预处理方式对绵羊皮明胶凝胶特性的影响OA

This study investigated the effects of three distinct pre-extraction treatments—acid,enzymatic and ultrasonic—combined with hot-water extraction on the yield,structural features,physicochemical properties,rheological behaviour,gel strength and functional performance of gelatin derived from dehaired sheep skins,with the aim of identi-fying an optimal processing strategy.Ultrasonic pretreatment produced the highest extraction yield(65.13％),significantly exceeding that of acid(42.31％)and enzymatic treatments(36.62％)(P<0.05).In contrast,acid pretreatment yielded the highest purity(92.4％),followed by the ultrasonic method(90％).Structural analyses revealed that gelatin from the ultra-sonic group retained the most intact collagen architecture:SDS–PAGE showed well-defined α-chains,FTIR spectra indi-cated greater hydrogen-bond preservation,and circular dichroism analysis revealed an α-helix content of 37.5％,markedly higher than those of the acid(5.3％)and enzymatic(10.6％)groups(P<0.05).In terms of rheological and gel-forming prop-erties,the ultrasonic group displayed superior melting temperature(39～42.7℃),dynamic viscosity,a higher proportion of high-molecular-weight fractions(≥10 kDa,75.68％)and greater gel strength(273.7 g).Its functional attributes—including emulsifying activity(12.46 m2/g),emulsion stability(842.13 min),foaming capacity(140.65％)and foam stability(20.94％)—were also significantly enhanced relative to the other treatments(P<0.05).Amino-acid profiles did not differ significantly among treatments(P>0.05),with glycine and proline remaining predominant.Collectively,these findings demonstrate that ultrasonic pretreatment simultaneously improves extraction efficiency,preserves molecular integrity and markedly enhances both gelation and interfacial properties,establishing it as a preferred strategy for producing high-quality sheep-skin gelatin and supporting its broader application in the food industry.