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Cereals including maize generally have limiting amino acids particularly lysine. In most cases, spontaneous fermentation is used to improve the nutritional profiles of maize‐based products. However, in such fermentation, biological risks including the presence of pathogenic microorganisms, chemical contaminants, and toxic compounds of microbial origin such as mycotoxins pose a health risk. The aim of this study was, therefore, to improve the nutritional properties of maize flour by reducing antinutritional factors through microbial fermentation by strains of Lactobacillus plantarum and Saccharomyces cerevisiae and their cocultures. A factorial experimental design was used to evaluate the effect of fermentation setups and time on proximate composition, antinutritional factors, and in vitro digestibility of proteins in maize flour. During 48 h of fermentation, protein content was improved by 38%, 55%, 49%, and 48%, whereas in vitro protein digestibility improved by 31%, 40%, 36%, and 34% for natural, Lactobacillus plantarum, Saccharomyces cerevisiae, and their coculture‐fermented maize flour, respectively. The highest improvement in protein content and its digestibility was observed for Lactobacillus plantarum strain‐fermented maize flour. Phytate, tannin and trypsin inhibitor activity were reduced significantly (p, This research showed that, fermentation with L. plantarum, S. cerevisiae and their co‐cultures resulted in an improved nutritional value of maize flour. Fermentation with these strains significantly increases the contents of protein and its digestibility of maize flour.

PurposeLand is an emotive issue for women in Kenya, majority of who still suffer the consequences of not having access to land, leading to economic insecurity. This paper aims at examining the effects of women access to land on household nutritional outcomes among smallholder farmers in Kenya.Design/methodology/approachThe study uses primary data collected from a sample of 384 small-scale women farmers selected using multi-stage sampling technique. For data analysis, household nutritional outcomes were measured using Households Dietary Diversity Scores (HDDS) and Household Hunger Scale Scores (HHS). Stratification multilevel and matching-smoothing approach that controls for pre-treatment heterogeneity bias and treatment effect heterogeneity bias was used in estimating heterogeneous effects of women access to land.FindingsThe analysis reveals that women access to land has a significant positive effect on household nutritional outcomes. All households across all propensity scores strata benefited significantly but differently from women access to land in terms of nutritional outcomes.Research limitations/implicationsEconometrically, propensity matching technique used in computing heterogeneity effects captures selection bias due to observable characteristics but it fails to capture selection bias due to unobservable factors. However, robust strategies were employed to ensure minimal estimation bias.Originality/valueThe paper provides insights on the determinants of women access to land and the influence women access to land has on household nutritional outcomes. In addition, by employing one of the conventional impact evaluation techniques, the paper contributes to knowledge by taking into accounts the heterogeneity in the effects of women access to land on household nutritional outcomes.

Storage conditions influence the nutritive value and quality of many legumes. The aim of this study was to evaluate the quality of beans stored under hermetic conditions as a strategy for preserving the quality of beans post-harvest. Three bean varieties [Rosecoco, small red (Wairimu)], and red mottled (Nyayo)] were adjusted to three moisture levels (12%, 15% and 18%) and stored in hermetic bags and ordinary polypropylene bags and sampled after 0, 45, 90, 135,180, 225 and 270 days for chemical and anti-nutritional analysis. Total soluble sugars, in-vitro starch and protein digestibility, free amino nitrogen, tannin content and phytic acid content of the beans were determined using standard methods. Results showed that the beans in hermetic bags had 22%, 23% and 18% higher total soluble sugars, in-vitro starch and protein digestibility, respectively, than those in polypropylene bag during storage. On day 225 of storage, beans in hermetic bags had the optimal in-vitro starch and protein digestibility, and tannin content. Principal component analysis indicated that nutrient and anti-nutrient retention of the beans was achieved with lower storage moisture and duration in hermetic bags. The results of this study can be used to explain the superiority of the hermetic storage technology over ordinary methods of beans storage, and by extension other legumes, in nutrient retention during storage., Graphical abstract Image 1, Highlights •PICS are superior to PPB bags in nutrient and quality retention of common beans during storage. •Beans in PICS bags had optimal starch and protein digestibility and tannin content on day 225 of storage. •Nutrient retention in beans was high at lower storage moisture and duration in PICS.

This study evaluated the effect of treatment with gum Arabic edible coatings on shelf life and quality parameters of mangoes during 20 days at room temperature. Apple variety of mangoes of uniform size were obtained from small holder farms in Makueni County, Kenya and dipped in various concentrations of gum Arabic solutions [0, 10, 15 and 20% (w/v)] for 1 h, ensuring the coating solution uniformly covered the surface. Control fruits were dipped in distilled water only. The fruits were then air-dried on trays, packed in cardboard boxes and stored at room temperature (23 ± 2 °C) and normal relative humidity (45–60%). Changes in weight loss, ascorbic acid content, s-carotene, total soluble solids (TSS), titratable acidity (TA) and pH were determined using standard methods. Gum Arabic coatings (all levels) significantly (p

The aim of this study was to assess the probiotic potential and safety profile of a Lactobacillus plantarum strain isolated from Kenyan spontaneously fermented milk, Amabere amaruranu. The Lactobacillus plantarum isolate was tested for temperature sensitivity (at 15°C, 30°C, 37°C, and 45°C), pH tolerance (at 2.0, 2.5, 3.0, 3.5, and 6.5 as control), and 0.4% phenol tolerance to observe its survival in the gastrointestinal tract of humans. For safety evaluation of the isolate, antagonistic activity was tested against pathogenic strains of Staphylococcus aureus, Escherichia coli, Salmonella enterica serovar Typhi, and Candida albicans, while antibiotic susceptibility pattern was examined using nalidixic acid, ampicillin, azithromycin, ciprofloxacin, tetracycline, gentamicin, and chloramphenicol antibiotic discs and haemolytic activity was done using lamb blood agar. Lactobacillus plantarum isolate had an optimal growth at 37°C, it also demonstrated low pH tolerance (2.0–3.5). It was able to maintain its viability (~100%) after exposure to 0.4% phenol. The selected isolate showed inhibition (antagonistic activity) against the pathogens with S. typhi having the largest (ZDI = 31.0 ± 1.73 mm) zone of diameter inhibition (ZDI) and Candida albicans having the least (ZDI = 18.0 ± 0.76 mm). Lactobacillus plantarum isolate was sensitive to Azithromycin, tetracycline and chloramphenicol and was intermediately sensitive to gentamycin, while it was resistant to nalidixic acid, ampicillin, and ciprofloxacin. The isolate also exhibited γ-haemolytic activity hence safe for use as a starter culture. The selected isolate can be used as a starter culture and a probiotic since it had excellent probiotic properties.

This study aimed at producing chia seed‐fortified pineapple jam and evaluation of its physicochemical and sensory characteristics. Five pineapple jam formulations were developed, starting with the basic formulation (jam 1/control) containing sucrose and added pectin. The other jams (jam 2, jam 3, jam 4, and jam 5) had sucrose and pectin but with chia seeds added at rates of 6.25, 12.5, 25, and 50% w/w, respectively. Crude protein of the jams was analyzed through macro Kjeldahl method, and the crude fiber was estimated by the Weende method. Thirty‐two semi‐trained panelists performed sensory evaluation test of the developed jams using 5‐point hedonic scale. Chia pineapple jam had golden color compared to control pineapple jam, which had yellow color. The fresh chia pineapple jams had significantly (p < 0.05) different protein and crude fiber contents in each sample. The protein content in the control was 0.53%, while it ranged between 1.60 and 8.60% for the chia seed‐fortified jams. For crude fiber, the values were 4.83% for the control and 5.38, 9.08, 13.33, and 21.02% for jam 2, jam 3, jam 4, and jam 5, respectively. General acceptability and sensory evaluation (flavor, color, and texture) showed significant (p < 0.05) differences compared to the control, while spreadability had no significant (p > 0.05) differences. The information obtained from this study indicates that chia‐fortified pineapple jam could be produced with favorable sensory attributes that could be used for jam making and other processed products to benefit from the functional components in the chia seeds.

Emerging economies have often poor hygiene practices in traditional milk and dairy production all over the world. Therefore, pathogenic bacteria in milk pose major public health concerns especially for those communities who still consume raw milk. Escherichia coli and coliforms are often used as indicator microorganisms, so their presence in food implies poor hygiene and sanitary practices. The main purpose of this article is to review information on milk quality and coliform bacteria contamination associated with the production and distribution of raw milk in some of the low and middle income economies around the world. Data reported on coliform counts in milk samples from some countries categorized as low and middle income economies in Africa, South America, Asia, and Europe. Local marketing of raw milk has been increased in the low and middle income countries because of low purchasing power of most native consumers. This population is at risk of illnesses from food-borne pathogens as a result of poor milk handling along the informal milk value chains. The regulatory bodies from these low and middle income countries are usually underfunded; therefore the safety standards of the milk chain cannot be sufficiently provided, endangering public health. On the other hand, there are huge losses of milk due to microbial spoilage in the low and middle income countries. So, it is necessary for the low and middle income countries to invest in infrastructures and establishments such as potable water supply to the dairy actors, increase the electricity connectivity from national grid and off-grid, improve the transport infrastructure, and financial support of the standards regulatory institutions. Paying attention to the mentioned actions can help to improve milk safety and quality and thereby reduce the risk of the food-borne illnesses. DOI: 10.29252/jfqhc.5.1.3

Processing mango (Mangifera indica L.) is one of the ways of minimizing post-harvest mango losses. Lactic acid bacteria (LAB) fermentation is a promising processing method to expand the diversity of processed mango products. The aim of this study was to develop fermented mango leathers and to evaluate the effect of LAB fermentation of mango pulp on the physicochemical, antioxidant, and sensory properties of mango leathers. Pulps of two mango varieties (apple and ngowe) were fermented at 37 °C for 24, 48, and 72 h using two LAB strains; Lactobacillus plantarum (DCRUST PKLP4) and Lactobacillus casei (LC-1) and its effect on physicochemical [pH, total soluble solids (TSS), titratable acidity (TA), moisture content (MC), fibre, and ash], antioxidant [vitamin C and total phenolic content (TPC)], and sensory properties on the mango leather determined. LAB fermentation significantly reduced pH, TSS and fibre content (p˂0.05), while increasing TA, TPC and ash contents but with no effect on vitamin C. L. plantarum had superior fermentation properties with regard to TPC compared to L. casei. In all the treatments, fermentation for 24 h was appropriate since extended fermentation (up to 72 h) did not significantly alter the physicochemical and antioxidant properties of the leathers or rather lead to reduced nutritional content. The mango variety and LAB strain significantly (p˂0.05) affected (individually and interactively) the physicochemical, antioxidant, and sensory properties of the mango leathers. Use of LAB fermentation is therefore recommended to enhance nutritional benefits and functional properties of dried fruit leathers as a way to increase their shelf life and minimize their post-harvest losses.

Taro (Colocasia esculenta) has great potential as an income generation, food and nutritional security crop in sub Saharan Africa. However, potential to bioaccumulate heavy metals is a food safety concern. In this study, variation and correlations of trace elements, anti-nutrients in raw taro corms and sensory attributes of taro crisps were evaluated. Trace elements were significantly (p

Many spontaneously fermented milk products are produced in Kenya, where they are integral to human diet and play a central role in enhancing food security and income generation. Some of these products have demonstrated therapeutic and probiotic effects although recent reports have linked some to death, biotoxin infections, and esophageal cancer. These products are mostly processed from poor quality raw materials under unhygienic conditions resulting to inconsistent product quality and limited shelf-lives. Though very popular, research on their processing technologies is low. This review provides a comprehensive summary of the most common spontaneously fermented milk products from Kenya including Mursik, Kule naoto, Amabere amaruranu and Suusa. Their production challenges and future perspectives are highlighted; emphasizing the need for application of high throughput biotechnologies in their study. Available literature on their microbiology, biochemistry, and chemical composition is summarized. Moreover, knowledge on the value of clean starting raw material, fermentation parameters definition, and employment of standard equipment are discussed. Key words: Starter culture, probiotics, lactic acid bacteria, fermented milk, high throughput biotechnology, spontaneous fermentation, Kule naoto, Mursik, Amabere amaruranu

This study evaluated the effect of treatment with gum Arabic edible coatings on shelf life and quality parameters of mangoes during 20 days at room temperature. Apple variety of mangoes of uniform size were obtained from small holder farms in Makueni County, Kenya and dipped in various concentrations of gum Arabic solutions [0, 10, 15 and 20% (w/v)] for 1 h, ensuring the coating solution uniformly covered the surface. Control fruits were dipped in distilled water only. The fruits were then air-dried on trays, packed in cardboard boxes and stored at room temperature (23 ± 2 °C) and normal relative humidity (45–60%). Changes in weight loss, ascorbic acid content, ß-carotene, total soluble solids (TSS), titratable acidity (TA) and pH were determined using standard methods. Gum Arabic coatings (all levels) significantly (p

This study attempted the processing and inclusion of insects into a local staple food to endear them to the population. Mature desert locusts (Schistocerca gregaria) and migratory grasshoppers (Acanthacris ruficornis) reared at Egerton University were dried and ground into powder then used to develop composite flours with malted finger millet flour. Proximate analysis and protein digestibility tests of the composite flours were done and their microbial loads (total viable counts, TVC; coliforms; Lactic acid bacteria, LAB; Yeasts and molds) were evaluated. The addition of locust and grasshopper flour increased the protein and fat contents of finger millet flour from 9.20 to between 13.60 and 27.30% and from 1.40 to 3.30–11.40%, respectively. Protein digestibility of the finger millet was improved by malting (from 71.50 to 91.50%) while that of the insect flours was high (approximately 90.00%). The microbial loads in individual products and in composite flours ranged between 106–108 cfu/g for TVC, 105–108 cfu/g for coliforms, 104–107 cfu/g for LAB, and 1.7–2.5 × 107 for yeasts and molds. Our study indicates that locusts and grasshoppers could be incorporated into existing staple foods to generate highly nutritious products that could be recommended to fight malnutrition.

Most plastics, materials, fuels and other organic chemicals are presently derived from fossil fuel feedstocks. Due to the finite nature and foreseeable depletion potential of these raw materials, concerted efforts are being explored to find sustainable alternatives to the fossil fuel feedstock-derived products. Among these, bioplastics and oligomers derived from fermentation of the renewable plant biomass are promising candidates to replace fossil-fuel-derived plastics. Bioplastics are a class of storage polymers synthesized by microorganisms. Natural plastics can also be produced via a bio-chemo process that combines fermentative production of monomers or oligomers, followed by a chemical synthesis process to produce a variety of polymers. These polymers, particularly polyhydroxyalkanoates (PHAs ) represent futuristic biomaterials owing to their biodegradability and biocompatibility. Furthermore, PHAs have physicochemical properties that are similar to petrochemical-based plastics hence their potential replacement. Designing efficient processes holds the key towards their adoption. This chapter discusses opportunities and challenges regarding the production of lactic acid (LA)-based polymers and related oligomers that can act as precursors for catalytic synthesis of polylactic acid (PLA ). It covers crucial steps of their production using genetically modified organisms and engineered enzymes as well as providing future developments.

In many African cultures, insects are part of the diet of humans and domesticated animals. Compared to conventional food and feed sources, insects have been associated with a low ecological foot print because fewer natural resources are required for their production. To this end, the Food and Agriculture Organization of the United Nations recognized the role that edible insects can play in improving global food and nutrition security; processing technologies, as well as packaging and storage techniques that improve shelf-life were identified as being crucial. However, knowledge of these aspects in light of nutritional value, safety, and functionality is fragmentary and needs to be consolidated. This review attempts to contribute to this effort by evaluating the available evidence on postharvest processes for edible insects in Africa, with the aim of identifying areas that need research impetus. It further draws attention to potential postharvest technology options for overcoming hurdles associated with utilization of insects for food and feed. A greater research thrust is needed in processing and this can build on traditional knowledge. The focus should be to establish optimal techniques that improve presentation, quality and safety of products, and open possibilities to diversify use of edible insects for other benefits.

Poly[(R)-lactate-co-(R)-3-hydroxybutyrate] [P(LA-co-3HB)] is a biobased polyester with semitransparent and flexible properties produced in engineered bacteria carrying an LA-polymerizing enzyme. In this study, we attempted to isolate the P(enriched LA-co-3HB)-degrading bacteria from soil samples in order to identify enzymes with the capacity to degrade this new type of polymer. Among approximately 500 samples, the Gram-negative bacterium C34, which exhibited potent P(enriched LA-co-3HB)-degrading activity, was isolated based on the decrease in the turbidity of culture medium supplemented with emulsified P(67 mol% LA-co-3HB). Based on its 16S rDNA sequence, this isolated bacterium was identified as a member of Variovorax sp.. Next, we attempted to isolate and purify the depolymerase that contributes to the polymer degradation from the culture supernatant of strain C34. The purified enzyme had a molecular mass of 42 kDa and exhibited degradation activity towards the P(67 mol% LA-co-3HB) as well as 3HB homopolymer [P(3HB)], but not LA homopolymers (PDLA and PLLA). On the other hand, a well-characterized depolymerase of P(3HB) derived from Alcaligenes faecalis T1 did not degrade P(67 mol% LA-co-3HB), PDLA or PLLA. This result suggests that the newly isolated depolymerase differs from the P(3HB) depolymerase from A. faecalis.

The gene encoding an FMN-dependent NADH azoreductase, AzrG, from thermophilic Geobacillus stearothermophilus was cloned and functionally expressed in recombinant Escherichia coli. Purified recombinant AzrG is a homodimer of 23 kDa and bore FMN as a flavin cofactor. The optimal temperature of AzrG was 85 degrees C for the degradation of Methyl Red (MR). AzrG remained active for 1 h at 65 degrees C and for 1 month at 30 degrees C, demonstrating both superior thermostability and long-term stability of the enzyme. AzrG efficiently decolorized MR, Ethyl Red at 30 degrees C. Furthermore, the enzyme exhibited a wide-range of degrading activity towards several tenacious azo dyes, such as Acid Red 88, Orange I, and Congo Red. These results suggested the sustainable utilization of G. stearothermophilus as an azo-degrading strain for AzrG carrying whole-cell wastewater treatments for azo pollutants under high temperature conditions.

P[(R)-2-hydroxybutyrate] [P((R)-2HB)] is an aliphatic polyester analogous to poly(lactic acid) (PLA). However, little has been known for its properties because of a high cost of commercially available chiral 2HB as a starting substance for chemical polymer synthesis. In this study, P[(R)-2HB] and P[(R)-2HB-co-(R)-lactate] [P((R)-2HB-co-(R)-LA)] with a new monomer combination were successfully synthesized in recombinant Escherichia coli LS5218 from less-expensive racemic 2HB using an R-specific polyester synthase. The cells expressing an engineered polyhydroxyalkanoate synthase from Pseudomonas sp. 61-3 and propionyl-CoA transferase from Megasphaera elsdenii were grown on LB medium containing 2HB and glucose in a shake flask and accumulated up to 17 wt % of P[(R)-2HB] with optical purity of99.1%. In addition, the same cells cultured in a jar-fermentor produced P(86 mol % 2HB-co-LA) copolymer. Notably, the molecular weights (Mw) of P(2HB) (27000) and P(2HB-co-LA) (39000) were 2- and 3-fold higher than that of P(2HB) previously synthesized by chemical polycondensation. P(2HB) was processed into a transparent film by solvent-casting and it had flexible properties with elongation at break of 173%, which was contrast to the rigid PLA. Regarding mechanical properties, P(2HB-co-LA) was tougher but less stretchy than P(2HB). These results demonstrated that P(2HB) has useful properties and LA units in 2HB-based polymers can act as a controllable modulator of the material properties. In addition, P[(R)-2HB] was efficiently degraded by treatment of Novozym 42044 (lipase) but not Savinase 16L (protease), indicating that the degrading behavior of the polymer was similar to that of P[(R)-LA].

Xylose, which is a major constituent of lignocellulosic biomass, was utilized for the production of poly(lactate-co-3-hydroxybutyrate) [P(LA-co-3HB)], having transparent and flexible properties. The recombinant Escherichia coil JW0885 (pflA(-)) expressing LA-polymerizing enzyme (LPE) and monomer supplying enzymes grown on xylose produced a copolymer having a higher LA fraction (34 mol%) than that grown on glucose (26 mol%). This benefit of xylose was further enhanced by combining it with an evolved LPE (ST/FS/QK), achieving a copolymer production having 60 mol% LA from xylose, while glucose gave a 47 mol% LA under the same condition. The overall carbon yields from the sugars to the polymer were similar for xylose and glucose, but the ratio of the LA and 3HB units in the copolymer was different. Notably, the P(LA-co-3HB) yield from xylose (7.3 g l(-1)) was remarkably higher than that of P(3HB) (4.1 g l(-1)), indicating P(LA-co-3HB) as a potent target for xylose utilization. (C) 2012 Elsevier Inc. All rights reserved.

Poly[3-hydroxybutyrate-co-3-hydroxyvalerate(3HV)] was produced in recombinant Escherichia coil LS5218 from the ruthenium-catalyzed cellulose hydrolysate and propionate. The strain was found to be resistant to 5-hydroxymethylfurfural (5-HMF), which is a major inhibitory byproduct generated in the cellulose hydrolysis reaction. The 3HV fraction was successfully regulated in the range of 5.6-40 mol%.

Pastoral communities in Kenya have used smoke from specific herbs as a technique of disinfecting milk-handling containers, preserving milk and to impart a characteristic desired flavour to raw camel milk. The smoking is expected to extend the shelf life of the camel milk, despite the high environmental temperatures (>28 °C). The aim of this study was to determine the antimicrobial effect of smoke on plastic milk-handling container surfaces and determine the efficacy of smoking as a preservation method. Smoked plastic milk-handling containers (n = 25) were conveniently collected from pastoral community households in Isiolo County, Kenya. Two containers were prepared by either washing and rinsing using hot water to be the negative control or rinsing and disinfecting using a chlorine-based agent to be the positive control. The inner surfaces of the containers were aseptically swabbed and analysed for total viable count (TVC), total coliform count (TCC), and lactic acid bacteria (LAB). The TVC from the smoked containers was 4.64 ± 0.43 log10 cfu/cm2 while the TCC was 4.00 ± 0.66 log10 cfu/cm2 and the LAB were 3.75 ± 0.59 log10 cfu/cm2, and those of the negative control (plain-water-washed non-smoked plastic container) were 5.99 ± 1.03, 5.07 ± 0.91, and 4.81 ± 0.81 log10 cfu/cm2 for TVC, TCC, and LAB, respectively. The mean microbial load of milk bulked in smoked containers was 5.10 ± 0.96, 3.61 ± 2.13, and 3.84 ± 2.22 log10 cfu/ml for TVC, TCC, and LAB, respectively, while the mean microbial load of milk bulked in chlorine-disinfected containers was 5.23 ± 1.11, 2.46 ± 2.18, and 2.04 ± 1.35 log10 cfu/ml for TVC, TCC, and LAB, respectively. The common types of microbes were Gram-negative rods (57.3 %), Gram-positive rods (25.5 %), and Gram-positive cocci (17.2 %). The most prevalent coliforms from all types of the containers and milk were Escherichia coli spp. and Enterobacter spp. while the LAB were Lactobacillus spp. and Lactococcus spp. Therefore, smoking of milk-handling containers can be recommended as an effective method for disinfection of milk-handling containers and as a method of preservation of camel milk in the arid and semi-arid areas of Kenya, where the cold chain or processing infrastructure is poor.