The texture of soft materials, such as yogurt, emerges from the complex interplay of their constituent molecules. While polysaccharides are widely used to modulate texture, achieving predictable outcomes is hindered by their structural heterogeneity. Here, we demonstrate that pectin molecular weight (Mw) acts as a master regulator for designing customizable yogurt textures through precise control of casein network assembly. By fractionating lemon pectin into discrete MW fractions, we achieved distinct viscoelastic landscapes in yogurt systems: intermediate Mw (20.01 kDa) induced weak, flowable gels by disrupting optimal pectin-protein interactions (electrostatic and hydrophobic interactions), whereas high and lower Mw (40.09 and 7.77 kDa) reinforced the network through enhanced protein-protein binding (disulfide bonding). This reveals a non-monotonic (U-shaped) dependence of gel strength on pectin chain length. Our findings provide a mechanistic framework for Mw-directed texture engineering, offering practical guidelines for developing texture-tunable foods tailored for vulnerable populations, such as the elderly and individuals with dysphagia. This work thereby advances the intersection of food science and human wellness.

In this study, the synergistic effects of mixed-strain fermentation (Lacticaseibacillus rhamnosus GG, Lactobacillus acidophilus NCFM, and Bifidobacterium animalis subsp. lactis Bb-12) on enhancing the nutritional profile and volatile components of apple puree were investigated. Under the optimal fermentation conditions, the apple puree demonstrated significant improvements: (1) Nutritional enhancement: 62.78% and 29.48% elevation in total phenolics and total flavonoids, and antioxidant capacities improvement; (2) Sensory modification: the achievement of superior sensory score (92.44), reduced sweetness, and enhanced sourness and umami; (3) Volatile components: the identification of 91 volatile components, with increased concentrations of alcohols, esters, ketones and acids, and decreased concentration of aldehydes. Notable increases in key esters and alcohols such as 3-methyl-1-butanol (23.00%), ethyl acetate (47.17%) and γ-butyrolactone (14.67%) contributed to a fruity top note and long-lasting creamy fragrance. Decreases in acetaldehyde (10.03%), propanal (45.71%) and (E)-2-heptenal (39.08%) mitigated harsh spiciness and enhanced masked fruity for a more balanced flavor profile; (4) Simulated digestion: total phenolics remained stable in the gastric phase, but increased by 305.13% during intestinal digestion, which indicated improved bioaccessibility. Overall, this study demonstrates that mixed-strain fermentation enhances the nutritional value of apple puree and provides valuable insights into the fermented fruit and vegetable industry.

Depression is a psychiatric disorder with the highest suicide rate, and current medication for depression often comes with numerous side effects during long-term treatment. The causes and pathogenesis of depression are complex. Many studies have suggested that various flavonoids, which widely distributed in plants, are significantly effective in improving depression. Additionally, a substantial body of recent research has demonstrated a close relationship between changes in the gut microbiota and the development of depression. Flavonoids can alter the composition and metabolites of the gut microbiota, thereby affecting human emotion and behavior through the microbiota-gut-brain axis. This article provides a review of research findings on the interaction between the gut microbiota and depression. It also discusses the potential mechanism through which flavonoids, via the gut microbiota, could ameliorate depression by regulating inflammatory factors, neurotransmitters, short-chain fatty acids, and other related factors, hoping to provide ideas for follow-up research to explore the pathogenesis, prevention and improvement of depression.