To improve the stability and quality of Huangjiu, five membranes with different molecular weight cut-offs (MWCOs; 0.2 μm, 50, 30, 10, and 1 kDa) were used to treat semi-dry and semi-sweet Huangjiu. The changes in turbidity and color difference during storage were systematically investigated, and the changes in thermal and cold stability, precipitationprone component content, antioxidant activity, volatile flavor profile, and sensory attributes were further analyzed. In addition, the effect of pretreatment with proline-specific endoprotease or Mazyme LP protease on the stability of Huangjiu with poor stability was examined. Non-targeted metabolomic analysis was subsequently performed on the membrane-treated and enzymatically treated groups with better effects. The results indicated that reducing membrane MWCOs significantly enhanced the stability of Huangjiu. Membranes with pore size ≤ 30 kDa effectively removed high-molecular-mass substances causing turbidity, maintaining the clarity of the wine under heating-freezing conditions. However, overly fine filtration (≤ 1 kDa) impaired the antioxidant activity and led to a deterioration in the sensory quality. Comprehensive evaluation indicated that 30 kDa ultrafiltration significantly improved the clarity and stability while effectively preserving the flavor and sensory attributes of Huangjiu. Furthermore, proline-specific endoprotease effectively hydrolyzed high-molecular-mass proteins in semi-dry Huangjiu, thereby helping to inhibit precipitate formation. Metabolomic analysis further indicated that enzymatic hydrolysis significantly increased peptide abundance through protein breakdown, thereby enhancing the stability of Huangjiu, whereas ultrafiltration inhibited precipitation by physically removing macromolecular substances. This study aims to provide a scientific basis for improving the stability and quality of Huangjiu by optimizing membrane separation parameters or applying precise enzymatic hydrolysis processes and to provide research directions for future exploration of synergistic applications of membrane filtration and enzymatic hydrolysis.

Our study aimed to explore the ability of extruded maize starch-chlorogenic acid (EMS-CHA) complexes to regulate blood glucose homeostasis. Extrusion processing was used to successfully prepare EMS-CHA complexes, accompanied by a structural transformation of starch from A-type to A+V-type semi-crystalline form. Notably, when chlorogenic acid (CHA) was incorporated at 2.0% (w/w) into maize starch (EMS-2.0CHA), the resistant starch content significantly increased to 30.35 ± 2.36%. This directly contributed to a reduced glycemic response, as evidenced by a lower postprandial blood glucose area under the curve (AUC) of 5.72 ± 1.13 mmol/h·L. The hypoglycemic effect of EMS-2.0CHA complex was further validated in diabetic rats. Compared with high-fat diet group, supplementation with EMS-2.0CHA complex significantly decreased fasting blood glucose levels to 11.75 ± 2.75 mmol/L and reduced the AUC to 15.15 ± 2.63 mmol/h·L. Importantly, these improvements were associated to enhanced pancreatic function: increasing insulin secretion, improving pancreatic mass and reduced apoptosis, thereby ameliorating insulin resistance. These findings initially clarify the mechanism by which dietary extruded maize starch-chlorogenic acid complexes alleviated insulin resistance and provided a better understanding of the influence of chlorogenic acid on starch that promotes body blood glucose homeostasis.