Method for improving yogurt coagulability through glutamine transaminase

Abstract

The invention discloses a method for improving yogurt coagulability through glutamine transaminase, and belongs to the technical field of milk product processing. The method comprises the following technological steps of 1, raw milk microfiltration; 2, mixing, wherein 0.001-0.005 mg / kg of casoid flour is added into the raw milk, and the mass fraction of alpha-casein in the casoid flour is 70% or above; 3, homogenizing; 4, pasteurization; 5, inoculation, wherein the sterilized milk is inoculated with lactic acid bacteria, 0.001-0.005 mg / kg glutamine transaminase is added, and even mixing is performed; 6, fermentation. Compared with traditional set yogurt, by means of the method, the yogurt has better coagulability and smoothness, and whey precipitation is reduced.

Description

technical field [0001] The invention belongs to the technical field of dairy product processing, and in particular relates to a method for improving the solidification of yoghurt by utilizing transglutaminase. Background technique [0002] Transglutaminase (protein-glutamic acid-γ-glutamine transaminase, TransglutaminaseEC2.3.2.13, TGase), is an enzyme that catalyzes acyl transfer reaction, it uses glutamine residue γ- The amide group acts as an acyl donor, and when the acyl acceptor is the ε-amino group or primary amino group of a lysine residue in a polypeptide, it catalyzes the intramolecular or intermolecular cross-linking of proteins, the connection between proteins, amino acids, and peptide chains ; When water is an acyl acceptor, it can catalyze the hydrolysis of glutamine groups in protein molecules. The reaction catalyzed by TGase can occur both intermolecularly and intramolecularly. The factors that determine the degree of intermolecular cross-linking reaction ar...

AI Technical Summary

Problems solved by technology

In the above method for preparing solidified yoghurt, although vacuum concentrated milk is added to the raw milk, the protein content in the raw milk is increased, resulting in an increase in the gel content in the fermented yoghurt, and the stability of the yoghurt is improved to a certain extent; however, Adding vacuum concentrated milk to raw milk also increases the content of nutrients such as fat and minerals in raw milk, and the increase in fat and mineral content will lead to an imbalance in the raw milk system, which will further lead to the stability of fermented yogurt Sex will decrease

In addition, the above-mentioned preparation method without adding solidified yogurt also has the following problems: 1. Before heat sterilization, add concentrated milk to raw milk, and the β-lactoglobulin in the raw milk is abnormally sensitive to heat. It is easy to deteriorate, which further leads to the deterioration of the stability of yogurt

2. This method is time-consuming and expensive

This method only focuses on the ratio of protein, and does not make an in-depth description of the substrate, enzyme concentration, activator, etc. of the biological enzyme-catalyzed reaction.