TITLE:
The Impact of Microbial Transglutaminase on the Quality and Antioxidant Activity of Camel-Milk Soft Cheese
AUTHORS:
Nagwa Hussein Ismail Abou-Soliman, Sameh Awad, Mahmoud Ibrahim El-Sayed
KEYWORDS:
Camel Milk, Soft Cheese, Transglutaminase, Texture and Yield, Antioxi-dant Activity
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.11 No.3,
March
5,
2020
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.