[Prevalence of Staphylococcus aureus resistant to methicillin in traditional cheese and cream: a study in city of Tabriz, Iran]

In recent years isolation of antibiotic resistant Staphylococcus aureus, especially methicillin resistant Staphylococcus aureus in food and food-producing animals has become more frequent. The aim of this study was to determine the prevalence of MRSAin traditional white cheese and butter presented in Tabriz by culture and PCR techniques, as well as the determination of their antibiotical susceptibility. In the present study, 250 traditional white cheese and butter samples were collected from different producers across Tabriz. Evaluation for contamination by coagulase positive Staphylococcus aureus was done using the Culturing method. The isolates were subjected to the PCR technique according to the Nuc gene in order to confirm Staphylococcus aureusand methicillin resistance to the gene [mecA] and the antibiotic resistance trend of the isolates were studied by the Disc Diffusion Agar method. The culture of the samples indicated that 26 cheese and 24 butter samples were contaminated by Coagulase Positive Staphylococcus aureus. Nineteen cheese samples and 11 butter samples were confirmed to be Staphulococcus aureus based on PCR using the Nuc primer gene. From a total number of 30 isolates containing the nuc gene, 11 had the resistant mec-Agene. In overall, from the evaluated samples 100% of the isolates demonstrated simultaneous resistance to more than 3 antibiotics. It can be stated that there was a considerable amount of Staphylococcus aureus which was resistant to a variety of antibiotics, most importantly methicillin resistant. Staphylococcus aureus in the evaluated samples

[Study of morphological and protective characteristics of beads obtained from microencapsulation of lactobacillus acidophilus probiotic as a predominant and natural flora in human gut]

Lactobacillus acidophilus as a probiotic has more useful effects and low viability of this bacterium and other probiotics under hard acidic-bile conditions of digestive system and food products, have encouraged researchers to find methods to solve this problem. Microencapsulation as one of the newest methods has noticeable effects in this field. The aim of this study was to evaluate the morphological and protective characteristics of beads obtained from microencapsulation of Lactobacillus acidophilus. After activation of starter culture of la5 in MRS-broth medium, in order to purification bacteria was used centrifuge device with speed of 10000rpm for 10 minutes. Microencapsulation was done by calcium alginate and resistant starch with extrusion method. Morphology of beads was evaluated by optical microscope. The study of beads stability was done for 12 hours and the study of survival microencapsulated bacteria was done for 120 minutes within hydrochloric acid, phosphate buffer [0.1 mol] and digestive powder inclusion solution. A morphological characteristics of beads was indicated by optical microscope. These results showed that the strength of beads in various environments is different and in this regard physical tension is very important. Under unfavorable environmental conditions, microencapsulation with calcium alginate and resistant starch was played an important role in the protection of lactobacillus acidophilus. The survival rate of microencapsulated bacteria in all conditions was significantly higher than free bacteria [P <0/05]. Morphological characteristics and strength of beads had great importance in theirs protective function of probiotic bacteria. Microencapsulation with calcium alginate and resistant starch plays an important role in increasing the rate of lactobacillus acidophilus survival

[Isolation and study on the technological and probiotic characterization of Lactobacilli in traditional white Lighvan cheese]

BACKGROUND: Probiotics and especially Lactobacilli are among the most important components widely used in food technology. Isolation and characterization of indigenous probiotics should be performed in native populations

OBJECTIVES:In order to isolate lactobacillus spp. from Iranian traditional Lighvan cheese to be used as starters, 15 cheese samples were randomly selected and tested for technological and probiotics properties

METHODS: Lactobacilli were characterized using culture-based and biochemical techniques and results were verified using PCR analyses of the 16S rRNA region. The probiotic characteristics of these bacteria were studied by acid and bile tolerance

The susceptibility of different isolates against a number of important antibiotics was tested

The technological traits of LAB were assessed using measurement of acid production and analyzing salt tolerance

The isolates were also screened for proteolytic and lipolytic activity

RESULTS: Of the 12 samples containing Lactobacilli, 10 belonged to L. plantarum while 2 were close to L. bulgaricus spp. All isolates were tolerant to 3% NaCl and 9 tolerated 6-8% NaCl. Almost all isolates were lipase-positive at 37 °C and 30 °C. Nine Lactobacilli were shown to be protease-positive at 37°C. Two isolates were completely tolerant to pH 1.55, 4 had intermediate resistance, 4 were of weak resistance and 1 was sensitive

All but one isolate were tolerant to 0.03% bile acid. Some isolates were shown to be sensitive to erythromycin, ampicillin, tetracycline, amikacin and rifampicin

CONCLUSIONS: Results indicate that most of the isolated Lactobacilli can be used as industrial cheese starters and/or as native probiotics in production of functional foods

[ effect of microencapsulation with calcium alginate and resistant starch on the lactobacillus acidophilus [LA5] survival rate in simulated gastrointestinal juice conditions]

Microencapsulation of probiotic cells is the newest method for increasing probiotics' survival in probiotic food products in gastrointestinal conditions and safely transferring them to the large intestine. The aim of this study was to investigate the effect of microencapsulation with calcium alginate and resistant starch on the lactobacillus acidophilus [La5], and the survival rate in simulated gastrointestinal juice conditions. Survivability of this bacteria was conducted in 0.6% bile salt solution and simulated gastric juice[PH1.55], followed by incubation in simulated intestinal juice with and without 0.6% bile salt. In this study the extrusion method was performed for the microencapsulation process. Data were analyzed using an independent t-test. Our results showed that survivability of microencapsulated cells in a simulated gastric juice condition, and also in simulated intestinal juice with and without 0.6% bile salt, is significantly more than free cells[p<0/05]

[Effect of drying process on the phenolic-compounds content and antioxidant activity of two varieties of date-palm fruit Kaluteh and Mazafati]

Date-palm fruit is an important horticultural fruit in Iran with a high nutritive value due to its contents of minerals, sugars, vitamins and antioxidant compounds. In this research the effects of drying process on phenolic-compounds content and antioxidant properties of two common date varieties in Kerman Province, Iran, namely, Mazafati and Kaluteh, were investigated. Two common date varieties in Kerman province, Iran, namely, Mazafati and Kaluteh, were chosen. They were dried by 2 methods - sun-drying and oven-drying at 500, 600, 700 and 800 C. The phenolic content was measured by the Folin-Ciocalteau method and the antioxidant activity by reducing-power assay, total antioxidant capacity, and DPPH methods. The drying process causes a decrease in phenolic compounds in comparison with fresh dates. The reductions in both total phenolic-compounds content and total antioxidant activity increased by increasing the drying temperature. The highest and lowest contents of phenolic compounds and antioxidant activity were found in the sun-dried and oven-dried [at 800°C] samples, respectively. The Mazafati variety had a higher content of phenolic compounds [780 mg galic acid/100 g dry weight] and a higher antioxidant activity [35% radical scavenging DPPH] than the Kaluteh variety [720 mg galic acid/100 g dry weight and 28% radical scavenging DPPH, respectively]. Keeping date fruits at a constant temperature for a long period also led to decreases in the phenolic-compounds content. Drying process results in decreases in phenolic compounds and antioxidant activity of dates; the higher the drying temperature, the higher in losses in phenolic compounds and antioxidant activity