Journal of Food Quality and Hazards Control

81-82

Authors: A. Hlali

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84-88

Authors: W.A. Istifanus, S.M. Panda

Background: Parasitic contamination of fruits and vegetables is one of the major causes of gastroenteritis in many parts of the world. The aim of this study was to determine the parasitic contamination in fruits and vegetables in the Bauchi area, North-East Nigeria. Methods: From May to July 2017, a total of 776 samples comprising 182 samples of four different types of fruits, and 594 samples of six different types of vegetables were screened by simple floatation and formol-ether concentration techniques. The isolated parasitic ova and cysts were identified on the basis of morphological characteristics with reference to the standard keys. The data were analyzed by chi-square test using SPSS computer software version 21.0. Results: Totally, 26 out of 182 fruit samples (14.3%), and 82 out of 594 vegetable samples (13.8%) were contaminated with various parasitic ova and cysts. Ascaris lumbricoides was the most common parasitic contaminant in both fruits and vegetable samples. The differences were not statistically significant in the prevalence rates of contamination among different types of fruits and vegetables (p>0.05). Conclusion: This study showed that contaminated fresh fruits and vegetables consumed in Bauchi, Nigeria are the major sources of parasitic infections and may have serious public health implications. It seems that health education with respect to personal hygiene and eating habits is the most practical and useful approach in order to desired control in the studied area. The local people must be effectively trained for proper washing and disinfecting of the fruits and vegetables prior to consumption.

94-101

Authors: A.N. Zifruddin, K.L. Thong

Background: Salmonella is one of the most common food-borne pathogens that can cause illness. In this study, the sensitivity and the specificity of Aptamer-Magnetic bead Separation-Polymerase Chain Reaction (AMS-PCR) method were determined for Salmonella spp. detection. Methods: Different concentrations of Salmonella enterica were mixed with streptavidin-magnetic beads coated with biotinylated DNA aptamer. The bound bacteria were eluted and tested with PCR targeting the invA gene of Salmonella. Ten different serovars of Salmonella enterica and four non-Salmonella were tested to determine the specificity of the DNA aptamer. For field application, 14 different food samples were tested and compared with the culture method. Results: The limit of detection of AMS-PCR method was 102 CFU/ml which was 10 times more sensitive than conventional PCR without AMS (103 CFU/ml). The AMS-PCR assay showed high specificity as it detected ten different serovars of Salmonella enterica with no cross-reactivity with other food-borne pathogens. AMS-PCR reduced the analytical duration from 6 to 7 h instead of 4 days by the culture method. Conclusion: In comparison with the culture method, AMS helped to improve the upstream sample preparation in reducing the pre-enrichment and enrichment times. So, it seems that combining AMS with PCR is cost-effective and time-saving. In addition, it is highly specific for monitoring of Salmonella spp. in food chain.

109-115

Authors: Y. Shahbazi, N. Shavisi

Background: One of the most well-known Iranian traditional cheeses is Koozeh. The aim of present work was to evaluate the survival of L. monocytogenes during ripening of Iranian traditional Koozeh cheese made from raw ewe's milk. Methods: A 2-factor experimental design was applied to study the effect of ripening conditions, including different temperatures (4, 9, and 14 °C) and different concentrations of NaCl (0, 8, 12, and 15%) on the survival of L. monocytogenes in the Koozeh cheese. Microbial analysis was carried out over a period of 150 days with sampling in every 10 days. SPSS software (v. 16.0) was used for statistical analysis. Results: Three NaCl concentrations (8, 12, and 15%) significantly affect the inactivation L. monocytogenes (p<0.05). After inoculation, L. monocytogenes populations were reduced most rapidly during the first ten days of storage (~0.5-1.5 log Colony Forming Unit/g) at three mentioned temperatures; after that, the bacteria were continually decreased, being below the detection limit (1 log CFU/g) at the end of ripening. Numbers of L. monocytogenes were reduced more effectively at 14 °C storage temperature than 9 and 4 °C (p<0.05). Conclusion: L. monocytogenes was declined drastically during ripening days and eliminated at the end of ripening of Koozeh cheese. L. monocytogenes counts were decreased during ripening of Koozeh cheese under adverse conditions such as high salt concentrations and high temperatures. However, since Iranian Koozeh cheese is made from raw and unpasteurized milk, there are still some concerns about health risk of L. monocytogenes in this product. Also, the effects of temperature and salting parameters on the sensorial properties of Koozeh cheese should be investigated in future.