Samuel Ayofemi Olalekan Adeyeye

Fungal mycotoxins in foods: A review

Abstract This study aimed to review fungal mycotoxins in foods, their roles and significance in human nutrition and health. This paper provided comprehensive information on the mycological quality and mycotoxin safety of foods. The review showed that moulds are multicellular fungi that form thin thread like structures called hyphae. They are widely distributed and found wherever moisture is present with adequate nutrients that can sustain their growth. Fungi are major spoilage of foods and feedstuffs. The proliferation of various fungi in agricultural products leads to reduction in yield and quality with significant economic losses. Fungi produce secondary metabolites which are referred to as mycotoxins which have been found to be present in most food substances. The mycotoxins are low weight metabolites which cause harm known as mycotoxicoses, in livestock, domestic animals and humans and therefore of public health significance. The production of mycotoxins is stimulated by certain environmental factors: Therefore the extent of contamination will differ with geographic location, agricultural methods and the susceptibility of commodities to the penetration of fungi during storage and processing periods. Fungi that produce toxins in food are therefore classified into field fungi and storage fungi based on their ecological requirements for growth. Mycotoxins have been reported in several food products such as cereals, legumes, processed flour, and smoked-dried fish and in dried meats.

Quality characteristics and acceptability of cookies from sweet potato – maize flour blends

Purpose – This study aims to assess the quality characteristics and acceptability of cookies from sweet potato–maize flour blends and to determine nutritional quality, color and palatability traits and to compare the effects with that of wheat cookies, so as to suggest a cost-effective production method to bakers and retailers. This would ensure food security, enhanced health, combat malnutrition problems and improve the production of the crops. Design/methodology/approach – Cookies were prepared by the method reported by Okaka and Isieh (1990), Abayomi et al. (2013), Onabanjo and Ighere (2014) with modification. Flour (200 g) from each sample of different flour blends was used for the experiment. Sugar (80 g) was creamed with margarine (100 g) until light and fluffy constituency was obtained using Kenwood chef with initial minimum speed, and the speed increased stepwise until the mark of 6 on the chef indicator was attained. Whole egg (60 g) was added, then followed by flour (200 g), powdered milk (20 g)...

A preliminary study on the quality and safety of street-vended warankasi (a Nigerian soft white cheese) from Ibadan, Oyo state, Nigeria

Purpose The purpose of this paper is to evaluate the quality and safety of street-vended warankasi, a Nigerian soft white cheese. Design/methodology/approach A total of 80 samples were collected in two batches of 40 samples each in January and June, 2015 from eight major markets from Ibadan, Oyo State, Nigeria. The samples were analyzed for the proximate components, quality indices (total soluble nitrogen, TSN and volatile fatty acid, VFA), and for the presence of pathogenic bacteria, Campylobacter jejuni (CJ), Listeria monocytogenes (LM), Mycobacterium tuberculosis (MT), Salmonella spp. (SS), Escherichia coli (EC), and Yersinia enterocolitica (YE), and heavy metals such as (lead (Pb), cadmium (Cd), mercury (Hg), and chromium (Cr) concentrations. Findings The results revealed that the values of moisture, protein, fat, crude fiber, and ash contents (%) of warankasi samples were in the range 46.26±1.41-51.24±1.61, 33.92±1.18-37.26±1.42, 6.74±0.64-8.33±0.96, 1.27±0.02-1.73±0.09, 1.31±0.03-1.78±0.08, respectively. The values of TSN (mgN/kg) and VFA (%) were in the range of 1.19+0.10-2.54+0.18, and 5.79+0.19-9.12+0.30, respectively. The results further revealed the presence of CJ and SS and the absence of LM, MT, EC, and YE from the warankasi samples. Heavy metals detected in all the warankasi samples were generally below the maximum acceptable limits set by the World Health Organization for Pb (0.3 ppm), Cd (0.2 ppm), Hg (0.2 ppm), and Cr (0.5 ppm) with the exemption of samples from Iwo Road and Ojoo which were higher than other samples. Research limitations/implications This research work was conducted between January and June, 2015 and better results could be obtained if the study had been done for a longer period of time. Practical implications The paper helps in showing the quality and microbial safety of street-vended warankasi and this may bring imperative information and general consciousness on the microbiological safety of warankasi. Originality/value Much has been done concerning warankasi processing but little work has been done concerning street-vended warankasi. Therefore, this study was carried out to assess it.

Effect of smoking methods on microbial safety, polycyclic aromatic hydrocarbon, and heavy metal concentrations of traditional smoked fish from Lagos State, Nigeria

ABSTRACT A study was carried out to investigate the effect of smoking methods on microbial safety, polycyclic aromatic hydrocarbon, and heavy metal concentrations of traditional smoked fish from Lagos State, Nigeria. One hundred samples of fresh fish were obtained from 20 different fishing communities/processing centers. The fresh fish samples were divided into two batches: The first batch was smoked with drum kiln and the second batch was immediately taken to the Fish Hatchery Unit, Federal University of Agriculture, Abeokuta for smoking with convective kiln. Laboratory analyses were carried out on the two batches for: microbiological (Coliform, Fuugi, Listeria monocytogenes, Salmonella paratyphi and Staphylococcus aureus), polycyclic aromatic hydrocarbon and heavy metals (mercury, lead, cadmium and chromium). The results of the microbiological, polycyclic aromatic hydrocarbon and heavy metal analyses revealed that there were significant variations (p < 0.05) between them. LC count of fresh silver catfish, spotted tilapia, bonga shad, Nigerian tongue sole, and Guinea barracuda samples were 1.9 × 102, 1.7 × 102, 2.0 × 102, 2.1 × 102 and 2.6 × 102 cfu/g and their drum kiln smoked samples were 4.0 × 10, 5.3 × 101, 6.0 × 101, 12.2 × 101 and 7.4 × 101 cfu/g, respectively, while samples from convective smoking kiln contain no strain of Listeria monocytogenes. The concentrations of the six major PAHs (fluorene, anthracene, benzo [b] fluoranthene, benzo [a] anthracene, benzo [a] pyrene and benzo [ghi] perylene) in the drum-smoked fish exceeded the EU maximum level of 5.0 μg/kg for BaP permissible in smoked fish, while samples smoked by convective smoking kiln showed levels below 3.5 μg BaP/kg. The study also showed that the levels of the four heavy metals investigated in the smoked fish samples are generally below the maximum permissible levels set by World Health Organization for Hg (0.2 ppm), Pb (0.3 ppm), Cd (0.2 ppm), and Cr (0.5 ppm) and hence pose no risk to smoked fish consumers.

The role of food processing and appropriate storage technologies in ensuring food security and food availability in Africa

Purpose This paper aims to review scientific contributions that are essential to reduce the challenges to food security in Africa through food processing and appropriate storage technologies. Design/methodology/approach Several literature studies on the role of food processing and appropriate storage technologies in ensuring food security and food availability in Africa were critically reviewed. Findings The study revealed that the world faces multiple challenges to food security including under nutrition and overconsumption, rising food prices, population growth, rapid diet transitions, threats to agricultural production, inefficient production practices and supply chains and declining investment in food system research. Many people lack adequate amounts of foods that are rich in the nutrients needed for a healthy and productive life. According to FAO, 1996, chronic undernutrition affects 43 per cent of the Africa’s population or some 215 million people in sub-Saharan Africa. Food security is highly instrumental to the economic growth and sustainability of any country. The use of simple but effective on- and off-farm storage facilities and agro-processing technology should be promoted to add value to products and increase their shelf-life. The Strategic Grain Reserve Scheme should be modernized, strengthened and upgraded to a National Food Reserve Program, which will enable it to handle all staples and essential food products. This will help in attainment of national food security goal. It is also crucial to promote and develop agro-processing in the various African countries for the evolution of virile agro-allied industries and rural micro-enterprises. Research limitations/implications The paper reviewed the role of food processing and appropriate food storage technologies in ensuring food security and availability in Africa. There are insufficient data and information on adoption of new food processing and appropriate storage technologies in Africa. Although, there have been some instances where the introduction of modern techniques has resulted in products rejection by consumers. Practical implications The paper helps in reviewing food situation in Africa and how to make food available for the people and Africa food secured. Social implications This paper revealed strategies that could be used to improve food security and ensuring food availability in Africa. Originality/value This review paper is of value to policymakers, government agencies responsible for food quality control and assurance and consumers to make food available and affordable for the people.

Assessment of quality and safety of traditional smoked spotted tilapia fish (Tilapia mariae) from Lagos State, Nigeria

Purpose – This study aims to assess the quality and microbial safety of traditional smoked spotted tilapia fish from Lagos State and, by doing so, determine the quality and microbial safety level of traditional smoked spotted tilapia fish, their distribution, effects and possible public health implications of the quality/rancidity indices and microorganisms on the consumers. Design/methodology/approach – Fresh spotted tilapia fish (100 samples) were collected from 20 different fishing/processing centres and divided into two batches. One batch was smoked with local drum kiln at processing centres, and the second batch was smoked with convective smoking kiln as control in the laboratory. Each batch was assessed for moisture content, protein content, fat content, crude fibre content, ash content, pH, thiobarbituric acid (TBA), total volatile base- nitrogen (TVB-N), trimethylamine (TMA), peroxide value (PV) and free fatty acid (FFA) values. Microbiological analyses were also conducted. Each batch was assessed...

Quality characteristics and chemical safety of fried and smoked West Africa Ilisha (Ilisha africana) from Ibadan, Oyo State, Nigeria

Purpose – This study aims to assess and compare the quality and safety of street-vended, ready-to-eat fried and smoked West African Ilisha fish from the major markets in Ibadan, Oyo State, Nigeria. Design/methodology/approach – A total of 50 samples each were obtained from ten major markets in Ibadan, Oyo State, Nigeria. Samples were analyzed in the laboratory for proximate, rancidity indices; i.e. peroxide value (PV), thiobarbituric acid (TBA), total volatile base-nitrogen (TVB-N), trimethylamine acid (TMA) and free fatty acid (FFA), polycyclic aromatic hydrocarbon (PAH) and heavy metals. Findings – The results showed that the mean PV (meq. peroxide/kg), TBA (mg Mol/kg), TVB-N (mgN/kg), TMA (mgN/kg) and FFA (%) contents within the fried fish samples ranged from 18.86-23.11, 2.08-2.98, 14.89-17.79, 1.98-2.89 and 2.46-5.98, respectively, while in the case of smoked fish samples, the corresponding contents were found to be 9.03-15.96, 1.03-1.59, 17.29-19.36, 2.15-2.68 and 1.13-1.62, respectively. The result...

An Overview of Traditional Fish Smoking In Africa

ABSTRACT This study was carried out to have a critical overview of traditional fish smoking in Africa. Fish is highly susceptible to deterioration without any preservative or processing measure, and due to its chemical composition, fish is a perishable food material, and its flavor and texture change rapidly during storage after death. Fish harvesting, handling, processing, and distribution provide livelihood for millions of people, as well as providing foreign exchange to many African countries. In many rural fishing communities, the infrastructures for post-harvest processing and preservation of fish are inadequate. As a result, losses reach up to 40% of the total catch by weight. The fishing industry, despite its importance, suffers from enormous post-harvest losses which are estimated at 35–40% of landed weight, and it is estimated that post-harvest losses remain about 25% of the total world catch annually. These losses have a profound adverse impact on fishing communities whose status and income often depend on post-harvest activities. Such losses also have a detrimental impact on the socio-economic life of the fishing communities and reduce the amount of animal protein available to a large segment of the population. In Africa, some 5% of the population, about 35 million people, depend wholly or partly on the fisheries sector, mostly artisanal fisheries, for their livelihood. Various traditional methods are employed to preserve and process fish for consumption and storage. These include smoking, drying, salting, frying, and fermenting and various combinations of these. In most countries in Africa, Nigeria, Ghana, Cote d’Ivoire, Togo, Benin, Senegal, Sierra Leone, Liberia, Kenya, Uganda, Tanzania, etc., smoking is the most widely practiced method: Practically all species of fish caught can be smoked, and it has been estimated that 70–80% of the domestic marine and freshwater catch is consumed in smoked form. However, different smoking methods are used in processing and preservation of fish by artisanal fishermen in Africa.

Safety Issues in Traditional West African Foods: A Critical Review

ABSTRACT Food safety is a global phenomenon and West African sub-region cannot be an exception. The public has become more concerned about the risks from food hazards in recent years and the need to take appropriate steps to reduce to barest minimum the issue of food hazards in West African sub-region. West African countries have a rich culture and tradition in food technology in preparing their foods. These foods play key roles in the culture, economy and food security of these countries. However, these traditional foods are still prepared at the household level under poor sanitary conditions and marketed through informal routes. They thus remain beyond any official control for their compliance to national regulatory standards. Therefore, their consumption is anticipated to put the public health at risk, although such risk has never been fully estimated on a scientific basis due to the lack of consumption patterns, epidemiological data, and appropriate surveillance programs in most of West African countries. This review provides a description of technologies of the most popular traditional foods of animal and plant origin in West Africa and discusses the potential microbiological and chemical risks associated with their consumption and the food safety challenges that they raise. The review also aims to draw the attention of stakeholders including decision makers in West African countries to the need to assess the health risks associated with the consumption of these traditional foods and consequently, take the necessary measures and steps to reduce such risks for safer foods in West African countries.

Assessment of quality and sensory properties of sorghum–wheat flour cookies

Abstract The study was undertaken to assess the quality and sensory properties of sorghum (Sorghum vulgare)–wheat (Triticum aestivum) flour cookies. The chemical, physico-chemical parameters and sensory qualities of flours/cookies were studied and compared with control cookies from wheat flour. Sorghum flour was produced from whole sorghum grains and then incorporated at 5–50% level in wheat flour. The results revealed that substitution of wheat flour with sorghum flour significantly (p < 0.05) increased the moisture, ash, crude fiber, protein and fat contents of the mixture increased as the percentage of substitution of sorghum flour increased. While the sugar and starch contents decreased as the sorghum flour substitution increased. The proximate composition (moisture, ash, crude fiber, fat, protein, starch and sugar) of wheat flour were 8.64 ± 0.18, 1.57 ± 0.04, 1.42 ± 0.05, 2.29 ± 0.06, 8.48 ± 0.12, 76.92 ± 0.31 and 1.68 ± 0.13 while that of sorghum flour were 10.28 ± 0.39, 2.41 ± 0.49, 2.32 ± 0.14, 3.83 ± 0.21, 10.72 ± 0.24, 70.38 ± 0.10 and 1.16 ± 0.02. The proximate composition of composite flours with different levels of sorghum flour substitution ranged from 8.76 ± 0.19 to 9.16 ± 0.31, 1.61 ± 0.05 to 1.88 ± 0.16, 1.48 ± 0.03 to 1.79 ± 0.10, 2.36 ± 0.07 to 2.74 ± 0.12, 8.54 ± 0.12 to 9.26 ± 0.24, 75.67 ± 0.30 to 72.94 ± 0.14 and 1.63 ± 0.11 to 1.32 ± 0.05. The calorific value of the cookies decreased from 489 ± 1.88 to 421 ± 1.48 cal/100 g as the percentage of sorghum flour increased in the wheat flour cookies. Sensory evaluation results showed that the color, texture, taste and overall acceptability changed significantly (p ≤ 0.05) with increase in sorghum flour substitution. The study concluded that cookies from sorghum–wheat flour blends are advantageous as a means of reducing heavy demands on importation of wheat by developing countries.