Effect of microbial transglutaminase crosslinking on the functional properties of yak caseins: a comparison with cow caseins

Abstract

Microbial transglutaminase (mTGase) crosslinking is a useful method for significantly improving the physical functionality of proteins. This study focused on the effect of mTGase modification on the functional properties of yak and cow caseins, including solubility, emulsifying property, water and oil absorption capacity, foaming property, and stability in the presence of Na + , Ca 2+, and Mg 2+. The results showed that the crosslinking degree of yak and cow caseins differed at the same mTGase concentration, but the change in functional properties of cow and yak caseins was similar. After mTGase crosslinking, the solubility of caseins decreased, while the emulsifying properties increased because of casein polymerization. MTGase crosslinking was very effective in improving water and oil absorption properties, stability in the presence of Na + , Ca 2+, and Mg 2+, and foaming activity, but did not affect the foam stability of cow acid caseins (caseins content of 94.22 %, w/w) and yak acid caseins (caseins content of 94.28%, w/w). The results could be used as a reference for selecting the proper modification method to improve the predetermined functional properties of caseins according to industrial processing requirements.

Microstructure of transglutaminase-induced gelatin-natamycin fungistatic composite films

“…Transglutaminase (TGase, EC 2.3.2.13,c-glutamyl-peptide, aminec-glutamyl transferase) from microorganisms has been widely applied in crosslinking. [19] It catalyses de-amidation, acyl transfer reactions, and crosslinks with protein intra-chain or inter-chain glutamine, to provide acyl peptide residues as acyl donors. [20] TGase can alter food matrices, generating improved texture and stability of food products, such as temperature, emulsifying property, gelation capacity, and other properties.…”

Microbial transglutaminase enhances antioxidant activity of yogurt through altering pattern of water‐soluble peptides and increasing release of amino acids

“…The mechanism behind lipid peroxidation inhibition assay is that an antioxidant can scavenge lipid‐derived radicals in a lecithin emulsion system (Power et al ., ). Therefore, an antioxidant with a better hydrophobic and emulsifying property could exhibit a better lipid peroxidation inhibitory property (Yang et al ., ). In this study, an increase in the peptide molecular weight did not result in an increase in their lipid peroxidation inhibitory feature except for the first peptide fraction (>30 kDa) (Fig.…”

“…These indicated that the microbial transglutaminase might alter the cross‐linking location of amino acids in the sequence of peptides, which resulted in the formation of more hydrophobic sites in the peptides (O'Sullivan et al ., ). Besides, the microbial transglutaminase has also been reported to play a positive role in enhancing the emulsifying property of peptides through inter‐ and/or intramolecular polymerisation of peptides (Yang et al ., ). Such interactions could form a barrier in the oil–water interface to block interactions between free radicals and lipid, which could prevent lipid peroxidation (Donnelly et al ., ).…”

“…Transglutamination is a reaction by which an isopeptide bond is formed between a free amine group and the acyl group at the side chain of protein‐bound glutamine under the activity of transglutaminase (Kieliszek & Misiewicz, ; Ibrahim et al ., ). Microbial transglutaminase has been widely applied in the biotechnological field to modify proteins (Yang et al ., ). For example, microbial transglutaminase resulted in the formation of low molecular weight peptides during the hydrolysis of bovine casein, and these low molecular weight peptides play a primary role in the DPPH radical scavenging activity (Guo et al ., ; Irshad et al ., ; Power et al ., ; Song et al ., ).…”

“…It has been reported that yogurt produced from milk fermentation with appropriate amounts of microbial transglutaminase exhibited stronger gel strength, better water‐holding capacity, and higher viscosity with a reduction in the yogurt syneresis (Fargemand et al ., ; Bönish et al ., ; Wróblewska et al ., ; Abou‐Soliman et al ., ). Meanwhile, the solubility, emulsifying activity and sensibility of casein in milk can be improved with the appropriate transglutaminase treatment (Yang et al ., ). However, excessive amount of microbial transglutaminase applied to milk fermentation has been reported to result in a coarser gel network with an unfavourable acceptability (Jaros et al ., ).…”