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.

Analysis of polychlorinated biphenyls (PCBs) in edible oils using the QuEChERS/GC-MS method: A health risk assessment study

Population growth has made it difficult to provide safe food; because various toxic substances such as polychlorinated biphenyls (PCBs) can contaminate food products such as edible oils which have very high-rate consumption worldwide. Aims of study are to determine the concentration of PCBs in edible oil samples and to evaluate the carcinogenic risk of PCBs in them among Iranian people by Monte Calo Simulation (MCS). After finding the location of high customer hyper market in Tehran, 42 samples of 7 various types of edible oils were collected; then PCBs content of them measured using the modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method and GC/MS technique. According to the findings the mean level of NDL-PCB in oil samples were ranged from 1.88 to 25.62 ng/g fat. Results of uncertainty analysis showed that among children the 95th percentile of Incremental Lifetime Cancer Risk (ILCR) were 7.80E-3, 5.37E-4, 5.37E-4, 2.00E-3, 1.59E-3, 13.9E-3 and 7.04E-4 for animal oil, corn oil, frying oil, olive oil, bran oil, sesame oil and sunflower oil, respectively. Also, the 95th percentile of ILCR among adults were 4.12E-2, 3.04E-3, 3.09E-3, 1.06E-2, 8.43E-3, 7.38E-3 and 3.74E-3 for animal oil, corn oil, frying oil, olive oil, bran oil, sesame oil and sunflower oil, respectively. The risk evaluation showed that in all edible oils the 95th percentile of simulated ILCR were more than 10-5, so it can be threatening health among both aging groups, although, the producers don't deliberately subject the users' lives to such danger, but high consumption rate and accumulation of PCBs in body tissues are contribute to increasing carcinogenic risk. Also, the 95th percentile of ILCR among adults were more than children, because the edible oil ingestion rate among adults was more than children.

Analysis and health risk assessment of nitrosamines in meat products collected from markets, Iran: with the approach of chemometric

The aim of study was evaluate of the concentration and health risk of nitrosamines in 150 meat products samples by using gas chromatography coupled with mass spectrometry (GC/MS), with the chemometric approach. Among the identified nitrosamines, the levels of N-nitrosopyrrolidine (NPYR), N-nitrosopiperidine (NPIP), and total nitrosamines in meat sausages samples were significantly higher than chicken sausages (p < 0.05). Principal component analysis and heat map visualization confirmed meat percentage and sausages type (meat or chicken) which had significant effects on nitrosamines content. The NPIP and NPYR intake was 1.17E-07 and 2.12E-07 mg/kg bw/day, respectively. The Monte Carlo simulation results indicated that the 95th percentile from NPIP and NPYR based on ILCR index were 9.07E-07 and 4.72E-07, respectively. In conclusion, the carcinogenic risk of nitrosamines was considerably lower than the safe risk limit (CR > 1E-4) recommended by United States Environmental Protection Agency for Iranian population.

Determination of melamine contamination in chocolates containing powdered milk by high-performance liquid chromatography (HPLC)

Melamine is widely being reported as a food adulterant. Although its toxicity is currently recognized, melamine adulterations of dairy products are ongoing to apparently increase the amount of protein. The study was conducted to investigate the determination of melamine amounts in chocolates containing powdered milk. In this study, 60 samples of chocolates containing powdered milk, both imported and domestic brands, were collected. The samples were prepared by solid phase extraction (SPE) and analyzed using high-performance liquid chromatography (HPLC). According to the results, melamine was found in about 94% of imported samples and about 77% of Iranian samples. Melamine concentration in imported samples ranged from 0.032 to 2.692 mg/kg, while in Iranian ones it ranged from 0.013 to 2.600 mg/kg. The mean melamine concentrations of foreign and Iranian samples were 0.685 ± 0.68 and 0.456 ± 0.73 mg/kg, respectively. Moreover, the limit of detection (LOD) and limit of quantification (LOQ) values of melamine were 0.017 and 0.052 μg/ml, respectively. The recovery rate (R%) at fortified levels of 1-2 mg/kg was found to be 89.20-95.69% with an RSD (Relative Standard Deviation) of 1.8-2.7%. Based on the study results, melamine was present in 85% of all samples and the melamine level in one Iranian brand and one imported brand was higher than the Codex Organization standard. However, the consumption of chocolates containing these low levels of melamine does not constitute a health risk for consumers.

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.

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).

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.

Effects of storage time and temperature on the antimony and some trace element release from polyethylene terephthalate (PET) into the bottled drinking water

Background and objectives

Heavy metals are considered as one of the major contaminants that can enter into the bottled waters. Antimony (Sb) is a contaminant, which may leach from the polyethylene terephthalate (PET) bottles into the water. The aim of this study was to investigate the content of antimony and other trace elements in bottled waters which was kept in varied storage conditions and temperatures.

Materials and methods

Five time-temperature treatments were carried out on five different brands of commercially available bottled waters. Heavy metal measurement was performed by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) method. Analysis of the collected data was processed by SPSS software.

Results

Antimony concentration was the main concern in our study. The concentrations increased in each of the sample during storage period at all temperatures. The results for different conditions were as follow: at 40°C, in outdoor and at room temperature the Sb concentrations were below the MCLs, i e. 6 ppb. However, at 65°C and 80°C for longer storage times Sb concentration exceeded the MCLs, and variations between the samples were significant (p ≤ 0.05). Storage time and temperature effects on the content of some other trace elements such as Al, Fe were also significant (p ≤ 0.05).

Conclusion

By increasing the duration of storage time and temperatures, antimony leaching from the PET bottles into the bottled water increased. The concentration of Al demonstrated an increase in higher temperatures and storage duration, whereas the content of Fe demonstrated no significant differences.