Hyaluronic acid modulates techno-functional and digestion properties of heat-induced ginkgo seed protein isolate gel

The industrial application of ginkgo seed protein isolated (GSPI) is limited by its poor gel performance. This study investigated the effects of pH (3.0, 5.0, 7.0) and molecular weight (50, 500, 1500 kDa) of hyaluronic acid (HA) on the physicochemical properties, textural characteristics, microstructure, and in vitro gastrointestinal digestion of heat-induced GSPI gels. The results indicate that gels formed at pH 3.0 may be suitable for individuals with dysphagia with storage and loss moduli lower than 15.8 Pa. The highest gel hardness was achieved by incorporating high molecular weight HA at pH 5.0 (100.4 g). At pH 7.0, GSPI gels with medium molecular weight HA exhibited the highest storage (28005 Pa) and loss moduli (8395 Pa). Fourier-transform infrared spectrum analysis revealed that increased pH fostered hydrogen bond formation, and interactions between protein molecules intensified with increasing HA molecular weight. HA promoted a more stable and compact network structure. In addition, the incorporation of HA accelerated the in vitro digestion rate by up to 70%. In summary, adjusting pH and utilizing HA with different molecular weights enables easy manipulation of the texture and digestibility of GSPI gels. These findings can provide a theoretical basis for the application of HA as a gel modifier in food and expand the application of GSPI in food processing.