Granular hydrogels with tunable properties prepared from gum Arabic and protein microgels.

Granular hydrogels have emerged as a new class of materials for 3D printing, tissue engineering, and food applications due to their extrudability, porosity, and modularity. This work introduces a convenient method to prepare granular hydrogel with tunable properties by modulating the interaction between gum Arabic (GA) and whey protein isolate (WPI) microgels. As the concentration of GA increased, the appearance of the hydrogel changed from fluid liquid to moldable solid, and the microstructure changed from a macro-porous structure with thin walls to a dense structure formed by the accumulation of spherical particles. At a GA concentration of 0.5 %, the hydrogels remained fluid. Granular hydrogels containing 1.0 % GA showed mechanical properties similar to those of tofu (compressive strength: 10.8 ± 0.5 kPa, Young's modulus: 16.7 ± 0.4 kPa), while granular hydrogels containing 1.5 % GA showed mechanical properties similar to those of hawthorn sticks and sausages (compressive strength: 300.4 ± 5.8 kPa; Young's modulus: 200.5 ± 3.4 kPa). The hydrogel with 2.0 % GA was similar to hawthorn sticks, with satisfactory bite resistance and elasticity. Such tunability has led to various application potentials in the food industry to meet consumer demand for healthy, nutritious, and diverse textures.

Effects of long-term administration of theasinensin A on healthy C57BL/6J mice: Enhancing the function of epididymal white adipose tissue and regulating the colonic microenvironment.

The effects of theasinensin A (TSA) on healthy C57BL/6J mice were investigated. Results showed that long-term administration of 100 mg/kg body weight/day TSA might be non-toxic to healthy mice based on the unaltered basal biochemical indicators related to glucose and lipid metabolism, inflammatory factors and hepatic injury. On the contrary, TSA stimulated the rate of lipid turnover and browning of white adipose tissues, accelerated the adipocytic energy mobilization, and then reduced the white adipocytic size, ultimately enhancing resistance to obesity in healthy mice. Furthermore, TSA not only up-regulated the expression of mucin, tight junction protein, and short-chain fatty acids receptor, but also regulated the intestinal microbiota by enhancing the typical beneficial microbe Akkermansia muciniphila, thereby modulating the colonic microenvironment. These results suggested that TSA had a potential strengthening effect on the resistance of healthy mice to metabolic disorders, which provides a theoretical basis for the utilization of TSA.

Fluoride induced leaky gut and bloom of Erysipelatoclostridium ramosum mediate the exacerbation of obesity in high-fat-diet fed mice.

INTRODUCTION: Fluoride is widely presented in drinking water and foods. A strong relation between fluoride exposure and obesity has been reported. However, the potential mechanisms on fluoride-induced obesity remain unexplored. Objectives and methods The effects of fluoride on the obesity were investigated using mice model. Furthermore, the role of gut homeostasis in exacerbation of the obesity induced by fluoride was evaluated. Results The results showed that fluoride alone did not induce obesity in normal diet (ND) fed mice, whereas, it could trigger exacerbation of obesity in high-fat diet (HFD) fed mice. Fluoride impaired intestinal barrier and activated Toll-like receptor 4 (TLR4) signaling to induce obesity, which was further verified in TLR4-/- mice. Furthermore, fluoride could deteriorate the gut microbiota in HFD mice. The fecal microbiota transplantation from fluoride-induced mice was sufficient to induce obesity, while the exacerbation of obesity by fluoride was blocked upon gut microbiota depletion. The fluoride-induced bloom of Erysipelatoclostridium ramosum was responsible for exacerbation of obesity. In addition, a potential strategy for prevention of fluoride-induced obesity was proposed by intervention with polysaccharides from Fuzhuan brick tea. Conclusion Overall, these results provide the first evidence of a comprehensive cross-talk mechanism between fluoride and obesity in HFD fed mice, which is mediated by gut microbiota and intestinal barrier. E. ramosum was identified as a crucial mediator of fluoride induced obesity, which could be explored as potential target for prevention and treatment of obesity with exciting translational value.

Zeaxanthin Dipalmitate-Enriched Emulsion Stabilized with Whey Protein Isolate-Gum Arabic Maillard Conjugate Improves Gut Microbiota and Inflammation of Colitis Mice.

In the present study, protein-polysaccharide Maillard conjugates were used as novel emulsifiers and bioactive carriers. Effects and potential mechanisms of zeaxanthin dipalmitate (ZD)-enriched emulsion stabilized with whey protein isolate (WPI)-gum Arabic (GA) conjugate (WPI-GA-ZD) and ZD-free emulsion (WPI-GA) on gut microbiota and inflammation were investigated using a model of dextran sulfate sodium (DSS)-induced colitis in mice. As a result, supplementation with WPI-GA and WPI-GA-ZD improved the serum physiological and biochemical indicators, decreased the expression of pro-inflammatory cytokines and related mRNA, as well as increased the tight junction proteins to a certain extent. 16S rDNA sequencing analyses showed that supplementation with WPI-GA and WPI-GA-ZD presented differential modulation of gut microbiota and played regulatory roles in different metabolic pathways to promote health. Compared with WPI-GA, the relative abundances of Akkermansia, Lactobacillus and Clostridium_IV genera were enriched by the intervention of WPI-GA-ZD. Overall, the designed carotenoid-enriched emulsion stabilized with protein-polysaccharide conjugates showed potential roles in promoting health.

The polysaccharides from the fruits of Lycium barbarum L. modify the gut community profile and alleviate dextran sulfate sodium-induced colitis in mice.

In the present study, the effects of a purified fraction of polysaccharides from the fruits of Lycium barbarum L. (LBPs), named LBPs-4, on the dextran sodium sulfate (DSS)-induced colitis in mice were evaluated. The results showed that LBPs-4 decreased disease activity index score, prevented colon shortening and reduced plasma levels of pro-inflammatory cytokines (tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), monocyte chemoattractant protein-1 (MCP-1) and prostaglandin E2) in mice with colitis. LBPs-4 could increase the relative abundances of Akkermansia and Bifidobacterium in gut microbiota, and it also mitigated the intestinal barrier damage by upregulating the level of tight junction protein ZO-1 and the number of goblet cells in colon. Moreover, the results of in vitro culture indicated that the growth of Bifidobacterium longum subsp. infantis CCX 19042 was promoted by LBPs-4, whereas the culture media of LBPs-4 by Bacteroides ovatus with or without addition of mucin could enhance the growth of Akkermansia muciniphila. Collectively, these results suggested that LBPs-4 should be potential prebiotics for the treatment of colitis.

(-)-5-O-(3-O-ß-d-Glucopyranosylcaffeoyl)-quinic acid from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching: Purification, identification and in vitro bioactivities.

Chlorogenic acids are important phenolics in the fruits of wolfberry, but little attention has been paid on their glucosylated forms. In the present study, a glucosylated form of chlorogenic acid was isolated from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching (also called yellow wolfberry) and identified to be (-)-5-O-(3-O-ß-d-glucopyranosylcaffeoyl)-quinic acid (5-CQA-3'ßG) by high resolution mass spectrometry and nuclear magnetic resonance spectrometry. The content of 5-CQA-3'ßG in the dried fruit was determined as 0.0293 ± 0.0015% by HPLC. In addition, 5-CQA-3'ßG showed a good scavenging capacity for 2,2'-azino-bis-(3-ethylben-zothiazoline-6-sulphonate) free radicals but had a relatively low reducing power and scavenging capacity for 2,2-diphenyl-1-picrylhydrazyl free radical. Moreover, the secretion of nitric oxide, tumor necrosis factor-α and interleukin-6 as well as related mRNA expression were reduced in lipopolysaccharide-stimulated RAW264.7 macrophage cells treated with 5-CQA-3'ßG. This is the first report describing purification, identification and bioactivity of glucosylated CQA from yellow wolfberry.

Application of protein-polysaccharide Maillard conjugates as emulsifiers: Source, preparation and functional properties.

The protein-polysaccharide conjugates formed by Maillard reaction can be used as novel emulsifiers in the food industry. Proteins and polysaccharides have extensive sources, and their emulsifying properties are highly dependent on their structural features. The Maillard conjugates can be prepared from conventional and novel methods, and these methods have different advantages and limitations in industrial applications. After an appropriate glycation, the conjugates show some modified or enhanced functional properties, including solubility, emulsifying property, thermal stability, foaming capacity, and gelation property. However, the research on the structure-function relationship of both proteins and polysaccharides is limited. It is necessary to well understand the characteristics of these biopolymers, and select appropriate conditions to control the process of Maillard reaction. Overall, the Maillard conjugates show great potential as the emulsifiers and stabilizers in the emulsion system. This review introduces the sources and structural characteristics of commonly used proteins and polysaccharides for Maillard reaction, outlines the methods (dry-heating, wet-heating, electrospinning, ultrasound, pulsed electric field, and microwave) for preparing Maillard conjugates and focuses on the improved functional properties (solubility, emulsifying, foaming and thermal properties) and the potential mechanisms.

Ultrasonic-assisted extraction and high-speed counter-current chromatography purification of zeaxanthin dipalmitate from the fruits of Lycium barbarum L.

Zeaxanthin dipalmitate (ZDP) is a major non-saponified carotenoid in fully ripe fruits of Lycium barbarum L. In the present study, response surface methodology was used to optimize the ultrasonic-assisted extraction (UAE) conditions of carotenoids from the fruits of L. barbarum, and the optimal extraction conditions were determined as follows: ultrasonic power of 360 W, ultrasonic time of 40 min and the ratio of extraction solvent to sample of 30 mL/g. An actual value of ZDP content of 5.40 mg/g and short extraction time indicated the efficiency of UAE. Furthermore, a promising high-speed counter-current chromatography (HSCCC) method was established for the purification of ZDP from the fruits of L. barbarum. With a developed two-phase solvent system composed of n-hexane/dichloromethane/acetonitrile (10/3/7, v/v/v), ZDP with a purity of higher than 95% was successfully isolated from the crude extract. This is the first report on the purification of ZDP by using HSCCC.