Glycyrrhiza is a well-known plant resource used for the production of extractum-glycyrrhizae; however, large amounts of Glycyrrhiza residues containing polysaccharides are produced, and these have not been well utilized until now. The aim of this study was to evaluate the Glycyrrhiza polysaccharides obtained from Glycyrrhiza residues as a potential gelatin replacer in yogurt. The incorporation of Glycyrrhiza polysaccharide (GP) at different concentrations accelerated the growth of lactic acid bacteria. Similar to the effect of adding gelatin (GE), GP could suitably improve the water-holding capacity (WHC) and texture of the yogurt. Moreover, the yogurt prepared with GP showed a higher viscosity and shorter transverse relaxation time of mobile water (T23) value than the control group (CG). Moreover, the microstructure analysis indicated that the casein network of yogurt with GP was more compact and cohesive than those of others. Yogurt prepared with 0.1% GPs exhibited the best sensory acceptance. The results indicated that small amounts of GPs can effectively replace gelatin as a thickener in yogurt with good quality.
In the study, natural deep eutectic solvents (NADESs) were used as alternatives to traditional chemical solvents for the extraction of polyphenols from Elaeagnus angustifolia L. Nine NADESs were tested for the first time and compared with ethanol and water (traditional solvents) regarding the extraction of phenolic compounds from E. angustifolia L. These solvents were particularly effective at extracting polyphenols, whose low water solubility usually requires high amounts of organic solvents. The solvent based on choline chloride and malonic acid provided optimal results and was selected for further optimization. The effects of material-to-liquid ratio, ultrasound time, and ultrasound temperature on the extraction efficiency were studied through single-factor experiments. These parameters were optimized by Box–Behnken design using response surface methodology. The optimal conditions identified were 49.86 g/mL of material-to-liquid ratio, 31.10 min of ultrasound time, and 62.35 °C of ultrasound temperature, resulting in a high yield of 140.30 ± 0.19 mg/g. The results indicated that the NADES extraction technique provided a higher yield than the conventional extraction process. The antioxidant activity of the extract of polyphenols from E. angustifolia L. was determined, and UPLC–IMS–QTOF–MS was used to analyze the phenolic compounds in it. The results revealed that the scavenging ability of 1,1-diphenyl-2-picryl-hydrazil and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) extracted by NADES was higher than that of polyphenols extracted by water and ethanol. Furthermore, a total of 24 phenolic compounds were identified in the extract. To the best of our knowledge, this is the first study in which a green and efficient NADES extraction method has been used to extract bioactive polyphenols from E. angustifolia L., which could provide potential value in pharmaceuticals, cosmetics, and food additives.
Natural polysaccharides are new popular healthy food material, and the materials are widely used in various functional foods. The influences of polysaccharides from Glycyrrhizauralensis on the quality and sensory properties of Chinese steamed bread (CSB), as well as the performance (starch digestion in vitro and starch staling) of CSB, were investigated in this study. The addition of Glycyrrhiza polysaccharide (GP) increased the specific volume of CSB in a dose-dependent manner, and the specific volume of CSB-2 was 2.55 mL/g. GP also contributed to the increase in hardness (from 1240.17 to 2539.34 g) and chewiness (893.85 to 1959.27 g) of fresh CSB. In addition, GP could maintain the integrity of the protein network within the CSB. The scores for sensory evaluation indicators of CSB-1 were relatively balanced. More importantly, the addition of GP altered starch digestive properties, and the content of the resistant starch (RS) was increased from 8.62 (CSB-0) to 43.46% (CSB-2). GP led to a significant reduction of the expected glycemic index (eGI) of CSB, and the eGI of CSB was decreased from 97.50 (CSB-0) to 73.8 (CSB-2), which was classified as a medium-GI (MGI) food. In addition, X-ray diffraction (XRD) and differential scanning calorimeter (DSC) revealed the addition of GP delayed the staling of CSB during storage. In general, adding the proper amount of GP could improve the quality of CSB and show the potential as a functional component of CSB to reduce the postprandial blood glucose level resulted by the CSB.