Designing microstructure into xanthan gum-enriched acid milk gels

RESEARCH OF RHEOLOGICAL PROPERTIES OF COMPONENTS OF THE DEVELOPED MILK-CONTAINING THERMOSTABLE FILLINGS

The research is devoted to the determination of the properties of the components of the developed milk-containing thermostable fillings and the establishment of the dependence of the effective viscosity on the temperature of the model system. In the work, studies are carried out for a model system containing xanthan gum; a model system containing tara gum; model system containing gelatin; a model system containing xanthan gum and tara gum; a model system containing xanthan gum, tara gum and gelatin; a model system containing xanthan gum, tara gum and sugar; model system containing xanthan gum, tara gum, skimmed milk powder; a model system containing xanthan gum, tara gum and maltodextrin. In this work, the dependence of the effective viscosity on the temperature of the model system is established. To achieve the aim, the following objectives are set: - determination of the dependence of the effective viscosity on the temperature of model systems with xanthan gum, tara gum, gelatin, sugar, skimmed milk powder and maltodextrin with different concentrations of these components; - establishment of the temperature range in which a sharp increase in the effective viscosity of the investigated model systems begins. An increase in the temperature of the system prevents gelation due to an increase in the intensity of Brownian motion and a decrease through it in the duration of the existence of bonds that arise between macromolecules. At the same time, a decrease in temperature promotes gelation, since this increases the number of contacts between macromolecules, which contributes to an increase in the strength of the so-called spatial network. In the article, the dependences of the effective viscosity on the temperature of model systems with xanthan gum, tara gum, gelatin, sugar, skimmed milk powder and maltodextrin with different concentrations of these components are obtained. Based on the obtained dependences, the established temperature ranges in which a sharp increase in the effective viscosity of the studied model systems begins

Physiochemical, texture properties, and the microstructure of set yogurt using whey protein-sodium tripolyphosphate aggregates as thickening agents

BACKGROUND

Polymerized whey protein-sodium tripolyphosphate can be induced to gel in an acidic environment provided during fermentation. The variety of thickening agent has an influence on texture that is an essential aspect of yogurt quality affecting consumer preference. Similar to polysaccharide stabilizers, the cold gelation properties of whey proteins can improve the body texture of yogurt products. Polymerized whey protein-sodium tripolyphosphate could be a favorable and interesting thickening agent for making set yogurt.

RESULTS

The effects of whey protein isolate (WPI), heat-treated whey protein-sodium tripolyphosphate (WPI-STPP), heat-treated WPI and pectin on the storage properties and microstructure of yogurt were investigated. All samples were analyzed for syneresis, pH, titratable acidity, viscosity, texture profile and microstructure during storage. The results showed that incorporating heat-treated WPI-STPP had a significant impact on syneresis (32.22 ± 0.60), viscosity (10 956.67 ± 962.1) and hardness (209.24 ± 12.48) (p < 0.05) with uniform body texture.

CONCLUSION

Yogurt fermented with modified WPI-STPP had higher levels of protein and better hardness compared with yogurt using pectin. The microstructure was observed to be a uniform and denser, complicated network. Heat-treated WPI-STPP may be useful for improving yogurt texture. © 2016 Society of Chemical Industry.

Effects of addition of hydrocolloids on the textural and structural properties of high-protein intermediate moisture food model systems containing sodium caseinate

High-protein intermediate moisture food (HPIMF) containing sodium caseinate (NaCN) often gave a harder texture compared with that made from whey proteins or soy proteins, due to the aggregation of protein particles.

Effect of Xanthan Gum on the Rheological Behavior and Microstructure of Sodium Caseinate Acid Gels

The aim of this work was to study the effect of xanthan gum (XG) on the gelation process of bovine sodium caseinate (NaCAS) induced by acidification with glucono-δ-lactone (GDL) and on the mixed acid gel microstructure. Before GDL addition, segregative phase separation was observed in all the NaCAS-XG mixtures evaluated. The gelation process was analyzed by using a fractional factorial experimental design. The images of the microstructure of the mixed acid gels were obtained by conventional optical microscopy and the mean diameter of the interstices was determined. Both the elastic character and the microstructure of the gels depended on the concentrations of XG added. As XG concentration increased, the kinetics of the gelation process was modified and the degree of compactness and elasticity component of the gel network increased. The microstructure of gels depends on the balance among thermodynamic incompatibility, protein gelation and NaCAS-XG interactions.