---

Dual properties of Enterococcus on the one hand, have made them suitable and accepted bacteria as starter cultures in the production of food products and probiotics, but on the other hand, because of antibiotic resistance properties and virulence factors, has resulted in concerns about the consumer’s health. In this study, in order to evaluate the antibiotic resistance of enterococcal isolates, the disk diffusion method was used. Also, culture-based method was applied for hemolytic and gelatinase activities. The results of the inhibition zone of Enterococcus isolates against common clinical antibiotics revealed that the isolates were sensitive to Vancomycin and Ampicillin and are resistant to Kanamycin and Streptomycin. The isolates showed very little resistance to Tetracycline and Chloramphenicol and none of the isolates were resistant to all tested antibiotics. Results obtained from hemolytic activity of isolates showed that none of examined isolates were capable of blood hemolysis and consequently no clear zone of inhibition in medium containing sheep’s blood. All of isolated were γ hemolytic and they have no hemolytic activity. Gelatinase activity results confirmed that none of the isolates are able to produce clear zone in tryptone soy agar containing gelatin.

 

---

Fermentation is one of the oldest techniques in food preservation, this process is defined as the biological activity of microorganisms to improve sensory, organoleptic and nutritional properties and produce a range of metabolites that inhibit the growth of unwanted microbial flora. As a result, fermented products have a shelf life substantially higher than raw materials and also have very beneficial effects on health. In this research, ginger in 4 and 8 % levels  and yogurt whey in 0 and 3 % levels, were added to the carrots and evaluated during of 0,4, 8, 16, 24 and 32 days of fermentation. The results showed that by adding 4% ginger, pH, mold and yeast count and L* index decreased, acidity, total count, lactic acid count, a* and b* color indexes and overall acceptance increased. In contrast, the addition of 8% ginger had a negative effect on the studied parameters and decreased the overall acceptance and enumeration of lactic acid bacteria. Addition of yogurt (3%) decreased pH, mold and yeast count and L* index, but increased acidity, total count also color indices a* and b* and overall acceptance. In the non-yogurt and non-ginger sample from the beginning to the end of the storage period, pH, total count and mold and yeast counts increased steadily, and overall acidity and acceptance decreased. Whereas in the samples containing ginger and yogurt, the pH and count of mold and yeast decreased as the fermentation time increased to the 16th day and overall count increased, lactic acid bacteria, acidity and total acceptance. According to the results of this study, using 4% ginger, 3% yogurt and 16 days fermentation time to increase shelf life and lactic acid bacteria and improve the sensory characteristics of fermented carrots.

---

Kaymak or Sarshir, a traditional dairy product, is served in Iranian breakfast. The aim of this study was to investigate the fatty acids profile, physicochemical properties (texture, color, pH, acidity, the content of dry matter, fat and protein) and organoleptic aspects of Gilanvand and Dalirankaymaks in comparison to the heavy cream. To study more closely the texture and appearance differences of these products, scanning electron microscope (SEM) images were also prepared. The obtained results showed that the contents of fat and dry matter in heavy cream were higher than the kaymaks; however, Gilanvandkaymak had the highest protein content, acidity, and b*-value. Based on the study of the fatty acids profile, palmitic acid and cis-oleic acid were recognized as the most dominated saturated and unsaturated fatty acids, respectively. Microstructural analysis of SEM revealed that the structure of the protein in the fat field was compact, irregular and abundant in Gilanvandkaymak which influenced the product properties. The hardness, gumminess, and adhesiveness of the heavy cream were highest in comparison to the kaymaks. The Gilamvandkaymak obtained higher scores in evaluating the taste and total acceptance. In conclusion, it can be mentioned that the Gilamvandkaymak will have high potential in marketability by considering its higher protein content as well as total acceptance.

---

In the present study, simultaneous evaluation for the survival ability of probiotic bacteria at pH 2.5, viability in the presence of pepsin-pancreatin, resistance to bile salt, Adhesion ability, bacterial resistance against antibiotic substances with measuring of minimum inhibitory concentration, auto-aggregation and co-aggregation with interference of (Escherichia coli (NCTC 12900 O157:H7), Salmonella enterica (ATCC 13076) and Listeria monocytogenes (ATTC 7644)) were investigated. In the test of Acid tolerance, it was found that all the strains except LF 55, 61 and F had high viability. Strains LF 56, LF 57, LF 55, O, F and strains LF 56, LF 57 and A7 showed that had the most resistant against pancreatin and in the presence of pepsin, respectively. Furthermore, all of the strains except La5, 52 and 49 were highly resistant to bile salts. Among the 19 strains, Lactobacillus gasseri had the highest adhesion ability (62.90%). Strain Lactobacillus plantarum LF 56 and Lactobacillus gasseri 54 C showed that had the highest potentials for auto-aggregation and co-aggregation (75.31% and 33%) on three pathogens, respectively. Several strains of Lactobacillus plantarum were sensitive to the studied antibiotic substance. However, strains M8 and M11 were resistant to Kanamycin and Chloramphenicol, and also, LF 55 and D showed high resistance against Ampicillin and Chloramphenicol, respectively. It was, moreover, found that Kanamycin, Tetracycline and Chloramphenicol had no significant influence on strains 61. It was demonstrated that Lactobacillus gasseri had medium resistance to Ampicillin, Erythromycin and Tetracycline, while Lactobacillus fermentum showed highly resistance to Ampicillin and Erythromycin. According to the results, human-isolated Lactobacillus gasseri gained the high scores in terms of probiotic properties as compared with other strains. Therefore, Lactobacillus gasseri can potentially protect epithelium tissue of intestine against pathogenic bacteria and it is a preferred candidate for prophylactic purposes, preventing of intestine infections and increasing of body immune system.