The Use of Trisodium Citrate to Improve the Textural Properties of Acid-Induced, Transglutaminase-Treated Micellar Casein Gels.

Hongliang Li,Yuan Li,Fazheng Ren,Chong Chen,Chang Yang,Zhishen Mu,Pengjie Wang

doi:10.3390/molecules23071632

Abstract

In this study, the effect of trisodium citrate on the textural properties and microstructure of acid-induced, transglutaminase-treated micellar casein gels was investigated. Various concentrations of trisodium citrate (0 mmol/L, 10 mmol/L, 20 mmol/L, and 30 mmol/L) were added to micellar casein dispersions. After being treated with microbial transglutaminase (mTGase), all dispersions were acidified with 1.3% (w/v) gluconodelta-lactone (GDL) to pH 4.4–4.6. As the concentration of trisodium citrate increased from 0 mmol/L to 30 mmol/L, the firmness and water-holding capacity increased significantly. The final storage modulus (G′) of casein gels was positively related to the concentration of trisodium citrate prior to mTGase treatment of micellar casein dispersions. Cryo-scanning electron microscopy images indicated that more interconnected networks and smaller pores were present in the gels with higher concentrations of trisodium citrate. Overall, when micellar casein dispersions are treated with trisodium citrate prior to mTGase crosslinking, the resulted acid-induced gels are firmer and the syneresis is reduced.

Highlights

Yogurt is a very popular fermented milk-based product worldwide due to its nutritional and sensory properties [1]
These findings suggested that the firmness of GDL-induced micellar casein gels was positively
These findings suggested that the firmness of GDL-induced micellar casein gels was positively related related to the amount of trisodium citrate

Summary

Introduction

Yogurt is a very popular fermented milk-based product worldwide due to its nutritional and sensory properties [1]. The acid-induced milk gels often have textural defects such as low firmness (fragile structure) and syneresis (low water holding capacity) during storage or following mechanical damage [2], which greatly reduce their sensory properties. The development of acid-induced milk gels with greater firmness and water holding capacity is an important issue. The firmness and water-holding capacity of acid-induced milk gels are closely related to their network structures. The primary building blocks of acid-induced milk gel network structures are proteins. Microbial transglutaminase (mTGase) is an enzyme widely used to form covalent links between individual protein molecules [3,4,5,6]. The textural properties of acid-induced gels prepared

Methods

Results

Conclusion