Phenolic metabolites changes during baijiu fermentation through non-targeted metabonomic.

To investigate the changes of phenolic metabolite during different grains fermentation stages of Chinse Baijiu, the ultra-performance liquid chromatography-quadrupole time of-flight mass spectrometry (UHPLC-QTOF-MS) was applied to identify and analyze the different phenolic metabolites, combined with principal component analysis and partial least squares discriminant analysis. Results indicated that significant differences in phenolic metabolites during different fermentation stages were found. Among the 231 phenolic metabolites detected, 36, 31, 19, 23, 14, and 50 differential phenolic metabolites were screened between different groups using partial least squares discriminant analysis. Twelve metabolic pathways with high correlation of differential phenolic metabolites and 23 main participating differential metabolites were identified through KEGG metabolic pathway enrichment analysis. The present study preliminarily revealed the differences of phenolic metabolites at different fermentation stages, and providing a theoretical basis for the further improving of the taste and quality of Chinese Baijiu.

Pectin from Citrus unshiu Marc. Alleviates Glucose and Lipid Metabolism by Regulating the Gut Microbiota and Metabolites.

The effects of pectin from Citrus unshiu Marc. on glycolipid metabolism, the morphologies of the pancreas and epididymal fat, the gut microbiota, and the metabolites of short-chain fatty acids (SCFAs) in db/db mice were investigated in this study. The results indicated that pectin reduced the levels of fasting blood glucose, glycated serum protein, triglycerides, total cholesterol, and low-density lipoprotein cholesterol while increasing the levels of high-density lipoprotein cholesterol. Meanwhile, pectin could improve the morphology of islet cells and inhibit the hypertrophy of adipocytes. Additionally, pectin not only regulated the intestinal flora dysbiosis in db/db mice, as shown by the increasing proportion of Firmicutes/Bacteroidetes and the relative abundance of Ligilactobacillus, Lactobacillus, and Limosilactobacillus, but also remedied the metabolic disorder of SCFAs in db/db mice. These results suggest that pectin could promote glucose and lipid metabolism by regulating the intestinal flora with changes in SCFA profile. This study proves that pectin might serve as a new prebiotic agent to prevent the disorder of glycolipid metabolism.

Regulating the physicochemical, structural characteristics and digestibility of potato starch by complexing with different phenolic acids.

The effects of ferulic acid (FA), protocatechuic acid (PA), and gallic acid (GA) on the physicochemical characteristics, structural properties, and in vitro digestion of gelatinized potato starch (PS) were investigated. Rapid viscosity analysis revealed that the gelatinized viscosity parameters of PS decreased after complexing with different phenolic acids. Dynamic rheology results showed that phenolic acids could reduce the values of G' and G″ of PS-phenolic acid complexes, demonstrating that the addition of phenolic acids weakened the viscoelasticity of starch gel. Fourier-transform infrared spectra and X-ray diffraction results elucidated that phenolic acids primarily reduced the degree of short-range ordered structure of starch through non-covalent interactions. The decrease in thermal stability and the more porous microstructure of the complexes confirmed that phenolic acids could interfere with the gel structure of the starch. The addition of different phenolic acids decreased the rapidly digestible starch (RDS) content and increased the resistant starch (RS) content, with GA exhibiting the best inhibitory capacity on starch in vitro digestibility, which might be associated with the number of hydroxy groups in phenolic acids. These results revealed that phenolic acids could affect the physicochemical characteristics of PS and regulate its digestion and might be a potential choice for producing slow digestibility starch foods.

Development and characterization of pH responsive sodium alginate hydrogel containing metal-phenolic network for anthocyanin delivery.

Favorable hydrogels can be used as a material to deliver bioactive molecules and improve the stability of bioactive substances, while their safety needs to be improved. In this study, protocatechuic acid (PCA) and Fe3+ were rapidly self-assembled to form a metal-phenolic network under different pH conditions, and then sodium alginate (SA) was added to prepare the SA/PCA/Fe hydrogel without adding other chemical reagents. The structural characteristic of SA/PCA/Fe hydrogel was characterized by infrared spectroscopy, X-ray diffraction analysis and scanning electron microscopy. The results showed that the structures of SA/PCA/Fe hydrogels prepared at different pH values were significantly different. The texture analysis, water-holding measurement and rheological analysis indicated that the SA/PCA/Fe hydrogel showed higher gel strength, water holding capacity and storage modulus. Thermogravimetric analysis illuminated that the SA/PCA/Fe hydrogel enhanced the thermal stability of free anthocyanins through encapsulating anthocyanins. Moreover, in vitro simulated digestion experiment revealed that SA/PCA/Fe hydrogel could control the release of anthocyanins in the simulated gastrointestinal tract. To sum up, this present study might provide a safer and feasible way for the delivery of bioactive substances.

Preparation and physicochemical properties characterization of hesperetin-grafted pectin conjugate.

Different ratios of hesperetin (HT) were successfully grafted onto pectin from basic water (PB) molecules via free radical-induced reaction. The structure of PB-HT conjugates was characterized by ultraviolet spectroscopy, infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Results indicated that HT was successfully grafted onto pectin molecules, and PB-HT-0.5 showed the highest HT content (103.18 ± 2.76 mg/g). Thermogravimetric analysis indicated that HT crystals showed good thermal resistance and could improve the thermal stability of PB-HT conjugates. Additionally, PB-HT conjugates showed good cytocompatibility and blood compatibility. This study provides a novel and efficient method to synthesize hesperetin-grafted pectin conjugate, which showed potential application in the fields of functional foods in the future.

Effects of citronellol grafted chitosan oligosaccharide derivatives on regulating anti-inflammatory activity.

In order to improve the anti-inflammatory activity of chitosan oligosaccharide (COS), chitosan oligosaccharide graft citronellol derivatives (COS-g-Cit1-3) were successfully synthesized via grafting citronellol (Cit) onto COS backbone. The degrees of substitution (DS) of COS-g-Cit1-3 were 0.165, 0.199 and 0.182, respectively. The structure of COS-g-Cit1-3 was confirmed by UV-vis, FT-IR, 1H NMR and elemental analysis. The in vivo anti-inflammatory activity evaluation results displayed that COS-g-Cit1-3 drastically reduced the paw swelling, and the oedema inhibitions were 22.58 %, 29.03 % and 25.81 %, respectively. The results indicated that the anti-inflammatory effects of COS-g-Cit1-3 were significantly higher than COS and COS-g-Cit2 exhibited the highest anti-inflammatory ability. The results also presented that COS-g-Cit1-3 reduced the expression levels of TNF-α by promoting the secretion of IL-4 and IL-10. Moreover, western blot analysis data proved that COS-g-Cit1-3 inactivated the NF-κB signaling pathway via inhibiting the phosphorylation of p65, IKBα and IKKß.

Chitosan oligosaccharide-g-linalool polymer as inhibitor of hyaluronidase and collagenase activity.

In this study, chitosan oligosaccharide (COS) was modified by grafting Linalool (Lin) on its backbone to improve its anti-inflammatory activity. By changing the molar ratios of COS to Lin, three different degrees of substitution COS-g-Lin1-3 were prepared. The degrees of substitution of derivatives were 0.65, 0.80 and 1.14 respectively. The structure of COS-g-Lin1-3 were characterized by UV-vis, FT-IR, 1H NMR and elemental analysis in order to show the COS-g-Lin1-3 successfully synthesized. Besides, the thermal stability, solubility, pH stability as well as crystallinity were also investigated. The results revealed that the derivatives exhibited higher thermal stability and more remarkable anti-inflammatory property against hyaluronidase and collagenase than that of COS. The good biocompatibility made this novel material a promising and effective compound for anti-inflammatory applications.