List of Articles Proteolytic activity

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  1 - The study of Technological Characteristics of Lactobacilli Isolated from Traditional Sheep and Cow Cheeses of Sangesar
  M. Hasani S.A. Mortazavi M. Hasani N. Ahmadi Kamazani M. Ghotbi
  Introduction: Lactobacillus genus is classified in the large group of lactic acid bacteria. All the organisms are gram positive and produce lactic acid by fermentation. These bacteria are found naturally in various foods and have been considered as a natural preservativ More

  Introduction: Lactobacillus genus is classified in the large group of lactic acid bacteria. All the organisms are gram positive and produce lactic acid by fermentation. These bacteria are found naturally in various foods and have been considered as a natural preservative in some of the traditional foods since the ancient times. The aim of this study is to evaluate the technological properties and usability of lactobacilli isolated from the traditional cow and sheep cheeses as starters in cheese and other fermented products. Materials and Methods: In this study, 12 Lactobacillus strains were obtained from the six traditional sheep and cow cheeses in Sangesar area (Semnan, Iran). Lactobacillus strains were confirmed by phenotypic tests. The isolated strains were evaluated as starter by the technical tests such as growth, acid production, proteolytic, amilolytic and autolytic activities. Results: The optimum growth temperature was at 30˚C for all the isolated strains. The highest growth rate was in the two isolated strains from cow cheese; LB2-1and LB2-5, respectively. The proteolytic activity was observed in three isolated strains from cow cheese; LB2-1, LB2-4and LB2-6, and the strain isolated from sheep cheeses (LB1-3). Amilolytic activity was observed in none of the isolated strains. The highest rate of acid production and autolytic activity was observed in isolated strain from cow cheeses (LB2-2) and the strain isolated from sheep cheese (LB1-1). Conclusion: In this study the isolated lactobacilli from traditional Sangesar cheeses showed desirable technological characteristics and high potential for application as a starter Manuscript profile
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  2 - Investigation of some technological properties of Enterococcus isolates in Iranian Motal cheese
  Fardin Kouhi حمید میرزائی yousef Nami Jalil Khandaghi Afshin Javadi
  10.30495/jfm.2022.1968051.1790
  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 technol More

  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. Manuscript profile