The Effect of Microbial Transglutaminase on the Viscosity and Protein Network of Kefir Made from Cow, Goat, or Donkey Milk

Abstract

In this study, we aim to decrease the fermentation time and to produce low-fat set-type kefir with adequate textural properties using microbial transglutaminase without inactivation. In addition, we reveal the effect of microbial transglutaminase, during and after fermentation, on kefir made with cow, goat, or donkey milk, which is a novel approach. Fermentation is followed by continuous pH and viscosity measurements; the final product is characterized by dry matter content, whey separation, protein pattern, and viscosity parameters, as well as gel firmness. The results show that already 0.5 U/g protein dosage of MTGase decreases pH levels independent of milk type, but MTGase does not influence the kinetics of fermentation. Apparent viscosity could be measured from different stages of fermentation depending on milk type (cow milk, 6 h; goat milk, 8 h; and donkey milk, 9 h). The final product characteristics show that the higher the casein ratio of the applied milk, the better the viscosity and gel firmness of the kefir due to the high reaction affinity of MTGase.

Comparison of quality properties of powder milk‐based camel cheese depending on calf rennet concentration and microbial transglutaminase

“…Cheese samples were prepared for SDS-PAGE analysis followed by a previously published method (Mbye et al 2021a). Gel electrophoresis was carried out according to our previous study (Darnay et al 2021) with slight modifications. Resolving gel solution (15%) was prepared by mixing 6 mL of 30% acrylamide/Bis solution (29:1), 2.7 mL of 2 M Tris HCl (pH 8.8), 75 μL of SDS solution 10% (w/v), 3.09 mL of deionised water, 75 μL of 10% APS (ammonium persulphate) and 9 μL of N,N,N 0 ,N 0 -tetramethylethylenediamine.…”

Comparison of quality properties of pasteurized milk‐based camel cheese depending on calf rennet concentration and microbial transglutaminase

“…Cheese samples were prepared for SDS-PAGE analysis followed by a previously published method (Mbye et al 2021a). Gel electrophoresis was carried out according to our previous study (Darnay et al 2021) with slight modifications. Resolving gel solution (15%) was prepared by mixing 6 mL 30% acrylamide/Bis Solution (29:1), 2.7 mL 2 M Tris HCl (pH 8.8), 75 μL of SDS solution 10% (w/v), 3.09 mL deionized water, 75 μL of 10% APS (ammonium persulphate) and 9 μL N, N, N 0 , N 0 -Tetramethylethylenediamine.…”