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

Abstract

This work investigated the effects of thermal processing methods commonly used in the dairy industry and prolonged treatment at different temperatures on the denaturation, microstructure, and functional properties of whey proteins (WP) from goat milk. The complete denaturation of WP was observed in goat milk treated at 85°C for 30 min, and at a higher temperature (>85°C), a considerable amount of WP was easily denatured. The low temperature, long time treatment had the least effect on the secondary structure, whereas ultra-high temperature treatment had the greatest effect, and the amount of regular structures decreased gradually with prolonged time. The most serious morphological damage occurred after treatment at 85°C for 30 min, which was consistent with the denaturation results. This result indicated that the denaturation degree, particle size, surface hydrophobicity, and microstructure had a strong influence on the functional properties of WP from goat milk after heat treatment. The heat treatment of goat milk at 65°C for 30 min and 85°C for 15 s increased the particle size, turbidity, zeta potential, and surface hydrophobicity of WP, and these increases ensured that the WP had a good emulsifying activity index, water-holding capacity, oil-holding capacity, foaming capacity, and foam stability. This study simulated the heat treatment conditions used in actual production, aiming to provide a theoretical basis for industry.

Foaming characteristics and impact of ethanol pretreatment in drying behavior and physical characteristics for avocado pulp powder obtained by foam mat drying

“…According to Zhao et al. (2020), goat milk can be effectively used as an ingredient in the food industry because of its outstanding interfacial properties and is usually used as an emulsifying and foaming agent (Nguyen et al., 2020; Roy et al., 2020). According to W. P. Silva et al.…”

“…Emustab R is one of the most used emulsifiers used in the food industry (Gomes et al, 2017a), and other ingredients such as powdered albumin, liquid egg white, protein isolates, and powdered milk have also been used in the production of fruit pulp foam (Benković et al, 2019;Col et al, 2021;Tavares et al, 2020). According to Zhao et al (2020), goat milk can be effectively used as an ingredient in the food industry because of its outstanding interfacial properties and is usually used as an emulsifying and foaming agent (Nguyen et al, 2020;Roy et al, 2020). According to W. P. , in the presence of goat's milk, the emulsifier molecules interact with other, probably hydrophobic, milk molecules, causing the product to expand in volume.…”

Effect of Heat Treatment on the Property, Structure, and Aggregation of Skim Milk Proteins

“…It can also improve the functional properties of some specific dairy products, such as yogurt and cheese (2,3). Heat treatment has a significant effect on the protein network of dairy product (4). It is well-known that heat-treated milk can form a gel network with better strength and firmness in a shorter time (5).…”

Comparative study on the microstructure and functional properties of casein in goat milk processed by different methods

“…Among the four heated groups, the content of β‐Lg was the lowest in HTST, followed by UHT, and was higher in LTLT and UP. This result was consistent with the previous research on whey protein and confirmed that heating treatment changed the protein monomer, resulting in interaction between CN and whey protein in goat milk and the formation of CN‐whey protein polymer (Sutariya et al ., 2017; Zhao et al ., 2020). Furthermore, the aggregation degree of the protein–protein interaction was affected by the temperature and time of heat processing.…”

“…The functional properties, including emulsifying activity index (EAI), emulsion stability (ES), foaming capacity (FC), foam stability (FS), water holding capacity (WHC) and oil holding capacity (OHC), were determined according to the method described by Zhao and Li (Zhao et al ., 2020; Li et al ., 2020).…”