Dandelion polysaccharides improve the emulsifying properties and antioxidant capacities of emulsions stabilized by whey protein isolate

In this study, the effects of dandelion polysaccharide (DP) and its carboxymethylated derivative (CMDP) on the emulsifying characteristics and antioxidant capacities of emulsions stabilized by whey protein isolate (WPI) were determined. The addition of both DP and CMDP reduced the particle size and zeta potential of the emulsions. Using 1.0 % WPI and 1.0 % CMDP as emulsifier, the emulsifying activity index (EAI) and emulsifying stability index (ESI) were 32.61 ± 0.11 m2/g and 42.58 ± 0.13 min, respectively, which were higher than the corresponding values of 27.19 ± 0.18 m2/g and 36.17 ± 0.15 min with 1.0 % WPI and 1.0 % DP. Fourier-transform infrared spectroscopy (FT-IR), far-ultraviolet circular dichroism (Far-UV CD), and fluorescence (FS) spectra analyses confirmed that the α-helix and β-sheet structures in WPI-polysaccharide complexes were reduced compared with those in pure WPI, whereas the random-coil content was enhanced by the addition of polysaccharides. Moreover, DP and CMDP effectively improved the antioxidant capacity and inhibited oxidation of the emulsions during storage. Therefore, DP and its carboxymethylated derivative exhibit great potential to be applied in the emulsion-based delivery system.

Carboxymethylation modification, characterization of dandelion root polysaccharide and its effects on gel properties and microstructure of whey protein isolate

In the present study, a native polysaccharide (DP) with sugar content of 87.54 ± 2.01 % was isolated from dandelion roots. DP was chemically modified to obtain a carboxymethylated polysaccharide (CMDP) with DS of 0.42 ± 0.07. DP and CMDP were composed of the same six monosaccharides including mannose, rhamnose, galacturonic acid, glucose, galactose, and arabinose. The molecular weights of DP and CMDP were 108,200 and 69,800 Da, respectively. CMDP exhibited more stable thermal performance and better gelling properties than DP. The effects of DP and CMDP on the strength, water holding capacity (WHC), microstructure, and rheological properties of whey protein isolate (WPI) gels were investigated. Results showed that CMDP-WPI gels had higher strength and WHC than DP-WPI gels. With the addition of 1.5 % CMDP, WPI gel had a good three-dimensional network structure. The apparent viscosities, loss modulus (G"), and storage modulus (G') of WPI gels were increased with the polysaccharide addition, the influence of CMDP was remarkable compared to DP at the same concentration. These findings suggest that CMDP may be used as a functional ingredient in protein-containing food products.

Polysaccharide from dandelion enriched nutritional composition, antioxidant capacity, and inhibited bioaccumulation and inflammation in Channa asiatica under hexavalent chromium exposure

Taraxacum mongolicum polysaccharide (TMP) exhibits anti-inflammatory and antioxidant activity, making it an attractive candidate for aquatic-product-safety applications. Here, this study was aimed to investigate the effects of dietary TMP on the growth, nutritional composition, antioxidant capacity, bioaccumulation and inflammation in Channa asiatica under hexavalent chromium stress. The C. asiatica was randomly distributed into five groups: The first group served as the blank control group (CK), the subsequent groups were fed TMP-supplemented feed (0, 0.5, 1.0 and 2.0 g/kg), respectively, and exposed to waterborne Cr⁶⁺ for 28 days. Our results indicated that the TMP effectively increased (P < 0.05) C. asiatica muscle flavour amino acid, total free amino acids, monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and EPA + DHA contents, enhanced positively antioxidant enzyme activity (GPX, SOD, CAT, T-AOC), reduced oxidative stress parameters (MDA, PC), and up-regulated antioxidant-related genes mRNA expression. Meanwhile, the appropriate amount of TMP supplementation also inhibited the bioaccumulation of Cr⁶⁺ in tissues and alleviated the inflammatory response (P < 0.05). Furthermore, sensory evaluation implied that the overall score of sashimi and cooked fillet in the 2.0 g/kg TMP group was the highest in the experimental group, second only to CK. In brief, these results elucidate that TMP-supplemented diets excellently ameliorated the growth, enriched nutritional composition and antioxidant capacity, and inhibited bioaccumulation and inflammation in C. asiatica exposed to waterborne Cr⁶⁺.