The effect of heat treatment on the microstructure and functional properties of whey protein from goat milk

摘要

This work investigated the effects of thermal processingmethods commonly used in the dairy industry andprolonged treatment at different temperatures on thedenaturation, microstructure, and functional propertiesof whey proteins (WP) from goat milk. The completedenaturation of WP was observed in goat milk treatedat 85°C for 30 min, and at a higher temperature(>85°C), a considerable amount of WP was easilydenatured. The low temperature, long time treatmenthad the least effect on the secondary structure, whereasultra-high temperature treatment had the greatest effect,and the amount of regular structures decreasedgradually with prolonged time. The most serious morphologicaldamage occurred after treatment at 85°C for30 min, which was consistent with the denaturationresults. This result indicated that the denaturationdegree, particle size, surface hydrophobicity, and microstructurehad a strong influence on the functionalproperties of WP from goat milk after heat treatment.The heat treatment of goat milk at 65°C for 30 min and85°C for 15 s increased the particle size, turbidity, zetapotential, and surface hydrophobicity of WP, and theseincreases ensured that the WP had a good emulsifyingactivity index, water-holding capacity, oil-holding capacity,foaming capacity, and foam stability. This studysimulated the heat treatment conditions used in actualproduction, aiming to provide a theoretical basis forindustry.