The effects of Zataria multiflora on inhibition of polyphenoloxidase and melanosis formation in shrimp (Litopenaeus vannamei)

Shrimp melanosis (black spot) is an important surface discoloration caused by polyphenol oxidase (tyrosinase) enzyme, which oxidizes phenols and leads to insoluble black pigments, the melanins. Sulphiting agents are widely used as melanosis inhibitors; but, the hazards related to sulphated foods, such as allergic reactions and severe disorders in asthmatic patients have created a necessity to find the effective natural alternatives. The current study was accomplished to assay the in vitro antityrosinase effect of Z. multiflora EO as well as its capability to retard the melanosis formation in shrimp during iced storage. According to GC/MS results, carvacrol, thymol and p-cymene were the major components of Z.multiflora EO, representing 50.8, 14.4 and 10.6, respectively. DPPH radical scavenging activity of EO was 0.8±0.02 mg/ml and 63.2% of tyrosinase activity decreased when EO with a concentration of 0.25% was applied. Furthermore, it has been observed that immersing the shrimps in 1% EO aqueous suspension retarded the melanosis formation in shrimp during 10 days of iced storage. It can be concluded that Z. multiflora EO could be used as an effective natural processing aid to increase the shrimp shelf-life during iced storage

Effect of and as probiotic on decreased absorption of cadmium in rat

Cadmium is a wide-spread heavy metal that causes a wide range of health problems in animals and humans. Many reports showed the biosorption of heavy metals by bacteria. The objectives of this study were to evaluate the potency of probiotics bacteria of Lactobacillus plantarum and Bacillus coagulans against cadmium adsorption in rats. Twenty four male adult Wistar rats were randomly divided into six groups. Cadmium treated groups received 1 ml of 100 µg/ml CdCl2 and probiotics groups were administrated 1 ml of (109 CFU/ml) of probiotics during 24 days by special gavage needle once daily. Levels of cadmium were determined by using graphite furnace atomic absorption spectrometry. Probiotics B. coagulans and L. plantarum caused 29.8% and 19.3% increasing in removal of cadmium through defecation and decreased 10.9 and 21.5 % of cadmium accumulation in kidney of Wistar rats. The results showed that oral administration of both probiotics offered a significant protective effect against cadmium adsorption in rats

Evaluation of physicochemical, textural and sensorial characteristics of low-fat or low-sugar synbiotic ice-cream

Replacing a part of fat and sugar in ice-cream by inulin and lactulose as prebiotic may create a healthier product. Two low-fat and two low-sugar synbiotic ice-cream samples were manufactured inoculated with Lactobacillus acidophilus or Bacillus coagulans. The physicochemical, textural and sensorial characteristics of the samples were compared with regular ice-cream as control. Low-fat and low-sugar synbiotic ice-cream formulations were prepared by replacing 5% of the fat and sugar contents of the control formula by inulin and lactulose, respectively. According to the results, although the total solids of the ice-cream mixes did not differ significantly, there were significant (

Survival of Lactobacillus acidophilus and Bacillus coagulans in probiotic and low-fat synbiotic ice-creams

In this study, survival of Lactobacillus acidophilus and Bacillus coagulans after freezing and during 90 days of storage at -18○C in probiotic and low-fat synbiotic ice-cream was evaluated. Addition to a control group (which was ordinary ice-cream), two probiotic ice-creams were formulated using L. acidophilus and B. coagulans and two synbiotic ice-creams were prepared using the aforementioned microorganisms but replacing 5% of milk-fat with inulin. The total solids of the ice-cream mixes did not differ significantly, however there was a significant difference (

Comparison of capillary zone electrophoresis and high performance liquid chromatography for the determination of histamine in bacterial culture media

The presence of histamine in foods is an important indicator of food spoilage and can also cause food poisoning in consumers. Therefore, monitoring of histamine level in food is important. This paper has focused on the comparing of capillary zone electrophoresis (CZE) with HPLC for the determination of histamine in tryptic soy broth. For this reason, the culture media was inoculated with a standard strain of histamine-producing Staphylococcus epidermidis TYH1, as well as S. capitis and S. carnosus strains harboring histidine decarboxylase-hdc. The migration time of histamine in CZE assay and retention time of HPLC were found 5.4 and 12 min, respectively. The calibration graph was linear ranged 6.25 to 200 μg/ml which was estimated using the regression equation of y=0.000004x (r2=0.999) for both methods. Determination of histamine produced by these three strains indicated no significant differences using CZE with HPLC methods. The results show that the CZE is suitable for the determination of histamine in bacterial culture, since, there is no need for initial preparation, simplicity, sensitivity and low cost

Study on physico-chemical properties of emulsion type sausage produced with aqueous extract of Biarum carduchcorum tenderizied meat

In order to improve the quality of meat such as tenderness, protein solubility, emulsification and water holding capacity, in the food industries, various methods have been employed. Application of the plant enzymes is considered as one of the most efficient methods for meat tenderization. The purpose of the present study was to evaluate the characteristics of emulsion type sausage made from tenderized cattle meat by hydro extract of Biarum carduchcorum. The proteolytic activity of the extract was determined using bovine milk casein as substrate. Post rigor thigh meat were tenderized by 100 and 150 enzyme units/ kg of the extract before used for production of sausage. Fresh post rigor thigh meat was used as control. Nitrogen solubility index (NSI), stability of sausage emulsion, texture analysis and organoleptic properties of sausages were determined. Our results showed a significant increase in the NSI of the experimental groups compared with the control (

Possibility of Biarum carduchcorum application as vegetable rennet in production of Iranian white cheese

Numerous attempts have been made to replace calf rennet with another milk-clotting protease because of limited supply and the high price of calf rennet.Biarum carduchcorum is rich in protease activities, therefore it is a probable candidate for substitution. No systematic study on the Biarum carduchcorum and its enzyme characteristics have been conducted so far. The purpose of this study was to prepare Biarumextract, determination of its protease activity for milk clotting and production of Iranian white cheese and study on the physicochemical and organoleptic properties of the product. After the cheese production by the vegetable extract (0.5% concentration) organoleptic, textural properties and nitrogen solubility index (NSI) were analyzed during 45 days of ripening compared to the control sample. The results of this study showed that the optimal protease activity of the extracted enzymes for milk clotting was at 45 oC, pH= 5 and 15 mmol/ml concentration of CaCl2.The cheese sample that was manufactured with vegetable enzyme had a bitter flavor and sharper odor. At textural analysis, the cheese had a lower hardness. Assessment of proteolysis during the cheese ripening by NSI measurement showed that the proteolysis severity of cheese sample produced with vegetable enzyme was significantly higher than the control sample. Therefore, it seems that aqueous extract ofBiarum in concentration used for the production of Iranian white cheese cannot be a suitable substitute for rennet

Introduction and comparison of measurement methods of antifungal properties of lactic acid bacteria in cheese

Various laboratory methods have been developed to evaluate the effectiveness of anti-mould effect of lactic acid bacteria. However, most of these investigations have been conducted in culture medium. Due to the occurrence of complex interaction between food components and antimicrobial substances produced by lactic acid bacteria, the result achieved from these studies may be different from those seen in food model. In various studies growth inhibition of molds on the surface of foods are considered as antifungal activity. Consequently, introduction and comparison of efficient methods for evaluation of anti-mould effect of lactic acid bacteria would be helpful. In this study, antifungal activity of lactic acid bacteria inoculated in cheese was estimated using Microdilution method. Pieces of cheese samples were overlaid with molds and the antifungal effect of this bacteria was studied against Aspergillus flavus and Aspergillus parasiticus. All three methods showed the effectiveness of lactic bacteria on mold inhibition. Comparison of the results showed that there was significant positive correlation between antifungal overlay assay and direct growth of mold on cheese, since this two test showed antifungal effect in the same way including interaction between bacteria and mold and also producing antifungal compound

Study on the overview on food borne bacteria in food with animal origin in Iran; Part three: seafood

The current retrospective study was focused on the contamination of seafood in Iran during the years 1999 to 2012. The isolates were Clostridium botulinum, Clostridium perferingense, Escherichia coli, Listeria monocytogenes, Salmonella, Shigella, Staphylococcus aureus and Vibrio parahemolyticus. C. botulinum type E was the most prevalent type of bacteria in the fisheries products, responsible for the most cases of botulinal food poisoning. The presence of coliforms and E. coli in the seafood was due to environmental pollution. Additionally, in the processed food, the contamination of potable water and poor handling of the products are the main sources. L. monocytogenes was isolated from fresh, frozen and processed food. The microorganism is able to grow in the refrigeration condition and multiply in the processed food. The temperature of cold smoking (20-30 ºC) cannot stop growing of Listeria. High prevalence of Salmonella in water and fisheries product was mainly because of the low environmental sanitation and various geographical conditions. However, Compost fertilizer and flowing of the swages through the farms were considered as the major source of contamination. S. aureus is not a typical microorganism of the fisheries farms but may contaminate them during the processing or in-appropriate handling of the products. V. Parahemolyticus is a normal habitant organism of the pelagic area. The organism usually find in the warm water and presents in the tropical conditions. Different species of Vibrio may contaminate the salty water in the warm seasons and so contaminate the aquatics farms in these areas. In general, the prevalence of vibriosis was associated with the consumption of semi-cooked food stuff and/or the secondary contamination of the processed ones

Study on the overview on foodborne bacteria in food with animal origin in Iran; Part four: Poultry and egg

In this study, the contamination of poultry meat and eggs to pathogenic bacteria was investigated in Iran, for over three decades. Health assessment of these two products is highly important due to their high level of consumption and consequent health risks of food borne diseases such as salmonellosis. Many reports indicate the presence of majority of pathogenic bacteria such as campylobacter, staphylococci, salmonellas, etc. in the poultry abattoirs across the country. It seems that most of these contaminations had been occurred through cross contamination during slaughtering or other stages of processing. Although many bacterial contaminations have been reported in eggs (e.g., streptococci, staphylococci, or Escherichia coli), most of studies have focused on salmonella as eggs are among the major transmission routes of this bacterium. In several suveys, salmonella has been isolated from the shell of the eggs of native breeds. According to the studies, campylobacter contamination has not been reported. Moreober, occurrence rate with other bacteria species was very low. It seems that due to the high proportions of chicken meat and eggs in the food basket of community, even low levels of contamination could be of great concern. It was concluded that maintaining of hygienic conditions and improving the knowledge of producers in the food production chain could be effective in reducing the overall contamination of pathogenic bacterial