عنایت بریزی

Considering the broad spectrum of using nanoparticles in food coatings as a potent antimicrobial agent and their possible cytotoxic effects and accidental consumption of these toxic materials, this study was performed. The present study aimed to investigate the cytotoxicity of chitosan and nano-chitosan in vitro.

This cross-sectional study was conducted in 2019 in the Laboratory of the Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, Iran. The XRD and FITR techniques were employed to study the characteristics of these nanoparticles. Moreover, two cell lines, HT-29 and Vero, were used to study the cytotoxic effects of chitosan and nano-chitosan by MTT assay, acridine orange, and ethidium bromide staining. One-way ANOVA and independent t-test were used to analyze the collected data with the help of SPSS software (version 19).

Based on the obtained findings, the maximum values of XRD at the angle of θ2 were observed at 20°. The highest peak appeared at 1530 cm-1, which was associated with tensile vibration of N-P-N. The spectrum diagram of chitosan due to the tensile vibration of synthetic nanochitosan of N-H bound appeared at 1646 cm-1. The results showed a proportional increase in the cytotoxicity with time and concentration of nanoparticles in the cells.

Since by increase in time and concentration of nanoparticles, toxicity was observed in cells; therefore, the time and concentration of chitosan nanoparticles are important in causing cytotoxicity. Considering the toxic effects of these nanocomposites on cancer cells, they can be used in cancer treatment, which requires further studies.

Nowadays, chemical food contaminants are considered among the serious health concerns in various countries. Arsenic and mercury are the most important heavy metals which cause different complications in humans. The present study aimed to determine the dietary intake of mercury and Arsenic using total diet study (TDS) method in the adult population of 20-50 years old in Shiraz. Total of 580 food items were prepared and classified into 129 composite samples. After preparation, the samples were digested. The concentration of mercury and Arsenic were measured using inductively coupled plasma–optical emission spectrometry (ICP-OES). The dietary intake of Arsenic and mercury was calculated based on the mean food intake. Fish had the highest concentration of Arsenic, and the snack samples contained the highest concentration of mercury. But it was found that the heavy metal intake is more affected by the quantity of the food consumed. Therefore, the highest contributor to dietary intake of Arsenic was drinking water and fruit, and the highest contributor to dietary intake of Arsenic was related to raw vegetables and dairy products. However, the mean daily intake of mercury and Arsenic was 0.2-8.65 µg/d and 6.5-81.81 µg/d, respectively, which is lower than the provisional tolerable weekly intakes (PTWI). Therefore, there is no health risk due to Mercury and Arsenic investigated in this research for the total diet in adult population in Shiraz.

The present study aimed to investigate the possibility of reducing energy content in emulsion type sausages by replacing fat with inulin. In the manufactured product, the fat content was reduced to 6%-18% and replaced by inulin and water. The quality of the resulting product was determined by chemical and texture profile analyses (TPA), color measurement and sensory evaluation. The results showed that replacing fat with inulin led to a significant energy content reduction of up to 64% (with 6% inulin and 12% water). In addition, color measurement, sensory evaluation and TPA were comparable to the traditional product in the inulin treated samples. The overall acceptability of all experimental groups was adequate; therefore, inulin is suggested as a good replacement for fat in emulsion type sausages.

C. jejuni and C. coli are considered as major causes of bacterial enteritis in human, worldwide. Birds are playing a substantial role in the transmission of infection. A relatively high prevalence of the infection in the rearing period leads to the cross-contamination during the slaughter processes which coincidently cause the contamination of poultry meat products. Investigation on the contamination of poultry carcasses at the end of rearing periods to C. jejuni and C. coli. In autumn 1388, total of 100 poultry farms were randomly selected, from which, 21 carcasses were chosen to collect a cecal specimen from each carcass. Each cecal contents of seven carcasses were then pooled, culture on a selective agar plate and enriched in a selective broth medium followed by culture on a selective agar plate. The isolates were finally confirmed using a multiplex-PCR assay. Total of 53.7% (70% of all the farms) were found positive using direct culture plating, whereas, 60% (76% of the farms) were positive when the samples were initially enriched in a selective broth. 31.3% to 35% and 36.7% to 40.0% of all the positives were respectively confirmed as C. jejuni and C. coli. A 6.3% increase in the isolation rate of Campylobacter, when the samples were initially enriched in the selective broth, was demonstrated. The present study revealed a considerable high prevalence of Campylobacter in poultry farms, and thus, a closer investigation on the possible risk factors involving in the contamination is essential. Furthermore, to reduce the risk of infection in human, improving the hygienic inspection in the poultry slaughter houses, is also recommended.

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.

The present work was carried out to study the effect of vacuum packaging and pomegranate peel extract (PE) treatments on the quality of pacific white shrimp (Peneous vannamei) during refrigerated storage. Changes in pH, thiobarbituric acid (TBA), total volatile base nitrogen (TVB-N), trimethylamine (TMA), aerobic plate counts, psychrophilic, lactic acid bacteria and enterobacteriaceae counts, melanosis and sensory characteristics were investigated in up to 10 days of storage at 4°C. Microbial growth of vacuum packed and PE treated (1 or 2%) shrimps were retarded during storage time in comparison with the control group (P<0.05). Furthermore, use of PE in combination with vacuum packaging enhanced the antimicrobial effect of vacuum packaging against the bacterial populations. Vacuum packaging demonstrated a significant reduction in TVB-N, TMA and TBA content of shrimps during refrigerated storage. However, use of vacuum packaging and PE in combination did not significantly improve chemical parameters of the samples. Hence, vacuum packaging is considered as an effective method to extend the shelf-life of shrimp and, when combined with PE, can dramatically improve the overall likeness and microbial quality of the product.