2, AMPK, Nfr2, and IκB-α expression. These results suggested that inosine pretreatment alters the intestinal microbiota structure and improves LPS-induced acute liver damage and inflammation through modulating the TLR4/NF-κB signaling pathway.

Oligomeric Procyanidins in Apple Polyphenol Are Main Active Components for Inhibition of Pancreatic Lipase and Triglyceride Absorption [Erratum: 2007 July 11, v. 55, no. 14, p. 5906.]

Abstract: Inhibitory effects of apple polyphenol extract (AP) and procyanidin contained in AP on in vitro pancreatic lipase activity and in vivo triglyceride absorption in mice and humans were examined. AP and procyanidin considerably inhibited in vitro pancreatic lipase activity. However, polyphenols, except for procyanidin, in AP (i.e., catechins, chalcones, and phenol carboxylic acids) showed weak inhibitory activities on pancreatic lipase. Procyanidins separated by normal-phase chromatography according to the degree of polymerization were also examined. Inhibitory effects of procyanidins increased according to the degree of polymerization from dimer to pentamer. On the other hand, pentamer or greater procyanidins showed maximal inhibitory effects on pancreatic lipase. These results suggested that with respect to in vitro pancreatic lipase inhibition, the degree of polymerization was an important factor and oligomeric procyanidin mainly contributed. Next, we performed a triglyceride tolerance test in mice and humans. Simultaneous ingestion of AP and triglyceride significantly inhibited an increase of plasma triglyceride levels in both models. These results suggested that the oligomeric procyanidins contained in AP inhibited triglyceride absorption by inhibiting pancreatic lipase activity in mice and humans.

Bitterness and astringency of tea leaves and products: Formation mechanism and reducing strategies

Abstract: The bitter and astringent taste of tea and tea extract is still not favored by many consumers, which limits its applications to bakery foods and functional foods. Many bitter and astringent compounds in tea leaves are susceptible, which transform during tea processing or can be modified by food production technologies. Besides, the accumulations of the major bitter and astringent compounds in fresh tea leaves, such as alkaloids and flavonoids, can be regulated by agronomic practices. Many attempts have been made to reduce the bitter and astringent compounds, in order to improve the sensory quality of tea and tea products. The aim of this review is to describe the characteristics of major bitter and astringent compounds in different types of teas as well as the bitterness and astringency reducing strategies from the aspects of preharvest, processing and post-processing. Alkaloids, catechins, anthocyanins, phenolic acids, flavonol glycosides, and theaflavins importantly contribute to the bitter and astringent taste of tea infusion, the contents of which can be modulated during preharvest, processing, and post-processing. Shade treatment is a conventional agronomic practice to reduce the bitterness and astringency of tea. Processing methods like oxidation, roasting/baking and microbial fermentation effectively reduce the bitter and astringent intensities of teas, but have restricted applications to special types of tea. There is a need of new compounds or strategies to decrease the bitterness and astringency of tea and tea products. Employment of these bitterness and astringency reducing strategies should consider the appearance or application requirements of final products.

Adzuki Bean Alleviates Obesity and Insulin Resistance Induced by a High-Fat Diet and Modulates Gut Microbiota in Mice

Abstract: Adzuki bean consumption has many health benefits, but its effects on obesity and regulating gut microbiota imbalances induced by a high-fat diet (HFD) have not been thoroughly studied. Mice were fed a low-fat diet, a HFD, and a HFD supplemented with 15% adzuki bean (HFD-AB) for 12 weeks. Adzuki bean supplementation significantly reduced obesity, lipid accumulation, and serum lipid and lipopolysaccharide (LPS) levels induced by HFD. It also mitigated liver function damage and hepatic steatosis. In particular, adzuki bean supplementation improved glucose homeostasis by increasing insulin sensitivity. In addition, it significantly reversed HFD-induced gut microbiota imbalances. Adzuki bean significantly reduced the ratio of Firmicutes/Bacteroidetes (F/B); enriched the occurrence of Bifidobacterium, Prevotellaceae, Ruminococcus_1, norank_f_Muribaculaceae, Alloprevotella, Muribaculum, Turicibacter, Lachnospiraceae_NK4A136_group, and Lachnoclostridium; and returned HFD-dependent taxa (Desulfovibrionaceae, Bilophila, Ruminiclostridium_9, Blautia, and Ruminiclostridium) back to normal status. PICRUSt2 analysis showed that the changes in gut microbiota induced by adzuki bean supplementation may be associated with the metabolism of carbohydrates, lipids, sulfur, and cysteine and methionine; and LPS biosynthesis; and valine, leucine, and isoleucine degradation.