Gelation mechanism of Antrodia cinnamomea polysaccharide-polymerized whey protein hydrogel and its application in set-type yogurt.

The study developed a novel heat-induced composite hydrogel (10% PWP + 0-6% ACP) by integrating polymerized whey protein (PWP, 10% w/v) with Antrodia cinnamomea polysaccharide (ACP, 0-6% w/v) as a texture modifier for set-type yogurt, and to elucidate its gelation mechanism. ACP incorporation progressively increased particle size (53.34-113.30 nm), shortened gelation time (1263.0-822.5 s). Simultaneous rheology-fourier transform infrared spectroscopy, two-dimensional correlation spectroscopy, and molecular docking collectively revealed that hydrogen bonding dominated network formation. The amide I band shifted within 1625-1631 cm-1, confirming ACP-induced conformational changes in the protein backbone. Molecular docking demonstrated that 1,3-β-D-glucan was bound stably to α-lactalbumin (-6.2 kcal/mol) and β-lactoglobulin (-5.7 kcal/mol) through hydrogen-bonding networks. When applied to yogurt at 2% (w/v), the hydrogel improved water-holding capacity (34.60%), increased hardness (3.58%), and enhanced richness perception while reducing bitterness. The findings provides theoretical and technical support for utilizing PWP-ACP hydrogels as functional texture modifiers in yogurt.