The Impact of Microbial Transglutaminase on the Quality and Antioxidant Activity of Camel-Milk Soft Cheese

Nagwa Hussein Ismail Abou-Soliman,Sameh Awad,Mahmoud Ibrahim El-Sayed

doi:10.4236/fns.2020.113012

Abstract

This study aimed at investigating the impact of adding microbial transglutaminase (MTGase) after rennet addition on some properties of fresh soft cheese made from camel milk. MTGase was added to milk at concentration of 80, 100 and 120 U/L after 20 and 30 min of renneting. The chemical composition, yield, hardness, antioxidant activity and sensory properties of cheese were estimated. Enzymatic protein crosslinking was analyzed by SDS-PAGE. Results revealed that MTGase-treated cheeses were higher in moisture and lower in protein content compared to control. In addition, the concentration of MTGase and time of addition significantly (P 0.05) impacted these parameters. Among treated cheeses, samples with 80 U of MTGase and addition time of 20 min were the highest in total solids and protein content. Adding MTGase significantly (P 0.05) increased the cheese yield, however, increased MTGase concentration at any time of addition did not improve it. The electrophoretic patterns of MTGase-cheese proteins showed a reduction in the intensity of caseins bands and the appearance of new protein fractions with high molecular weights. However, the changes in the intensity of the whey proteins bands were not sufficiently clear as caseins. The cheese hardness was significantly (P 0.05) affected by adding MTGase. Cheese containing 80 U of MTGase had the highest hardness value compared to control and other treated samples. The antioxidant activity of cheese was negatively influenced by adding the enzyme. The use of MTGase enhanced the mouthfeel, texture and overall acceptability of cheese. However, the effect of MTGase concentration and addition time was not significant (P > 0.05) on the sensory attributes. In conclusion, adding MTGase to milk at concentration of 80 U after 20 min of renneting is recommended to improve the yield, textural and some sensory properties of fresh soft cheese made from camel milk.

Highlights

Camel milk plays an important role in nutrition, in hot and dry zones, in which milk is consumed fresh or as fermented milk
This study aimed at investigating the impact of adding microbial transglutaminase (MTGase) after rennet addition on some properties of fresh soft cheese made from camel milk
The aim of the present study was to investigate the effect of adding MTGase, with different concentrations, after renneting on the yield, texture, quality and antioxidant activity of soft cheese made from camel milk

Summary

Introduction

Camel milk plays an important role in nutrition, in hot and dry zones, in which milk is consumed fresh or as fermented milk. Camel milk fails to form an actual curd structure, but just flakes that lack firmness are produced [3] as well as the cheese yield is low [4]. All of these problems are related to the nature of camel milk. Camel milk often has a lower content of dry matter, casein [3]. It contains smaller fat globules [5]. The ratios of casein fractions to whole casein in camel milk can negatively impact the curd coagulation and firmness, as β-, αs1- and κ-caseins constitute about 65%, 21% and 3.47%, respectively of whole casein [6]

Objectives

Methods

Results

Conclusion