JOURNAL OF FOOD HYGIENE
Year:2016 | Volume:6 | Issue:3 (23) |Papers Count:8

Cheese is a good source of protein, vitamins and minerals, especially calcium and phosphorus. Changes in the physical, chemical and microbial properties can affect the shelf life of the product. Therefore, increasing the shelf life of this dairy products is very important. The effect of whey protein concentrate-based edible coatings containing Natamycin (at 0.01, 0.02 and 0.03 percent concentrations) on the shelf life of Iranian white cheese were studied during 60 days. The results showed that the optimized coatings containing 0.03% Natamycin can prevent the growth of Penicillium chrysogenum up to 60 days, while different treatments of coatings had not significant effect on organoleptic properties fat, pH, and acidity of the cheese samples. However it resulted in a loss of 11% of the moisture content. It was concluded that whey protein concentrate-based coatings containing Natamycin can extend the shelf life of Iranian white cheese.

Plants are riched by phenolic compounds and considered as the main natural antioxidants. Many efforts have been recently made to clarify the source of natural antioxidants and their roles to protect from oxidative stress injuries. The present study was aimed to qualify the phenolic compounds of pomegranate peel extract (PPE) of Rabbab variety and their antioxidant effect to substitute the synthetic compounds. Folin- Ciocalteu method was employed to investigate phenolic compound, while, spectrophotometery is used to measure flavonoid, antocyanin and oxidative ability. The antioxidant activity of different concentration of PPE was measured using DPPH. Results showed the concentrations of 70.83 mg TAE/g, 21.33 mg CE/g and 136.66 mmol/100 mL corresponding to the phenolic, flavonoid and antocyanin compounds, respectively. The antioxidant effect by linoleic system has shown to inhibit 89.61% of linoleic oxidation in the methanolic extract of PPE. Increasing the concentration of phenolic compound was simultaneous to raise its effect and a significant correlation between the antiradical activity and its reduction ability in the methanolic extract. The current results revealed the antioxidant activity of methanolic extract of Rabbab variety PPE and thus are recommended to apply in food industries.

This study aimed to investigate the concentration of mercury in Acanthopagrus latus of Bahmanshir River using atomic absorption spectrophotometer and also to estimate the consequent health hazard. For this purpose, 30 samples of fish were prepared from Choebdeh seaport. The average concentration of mercury of Acanthopagrus latus was 0.24±0.08 mg/Kg of fresh wet weight of muscle. The results showed that average concentration of mercury in muscle of Acanthopagrus latus was less than the international organizations standards. According to Statistical Yearbook of Iran Fisheries Organization, the calculations indicated that daily and weekly mercury uptake for the adult Iranian consumers (70 Kg), was 0.000085 mg/Kg/day and 0.000595 mg/Kg/weekly. In addition, it was revealed that HQ index for Acanthopagrus latus was 0.85 which was estimated below 1. Accordingly, maximum daily intake of fish contaminated with 0.24 mg mercury/Kg wet weight for a 70 Kg person was estimated at 29 g/day and 203 g/week.

Although antibiotics are widely used for the treatment of infectious diseases‚ there may have consequences such as adverse drug reactions and antibiotic resistance. The aim of recent study was to compare the antibacterial activity of aqueous and alcohol extracts of Coriandrum sativum on Staphylococcus aureus, Listeria monocytogenes, S almonella typhimurium and Escherichia coli. The antibacterial properties of the extracts were assayed using well diffusion and Microtitr plate (for determining the MIC and MBC). Results of well diffusion method showed that S. aureus and L. monocytogenes were sensitive but E. coli and S. typhimurium were found resistant against both aqueous and alcohol extracts. The MIC and MBC for S. aureus was estimated at 6.25 mg/ml and 12.5 mg/ml, respectively. It was concluded that aqueous and alcohol extracts of Coriandrum sativum were effective on Gram-positive bacteria, however they were ineffective against Gram-negative strains used in this experiment.

Saccharomyces cerevisiaeis one of the major microorganisms widely used in food fermentation, and the ability of its strains to reduce the level of aflatoxins has been reported. The aim of this study was to test the capability of S. cerevisiae strains on reduction of aflatoxin B1, B2, G1 and G2 levels. For this reason, standard strains of PTCC 5052 and PTCC 5269 were cultivated on Yeast Mold Agar. Afterwards, cell suspension containing 107 cell/ml was spiked into PBS (pH=7.2) containing 20 ng/ml of each B1, B2, G2 and G1 aflatoxins. Aflatoxin levels were determined using HPLC and immunoaffinity columns. The results show that different strains of S. cerevisiae reduced the aflatoxin levels in a different rate and various durations. At the time 320 min the PTCC 5052 strain reduced the aflatoxin B1, B2, G1 and G2 levels to 11.2, 13.9, 8.0 and 8.1%, respectively; meanwhile, these results for the PTCC 5269 strain 9.5, 8.0, 2.3 and 16.2%, respectively. Results suggested that different strains of S. cerevisiae had a different reduction rate on aflatoxins. Moreover, the strains need to have sufficient time to absorb the maximum amounts of aflatoxin.

Effectiveness of probiotic food depends on the survival of probiotic in foods. Therefore, it is important to monitor the survival of probiotic organisms during the production and storage of foods. In this research, barley beta-glucan as a fat replacer was added to the low fat probiotic yoghurt and survival of Lactobacillus acidophilus was investigated. Beta-glucan was added to the yoghurt at four levels of 0.25, 0.5, 0.75 and 1%. Survival of L. acidophilus was evaluated at 0, 1, 7 and 14 days of storage. Also, its physicochemical and sensory properties were determined at 7 day of storage. L. acidophilus count increased significantly up to the level of 0.75% beta-glucan (p<0.05) due to the prebiotic effect of this compound. Survival of L. acidophilus in yoghurt containing 1% beta-glucan was less than the other samples. Physicochemical results showed that the treatment had significant effects (p<0.05) on the acidity and syneresis up to level of 0.75%. Results showed that the treatment had significant (p<0.05) effect on pH which decreased by beta-glucan addition. The results also showed that addition of beta-glucan up to 0.5% decreased WHC and increased viscosity significantly (p<0.05). Results of this research showed that beta-glucan could be used successfully as a functional fat replacer in low fat synbiotic yogurts at level 0.5%.

Heavy metals are considers as significant environment pollutants. Their entrance into food chain is a serious health hazard to humans. This study was conducted to determine the concentrations of Cadmium, Zinc and Manganese in root, stalk and leaf portions of spinach and tomato. For this reason, during 2014 in Hamedan city, 3 farms with 5 repetitions from each farm were sampled. Samples were subjected to acid-digestion and the concentrations of the elements were assayed by inductively coupled plasma (ICP). According to the results, the average concentrations of heavy metals in root, stalk and leaf of spinach was estimated at: cadmium, 0.14, 0.24, 0.34 mg/kg, zinc, 15.53, 24.82, 35 mg/kg and manganese, 26.59, 24.42, 45.38 mg/kg, respectively. The data for the tomato samples were: cadmium, 16.20, 24.42, 33.81 mg/kg, Zinc, 21.48, 39.74, 52.92 mg/kg and manganese, 26.60, 42.41, 61.90 mg/kg, respectively. The mean concentration of cadmium and manganese in spinach and tomato showed a significant difference with the WHO/FAO standard limit. However, in the case of zinc the difference was insignificant. It was concluded that in this experiment the spinach and tomato samples were polluted with higher concentration of cadmium and manganese than the approved limit of WHO/FAO and therefore was found risky for the consumers.

Iran has a long history in the production of various types of traditional cheese in different areas. Amongst, fresh and pot cheeses are very popular due to their organoleptic properties. The objective of this study was to isolate and identify Enterococcus spp. in traditional fresh and pot cheese. For this reason, 22 pot cheese and 28 fresh cheese samples were obtained randomly from the rural areas of Khoy city. Enterococcus species were isolated and identified by biochemical assays. Moreover, salt content and pH value of the cheese samples were determined. The results showed that 95.45% (21.22) of pot cheese and 89.29% (25.28) of the fresh cheese samples were contaminated with E. faecium, meanwhile the other Enterococcus spp. we’re not isolated. There was no statistically significant relationship between pH, salt and the occurrence of Enterococcus. It could be concluded that the high occurrence rate of E. faecium indicated an unsatisfactory hygienic condition in traditional fresh and pot cheeses produced in Khoy.