Effect of dynamic ultra-high pressure homogenization on the structure and functional properties of whey protein

Abstract

The effects of dynamic ultra-high pressure homogenization (UHPH) on the structure and functional properties of whey protein were investigated in this study. Whey protein solution of 10 mg/mL (1% w/w) was prepared and processed by a laboratory scale high pressure homogenizer with different pressures (25, 50, 100, 150, 200, and 250 MPa) at an initial temperature of 25 °C. Then, the solution samples were evaluated in terms of secondary structure, sulfhydryl and disulfide bond contents, surface hydrophobicity, average particle size, solubility, foaming capacity, emulsifying activity, and thermal properties. It was found that the secondary structure of whey protein changed with the dynamic UHPH treatment. The interchange reaction between the disulfide bond and the sulfhydryl group was promoted and the surface hydrophobicity significantly increased. The functional properties of the whey protein accordingly changed. Specifically, after dynamic UHPH treatment, the average particle size of the whey protein and emulsion decreased while the solubility, the foaming capability and the emulsification stability increased significantly. The results also revealed that with the dynamic UHPH at 150 MPa, the best improvement was observed in the whey protein functional properties. The whey protein solubility increased from 63.15 to 71.61% and the emulsification stability improved from 195 to 467 min.

High‐pressure homogenisation—Lactobacillus induced changes in the properties and structure of soymilk protein gels

“…This indicates that some hydrogen bonds stabilising the protein secondary structure were disrupted during HPH treatment, leading to partial denaturation and unfolding of the protein molecules, unfolding the ordered structure of the protein, and an increase in the disordered system (Xu et al ., 2017). The rise of β‐sheet and β‐turn content indicated that HPH promoted the exposure of hydrophobic active sites and protein–protein hydrophobic interactions in the soy protein structure, which was beneficial in accelerating the formation of soluble aggregates in the denatured soybean protein molecule (Wang et al ., 2020).…”

Storage Drives Alterations of Proteomic and Protein Structural Properties in Rice (Oryza sativa L.)

“…Sulfhydryl is the most active amino acid side-chain group of protein degradation [ 20 ]. The protein oxidation level is always evaluated by the abundance of free sulfhydryl and disulfide bonds [ 17 , 21 , 22 ]. The free sulfhydryl content decreased significantly, and the disulfide bond content increased significantly in the stored samples ( Figure 1 ).…”

Effect of high pressure homogenization on aggregation, conformation, and interfacial properties of bighead carp myofibrillar protein

“…It manifested that HPH treatment induced the fracture of myofibrillar protein aggregates. Many studies stated that intense mechanical forces could cause the size reduction of protein aggregate, such as clam protein isolate (Wu et al., 2019b), cod protein (Ma et al., 2019), whey protein (Wang et al., 2020) and hazelnut meal proteins (Sarıcaoğlu et al., 2018). Due to the decrease of aggregate size, the increase of aggregate superficial area can promote the interaction between protein and solvent.…”

“…These mechanic forces have the ability to modify the aggregation state and conformation of proteins, and thus alter their functional property. Many food proteins have been processed by HPH to achieve targeted functionality (especially emulsifying and foaming properties), mainly including milk protein (Wang et al., 2020), legumes protein (Yang et al., 2018) and nut protein (Sarıcaoğlu et al., 2018). HPH treatment generally decreases particles into small size (Sarıcaoğlu et al., 2018).…”