Characterization and improvement of rheological properties of sodium caseinate glycated with galactose, lactose and dextran

Abstract

The aim of this work was to investigate the effect of non-enzymatic glycosylation with galactose, lactose, and kDa dextran on the rheological properties of sodium caseinate. To promote the formation of covalent complexes, the reaction was done in solid state (aw=0.67), pH 7.0 (0.1 M sodium phosphate buffer), and temperature set at 50 and 60ºC. The progress of Maillard reaction was indirectly traced by measuring the formation of the Amadori compound, through furosine (2-furoylmethyl-lysine) analysis, and brown polymers, and the resulting glycoconjugates were characterized by LC/ESI-MS and SEC. Results showed a higher reactivity of galactose than lactose and dextran to form the glycoconjugates, due to its smaller molecular weight. Glycation with galactose and lactose increased the viscosity of caseinate and also altered its flow characteristics from Newtonian to shear-thinning. Oscillatory testing showed a higher elastic modulus (G") in glycoconjugates when compared to non-glycated caseinate, especially with galactose, where a gel like behavior was observed after long incubation times. Glycation with dextran did not produce substantial improvements in the rheological properties of caseinate, probably due to the limited extent of the reaction. Our results show that by controlling the rate and extent of the Maillard reaction is a technologically feasible operation to improve the viscosity and gelling properties of sodium caseinate-based ingredients.

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

“…Such buffers frequently contain urea [30,53,89,91,131], SDS [115,132], or guanidine hydrochloride [116]. Using non-denaturing buffers for studying sodium caseinate has been reported to result in an additional high molecular weight fraction composed of mainly non-covalently associated aggregates [89,133]. To cleave disulphide bonds reducing agents such as dithiothreitol or β-mercaptoethanol are added to ensure separation only according to the cross-linking reaction that is studied.…”

“…Similar to gel electrophoresis, the most simple application of SEC under denaturing and reducing conditions is for verification that polymerisation occurred, e.g., [54,116,133,134,147]. In several studies, Bönisch et al used SEC to investigate the action and inactivation of an inhibitor of Another limitation is that whey proteins may be less effectively separated from caseins.…”

“…Similar to gel electrophoresis, the most simple application of SEC under denaturing and reducing conditions is for verification that polymerisation occurred, e.g., [54,116,133,134,147]. In several studies, Bönisch et al used SEC to investigate the action and inactivation of an inhibitor of TGase indigenous to milk [135][136][137], and to show that casein polymerisation by transglutaminase declines during yoghurt fermentation as the enzyme loses its activity below pH 5 [138].…”

Modifications of structures and functions of caseins: a scientific and technological challenge

“…In another publication, the same team (Darewicz et al 1999b) reported structural changes deduced by modification of absorption spectra in UV and a better heat stability of β-casein after its glycation. Corzo-Martinez et al (2010) worked on the characterization and improvement of rheological properties of glycated sodium caseinate with galactose, lactose, and dextran. They showed a higher reactivity to form glycoconjugates for galactose compared to lactose and dextrans, due to its smaller molecular weight.…”

Acid-Induced Aggregation and Gelation of Bovine Sodium Caseinate-Carboxymethylcellulose Mixtures

“…NaCAS is commonly employed as additive in a great variety of food products because of its high emulsifying, water-binding and gelation capabilities, its heat stability and its contribution to the food texture and juiciness. Waterholding capacity and gelling properties are used to improve rheological properties, texture, stability, and appearance of many food products such as processed meats, surimi, cheese, www.intechopen.com yogurt and confectionary products (Corzo-Martínez et al, 2010). Some of these properties make caseinates useful and desirable ingredients in the preparation of bakery and confectionery products, where they can be used as milk substitutes (Gaucheron, 1997).…”