Effect of Ultra-filtration Membrane Aperture on Storage Stability and Flavor of Bottled Huangjiu

During the storage and sale of bottled huangjiu, precipitation caused by non-biological factors frequently compromises consumer acceptance. Although ultrafiltration has been widely used to control huangjiu's non-biological stability, this treatment's impact on colloidal properties and precipitable components remains unclear. In this study, bottled huangjiu was treated with ultrafiltration membranes featuring pore sizes of 50, 30, 10, 5, and 3 kDa, monitoring colloidal stability parameters (turbidity, polyphenol turbidity, centrifugal sedimentation rate, particle size, and zeta potential) after 1, 150, and 270 days of storage. The precipitable components, antioxidant properties, physicochemical indices, and volatile and non-volatile substances of huangjiu in the later storage period (270 days) were determined, the sensory and color changes of huangjiu were evaluated, and the optimal pore size of ultrafiltration membrane was determined. Results demonstrated that ultrafiltration notably diminished turbidity, polyphenol-related turbidity, and centrifugal sedimentation rates in the huangjiu, significantly enhancing its storage stability. Both the 50 kDa membrane and smaller pore sizes yielded optimal treatment outcomes. Colloidal property assessments suggested that ultrafiltration may have eliminated large molecular proteins, resulting in a reduced mean particle size of the huangjiu colloid, a more uniform particle size distribution, and an elevated zeta potential. Over the storage period, the 50 kDa ultrafiltration membrane more effectively preserved the flavor and color of the huangjiu, whereas membranes with 30 kDa and smaller pore sizes caused varying degrees of flavor weakening and color lightening. The retention of antioxidant activity, volatile compounds, and non-volatile constituents decreased with smaller membrane pore sizes., The 50 kDa membrane had the least impact on functional components, volatile compounds, and non-volatile constituents. This study elucidates the comprehensive effects of ultrafiltration on colloidal stability, precipitable components, functional constituents, and sensory properties in bottled huangjiu. Considering stability enhancement, flavor preservation, and sensory acceptance, the 50 kDa ultrafiltration membrane showed the best application potential in solving the precipitation problem in huangjiu processing, providing scientific guidance for quality optimization.