21 research outputs found
Fungal dissemination by housefly (Musca domestica L.) and contamination of food commodities in rural areas of South Africa
Abstract: Several insects that act as vectors, including houseflies (Musca domestica L.), are often considered to be an important source of fungal contamination in human foods.Houseflies are also involved in the transmission of bacterial pathogens that may pose a serious hazard to human health. Thus, the rural population of South Africa, as typified by that in the Gauteng Province investigated in this study, is at high risk from fungal exposure disseminated by houseflies and it is therefore important to assess the role of flies in contaminating various food commodities. Eighty four samples of houseflies (captured fromhouseholds and pit toilets)were studied for their potential to carry fungal spores into food commodities. The fungi occurring in samples of rawmaize (15) and porridge (19)were also assessed. Fungal isolates were identified based on morphological characteristics by conventional identification methods. Fifteen genera of fungi were isolated and identified, of which Aspergillus, Fusarium, Penicillium, Cladosporium, Moniliella and Mucor were the most prevalent in all three sample types analysed. The incidence rates of fungal contamination per total fungal count isolated in houseflies, maize and porridge were recorded with mean fungal load of 2 × 108 CFU/ml, 1 × 107 CFU/g and 2 × 107 CFU/g respectively. Additionally, A. flavus, A. parasiticus, F. verticillioides, F. proliferatum, P. verrucosum, P. aurantiogriseum and M. suaveolens were the most frequent fungal isolates in houseflies with incidence rate of 34%, 11%, 27%, 21%, 22%, 17% and 32% respectively. F. verticillioides, A. flavus, A. niger and P. oslonii were the most prevalent species contaminating porridge and maize with incidence rate of 23%, 32%, 16% and 28% in maize samples,while incidence rates of 59%, 15% and 29% were recorded in porridge samples with the exception of F. verticillioides. The prevalence of these genera of fungi may pose serious health risks
Fermented Pulse-Based Food Products in Developing Nations as Functional Foods and Ingredients
Pulses play a significant and diverse role in the agricultural systems and diets of underprivileged populations worldwide. They are ideal produce for reducing poverty, improving human health and nutrition, and enhancing resilience of the ecosystem. Fermentation is a processing technique that has been used for decades to transform food produce with improved health, functional, and nutraceutical benefits. In tandem with the United Nations’ (UN’s) sustainable development goal Number 3, fermented food products from pulses with health benefits align with this initiative to end hunger, achieve food security, and improve nutrition. In solidarity with the celebration of International Year of Pulses 2016 (IYP2016) and considering the relative neglect of pulses as compared with other food groups, this chapter would be vital in positioning pulses and fermented products from them as readily available functional foods. With increased interest in fermentation, fermented pulse-based foods have been identified as excellent sources of bioactive and functional foods. Thus, fermented pulse-based products present a viable alternative, relatively available, affordable, and cheap source of foods with properties beyond that of basic nutrition
Subcritical Water Extraction and Its Prospects for Aflatoxins Extraction in Biological Materials
Aflatoxins (AFs) are well-known mycotoxins and contaminants of various agricultural commodities globally that are linked to a wide range of adverse health and economic complications. Because of their incessant proliferation and deleterious consequences, it has become mandatory to routinely monitor the levels of these toxins in agricultural products before they go into the market. Essentially, effective analysis is an important component of AFs control, and extraction is a necessary step for their analysis, irrespective of the protocol adopted. Conventional methods for AF extraction are expensive, the processes involved are tedious and utilize large quantities of organic solvents that are environmentally unfriendly. This has necessitated the quest for alternatives that are ‘green’, cost-effective and easy to perform. In this regard, subcritical water extraction (SWE) is a viable alternative that has proven to be effective in the extraction of other bioactive compounds. This chapter presents a critical appraisal of the principles and dynamics of SWE, and its current applications as a viable tool in the extraction of AFs from various biological matrices. Although further research needs to be performed to enhance its applicability, the adoption of SWE in the extraction of AFs seems very promising and needs to be properly exploited
Mitigation of Acrylamide in Foods: An African Perspective
Acrylamide (ACR) is a possible human carcinogen, with neurotoxic properties. It is a heat-generated food toxicant particularly found in carbohydrate-rich foods. Its occurrence is of global concern and constitutes a major challenge to food safety, due to its presence in several thermally processed foods worldwide. Since its discovery, ACR has been recognized as one of the most widely investigated heat-induced food contaminant, and several reports on its formation and occurrence since its discovery have been reported. However, information on the extent of ACR occurrence in foods consumed in different parts of Africa is rather too limited. This is particularly a concern considering that most carbohydrate-based foods, subjected to varying degrees of thermal processing, are consumed as staple diets almost on daily basis in the continent. As such, African populations may be exposed to high levels of ACR daily. Thus, this chapter covers the formation, occurrence and health impact of ACR in foods. It further summarizes previous studies looking at ACR reduction and mitigation strategies, especially those that may be applicable in the continent. Adequate sensitization of the populace about the prevention of ACR as a food contaminant is essential to ensure the safety of heat-processed carbohydrate-rich foods in the continent
Mineral-PET: Kimberlite sorting by nuclear-medical technology
A revolutionary new technology for diamond bearing rock sorting which has its roots in medical-nuclear physics has been taken through a substantial part of the R&D phase. This has led to the construction of the technology demonstrator. Experiments using the technology demonstrator and experiments at a hospital have established the scientific and technological viability of the project
Histological Observation and Expression Patterns of antimicrobial peptides during Fungal Infection in Musca domestica (Diptera: Muscidae) Larvae
Investigation of fungal dissemination by Housefly (Musca domestica L.) and contamination of food commodities in selected rural areas in South Africa
Abstract: Houseflies, Musca domestica Linnaeus, are commonest insects of both farms and homes. This species have increasingly overcrowded human dwellings, particularly in rural areas and constitute a health hazard. These flies are not only a nuisance, but they can also transport disease-causing organisms. This may lead to the spread of diseases and also mycotoxin-producing fungi. As a result, frequent exposure to the activity of houseflies will have an impact on public health. Houseflies are dominant in exposed items such as drinking water, food and human faeces. The study was conducted to determine the potential of houseflies in enhancing fungal contamination of food commodities. A total of 183 samples of houseflies (122), maize (15), porridge (19) and water (27) samples collected from Gauteng Province of South Africa were screened for fungi contamination by serial dilution technique on agar plates following DNA sequencing. In this case, 729 fungal isolates were identified with the most commonly isolated fungi belonging to the genera of Aspergillus, Fusarium and Penicillium. On the other hand, Aspergillus flavus was by far the most common, followed by A. niger, A. parasiticus and A. fumigatus. The most common Fusarium species were F. verticillioides, F. proliferatum, F. oxysporum and F. culmorum. Among the Penicillium species, Penicillium aurantiogriseum, P. brevicompactum, P. oslonii and P. verrucosum were the most common fungi. The incidence rates of fungal contamination per total fungal count isolated in houseflies, porridge, maize and water were recorded with fungal load of 2 x 108 CFU/ml, 2x 107 CFU/g, 1x 107 CFU/g and 1 x 102 CFU/g. Aspergillus, Fusarium and Penicillium species recovered were further confirmed and quantified for the production of aflatoxins (AFB1, AFB2, AFG1 and AFG2), deoxynivalenol (DON), fumonisin B1 (FB1) ochratoxin A (OTA) and zearalenone (ZEA) by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). The analysis of houseflies isolates by TLC revealed that FB1 was found with the highest incidence rate of 62 (73%) while, ZEA and DON had the lowest incidence rate of 15 (18%) and 8 (9%). For Fusarium isolates (66) from maize, only 11 (17%) of the extracts were positive for FB1 from F. verticillioides. The fluorescence of AFs and OTA viewed under ultra violet light revealed that some isolates were positive showing a light blue fluorescence for AFB1 and AFB2, light green fluorescence for AFG1 and AFG2, while a blue-green fluorescence was observed for OTA. According to the results on HPLC, Aspergillus flavus and A. parasiticus were found to be the main producers of AFB1, AFB2, AFG1 and AFG2, while A. carbonarius, A. niger and A.D.Tech. (Biomedical Technology
The exposure of a rural village population in Limpopo province to fungi and mycotoxins with particular reference to fumonisin B1
M. Tech.Fusarium species are common contaminants of maize and are also capable of producing mycotoxins, in particular the fumonisin. These are implicated in animal and human mycotoxins fumonisin B1 (FB1) for example, has been associated in the aetiology of oesophageal cancer in South Africa and other parts of the world, i.e., China and Iran. Because maize is the staple diet of the South African rural population, this study was designed with the aim of monitoring Fusarium spp. and FB1 in the food of rural people of Venda, Limpopo province of South Africa, during the course of processing maize into porridge which gave a means of estimating dietary exposure to this mycotoxin. Measurement of fumonisin in the excreta of these people allowed a determine of the extent to which FB1 the body is actually exposed to the mycotoxin.Fumonisin B1 has been identified as a major fungal contaminant on maize, especially in the home grown crops intended for human consumption. Thus the rural population of Limpopo Province is at high risk from FB1 exposure and it is therefore of importance to assess this exposure by the analysis of suitable samples.It can be seen that levels of FB1 in maize from Venda are quite high, as several of these samples had exceeded levels above 1750 μg/kg as recommended as maximum tolerance levels by theEuropean Commission. It is equally seen that a much higher proportion of this mycotoxin was destroyed by processing maize to porridge. And because porridge and other maize-based products are usually consumed on a daily basis, the low levels found in the present study must not be under-estimated, as such levels may accumulate over time and cause more severe chronic effects in humans. When setting daily tolerable levels of FB1 in foods in South Africa, it is imperative to take into account the food habits, especially those within the rural communitie
Breastfeeding and Complementary Feeding Practices among Caregivers at Seshego Zone 4 Clinic in Limpopo Province, South Africa
Breastfeeding and complementary feeding are key components of infant and young child feeding that ensure healthy growth, survival, and development. Initiating breastfeeding within an hour after delivery, exclusively breastfeeding for six months, and introducing complementary feeding at six months while continuing breastfeeding up to 24 months or beyond, helps in the prevention of malnutrition, which is a public health problem. The aim of this study was to determine breastfeeding and complementary feeding practices among caregivers of children under 24 months in Seshego, Limpopo Province. A quantitative and cross-sectional design was applied to collect data from 86 caregivers using convenience sampling. A structured questionnaire was utilised to gather data and analysed through statistical software, using descriptive and inferential statistics. Chi-square tests were used to determine associations at a 95% confidence interval where a p-value of <0.05 was considered statistically significant. The findings show that 55% of participants had good breastfeeding and complementary feeding practices. Moreover, 94.2% of participants breastfeed within an hour after delivery at a healthcare facility. Only 43.6% of children were exclusively breastfed. Most participants (52.3%) gave children food before six months and 45.1% introduced complementary feeding at the appropriate age. Also, 69.7% of children across all age groups were not given infant formula. No statistical association was observed between feeding practices and sociodemographic. Breastfeeding was initiated within an hour after delivery at the healthcare facilities, however, post discharge exclusive breastfeeding maintenance remains a challenge. Few infants were introduced to complementary feeding at the appropriate age. A post discharge intervention to practice exclusive breastfeeding, continued breastfeeding, and introduction of appropriate complementary feeding is recommended