The effect of Zataria multiflora Boiss Essential oil on the growth and citrinin production of Penicillium citrinum in culture media and cheese.

The effect of Zataria multiflora Boiss Essential oil (EO) on the growth, spore production, and citrinin production of Penicellium citrinum PTCC 5304 in the culture media as well as Iranian ultra-filtered white cheese in brine was investigated. Radial growth and spore production on the potato dextrose agar (PDA) were effectively inhibited by EO in a dose-dependent manner. At 200 ppm, the radial growth and sporulation declined by 92% and 100%, respectively. The growth was completely prevented at 400 ppm of EO on PDA and the minimum fungicidal concentration (MFC) of the oil was estimated at 400 ppm. Furthermore, the Zataria multiflora also significantly suppressed the mycelial growth and citrinin production in broth medium at all investigated concentrations (P < 0.05). At 150 ppm of EO, the citrinin accumulation and mycelial growth reduced by 88.6% and 89.6%, respectively. The EO was tested at all concentrations and the findings show an inhibitory effect of P. citrinum against the radial fungal growth and citrinin production in cheese. However, no concentration of EO could completely inhibit the growth and production of citrinin in cheese. We therefore concluded that Zataria multiflora has the potential to substitute the antifungal chemicals as a natural inhibitor to control the growth of molds in foods such as cheese.

Survey on the effects of electron beam irradiation on chemical quality and sensory properties on quail meat.

INTRODUCTION: Irradiation is one of the intervention strategies for effective control of food-borne pathogen microorganisms, which reduces microbial load and extends the meat shelf life. MATERIALS AND METHODS: This experimental study was carried out on quail meat. Quail meat samples were treated with electron beam irradiation at doses of 0.5, 1, and 3 kGy and stored at 4 ±â€¯1 °C for 15 days. Five days after irradiation, the chemical and organoleptic changes in the quail meat were evaluated for 15 days. Total volatile basic nitrogen and TBA were also measured to investigate chemical changes. RESULTS: Irradiation significantly reduced the amount of total volatile basic nitrogen in irradiated samples. Furthermore, the increase of TBA level was significant in irradiated samples, which had a direct correlation with irradiation dose and storage/shelf life duration. Despite the increase of thiobarbituric acid, irradiation had no significant effect on the sensory properties of quail meat. CONCLUSION: Irradiation of quilt meat resulted in extension of the meat shelf life to at least two weeks at refrigeration temperature by decreasing the corrosion-causing microorganisms and improving microbial quality, while the sensory properties of meat were preserved. Regarding the increase in the oxidation level at high doses of the electron beam and the absence of significant differences in the studied dosages in reducing the total amount of total volatile basic nitrogen, it is recommended to apply electron beam irradiation at doses of 1.5 and 3 kGy to extend the meat shelf life and preserve the quality/health of the quail meat.

Effects of Simple and Microencapsulated Lactobacillus acidophilus With or Without Inulin on the Broiler Meat Quality Infected by Avian Influenza Virus (H9N2).

The aims of the present study were to investigate the effects of simple and microencapsulated Lactobacillus acidophilus as probiotic with or without inulin as prebiotic on meat quality of broiler infected by avian influenza virus (H9N2). Two hundred-day-old chicks were randomly allocated into 14 groups based on simple, microencapsulated probiotic and prebiotic and based on vaccination and challenge with H9N2 virus. Groups 1-7 contained 20 chicks, and groups 8-12 and 14 contained 10 chicks. Group 13 was derived from group 1 with 10 chicks at challenge day with avian influenza virus (AIV). Half of the groups were vaccinated by H9N2 vaccine on day 5. All groups except the negative control and positive vaccine control were challenged with 106.5 EID50 of low-virulence H9N2 AIV at day 21. Each bird was received 109 CFU of simple or microencapsulated probiotic on days 0 and 17 by gavage. Prebiotic as dose as 0.1 % of feed weight was used daily. Increase in water-holding capacity, dry matter, ash and protein content, and decrease in dripping loss plus beneficial changes in lightness and redness of breast meat were detected in response to probiotic especially microencapsulated synbiotic. In conclusion, probiotic alone or with prebiotic was able to improve the physicochemical properties of chicken breast muscle in both healthy and AIV-infected chickens.