Journal of Food Safety and Hygiene
Volume:8 Issue: 2, Spring 2022

Snail meat is a source of food and livelihood for many inhabitants especially in sub-Saharan Africa. They are consumed in households or traded at local and international markets. However, African land snails are rarely farmed but picked from environments that include decaying vegetation, soil debris, and untreated human and household wastes. These ‘snail natural habitats’ may contain microbial pathogens that could easily be ingested by snails and transmitted to snail meat handlers and consumers. The objective of this study was to investigate published information that establishes the local consumption practices of African land snails as a credible source of foodborne infections. Acknowledging the nutritional benefits of consuming snails, this research revealed local practices in snail gathering, handling, preparation and preservation could significantly contribute to food-related disease burdens to Africans and several African snail meat-exporting countries. With this, national and international food safety regulations are required for African snail meat consumption.

This study evaluated the antioxidant and antibacterial properties of date (Phoenix dactylifera L.) seed extracts against some bacterial pathogens of food-borne diseases. The phytochemical constituents and antioxidant properties of the date seed were determined using a standard chemical method. In vitro antibacterial activities of the crude extracts of date seeds against the pathogens were determined using the agar well diffusion method. The phytochemical screenings of the extracts revealed the presence of oxalate, phytate, flavonoid, saponin, tannin and cardiac glycoside. The screening of the date seed extracts for antioxidant compounds revealed varied concentrations of total antioxidant capacity, ferric reducing antioxidant property and flavonoid. Methanol and aqueous date seed extracts exhibited appreciable antibacterial activity against E. coli, K. pneumoniae, S. typhimurium, B. subtilis and S. flexneri whereas, n-hexane extract had a mild effect on all test organisms. At 200 and 100 mg/mL of the crude extracts, all the test isolates were inhibited. Varied Minimum inhibitory and Minimum Bactericidal Concentrations of different date seed extracts showed potential bacteriostatic and bactericidal action against the test pathogens. It can be deduced that the important bioactive compounds in date seeds may be responsible for the observed antibacterial activity against the causative agents of food-borne illnesses.

Consumption of aflatoxins contaminated foods has led to detrimental health effects worldwide, with even more severe cases in African countries including Tanzania. A cross sectional study was conducted to assess awareness and aflatoxins contamination of sesame seeds in Lindi and Mtwara regions. Subsequently, a total of 70 sesame seed samples were randomly purchased from local markets for aflatoxin determination using High Performance Liquid Chromatography (HPLC). Qualitative data were analyzed using SPSS 20 for descriptive and correlation analysis. Results show that 82.4% of the respondents were not aware of aflatoxin contamination of agricultural produce. Awareness was negatively correlated to the levels of education (p=-0.309) and positively correlated with gender whereby men were more aware than women (p=0.03). On the other hand, 37 out of 70 sesame seeds samples were contaminated with total aflatoxins at a range of 0.009 ng/g to 5.557 ng/g. Although none of these samples exceeded the Tanzania maximum limits of 10 ng/g for total aflatoxins, 2 samples exceeded the maximum limit of 4 ng/g set by the European Union. Furthermore, Aflatoxin B1 was detected in 13 samples moreover the concentration was below the Tanzania and EU maximum limit of 5 ng/g and 2 ng/g respectively. Though the contamination was below the national maximum limits and limited to one agro-ecological zone and season, these findings provide useful insights on aflatoxins contamination of sesames seeds from the two main growing regions in Tanzania.

Six varieties of Tunisian durum wheat, barley and oat cultivars namely Maali, Karim, Rihane, Manel, Meliane and Ghzella were analyzed for their physicochemical properties, antioxidant activities and phenolic acids profile. Results showed that there are significant (p < 0.05) differences in moisture (11.8-12.8%), proteins (10.98-12.09%), neutral detergent fibre (NDF) (47.67-67.39%), ash (2.4-3.93%), fat (2.6- 6.75%), and carbohydrates (64.78-70.95%) contents between all studied varieties. Cereal grains were also a good source of potassium, sodium, calcium, zinc and iron. The results revealed that oat Meliane (5.9%) and barley Rihane (5.4%) varieties are good sources of dietary fiber β-glucan compared to the other varieties. Rihane, Meliane and Maali varieties had the highest total phenolic, total flavonoids and total condensed tannin contents. Antioxidant activity of whole grain extracts was performed using the 2,2-diphenyl-1-picrylhudrazyl (DPPH) test and revealed that barley Rihane had the best radical scavenging activity compared to oat and durum wheat varieties. The RP-HPLC analysis revealed that Tunisian barley, oat and durum wheat varieties are a good source of phenolic components and natural antioxidants.

Refrigeration is one of the common and safest food methods aided by the refrigerator which works by distorting the activities/growth of microorganisms. Nevertheless, the refrigerator could be a transmission source of non-pathogenic and pathogenic bacterial strains involved in food spoilage and foodborne infections. The study seeks to assess the knowledge of students and retailers on microbial contamination of refrigerators. Also, the study would determine the occurrence and antimicrobial resistance profile of Staphylococcus spp. and Listeria spp. isolates. The swab-rinse method was employed for sampling refrigerators used by students (n=86) and retailers (n=38) with a total of 248 samples (Interior surfaces n=124, Exterior surfaces n=124). The swab samples were directly streaked on Mannitol Salt Agar and Oxford Listeria Agar Base for the isolation of Staphylococcus spp. and Listeria spp., respectively. Antimicrobial-resistant profile was determined using the Kirby-Bauer disc diffusion method against vancomycin (30 µg), ampicillin (10 µg), and penicillin-G (10 µg). Of the 110 isolates identified, Staphylococcus spp. were (95) with a prevalence of (86.36%) and Listeria spp. were (15) with a prevalence of (13.64%). Antibiotic resistance was most common to penicillin-G (67.27%) followed by ampicillin (60%), and vancomycin (22.73%). This study confirms the presence of cold-tolerant bacteria in refrigerators. Thus, making refrigerators used by students and retailers a potential source of bacterial transmission and/or contamination.

Raw milk is sterile when secreted by healthy cows however it is contaminated with different microorganisms and Streptococci commonly present in the milk ducts as well as teats. The bacterial count in raw milk ranges from a few hundred to several thousand per mL of milk however it is harmful to human health under unpasteurized conditions. Milk sanitization methods rely on the principle of preventing the growth and development of microbes and thus maintaining their nutritional quality. This study was carried out to investigate the effect of microwave radiation on the microbial quality and safety of bovine raw milk. To do so, the effect of microwaves at a frequency of 35 KH and powers of 180, 300 and 850 W for 0, 30, 60 and 90 s on the destruction of pathogens and reduction of microbial load of milk (total bacterial count, coliforms, Escherichia coli, Staphylococcus aureus, molds and yeasts) was investigated. The results showed that microwave treatment had a significant effect on reducing the number of microorganisms in milk samples (p <0.0) with the power of  850 W being the most effective power for reducing the number of S. aureus, coliforms, molds, yeasts as well as total bacterial count. Faster heating with higher energy efficiency is the main advantage of the microwave process for foods. In fact, the microwave method can be a potential and effective method for decreasing the microbial load of raw milk.