JOURNAL OF FOOD HYGIENE
Year:2017 | Volume:7 | Issue:1 (25) |Papers Count:8

Bioactive peptides, are inactive components within the structure of the protein and when they are released by enzymatic hydrolysis, show different physiological functions. Recently, the identification and characterization of bioactive peptides derived from plant and animal sources and different microorganisms is highly regarded. They are produced during enzymatic hydrolysis by gastrointestinal enzymes or enzymes extracted from microorganisms and plants or by proteolytic starter cultures during fermentation process and exhibit different activities including: opioid, mineral binding, immunomodulatory, antioxidant, antimicrobial, anti-inflammatory, chlosterol lowering and so on. Take advantage of bioactive peptides as components of health is related to bio stability assurance, bioavailability and safety of them. The use of computer-based techniques and the use of various databases completed in laboratory studies, have provided the possibility of studying the mechanisms of action of different peptides.

Aloe veragel contains a blend of carbohydrates, enzymes, vitamins and minerals, and has antimicrobial and anti-oxidant properties. In this study, after extraction and homogenization of Aloe vera gel, the effect of various concentrations (0.5, 1, 2, 5, 10 and 15%) of the gel was investigated on flavor microbial flora (total microbial count and mesophilic lactic acid bacteria) and also its inhibitory effect on Penicillium citrinum (PTCC 5304) in cheese. Results of sensory evaluation showed that cheeses produced with the concentrations of 0.5 and 1% gel had the highest acceptance. Moreover, it was revealed that in the control sample the number of total count and lactic acid bacteria increased in from 1 to 3 months of storage; meanwhile in the gel-containing samples the microbial populations reduced during the same period. In addition, Aloe vera gel at the concentration of 15% caused 37.3% inhibition of P. citrinum in. It was concluded that some concentration of Aloe vera gel could retard the growth of P. citrinum without sensory defects.

This study was conducted aimed to assess the potential risk of heavy metals on human health resulting from consumption of vegetables. To this end, the vegetables grown around town and industrial center of Zanjan were sampled randomly. Plant samples were digested using hydrochloric acid (HCL) 2 M and concentration of elements (Pb, Zn, Cu, Ni and Cr) were recorded by atomic absorption. Obtained means of heavy metals in all vegetables (N=32) for Zn, Pb, Cu, Ni and Cr is 98.8, 31.9, 19.3, 4.4 and 2.3 mg/kg, respectively. The highest amount of metal pollution index (MPI) in the basil and the lowest was observed in the garden cress (respectively 16.46 and 4.88). Daily intake (EDI) for zinc, copper and chromium in all age groups was lower than the provisional tolerable daily intake (PTDI). This amount for nickel was 2, 1.6 and 1.3 %, and for Pb 28.1, 22 and 19 % higher than PTDI in children, adults and seniors, respectively. The potential risk (THQ) was calculated in all age groups as Pb>>Cu>Zn>Ni>Cr. The potential risks (THQ) of chromium, nickel and zinc were calculated lower than 1, for copper a bit more of 1 and for lead much higher than 1. Health index (HI) for children, adults and the elderly was estimated 31.331, 24.58 and 21.14, respectively, with the largest contribution of the lead (89.7%).

Escherichia colias a fecal contamination and is considered as an index in water. The aim of this study was to determine the phenotypic and genotypic characteristics of E. coli and antibiotic resistance of the isolates collected from qanats and springs in East-Azerbaijan province. For this purpose, 118 samples were selected from above mentioned area and examined by MPN method. The positive coliform samples were identified by phenotypic and genotypic methods. Afterwards, to determine the genetic diversity of E. coli isolates, phylogenetic typing we conducted by means of multiplex PCR. To determine the antibiotic resistance profile, antibiotic discs of Nalidixic Acid, Co-trimoxazol, Amoxicillin, Gentamaicin Ciprofloxacin, Chloramphenicol, Imipenem, Cefotaxime and Ceftazidime antibiogram were used. Based on results, 48% of the samples were evaluated as positive for coliform including 40% for E. coli and 19% for Klebsiella. Amongst 23 isolates confirmed as E. coli by PCR. Phylogenetic typing revealed that 44% of E. coli strains belonged to type D and B2 and 56% belonged to A and B1 phylotypes. Antimicrobial susceptibility pattern showed that 92% of E. coli isolates were resistant to Amoxicillin. All E. coli isolates were sensitive to Imipenem. It was concluded that presence of pathogenic E. coli with high rate of antibacterial resistance in waters source could be considered as a human health hazard.

Alkaline phosphatase is an indigenous milk enzyme and is probably, the most important indigenous milk enzyme from a dairy technology viewpoint which is used to determine the efficacy of the pasteurization process. The aim of this study was to assess the alkaline phosphatase activity of 200 samples of industrial and traditional yoghurt, ice cream and cheese, as well as raw and pasteurized milk samples. To achieve this purpose, p-nitrophenylphosphate was used as substrate and the amount of liberated p-nitrophenol was measured spectrophotometrically. The amount of liberated p-nitrophenol in all samples of raw milk was very high (6839±4070 mg/ml) but in pasteurized milk samples, the amount was in the range of 0.75-52.96 mg/ml and 88% of the samples had less than 10 mg p-nitrophenol/ml, the maximum permissible limit of p-nitrophenol in pasteurized products. The amount of liberated p-nitrophenol was in the range of 5.68-1210 mg/ml and 2.61-18.22 mg/ml in traditional and industrial cheese samples, respectively and it was estimated at the range of 0.75-26.67 mg/ml and 0.71- 35.82 mg/ml for traditional and industrial ice cream samples, respectively. The lowest alkaline phosphatase activity was observed in both industrial and traditional yoghurt samples. Meanwhile, p-nitrophenol in 12% of industrial cheese, 44% of traditional cheese and 16% of both industrial and traditional ice cream samples was higher than 10 μg/ml which could be due to the inadequate pasteurization of the product or cross contamination with raw milk. The results of the present study showed a need for more strict attention in the pasteurization of milk and its products.

Some medical plants which are rich in phenolic compounds (flavnoieds, tannis and anthocyanin) have drawn increasing attention as the most important natural antioxidant source by many developed countries. Laurus nobilis is one of the medical plants that grow in various regions of Iran. This plant is known to have many benefits and medical properties such as diuretics and mosaics. Furthermore, Laurus nobilisis used in treatment of gastrointestinal problems; especially it is effective in elimination of stomach gas. In this experiment, we studied antioxidant and antibacterial effects ofLaurus nobilis plant.To this purpose, the efficiency of aqueous solvent extract, phenolic compounds, DPPH radical scavenging and ferric-reducing power and ABTS free radical scavenging were examined. Antibacterial characteristic of the aqueous extract was evaluated onStaphylococcus aureus and Escherichia coli. The result showed that aqueous extract ofLauros nobilis had 14.8% extraction efficiency with high rate of phenolic compounds (99.9±9.95 mgGAE/g), low IC50 in DPPH test (2.813 mg/mg), high rate of ferric reducing power (22.15±2.10 mmol Fe2+/g) and ABTS free radical scavenging (22.87±2.03 mg AAE/g).The result of antibacterial test also indicated that aqueous extract had high antibacterial effect on S. aureus (18±0 mm) and E. coli (18±0 mm). These facts showed high antioxidant and antibacterial activity oflerual’s extract.

The aim of this study was to achieve a quick and simple quantitative and qualitative method to detect even the trace amount of added soda in raw milk, since the existing tests methods are not applied in practical and real terms. For this purpose, after determining the microbiological and chemical characteristics of the raw milk, the samples were divided into 4 groups. Each group was added by different values of lactic acid, and then different rates of soda were added to the samples. Tests for acidity, pH value, electrical conductivity, alcohol, ash and Rosalic acid were conducted. According to the results with increasing the amount of soda, the electrical conductivity and total ash were increased, however the acidity was decreased. No significant correlation was observed between the added soda and pH value. Alcohol test had the same results on all samples. Rosalic acid test was negative in all treatments. In the case of alkaline ash, in none of the samples the volume of hydrochloric acid consumed reached to 1.2 ml. It was concluded that Rosalic acid test did not work for the detection of soda in raw milk; in addition alkaline ash test did not specify the small amounts of soda. Among the various tests electrical conductivity assay was found to be credible and could be used to detect and quantify the added soda in raw milk.

The Aim of this study was to investigate the effect of intensive endurance exercise and probiotic supplementation on aerobic, anaerobic power, white blood cell (WBC), lymphocytes (LYM), monocytes (MON) and neutrophils (NUT) in young Football players. This study was semi-experimental, 36 young Football players with height 172 ± 0.77 cm, weight 66.76±5.87 kg and BMI 21.27±2.09 kg/m2, randomly assigned into control (n=18) and experimental (n=18) groups. Medical examinations and physical fitness tests were performed before and after training done. They performed a training program for 8 weeks, three times a week, every session 90 to 120 min. Experiment group consumed 400 ml probiotic yoghurt one hour before every session of training. Both groups trained aerobic exercise with 60-75% and anaerobic with 80-100% (MHR). To determine the variables blood samples were taken four times. Initially, before the training program, there were not significantly different amounts of variables. After 8 weeks in the experiment group, the levels of lymphocytes and neutrophils significantly increased. Any report about URTI infection was not observed. Eight weeks training improved the aerobic and anaerobic power, meanwhile reduce the incidence of URTI after ingestion of probiotic yoghurt. As a conclusion, it is recommended to the athletes to consume probiotic supplement before intensive endurance exercises.