High-pressure homogenization of gelatin Alteration of the physicochemical and interfacial properties of gelatin after high-pressure homogenization

Abstract

Abstract The aim of the present study was to investigate the effects of high-pressure homogenization (HPH) on the functional, physicochemical, and structural properties of gelatin. Regarding this goal, gelatin was prepared at concentrations of 3, 6, and 9% and homogenized at 100 MPa via single, double, and triple passes. The FTIR and sulfhydryl content results indicated that HPH could destroy hydrogen bonds, leading to the protein unfolding after a single HPH cycle. Based on the CD spectroscopy, the structural packing of gelatin was altered after HPH treatment. Also, the bathochromic shift of gelatin λmax at UV spectra confirmed protein unfolding after a single pass. As a result of this process, the microstructure of gelatin gel was altered, and the pore shape changed from a polygon, a well-oriented shape to an unordered structure. The protein unfolding could increase emulsifying and foaming capacity and stability. In contrast, the strain sweep and temperature sweep of gels indicated that the HPH treatment of gelatin had an undesirable effect on gel strength and decreased the elasticity and viscosity of the gel. Therefore, HPH will be a promising method to promote the functional properties of gelatin for its application in the food industry.