Microbiological and Chemical Properties of Siahmazgi Cheese, an Iranian Artisanal Cheese: Isolation and Identification of Dominant Lactic Acid Bacteria

Abstract

In this study, the chemical and microbiological properties of Siahmazgi cheese, an Iranian artisanal cheese made of unheated ewe and goat milk without addition of starter culture, were evaluated. The pH of the samples ranged from 4.76 to 5.18. The average numbers of total viable count and lactic acid bacteria (LAB) in cheese samples were 3.7 × 10 6 and 6.9 × 10 6 cfu/g, respectively. Coliforms and Enterobacteriaceae were absent in all the samples. A total of 125 LAB isolates were selected according to their Gram-positive and catalase-negative characteristics, out of which 23 strains were cocci and 102 were lactobacilli. Identification of the selected isolates was done through biochemical tests and 16s rDNA sequencing. Isolated strains were identified as Lactobacillus plantarum group (41.6%), Lactobacillus brevis (39.2), Lactobacillus parabuchneri (0.8%), Enterococcus faecium (13.6%), Enterococcus durans (3.2%) and Pediococcus parvulus (1.6%). The results of this study showed the microbiological diversity of traditional Siahmazgi cheese. PRACTICAL APPLICATIONSExploring the microbiological diversity of traditional dairy products is required for selection of appropriate strains to manufacture the products with consistent quality and original taste on industrial scale.

Technological properties ofLactobacillus plantarumstrains isolated from Siahmazgi cheese

“…Resistance of LAB strains to different salt concentrations is an index of salt concentrations used during the production of dairy products. Partovi et al () showed that the range of salt concentrations in Siahmazgi cheese were 3.76–5.22% as most of L. plantarum strains isolated from Siahmazgi cheese could grow at salt concentrations of 2–8%. Growth curve and behavior of L. plantarum strains in different environmental conditions have been shown in Figures .…”

“…Resistance of LAB strains to different salt concentrations is an index of salt concentrations used during the production of dairy products. Partovi et al (2015) showed that the range of salt concentrations .05). Surprisingly, specific growth rates of SC6 and SA32 strains showed no significant difference under different environmental conditions.…”

“…The author studied the microbial and chemical properties of Siahmazgi cheese for the first time and identified the majority of the LAB found using biochemical methods and 16s rDNA analysis (Partovi et al, ). L. plantarum was the major strain isolated from Siahmazgi cheese with 41.6% occurrence among the total LAB (Partovi et al, ). This microorganism has been isolated from a large number of traditional dairy products (Badis, Guetarni, Moussa Boudjema, Henni, & Kihal, ; Mathara, Schillinger, Kutima, Mbugua, & Holzapfel, ; Ztaliou, Tsakalidou, Tzanetakis, & Kalantzopoulos, ).…”

Investigating and Comparing the Physicochemical, Microbial and Sensory Characteristics of Traditional and Pasteurized Siahmazgi Cheese

“…Mirza Alizadeh et al, [6], evaluated the traditional cheese samples in Zanjan province, it was found that reducing pH to 4.2 caused the destruction of bacteria, including Staphylococcus aureus, in these cheeses. Partovi [7] also, mentioned a high rate of infection with Staphylococcus aureus in traditional Siahmazgi cheeses due to the use of raw milk and failure to comply with safety standards. Loghmanifar et al, [14] studied the Siahmazgi cheese samples in Rasht and found the 95% of the samples were infected with Staphylococcus aureus.…”

“…Cheese is divided in terms of solids content to very hard, hard, semi-hard and soft (the International cheese Codex). The Siahmazgi cheese is very hard with medium fat [7]. In general, Siahmazgi cheeses are important in terms of its quality and its economical values.…”