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Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer’s postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R 2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination.

The levels of acrylamide intake because of potato crisps consumption remains unknown in Kenyan context. This study assessed the exposure to acrylamide because of consumption of potato crisps in Nairobi, Kenya. A cross-sectional survey was carried out among 315 crisps consumers in Nairobi, and consumption patterns were collected using a pre-tested structured 7-day recall questionnaire. A total of 43 branded and 15 unbranded potato crisps samples were purchased in triplicates of 100 g and acrylamide was quantified using a gas chromatograph with a flame ionization detector. Consumption data were combined with the data on acrylamide contents from which dietary acrylamide intake was calculated using a probabilistic approach based on @Risk TopRank 6 risk analysis software for excel. The mean estimated acrylamide intake was 1.57 µg/kg body weight (BW) per day while the 95th (P95) percentile was 5.1 µg/kg BW per day, with margins of exposures (MOE) being 197 and 61, respectively. The intake of acrylamide was significantly (P < 0.05) higher in unbranded crisps with a mean value of 2.26 and 95th percentile of 6.54 µg/kg BW per day, MOE being 137 and 47, respectively. There were extremely lower MOE indicating higher exposure to acrylamide by the consumers mainly because of the higher acrylamide contents in potato crisps, and hence the need for mitigation measures.

Cowpea (Vigna unguiculata) leaves are nutritious indigenous vegetables that are produced and consumed among local communities in Kenya. However, seasonal production limits their utilization. The study investigated the changing trends in the consumption and utilization of cowpea leaves among cowpea producing households in arid and semi-arid land (ASAL) areas. A cross-sectional survey of randomly selected households producing and consuming cowpea leaves was carried out in Eastern and Coastal ASALs of Kenya to determine the trends and constraints in the production and utilization of the vegetable, thus evaluating its efficiency as a food security crop. The average household production in a season was found to be 3.03 ± 0.9 of 90 kg bags. Lesser severity of the constraints, poor soils, drought, lack of access to seeds and massive spoilage with an odds ratio of 0.4, 0.9, 2.0 and 2.3, respectively, significantly (p < 0.05) predicted the production quantities among households, R2 = 0.21. The study also found that the reliance on own production among households for sourcing the leaves in-season and off-season was 97.5% and 24.9%, respectively. The households consumed the leaves in boiled (87.5%), sundried (27.5%) or blanched (13.6%) forms. Households in the coastal ASALs significantly (p < 0.05) consumed more of dried forms (odds ratio: 3.3) but less of boiled ones (odds ratio: 0.1) than those in the Eastern parts. Households that had more members or a female deciding the food to be bought had significantly (p < 0.05) higher frequency of consumption of cowpea leaves. Marketing challenges, lack of access to inputs and inadequate postharvest technologies for preservation of the vegetables constrained the production and utilization of cowpea leaves. In order to promote the availability and utilization of cowpea leaves both in and out of season, accessibility of good quality seeds and postharvest management are necessary.

Technological advances in baking have enabled the use of bread as a food vehicle for various nutrients through use of composite flours. Orange-fleshed sweetpotato (OFSP) puree subjected to cold chain storage has been used to enrich bread with beta-carotene. However, this has proven expensive and inconsistent in supply of puree. This study sought to develop shelf-storable OFSP puree bread with similar sensory qualities to fresh OFSP puree bread. Bread in which two treatments of shelf-storable OFSP puree (treatments 1 and 2 with 0.5% potassium sorbate+0.5% sodium benzoate+1% citric acid and 0.2% potassium sorbate+0.2% sodium benzoate+1%citric acid respectively) were incorporated at 30% and 40% and were subjected to descriptive sensory analysis with white and fresh puree breads as controls. The results indicate that both the 40% and 30% wheat substitution with either treatment 1 or 2 OFSP puree bread are acceptable to the consumers, p

Regular monitoring of pesticide residues in potatoes (Solanum tuberosum L.) is important to ensure a low risk of pesticide toxicity to consumers. An efficient, modified quick easy cheap effective rugged safe‐dispersive‐solid‐phase extraction (QuEChERS‐ d‐SPE) was optimized and validated for quantification of pesticide residues (metalaxyl, chlorpyrifos, λ‐cyhalothrin, and cypermethrin) in popular Kenyan potato varieties "Shangi," "Tigoni," and "Dutch Robyjn," grown under controlled field conditions using gas chromatography with tandem mass spectrometry (GC‐MS/MS). An evaluation of the effect of five spraying frequencies (unsprayed, 5, 7, 10, and 14‐day intervals) of metalaxyl‐based fungicides on residue levels in harvested potatoes was simultaneously done. Metalaxyl residue levels in the varieties were determined for each spraying regime. Method validation showed good linearity (r2) of 0.988–0.999, detection limit (0.37–0.61 µg/L), quantification limit (1.20–1.84 µg/L) while recovery (71%–94%), and precision (relative standard deviation of 2.3%–24.1%) were used to determine the accuracy of the method. Pyrethroids (cypermethrin and λ‐cyhalothrin) and organophosphates (metalaxyl and chlorpyrifos) were detected in the potato samples. Residue levels of the compounds were not significantly different (p = 0.05) between varieties except for chlorpyrifos. Cypermethrin was the residue compound detected at the highest mean level with 17.4 µg/L, followed by metalaxyl, chlorpyrifos, and λ‐cyhalothrin, at 2.88, 1.05, and 0.15 µg/L, respectively. Residue levels at different spraying frequencies varied statistically between varieties (p = 0.05). Dutch Robyjn sprayed at seven days' intervals had the highest residue level of 9.49 ± 0.26 µg/L. QuEChERS‐d‐SPE with GC‐MS/MS has shown suitability for routine pesticide residue monitoring in potatoes. The potatoes grown under the controlled experimental conditions did not present any concern for human health, as the pesticide residues detected were below Codex maximum residue levels of 500 µg/L. Core Ideas: Potato field production in Kenya is characterized by intensive pesticide application.There is limited data available locally about the type of pesticide or their residue levels present in potatoes.Pyrethroids and organophosphates were detected and quantified in the potato samples.Cypermethrin was the highest residue compound detected, though below Codex MRLs while λ‐cyhalothrin was the lowest.Highest residue in cypermethrin in Dutch Robyjn, metalaxyl in Shangi, and chlorpyrifos and λ‐cyhalothrin in Tigoni. [ABSTRACT FROM AUTHOR]

Food safety management implementation is vital in food industries. Hazard Analysis Critical Control Points (HACCP) implementation in maize millers help in identifying aflatoxin hazards, prevent, reduce or eliminate them. Knowledge, attitude and practices (KAP) towards HACCP on aflatoxin determine the safety of the end product from its contamination. The main objective was to determine KAP on HACCP in Kiambu county maize millers in aflatoxin control. Clustering and systematic sampling methods were used to sample the 30 maize millers. 150 questionnaire respondents were selected randomly from the milling sub-sections. Multivariate probit model and multinomial logit model were used as the analytical framework for evaluating KAP. 60% of the respondents were male, 34% had completed university and 80% of the respondents from management section had completed university while dispatch section respondents had the lowest education level. HACCP average knowledge was 57.5%, 74.43% being highest from management section. HACCP attitude mean score was 3.326, management section showing more positivity with a mean of 3.633. Sufficient training and recruitment of food safety related experts across all sub-section would improve KAP towards aflatoxin reduction to the maize flour. [ABSTRACT FROM AUTHOR]

Aflatoxins are known to cause devastating acute and chronic effects in humans and animals. The objective of the study was to determine the influence of postharvest practices and storage conditions on aflatoxin contamination in maize in two counties. Aflatoxin levels in 144 maize samples from different maize storage conditions were determined. While sampling, a structured questionnaire was also administered to evaluate farmer’s postharvest practices. Makueni County had the highest percentage of aflatoxin positive samples with up to 174 ppb attributed to the long storage under unfavourable conditions. On the other hand, Baringo County had lower positivity associated with the harvesting season at the time of sample collection. The type of storage condition had a significant effect on the extent of contamination and accounted for 11% of the variation (R2 = 0.11). Gunny bags were the most common type of storage condition and had the highest level of contamination in both the counties. Metallic bins had the lowest level of contamination. Aflatoxin G1 and G2 were predominant in samples from Baringo County, while aflatoxin B1 and B2 were predominant in samples from Makueni County. The study concluded that the type of storage condition significantly contributes to the aflatoxin contamination in the stored maize. Proper drying of maize to the recommended moisture content and subsequent storage in hermetic structures will reduce the cases of aflatoxin contamination. [ABSTRACT FROM AUTHOR]

Phytochemicals enhance human health by acting antagonistically on incidences of cancer and other chronic diseases. They are considered indispensable in a variety of nutraceutical, pharmaceuticals, and medicinal and cosmetic applications. This study evaluated the effects of common processing methods on inherent phytochemical content in the roots and leaves of orange‐fleshed sweetpotato (OFSP) varieties called Kabode and SPK031. Yellosp and Whitesp, which are local sweetpotato varieties, were also included as check for roots and leaves, respectively. The sweetpotato products prepared for phytochemical analysis were boiling roots and leaves, frying chips and crisps, baking bread (for roots only), and fermenting and dehydrating leaves. Phytochemicals that were assessed included vitamin C, total phenolics and flavonoids, tannins, phytates, and soluble oxalates. Results indicated that retention of vitamin C was highest in boiled roots (85%–95%), followed by fries (71%–94%) and crisps (44%–76%), whereas the least retention was in bread (4%–11%) and leaves (0%–27%). Total phenolics, flavonoids, and antioxidant activity in leaves significantly (p <.05) varied with the type of processing. Higher retention of these phytochemicals was observed in processed roots but was lowest in bread. Boiling retained more than 100% of all carotenoids, while fermenting and drying the leaves retained 58–62 and 22%–48%, respectively. Frying retained more than 100% of the β‐carotene in the roots, while boiling retained 96%–100%. All processing methods significantly (p <.05) reduced antinutrients in leaves and roots. Fermentation of leaves had higher reduction of oxalates, tannins, and phytates, while boiling had the least effect. It is concluded that traditional boiling enhances phytochemical retention in roots but degrades most of them in leaves. [ABSTRACT FROM AUTHOR]

In most parts of Africa, the process of fermentation is not controlled and does not adhere to good manufacturing practices, therefore spoilage and pathogenic microorganisms can alter the quality of the end product and may cause foodborne illness. Traditional fermented products are mostly processed in an environment which creates a selection of microorganisms that produce the desired end product. In an attempt to find Lactobacilli which have probiotic properties and can be used in the development of starter culture for controlled fermentation of cereal products, the microbial populations of maize flour, overnight soaked dough, fermented cooked porridge, Mkarango and Busaa were enumerated and the inherent lactobacilli isolated. The microbial and biochemical profiles of the 6 days spontaneous Mkarango fermentation process were determined. The total viable count was 6.93 log cfu/g for fermented cooked porridge, 7.70 log cfu/g in Mkarango and 8.58 log cfu/g for Busaa. Lactobacilli counts were higher in maize flour with 7.43 log cfu/g while Enterobactericeae were lower in Mkarango. The highest moulds and yeasts counts were observed for Busaa, 7.25 log cfu/g. The lactobacilli isolates from fermented maize based products from western Kenya were predominantly Lactobacillus fermentum and Lactobacillus Plantarum. During fermentation time, Lactobacilli increased from 6.62 to 12.46 log cfu/g after 3 days of fermentation. From day 4, an increase in moulds and yeast count was observed, varying from 8.42 to 10.53 log cfu/g. Enterobactericeae count decreased from 5.99 log cfu/g on day 1 to less than 1 log cfu/g on day 6. Titratable acidity increased from 0.32% to 0.73% on day 5. Inversely, the pH of Mkarango decreased sharply from 6.64 to 3.64 on day 5 and slightly increased on the last day of fermentation. The microbial status of finished fermented maize based products is predominated by Lactobacilli and their isolates are predominantly Lactobacilli especially Lactobacillus fermentum and Lactobacillus Plantarum though further molecular tests are needed to confirm the species. [ABSTRACT FROM AUTHOR]

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beef dried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimental data with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE) and coefficient of determination (R²). Determination of effective moisture diffusivity (Deff) from the experimental drying data was done and sensory quality of the optimized dried cooked and uncooked beef samples evaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m²/s, increasing with an increase in air temperature and beef slice thickness. Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P = 0.05) scores between the cooked and uncooked dried beef samples. [ABSTRACT FROM AUTHOR]

Technological advances in baking have enabled the use of bread as a food vehicle for various nutrients through use of composite flours. Orange-fleshed sweetpotato (OFSP) puree subjected to cold chain storage has been used to enrich bread with beta-carotene. However, this has proven expensive and inconsistent in supply of puree. This study sought to develop shelf-storable OFSP puree bread with similar sensory qualities to fresh OFSP puree bread. Bread in which two treatments of shelf-storable OFSP puree (treatments 1 and 2 with 0.5% potassium sorbate+0.5% sodium benzoate+1% citric acid and 0.2% potassium sorbate+0.2% sodium benzoate+1%citric acid respectively) were incorporated at 30% and 40% and were subjected to descriptive sensory analysis with white and fresh puree breads as controls. The results indicate that both the 40% and 30% wheat substitution with either treatment 1 or 2 OFSP puree bread are acceptable to the consumers, p<0.05. The saltiness, smoothness and crumb color scores for shelfstorable OFSP puree bread were similar to those of fresh puree bread but were significantly (p<0.05) higher than that of white bread. Shelf-storable OFSP puree bread had similar sensory profile to fresh OFSP puree bread thus can be exploited as an alternative to fresh puree bread. [ABSTRACT FROM AUTHOR]

Resistant starch is known to impart a number of health benefits to consumers. It is therefore desirable to increase the content of resistant starch inpopular foods such as yoghurt. Thecurrent research investigated the effect of cassava resistant starch synthesized by heat-moisture treatment of starch from I92/0057 cassava variety onphysico-chemical properties and sensory attributes of yoghurt. Cassava starch rich in resistant starch was incorporated into yoghurt in the proportions of 0, 0.1%, 0.5% and 1%. Corn starch (0.6%) was used as control. Yoghurt was stored at 4 oC for 21 days and the effect of starch modification on resistant starch content, viscosity, syneresis, total solids, acidity, lactic acid bacteria count and sensory properties were determined on weekly basis. Applying cassava starch rich in resistant starch into yoghurt in the proportions of 0.5% and 1% had significantly higher (p≤0.05) resistant starch content of yoghurt reaching 3.40 g/100 g and 5.58 g/100 g on day one and 1.92 g/100 g and 4.47 g/100 g on day 21, respectively. There was a significant correlation (p≤0.05) between resistant starch concentration and the physico-chemical properties of yoghurt. Yoghurt treated with 1% resistant starch enriched cassava starch had the highest viscosity during cold storage which was determined as 2721.5 mPa s, mPa s, 2650.0 mPa s and 1034.5 mPa s at day 1, day 7, day 14 and day 21 respectively and it had the least syneresis (22.25%). Addition of cassava starch rich in resistant starchsignificantly increased (p≤0.05) the total solids content of yoghurtbut did not significantly (P>0.05) change the sensory properties of yoghurt. The application of 1% of resistant starch enriched cassava starch as yoghurt thickener produces significant quantity of resistant starch in yoghurt with acceptable sensory and physico-chemical properties. [ABSTRACT FROM AUTHOR]