Investigation of some technological properties of Enterococcus isolates in Iranian Motal cheese

Subject Areas : Experimental Studies

Fardin Kouhi ¹ , حمید میرزائی ² , yousef Nami ³ , Jalil Khandaghi ⁴ , Afshin Javadi ⁵

1 - Department of Food Hygiene, Faculty of Veterinary Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran.
2 - هیت علمی و معاون آموزشی و تحصیلات تکمیلی
3 - Department of Food Biotechnology, Branch for Northwest & West region, Agricultural Biotechnology Research, Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
4 - Department of Food Science and Technology, Sarab Branch, Islamic Azad University, Sarab, Iran.
5 - Department of Food Hygiene, Faculty of Veterinary Medicine, Tabriz Medical Sciences, Islamic Azad University, Tabriz, Iran.

Received: 2022-09-20 Accepted : 2022-11-28 Published : 2023-03-21

Keywords: Enterococci, Technological features, Proteolytic activity, Amylolytic activity, Diacetyl production,

Abstract :

The existence of different species of Enterococcus, which have a significant effect on the technological characteristics of cheese, particularly its flavor, has been established in milk and dairy products. This study aimed to explore some of the most significant technological features of Iranian Motal cheese-derived Enterococcus isolates with probiotic characteristics. For this, first the growth rates of Enterococcus isolates at 25, 30, 37, and 43 °C were measured, and their ability for acidification was then assessed by measuring pH and acidity by incubation at the optimal temperature for zero, 4, 8, 24, 48 and 72 hours. Subsequently, enzymatic aspects related to technological features including proteolytic and amylolytic activity as well as diacetyl production were evaluated. The results showed that the growth rates of 3TB and 7KB strains belonging to E. durans and E. faecium were greater at 30 °C and that other isolates had the maximum growth rates at 43 °C. Beginning with the fourth hour of incubation, the examined enterococci significantly decreased pH and increased acidity so that, all of the isolates were able to coagulate milk within 72 hours of incubation at the proper growth temperature, with the exception of the 3TB and 7KB strains. It was also observed that isolates 5C, 1D and 3B had all three desired technological characteristics. Overall, examined isolates, particularly the 5C, 1D, and 3B strains, can be employed as an adjunct culture for the manufacture of fermented dairy products such as various cheese types due to their appropriate technological properties.