Antioxidant activity and semi-solid emulsification of a polysaccharide from coffee cherry peel

Effect of modifications on structure, physicochemical properties and lead ions adsorption behavior of dietary fiber of Flammulina velutipes

The health effects of dietary fiber have been widely concerned, which are closely related to physicochemical properties. This study focused on soluble dietary fiber of Flammulina velutipes (FDF), evaluated the effects of modifications on structural characterization, the physicochemical properties and the heavy metal adsorption characteristics, and further clarified underlying mechanisms on Pb2+ adsorption behavior of FDFs. The results showed the modifications of extrusion and cellulase improved the yield of FDFs, increased the release of active groups and enhanced the adsorption ability in vitro. Besides, Pb2+ adsorption altered porous structure and led to the presence of carboxylate. It was a spontaneous endothermic reaction and can be fitted by the pseudo-second-order kinetic equation. The Freundlich equation was suitable to describe the adsorption isotherm. These results highlighted potential applications of the dietary fiber modification and laid the theoretical foundation for the modification processing of F. velutipes and protection from food-derived heavy metal toxicity.

The composition and bioactivity of bound polyphenols from coffee dietary fiber during in vitro Simulating digestion

Dietary fiber from coffee peel is rich in bound polyphenols good for human health due to the antioxidant activity. In this study, we evaluated the bound polyphenol release conditions and activities in coffee peel soluble dietary fiber (CPSDF) in the process of in vitro simulation digestion. The CPSDF structure became loose and porous due to simulated digestion but retained the polysaccharide backbone. Widely-targeted metabolomics analysis identified 550 metabolites, with phenolic acids and flavonoids being main differentially expressed metabolites in digested products (82.18% in total). The most significant increase in the 5,7,8,3',4'-pentamethoxyflavanone content and decrease in the 3,5-dihydroxyacetophenone content were observed after digestion (undigested vs S-intestine). Additionally, the changes in antioxidant and enzyme inhibitory activities followed the same pattern as that observed for total phenolic content. The enzyme inhibitory and antioxidant activities of gastric digestion products were greater than those of the oral and small intestinal digestion products. The present work provided the theoretical foundation for developing high-value CPSDF products and reusing coffee peel waste.

Effects of Ultrasound-Assisted Treatment on Physicochemical Properties and Biological Activities of Polysaccharides from Sargassum

The aim of this study was to investigate the effect of ultrasonic treatment on the physicochemical properties and bioactivities of polysaccharides from Sargassum samples (SPs) extracted with different solvents. The alkali-assisted extraction of polysaccharide (SPA), acid-assisted extraction of polysaccharides from (SPB), and hot water extraction of polysaccharides (SPCs) were perofrmed on Sargassum. Ultrasonic treatment was performed with the SPA, SPB, and SPC in turn, and named USPA, USPB, and UPSC, respectively. The results showed that SPs mainly consisted of mannose, glucose, xylose, rhamnose, galactose, fucose, glucuronic acid, mannuronic acid and guluronic acid. The molecular weight of SPA (434.590 kDa) was the lowest under different solvent extractions, and the molecular weights of SPA, SPB, and SPC were reduced after sonication. SPA had a high carbohydrate content of (52.59 ± 5.16)%, and SPC possessed a high sulfate content of (3.90 ± 0.33)%. After ultrasonic treatment, the biological activities of SPs were significantly increased. The α-glucosidase inhibition assay reflected that the IC50 values of the ultrasonic treatment SPs were significantly reduced, and USPA showed the best activity, with an IC50 of (0.058 ± 0.05) mg/mL. Antioxidant assays demonstrated that USPC exhibited greater DPPH- and ABTS-scavenging capacity. In the anti-glycosylation assay, SPs after sonication demonstrated excellent inhibition of glycosylation products and protein oxidation products, with USPA showing the highest inhibition rate. In conclusion, the biological activities of SPs were enhanced after ultrasonic treatment. This study provides a theoretical reference for their use in food and medicines.

Polysaccharides from fruit and vegetable wastes and their food applications: A review

Fruit and vegetables are a great source of nutrients and have numerous health benefits. The fruit and vegetable industry produces enormous amounts of waste such as peels, seeds, and stems. The amount of this waste production has increased, causing economic and environmental problems. Fruit and vegetable wastes (FVWs) have the potential to be recovered and used to produce high-value goods. Furthermore, FVWs have a large variety and quantity of polysaccharides, which makes them interesting to study for potential industrial use. Currently, the investigations on extracting polysaccharides from FVWs and examining how they affect human health are increasing. The present review focuses on polysaccharides from FVWs such as starch, pectin, cellulose, and inulin, and their various biological activities such as anti-inflammatory, anti-tumor, anti-diabetic, antioxidant, and antimicrobial. Additionally, applications as packaging material, gelling agent, emulsifier, prebiotic, and fat replacer of polysaccharides from FVWs in the food industry have been viewed in detail. As a result, FVWs can be reused as the source of polysaccharides, reducing environmental pollution and enabling sustainable green development. Further investigation of the biological activities of polysaccharides from FVWs on human health is of great importance for using these polysaccharides in food applications.

Polysaccharides from waste Zingiber mioga leaves: Ultrasonic-microwave-assisted extraction, characterization, antioxidant and anticoagulant potentials

Zingiber mioga is a highly economic crop that is used to produce vegetables, spices and herbal pharmaceuticals. Its edible flower bud contributes most to the economic value, but the big leaves were discarded as agricultural waste, which urgently needs to be exploited. In this work, polysaccharides from waste Z. mioga leaves (PWZMLs) were extracted using ultrasonic-microwave-assisted extraction (UMAE). After purification and characterization, the antioxidation and anticoagulation of PWZMLs were evaluated to appraise the potential in cardiovascular protection. Under the liquid-solid ratio of 26: 1 mL/g, after ultrasonication at 495 W for 10 min, followed by microwaving at 490 W for 5 min, the yield of PWZMLs achieved to 6.22 ± 0.14 %, notably higher (P < 0.01) than other methods, and ultrasound contributed more to the yield than microwave. Various analyses confirmed that PWZMLs were negatively charged polysaccharides with galacturonic acid the dominant uronic acid. PWZMLs exerted excellent antioxidant capacity, especially for scavenging 1, 1-diphenyl-2-picrylhydrazyl radical. PWZMLs also elicited promising anticoagulant property, particularly for prolonging activated partial thromboplastin time and lowering fibrinogen, which were almost equivalent to heparin at the same concentration. PWZMLs contained two polysaccharide fractions (199.53 and 275.42 kDa) that could synergistically contribute to the pronounced antioxidant and anticoagulant activities. The PWZMLs extracted with optimized UMAE have great potential in cardiovascular protection.