Investigation of melamine and cyanuric acid concentration in several brands of liquid milk and its non-carcinogenic risk assessment in adults and infants.

In this study, the melamine and cyanuric acid concentration of widely used milk brands and the probability of non-carcinogenic risk of the brands for adults and infants were investigated. These values were 1.37 mg/L, 1.10 mg/L, and 1.09 mg/L, which corresponded to creamy sterilized sample, high-fat (creamy) pasteurized sample, and low-fat (less-creamy) pasteurized sample, respectively. Similarly, the highest amount of cyanuric acid occurred in brand A with the values of 0.79 mg/L, 0.65 mg/L, and 0.64 mg/L, which was reported in the same samples mentioned for melamine. The HQ (Hazard Quotient) of melamine in the brands of A, B, C and D for adults was 0.0025, 0.0011, 0.0006 and 0.0008 respectively. These values for infants were reported as 2.2280, 0.9444, 0.5714 and 0.6714 respectively. The risk probability of melamine for adults was less than 1. However, the HQ in brand A for infants was greater than 1 (2.380), which indicate the high probability of non-carcinogenic risk. Furthermore, the HI (Hazard Index) values of the brands of A, B, C and D for infants were 2.7913, 1.1737, 0.7067 and 0.838, respectively. The simultaneous melamine and cyanuric acid in the brands A and B in for infants increase the non-carcinogenic risk probability by approximately 2.8 and 1.2 times, respectively. The results revealed that the melamine and cyanuric acid concentrations in creamy milk samples (0.5%) were higher than in less-creamy milk samples (2.5%). Moreover, the amount of the compounds in sterilized milk samples was higher than pasteurized. In this study, a conversion factor (0.7) was proposed in order to find out the concentration of cyanuric acid in milk sample with the amount of melamine is known but the cyanuric acid concentration is unknown.

Incorporation of nanoencapsulated garlic essential oil into edible films: A novel approach for extending shelf life of vacuum-packed sausages.

The efficacy of chitosan (CH) and whey protein (WP) films impregnated with garlic essential oil (GEO, 2% v/v) or nanoencapsulated GEO (NGEO, 2% v/v) to extend the shelf life of refrigerated vacuum-packed sausages were assessed and compared during 50 days. The primary evaluation of GEO and NGEO showed that GEO had a considerable amount of active compounds diallyl sulfide derivatives (~67%) and the mean size and zeta potential of NGEO were 101 nm and -7.27 mV, respectively. Based on the microbiological and lipid stability analysis of the sausages, all active films retarded lipid oxidation and the growth of main spoilage bacterial groups compared to the control, and CH film containing NGEO exhibited the best result with the peroxide value, thiobarbituric acid reactive substances and aerobic plate count of 0.37 (meq/kg lipid), 0.47 (mg malondialdehyde/kg) and 3.69 (log CFU/g), respectively, on day 50. The nanoencapsulation of GEO made no significant differences in the sensory properties comparing to free-GEO samples (P < .05).

Biocontrol effect of Kluyveromyces lactis on aflatoxin expression and production in Aspergillus parasiticus.

Aspergillus parasiticus is one of the most common fungi able to produce aflatoxins, which are naturally occurring carcinogenic substances. This study evaluated the effects of the safe yeast, Kluyveromyces lactis, on fungal growth, aflatoxin production and expression of aflR gene in A. parasiticus. Antifungal susceptibility was evaluated by exposing A. parasiticus to different amounts of K. lactis, and aflatoxin production was measured using high-performance liquid chromatography. Expression of the aflR gene was determined by measuring the cognate aflR mRNA level by quantitative real-time reverse-transcription polymerase chain reaction assay. The growth of A. parasiticus was inhibited by 7 days of incubation at 30°C with a minimum population of 1.5 × 105 CFU/ml of K. lactis, which also suppressed expression of the A. parasiticus aflR gene, reducing the total production of aflatoxins by 97.9% and aflatoxins B1, B2, G1 and G2 by 97.8, 98.6, 98 and 94%, respectively. Accordingly, K. lactis could be considered as a potential biocontrol agent against toxigenic molds in food and animal feed.

A simple and accurate PCR method for detection of genetically modified rice.

BACKGROUND: Legislation regulating for labeling and use of genetically modified (GM) crops are increased considerably worldwide in order to health and safety assurance of consumers. For this purpose, a polymerase chain reaction (PCR) method has been developed for detection of GM rice in people's food diet. METHODS: In this study, eighty-one non-labeled rice samples were collected randomly from different market sites of Tehran, Iran. In order to analysis, rice genomic DNA was extracted using MBST DNA extraction kit and subsequently, sucrose phosphate synthase (SPS) gene was used to confirm the quality of extracted DNA. Then, cauliflower mosaic virus (CaMV) 35S promoter and Agrobacterium nopaline synthase (NOS) terminator were selected as screening targets for detection of GM rice sequences by PCR. RESULTS: According to our results, 2 out of 81 (2.4%) samples tested were positive for CaMV 35S promoter while no positive result was detected for NOS terminator. CONCLUSION: The obtained data indicated that this method is capable to identify the GM rice varieties. Furthermore, it can demonstrate the possibility of the presence of GM rice in Tehran's market, thus putting emphasis on the requirement for developing a precise approach to evaluate this product.