A novel low-molecular-weight pectin from sand pear (Pyrus pyrifolia Nakai) pulp improves the quality of yogurt: a comparative study with fructooligosaccharide

Pectin was extracted from sand pear pulp with a yield of 0.51 ± 0.02 g/kg. • The molecular weight of pectin was 7733 g/mol with DE 71%, noted as LMW-pectin. • LMW-pectin changed the total acids and textural structure of yogurt. • LMW-pectin affected the odor and taste of the yogurt significantly. • LMW-pectin changed the rate of Bacillus via bacterial diversity analysis. In this study, low-molecular-weight pectin (LMW-pectin) was extracted from sand pear pulp, and its effect on the quality of yogurt was studied compared to the commercial fructooligosaccharide (FOS). The structural properties of LMW-pectin were relative molecular weight: 7733 ± 4 g/mol, galacturonic acid content: 732 ± 9 g/kg, and degree of esterification: 71 ± 2%. Compared with the control, LMW-pectin at 7.0 g/kg slightly increased the water-holding capacity (from 45.71% to 46.53%) and significantly reduced the total acid content (from 6.42 g/kg to 5.24 g/kg) and hardness (from 114.27 N to 76.73 N). LMW-pectin also reduced the gel strength of yogurt slightly. It also could modulate the tastes (particularly bitterness and astringency) and aromas via increasing the concentrations of specific esters, making the yogurt demonstrate cheesy, fragrant odors. LMW-pectin increased the relative abundance of Bacillus from 0.91% to 6.78%. LMW-pectin increased the concentrations of medium-chain fatty acids, odd-chain fatty acids, and unsaturated fatty acids. LMW-pectin also increased the scores of taste and odor in yogurt significantly. In contrast, FOS only affected gel strength, electronic tongue values, and the concentrations of volatile compounds. LMW-pectin can serve as a functional additive for improving the texture, flavor, and nutritional quality of yogurt, providing a practical strategy for utilization in the dairy industry.