فهرست مطالب

  • Volume:5 Issue: 1, 2019
  • تاریخ انتشار: 1398/10/10
  • تعداد عناوین: 9
  • Leila Peivasteh Roudsari, Mohaddeseh Pirhadi, Hadis Karami, Behrouz Tajdar Oranj, Ebrahim Molaee Aghaee, Parisa Sadighara* Pages 1-9

    Probiotics are commonly defined as live microorganisms (yeast or bacteria), when getting ingested in adequate amounts, they exhibit the beneficial effects on the host. During the past two decades, probiotic microorganisms as health-promoting agents have been increasingly added to various types of food products, especially in fermented food and also drugs. Due to the importance of food safety aspects of the human diet and with regards to some adverse effects of probiotics for human, we decided to carry out a review on probiotics and their adverse effects byresearch in literature. Previous studies indicated that several aspects, including safety, functional and technological characteristics, have to be considered in the selection of probiotic microorganisms. Safety aspects include origin (gastrointestinal tract of healthy human), non-pathogenicity and antibiotic resistance. Some probiotic microorganisms such as enterococci have been considered as an opportunistic pathogen for humans and cause disease, possess agents for antibiotic resistance and potential virulence factors. The bacteria used as a probiotic in food should be completely safe. Probiotic bacteria should be chosen from the healthy human micro-flora and should not have any antibiotic resistance that would prevent treatment of a rare probiotic infection. This review focused on key issues concerning the safety aspects of probiotics added to particular food products for improvement of general health and also discussed the criteria for probiotic selection in details.

    Keywords: Probiotic, Food safety, Pathogenicity
  • arinade Adejumoke Omotayo, Oladipo Oladiti Olaniyi*, Bamidele Juliet Akinyele Pages 10-18

    This work described the isolation and identification of bacteriocin-producing lactic acid bacteria (LAB) from ‘Kati’(a sorghum based fermented food), and to evaluate the antibacterial effect of bacteriocin on selected pathogenic bacteria. The identities of the isolates were revealed to be as Lactobacillus plantarum, L. brevis, L. fermentum KAT1, L. fermentum KAT2 and Lactococcus lactis using 16S rRNA gene sequence analysis. Out of 28 LAB, five were found to inhibit selected pathogenic bacteria namely; Escherichia coli, Staphylococcus aureus, Salmonella typhimurium and Bacillus cereus. The unpurified bacteriocins produced by the isolated LAB were characterized with respect to the effect of temperature, pH and surfactant. The test isolates showed activities of 6400, 6400, 6400, 3200 and 1600 AU/ml respectively. Crude bacteriocin from L. brevis and L. lactis were the most heat stable at 121ºC for 60 min. Bacteriocins from L. plantarum, L. lactis and L. fermentum KAT1 showed the highest antibacterial activity and stability at pH 2.0 to 6.0. Exposure to Tween 20 increased the bacteriocin activity of the LAB isolates except for L. fermentum KAT2 where loss of activity occurred. The findings from this study suggest that bacteriocinogenic LAB present in ‘kati’ have potentials to inhibit pathogenic/spoilage microorganisms in foods.

    Keywords: Crude bacteriocins, Lactic acid bacteria, Bacterial pathogens, ‘Kati’, Antibacterial activity
  • Courage Kosi Setsoafia Saba *, Mariam Vivian Antwi, Frederick Adzitey Pages 19-23

    The most popular street vended foods in Ghana; fried rice, Jollof and Waakye were examined inthe Tamale Metropolis from April to May 2015 to determine the prevalence of B. cereus. Street vended Fried rice, Jollof rice and Waakye were purchased, transported aseptically and Bacteriological Analytical Manual guidelines were used to isolate and enumerate B. cereus. The samples were classified based on the microbial loads of <103 cfu/g, 103≤104 cfu/g and >105 cfu/g for satisfactory, borderline and unsatisfactory respectively. Fried rice recorded the highest number of unsatisfactory samples 18/30 (60.0%), followed by Waakye 8/30 (26.7%) and the least was Jollof 7/30 (23.3%). There is the need for regular training for vendors and further work to determine toxins produced by B. cereus.

    Keywords: Bacillus cereus, Boiled, fried rice, Street food, Food safety, Ghana
  • Kate Bigson *, Edward Ken Essuman, Gifty Serwaa Otoo, John Nsor Atindana Pages 24-29

    This research was designed to evaluate how foodstuffs are acquired and stored prior to meal preparation under the Ghana School Feeding program in Wa and Cape Coast schools. A cross-sectional and descriptive survey research designs were used in the study. A purposive and simple random sampling technique was employed in selecting 120 participants computed with Graph pad prism version 16, statistical software. Information was obtained using questionnaire, observation and unstructured interview instruments. Data were analysed using Statistical Package for Social Science software version 22 and results represent in tables and charts. Findings revealed that most schools did not have food storage places. This situation may force kitchen staff to keep the food ingredients in their homes and bring them when the need be. Kitchens were mostly shed and firewood was mostly used as cooking fuel. It was observed that some of the caterers bought some food ingredients from hawkers who found their ways to the school compounds. Almost all the kitchen staff (97.3% for Wa and 100.0% for Cape Coast) buy from the open market and not the farm gate. This has resulted in food insecurity in some of the regions. Owing to the findings, it was recommended that government should enact policies for all caterers to buy directly from the farm gate at cheaper prices; designated and well-built kitchens, as well as dining rooms, be provided for schools.

    Keywords: Farm gate, Open market, Storage facilities, School feeding program, Procurement
  • Oladipo Oladiti Olaniyi *, Juliet Bamidele Akinyele Pages 30-38

    The possible health threat accompanied with the ingestion of ‘Burukutu’, an alcoholic beveragemade from fungal contaminated cereals grains calls for regular inspection. The study aimed at the isolation of toxigenic Aspergillus flavus and quantification of aflatoxins in‘Burukutu’ sold in Akure, Nigeria. The fungi associated with the samples were isolated and counted using standard microbiological methods. Aflatoxins were extracted from 64 samples using different solvents and analyzed with the aid of High Performance Thin-Layer Chromatography (HPTLC). The aflatoxins in the samples applied on pre-heated HPTLC plates were estimated under fluorescent UV light. Cooked fermented milled malted grains ‘Burukutu’ (CFMMG) had the highest fungal counts of6.8×102 and 2.9×102 cfu/ml at 24 and 48 h of incubation respectively. The fungal isolates identified from the samples were: Aspergillus flavus, Fusarium solani, Rhizopusstolonifer, A. fumigatus, A. niger, Penicillumitalicum, Saccharomyces cerevisae and Candida krusei. All the analyzed samples showed varied quantity of aflatoxin concentrations. The overall quantification of aflatoxins G1, G2, B1 and B2 revealed significant reduction in end products ‘Burukutu’ whencompared with the substrates from which it was made. Different general fungi associated with ‘Burukutu’ were identified. There was also a decline in the level of aflatoxins in ‘Burukutu’ whichwas a product of natural fermentation.

    Keywords: Aflatoxins, Aspergillus flavus, Maize grains, Bio-detoxification
  • Reza Alizadeh, Amir Amniattalab ٭ Pages 39-45

    This study was carried out for the evaluation of the prevalence rate and the pathology of various lesions in the confiscated livers of slaughtered Azeri buffaloes at Urmia Abattoir, Northwest Iran. Livers of 306 Azeri buffaloes were inspected grossly during five months according to their color and consistency changes in Urmia Abattoir. Among the inspected carcasses, livers of 28 buffaloes had various lesions. The collected tissue samples of confiscated livers were placed in 10% buffered formalin as a fixative solution in order to prepare pathologic sections with a thickness of 6 μm. The sections were stained by haematoxylin and eosin (H&E) and periodic acid schiff (PAS) methods. The most common pathologic changes in the confiscated buffalo livers were fatty change (46.4%), hepatitis and cholangitis (42.9%), and bile duct hyperplasia (39.3%) respectively. The results of this study have shown that there was a significant difference (p<0.05) between hepatic congestion and sex. In addition, there was no significant difference (p>0.05) between hepatic lesions and age. The results of this study have revealed that fascioliasis has an important role in the creation of some hepatic lesions such as bile duct hyperplasia, fatty change, and hepatitis in buffaloes. Since various hepatic lesions can reduce buffalo productions and has negative influence on animal reproduction, it is necessary to pay more attention to accurate performing of antiparasitic program and the evaluation of possible role of poisonous plants, heavy metals, and mycotoxins in the generation of hepatic lesions of buffaloes.

    Keywords: Pathology, Azeri buffalo, Hepatic lesions, Urmia abattoir
  • Naficeh Sadeghi *, Masoomeh Behzad, Behrooz Jannat, Mohammad Reza Oveisi, Mannan Hajimahmoodi, Mohammad Mozafazri Pages 46-50

    Histamine is one of the well-known biogenic amines and responsible for causing allergic reactions. The presence of biogenic amines in the foodstuff is harmful, if it enters in a large amount to blood. In sea-food products, due to lack of proper storage at appropriate temperatures (freezing), histamine may be formed and will remain in the product, since it is already dry and heat resistance. Hazard of histamine consumption and average amount of canned fish consumed worldwide makes histamine measurement in canned fish very important. In this study 56 samples from 22 different brands were assessed and Enzyme-Linked Immunosorbent Assay (ELISA) was used by spectro-photometry for histamine detection. Our study showed that histamine levels in canned fish available in Tehran market, though it is high (5.75±5.98 mg/100 g tuna), but is not in a hazardous state (p<0.01). Our research showed that lowest and highest histamine concentration were 2.14±0.17 and 21.69±0.11 mg/100 g of fish respectively. It also indicates that medium does not affect the histamine content. There were no significant differences in the samples of fish and tuna fish for histamine. The amount of histamine in the tuna was below the standard limit (<50 mg histamine/100 g). Further studies should be carried out to investigate the presence of histamine in various fish and other sea-food.

    Keywords: Canned tuna, Enzyme-linkedimmunosorbent assay, Fish, Histamine, Scombroid poisoning
  • Sukhuntha Osiriphun*, Phichaya Poonlarp, Danai Boonyakiat, Patcharin Raviyan Pages 51-57

    Fresh cut vegetables are a source of minerals, vitamins, and phytonutrients that are convenient foods for consumers which are following the global trend of inclination toward healthy food. In terms of food safety, contamination of vegetables with microorganisms can occur at multiple points along the supply chain. This study was conducted to investigate the risk factors of Escherichia coli and Staphylococcus aureus which contaminate freshly cut vegetables during production (receiving, washing, centrifuging, and packing areas) by using a statistical method for sensitivity analysis and an exposure assessment model complying with the @RiskTM software program. At washing step, the numbers of S. aureus found in the vegetables and water were 0.79±1.76 Log cfu/g and 0.68±1.52 Log cfu, respectively. For the equipment, the hand, and the table stabbing samples, the numbers of S. aureus were 0.48±1.07 Log cfu/25 cm2, 1.81±1.69 Logcfu/25 cm2, and 0.54±1.21 Log cfu/25 cm2, respectively. An amount of E. coli of 0.48±1.07 Log cfu/25 cm2 was found in the table swabbing samples at the packing area. E.coli and S. aureus were not found in any of the mixed fresh-cut salad samples; therefore, the product samples could be considered safe for consumers. The result of the sensitivity analysis showed that the temperature and pH of water samples were the important factors in the washing process. The suggested interventions included monitoring and maintaining the water temperature at 5°C; also, maintaining the pH of water between 6.5 and 7.5 could help to reduce pathogen contamination of freshly cut vegetables.

    Keywords: Sensitivity analysis, Mixed salad vegetables, Escherichia coli, Staphylococcus aureus
  • Nabi Shariatifar *, Ebrahim Molaee aghaee Pages 58-59

    Coronaviruses include viruses that cause colds and seasonal flu. COVID-19 belongs to the Coronaviruses family that causes acute respiratory involvement. Diseases such as Severe Acute Respiratory Syndrome (SARS) and Middle Eastern Respiratory Syndrome (MERS) are also part of the Coronavirus family. COVID-19 is a new strain of this virus that has not been previously identified in humans and was first detected in Wuhan, Hubei Province, China (1). Food contamination can occur through the hands, sneezing and coughing of workers responsible for the preparation and packaging of food, and according to the World Health Organization's findings, consumption of contaminated raw and unclean food can cause human disease (2).