Search

There is growing interest in Sub-Saharan Africa for substituting maize with climate-smart crops like sorghum and millets in local food processing. We conducted a survey to explore current variations in processing and consumption practices for Mahewu, a traditionally fermented cereal beverage from Zimbabwe. Processing involved cooking a cereal porridge, adding cereal flour or malt as a starter ingredient, and fermenting for 12–48 h. Ingredient availability was the main driver for porridge ingredient choice (42% of respondents) with the most preferred being maize (55% of respondents), pearl millet (22%) and sorghum (9%). Final product taste had the most influence on starter ingredient choice, with most respondents preferring pearl millet flour (23%), finger millet malt (22%), wheat flour (17%), and sorghum malt (13%). Our study proves that maize can be replaced with sorghum and millet in Mahewu processing, thus increasing the climate-resilience of future food systems, and demonstrates that traditional practices harbour clues for adapting current practices.

Wheat, the most important food crop, can be stored for a much longer time than potato. It is ground and made into flour or pasta that can be turned into bread or a dish at any time. Potato is only storable for a limited period, so it floods the market at harvest. Major benefits of processing for growers include regulating the availability of markets and price through contracts, and the decrease in the number of consumers buying fresh tubers is compensated by processors buying raw material. Processors add value and employment and consumers are offered a wide array of affordable and convenient products. Large potato processing companies produce annual sustainability reports advocating measures for growers to spare the habitat, more efficient processes in factories, newer and healthier products and supporting communities. These are recorded and viewed in a theoretical triangulation from the angles of processors, and those trying to bend the rules. The industry, especially when expanding to new (developing) markets, faces political, economic, social, technological, environmental and legal (PESTEL) issues that fluctuate according to the presence of a raw material base, competition and buying power and culture of the consumers., Wheat, the most important food crop, can be stored for a much longer time than potato. It is ground and made into flour or pasta that can be turned into bread or a dish at any time. Potato is only storable for a limited period, so it floods the market at harvest. Major benefits of processing for growers include regulating the availability of markets and price through contracts, and the decrease in the number of consumers buying fresh tubers is compensated by processors buying raw material. Processors add value and employment and consumers are offered a wide array of affordable and convenient products. Large potato processing companies produce annual sustainability reports advocating measures for growers to spare the habitat, more efficient processes in factories, newer and healthier products and supporting communities. These are recorded and viewed in a theoretical triangulation from the angles of processors, and those trying to bend the rules. The industry, especially when expanding to new (developing) markets, faces political, economic, social, technological, environmental and legal (PESTEL) issues that fluctuate according to the presence of a raw material base, competition and buying power and culture of the consumers.

Potato has strong links between the actors as varieties bred by breeders, crop management of growers and site location of processors strongly influence the yield and quality of the finished products. Here, the actors (breeders, growers, processors, retailers and users) in the value chain are recognized, and their information and material flows identified. The influence of genotype, environment and crop management and the efficient use of resources during the production of raw material, tubers harvested for processing purposes, are delineated. It is shown that climate change affects performance and that consumers looking for quality and new products are hardly interested in the primary processes, nor are breeders and processors showing interest in consumer concerns. Crop performance is dependent on yield and quality (dry matter, sugars, tuber size and desired and undesired constituents). Factory performance relies on recovery, reuse of rejects and avoidance of wastes. Heatmaps drawn of classes of productivity and losses and their attributes reveal where gains are to be made on fields, farms and factories to improve efficiencies, reduce the impact on the environment, and opportunities for decarbonisation., Potato has strong links between the actors as varieties bred by breeders, crop management of growers and site location of processors strongly influence the yield and quality of the finished products. Here, the actors (breeders, growers, processors, retailers and users) in the value chain are recognized, and their information and material flows identified. The influence of genotype, environment and crop management and the efficient use of resources during the production of raw material, tubers harvested for processing purposes, are delineated. It is shown that climate change affects performance and that consumers looking for quality and new products are hardly interested in the primary processes, nor are breeders and processors showing interest in consumer concerns. Crop performance is dependent on yield and quality (dry matter, sugars, tuber size and desired and undesired constituents). Factory performance relies on recovery, reuse of rejects and avoidance of wastes. Heatmaps drawn of classes of productivity and losses and their attributes reveal where gains are to be made on fields, farms and factories to improve efficiencies, reduce the impact on the environment, and opportunities for decarbonisation.

In supermarkets in the Netherlands, well over 150 potato products are displayed. They can be distinguished by heating characteristics (boiled or fried), appearance (e.g., intact tuber pieces or formed hash browns), dehydrated (e.g., snacks and flour) and storage temperature (e.g., ambient and frozen). Fancier products (frozen formed versus chilled blanched) require more processes and operations in factories and are more expensive; consumers appreciate them because they offer more convenience. Heatmapping and hierarchical clustering were carried out twice within the domain of classes of products and their attributes. In a theoretical triangulation, consumers give high scores to low prices and a wide range of products, tastes and sizes where processors give these attributes a low score. Processes in factories include dehydration, heating, cooling and transformation. Examples of the latter are modification of starch to increase the range of applications in the food industry, forming of mash and shreds to produce croquettes and hash browns and expansion to make snacks. Processes require operations such as washing, cutting, blanching and packing. In total, between the arrival of the tubers at the gate and leaving as packed products to outlets, 66 operations are distinguished. French fries undergo some 30 operations and to produce flakes, 8 suffice. Heatmapping and hierarchical clustering differentiate a group of physical operations (with attributes associated with heating and cooling that require much energy) and mechanical ones (related to separation, grading, sorting for instance and size reduction of which shredding is an example that require little energy). The wide range of operations in large factories, reducing the moisture content and longtime storage at low temperatures, distinguishes potato from wheat that has fewer operations while increasing the moisture content in relatively small bakeries and the product, bread, stored for about one day in ambient condition

The processing potato ontology includes the three domains of growers, processors and cooks producing tubers, products and dishes, respectively. Dishes consist of three subdomains: types of dishes prepared from products, kitchen operations and consumer preferences. Preparing meals with potato as ingredients dates from the time of the domestication of the crop in the Andes region. It involves washing, peeling, partitioning in smaller sections and heating to gelatinize the otherwise, for non-ruminants, indigestible starch. Since the Columbian Exchange, both the crop and processing expanded globally. The history of potato processing starts with the pre-historic pre-Columbian era when drying as a means to preserve and render the tuber less bulky and making flour and alcoholic drinks were common practice. Once the crop was a global food crop, processing established, initially into an array of nourishments for seafaring and military purposes and later for aviation, convenience and to satisfy hedonistic needs. The domains are studied through a four-tier analysis: first a description and delimitation of the domain are made, next allocation of classes with their attributes followed by awarding a value to an attribute as to the degree it applies to the class, yielding a heatmap, and fourthly, a dendrogram is produced that shows clustering of classes and of attributes with similar features.

Improving the technological functionality of climate-resilient crops (CRCs) to promote their use in staple foods, such as bread, is relevant to addressing food and nutrition security in Africa. Dry heating of cowpea flour (CPF) was studied as a simple technology to modulate CPF physicochemical properties in relation to bread applications. For this purpose, the melting behavior of cowpea starch and proteins in CPF was first studied and modeled using Flory–Huggins theory forpolymer melting. Next, dry-heating conditions were investigated based on the predicted biopolymer melting transitions in CPF to be well below starch and protein melting. The pasting properties (i.e., peak viscosity, final viscosity, breakdown and setback) of CPF could be selectively modulated depending on temperature-time combinations without altering the thermal behavior (i.e., melting enthalpies) of CPF. Water-binding capacity and soluble solids decreased with the increased severity of the temperature-time combinations. Dry-heated CPF added to CRC-based bread significantly improved crumb texture. In particular, dry heating at 100 C for 2 h provided bread with the highest crumb softness, cohesiveness and resilience. The positive effects on the crumb texture could be largely related to enhanced starch integrity, as indicated by a reduction in breakdown viscosity after treatment. Overall, dry heating of CPF under defined conditions is a promising technology for promoting the use of CPF as a techno-functional and protein-rich ingredient in bread-type products.

Cereals contributes a substantial proportion of the food supply for humans and animals globally, including in the Sub-Saharan Africa (SSA) where they form a major source of dietary energy and protein intakes as staple foods. Beside their importance to food supplies and health, they contribute to improved income among the most food‐insecure population groups in SSA countries. However, most of cereals are consumed as refined products (dehusked or polished) to improve their sensory properties. This renders the processed cereal-based products of poor nutritional quality as the refining process also removes important nutrients beneficial to health. On the other hand, there is increasing trend of consumers wanting more cereal-based healthy foods containing specific health-promoting properties. In this sense, immature cereal-based products such as pepeta, a locally processed immature rice flakes from Tanzania, appear to be among the many alternatives to pursue the goal of better cereal-based nutrition due to their nutritional potential benefits. It has been found that immature cereals and their products contain higher amount of numerous nutrients beneficial to health, including dietary fiber, vitamins, minerals and phytochemicals, compared to their mature counterparts. This thesis work focused on finding ways to improve the nutritional quality of indigenously processed immature rice-based products by using scientific approach to valorise their utilisation. The present work has increased the scientific knowledge on understanding the nutritional quality, and in-vitro starch and protein digestion properties of immature grains, as well as the changes they undergo upon processing into so-called pepeta. Besides, the best pepeta processing conditions for improvement of specific nutritional and functional properties were recommended. Furthermore, an overview of the opportunities, challenges, and future developments of the utilisation of immature cereals grains and their products w

Hidden hunger, due to regular consumption of a diet deficient in micronutrients, may persist unabated, especially in low-and-middle-income countries of the world, unless more attention is focused on developing healthy and nutritious foods to alleviate the burden. Several nutritional interventions have been implemented for decades but one of the most sustainable food-based solutions proffered in recent times is the twin-strategy of biofortification and food-to-food fortification. In response to the challenge of combating hidden hunger, the yellow cassava biofortified with pro-vitamin A carotenoids was introduced to sub-Saharan Africa. However, yellow cassava is still low in minerals such as iron and zinc, hence the need to incorporate micronutrient-rich and affordable food ingredients such as the African leafy vegetables. To ensure an adequate intake of the much-needed micronutrients, we developed pasta, a widely consumed, healthy and affordable food product with the yellow cassava with two leafy vegetables, amaranth and fluted pumpkin incorporated. The increasing demand by consumers for gluten-free pasta as a functional food also focused attention on cassava as a gluten-free ingredient. This thesis, therefore aimed at evaluating the nutritional, sensorial, technological and functional aspects of the novel vegetable fortified yellow cassava pasta to gain more insights into its contribution to a healthier living for the consumers.In Chapter 2, using consumer survey focus group discussions and sensory studies, we evaluated the acceptance of yellow cassava pasta and African leafy vegetables. We found the main driver of intended consumption among the consumers in Nigeria to be related to health concerns. Also, yellow cassava pasta was acceptable to the consumers while fluted pumpkin (Telfairia occidentalis) was the most preferred leafy vegetable followed by amaranth. The low awareness of yellow cassava among the consumers was also highlighted with solutions proffered to

The effect of one or two thermal treatments during pineapple juice production was evaluated on pH, vitamin C and microbiological evolution of 6 categories of juice during 12 months of storage. Three pasteurization temperatures (75°C, 80°C, 85°C) combined with one (1T) or two (2T) thermal treatments defined the juice category. Storage test consisted of green-glass bottled juices packaged in closed boxes, kept at ambient temperature. Analyses were performed each 4 months from production date (0 month). As results, the juices pH was 3.90 - 4.14 after production and no significant variation (p ≥ 0.05) occurred during storage, except for juices 80°C, 1T and 80°C, 2T at 12 month. The microbiological quality of all juices after production revealed conformity with standards. Enterobacteria and lactic acid bacteria were totally absent all the time. Mesophilic bacteria and yeasts and moulds counts generally decreased in each juice during storage. The initial vitamin C content significantly (p<0.05) varied from 4.52 to 23.48 mg/100ml in the juices and so decreased through storage. Juices pasteurized at 75°C contained more initial vitamin C but their content was quickly lost. Vitamin C was more stable in the most thermally treated pineapple juices throughout storage, especially in juice 85°C, 2T.

Feeding 2.4 billion mouths in Africa by 2050 will require all hands on deck as the demand for cereals may triple. Viable options to feeding Africa include measures with respect to (a) food technology, e.g. improved utilization of the available crops and their by-products, (b) plant breeding, e.g. through bio-fortification, and (c) agronomy, e.g. yield improvement and sustainable crop intensification. Although the latter two options have received most research traction, the current cereal yields in sub-Saharan Africa (SSA) is about 20% of its potential. Crop intensification has huge economic and environmental implications while biofortified crops have not received the expected adoption. This reinforces the importance of strategies aimed at optimizing crop utilization such as the prevention of food and nutrient losses as well as enhancing product diversification from existing climate-resilient crops to feed the ever-rising population. Matching consumer preferences and enhancing the ease of processing of maize into different food types will support better use, with positive consequences on reducing malnutrition and alleviating poverty.Many high potential maize products that are localized or confined to particular communities can be scaled up across the continent and beyond for prosperity, as elaborated in chapter 2. This will require standardization of the processing conditions for effective monitoring and evaluation. Curbing nutrient loss during post-harvest handling of maize will enhance the nutritional status of Africans relying on maize as a staple crop. Furthermore, research on more effective ways to enhance the protein quality i.e. tryptophan and lysine as well as vitamin content of maize-based foods especially through novel fermentation technique is important. Novel fermentation techniques such as the use of microbial fortification or bio-enrichment using high lysine producing microorganism could help to ameliorate the poor protein quality of maize foods. This w

Rice is commonly consumed as fully mature grain, but immature rice is considered to have better nutrient and technological properties. This is attributed to changes in content and profile of nutritional and functional compounds during maturation. This study assessed the effect of maturity on nutrient content of rice grains, and in vitro digestibility of starch and protein, for immature rice grains of TXD306 and Lawama varieties. The effect of processing of immature rice into so-called pepeta, traditionally produced from immature rice grains and widely consumed in Tanzania, was studied as well. The results showed reductions in lipid, protein, ash, thiamine, nicotinic acid, nicotinamide, and soluble and insoluble dietary fibre contents during rice grain development. However, no effect of maturity on in vitro starch and protein digestibility was observed. The contents of protein, ash, lipid, nicotinamide, iron, zinc, and total, soluble and insoluble dietary fibre were higher in pepeta from both varieties than in the corresponding rice grains. Protein digestibility of pepeta flour was 58.9% higher than that of cooked rice for variety TXD306, and 73.8% higher for Lawama. Differential scanning calorimetry indicated that starch of processed immature rice was completely gelatinized whereas its susceptibility to digestion in vitro was slightly lower than for cooked rice, possibly due to the higher cellular integrity retained after processing. These results demonstrate that pepeta-type processing improves the nutritional properties of rice and its potential use as a snack or ingredient in cereal-based formulas.

Traditional fermented products are an important part of the diet in many African countries. These products can provide much of the needed proteins, vitamins and other micro-nutrients to its consumers, which include young children. Also, traditional fermented products are rooted in the local context and have high social and cultural value. Increasing our understanding of these spontaneously fermented products can be used to increase the value chain of these products in order to increase economic stability of producers as well as nutritional intake in rural and urban areas. Most traditional fermented products are produced by spontaneous fermentation, meaning that there is no starter culture added to initiate fermentation. As a consequence these products contain a diverse microbial community, which are responsible for the characteristics of the product. Often a back-slopping method is used, where a portion of previously fermented product inoculates fresh raw material. Unknowingly, producers of these products have domesticated these bacterial communities and allowed the species to co-evolve within their community. In this way, these bacterial communities form a model system for ecological and evolutionary research. Historically, experimental evolution was mainly performed with single organisms. In recent years the interest in how individuals evolve in the context of ecosystems is growing. This eco-evolutionary research needs model systems that can represent natural communities in their interactions and complexities, while still being a tangible model system. In this thesis I investigated the microbial communities that are responsible for the fermentation and used the constituting bacteria to learn about bacterial community dynamics over time. This was done by combining three disciplines: 1) Food Microbiology, on the conversion of compounds by bacteria during spontaneous fermentation; 2) Evolution, on the changes in the fermenting community over time under selection pres

Fermented dairy products are an important part of the human diet because they provide nutrients and extend the shelf life of raw milk, which is perishable. In Africa, there are several traditionally fermented milk products (TFMPs) mostly, produced at household level for domestic consumption such as mabisi from Zambia. Mabisi is made by spontaneous fermentation of raw milk at ambient temperature in a calabash, plastic or metal container for two days. The main aim of this study was to characterise the microbial community composition of mabisi and optimise its production process. Thus, a survey was carried out to determine the different production practices/methods of mabisi, key production parameters, uses and microbial community composition. Then, a laboratory experiment was carried out to determine the effect of fermentation temperature on the quality of mabisi and its microbial community composition. Furthermore, a field experiment was also conducted to determine the microbial dynamics of three types of mabisi. We found seven different production methods of mabisi, which include tonga, barotse, backslopping, illa, creamy, cooked and thick-tonga mabisi. Tonga mabisi was found to be the most popular and widely produced mabisi variant throughout the country by all ethnic groups. The key production parameters identified were: type of fermentation container, fermentation temperature, backslopping, alternate removal of whey in combination with addition of raw milk, heating and cooling, fermentation time and finally, agitation (churning). We further found that mabisi is a versatile product with various uses. The microbial community composition of mabisi from across the country was unravelled and showed that the top 10 most abundant genera were Lactococcus, Lactobacillus, Streptococcus, Enterobacter, Klebsiella, Kluyvera, Aeromonas, Acinetobacter, Buttiauxella and Citrobacter, which belong to two phyla, Firmicutes and Proteobacteria. The microbial community composition was

Fermentation is the oldest technology used in the production of many traditional cereal-based beverages across Africa. Munkoyo, a spontaneously fermented cereal-based beverage from Zambia and Democratic Republic of Congo is one of those beverages and the focal product studied in this thesis. It is consumed by large parts of the population, as an energy drink during travel or work on the field and is also consumed at social gatherings like wedding festivals and funerals. The processing of Munkoyo has to date not been standardized and greatly varies between different regions and processors. This may affect the quality and the safety of the beverage. Optimization of the processing methods and microbial composition of Munkoyo to attain good quality and a safe product can be a milestone leading to increased consumption of the beverage. Like all fermented foods, processing of Munkoyo relies on microbial activity transforming raw materials (cereals such as maize, millet and sorghum) into a processed product. The thesis focused on understanding the art of making Munkoyo by surveying different processors and linked this to the microbial community composition of fermenting microbes and their functionality in producing aroma compounds. Further, we investigated whether the source of the fermenting bacteria could lie in the Rhynchosia roots that are added during processing. Chapter 2 describes a survey using a semi structured questionnaire and focus group discussions in Lusaka, Chongwe, Chibombo and Mumbwa. The survey revealed that Munkoyo is consumed by the entire population, as an energy drink, during long hours of manual work, at social gatherings and is mainly processed at household level. Characterization of the bacterial communities of over 90 samples with 16S amplicon sequencing on DNA extracted from the entire bacterial community revealed six families of mainly lactic acid bacteria to dominate the bacterial communities. Chapter 3 reports that there are principally three

Bambara groundnut (Vigna subterranea (L.) Verdc.) is an underutilized crop native to sub-Saharan Africa. Its utilisation is limited due to the development of the hard-to-cook (HTC) phenomenon during storage. Various factors have been implicated in the development of the HTC phenomenon. Alkaline rock salts, such as gowa, are known to reduce cooking time. In this research, red bambara groundnuts were cooked in deionised water, 0.5 g/100 mL gowa and 0.5 g/100 mL NaHCO3. The salts caused 20 and 13% reduction in cooking time, respectively. The decrease of hardness and the kinetics of water absorption by the beans are even more influenced by the alkaline cooking. The comparative effect of NaHCO3 and deionised water on polyphenol profile in the beans and in the boiling water during cooking also showed clear differences among the samples. Catechin and epicatechin were the main polyphenols in bambara groundnuts for all treatments investigated and their release in water was faster in alkaline solutions. This study demonstrated that alkaline salts contribute to increased solubilisation of polyphenols in relation to cooking time reduction. Data indicate that the action of the salts favours polyphenol solubilisation thereby altering the structure of the lamellae and reducing hardness.

The aim of this study was to develop a nutrient-enhanced millet-based composite flour incorporating skimmed milk powder and vegetables for children aged 6–59 months. Two processing methods were tested to optimize nutrient content and quality of millet-based composite flour, namely germination for 0, 24 and 48 hr and roasting at 80, 100, and 140°C. The amount of ingredients in the formulation was determined using Nutri-survey software. Germinating millet grains for 48 hr at room temperature significantly (p < 0.05) increased protein content (9.3%–10.6%), protein digestibility (22.3%–65.5%), and total sugars (2.2%–5.5%), while phytate content (3.9–3.7 mg/g) decreased significantly (p < 0.05). Roasting millet grains at 140°C significantly (p < 0.05) increased the protein digestibility (22.3%–60.1%) and reduced protein (9.3%–7.8%), phytate (3.9–3.6 mg/g), and total sugar content (2.2%–1.9%). Germinating millet grains at room temperature for 48 hr resulted in millet flour with the best nutritional quality and was adopted for the production of millet-based composite flour. Addition of vegetables and skimmed milk powder to germinated millet flour significantly (p < 0.05) increased the macro-and micronutrient contents and the functional properties of millet-based composite flour. The study demonstrated that the use of skimmed milk powder and vegetables greatly improves the protein quality and micronutrient profile of millet-based complementary foods. The product has the potential to make a significant contribution to the improvement of nutrition of children in developing countries.

Bambara groundnut (Vigna subterranea (L.) Verdc.) is a legume crop with great agronomic and nutritional potential to alleviate malnutrition and improve food security of many rural communities in semi-arid regions of sub-Saharan Africa. Optimal use of bambara groundnut is limited due to the hard-to-cook (HTC) phenomenon and the lack of adequate processing and cooking techniques. To optimise use, this thesis explored various methods of managing the hard-to-cook phenomenon in the context of resource-limited communities. Long cooking time, milling challenges and firewood and water shortages were the constraints to processing and consumption of bambara groundnut. Useful techniques to process HTC legumes found include cooking with alkaline salts; and soaking, roasting and milling in the production of grits and flour. Results on reviewed published data implicated microstructural and compositional changes as factors leading to the development HTC phenomenon. Cooking bambara groundnut seeds with alkaline rock salts (0.5% NaHCO3 and 0.5% gowa) caused 13 and 20% reduction in cooking time, respectively. The contribution of bambara groundnut phenolic compounds to salt softening effects was evaluated by monitoring phenolic compounds solubilisation pattern in relation to cooking time reduction. Protocatechuic acid, catechin and epicatechin were indicators of softening in relation to cooking time reduction. Grit production was an efficient sustainable way of circumventing the HTC phenomenon as shown by a better processing aptitude as compared to traditional boiling of whole seeds. Different methods of grit processing had a similar dehulling efficiency with no significant varietal influence. Both traditional boiling and grit production improved IVSD, IVPD and mineral bioaccessibility. Dry roasted grits had the lowest IVPD (42%), followed by the combined soaking and roasting (45%), soaking (48%) and boiling (68%). Additionally, grit production was superior in improving mineral bioacc

Monkey orange (Strychnos spp.) is a widely distributed fruit species in Southern Africa commonly consumed by the local population. It has potential to improve the nutritional status of rural populations, being a precious food source in areas with periodic shortages. The present thesis focused on optimization of indigenous processing of S. cocculoides to reduce fruit losses and contribute to food security and livelihoods of vulnerable rural communities in the production areas. Based on an extensive literature review, monkey orange was found to be rich in vitamin C (88 mg/ 100 g), Zn (28 mg/100 g) and Fe (140 mg/100g) and is consumed as fresh or processed as an ingredient to other food products by the local population. A survey conducted in the wet and dry regions of the country showed that most of the fruits and their products are wasted because of limited harvest time, process control and storage conditions, leading to variability in shelf life and sensory quality, thereby impacting nutritional quality. S. cocculoides and S. spinosa juice were used by the majority of respondents as a functional ingredient in maize porridge production. The major constraint to be solved are seed-pulp/juice separation for optimization of juice extraction. Enzymatic treatments were done to improve pulp and juice yield. Prior to treatments, a total of 16 known phenolic compounds predominantly belonging to the phenolic acids, flavonoids and iridoid glucosides classes were tentatively characterized for the first time in S. cocculoides using HRMS and LC/MS/MS to confirm iridoid presence. Overall, the results showed that enzymatic treatments increased pulp yield by 26 % , physicochemical quality (38 % increase in juice clarity), content of phenolic compounds (kaempferol, quercetin, caffeic acid, protocatechuic acid, IGs) and antioxidant activity. The effect of using juice macerated with and without enzyme on the bioaccessibility of main phenolic compounds and micronutrients was assessed duri

Cereals are mainly used as staple foods as well as for animal feed and biofuel. In addition, certain cereals are of interest to the food industry for more specific reasons. This is the case for dye sorghum (Sorghum bicolor), due to its ability to produce significant amounts of pigment that potentially can be used as a food colorant. The red leaf sheaths formed by dye sorghum are used in Benin to produce a red biocolorant, which is also used in for foods. The red biocolorant is a rich source of 3-deoxyanthocyanidins (i.e. apigeninidin and luteolinidin). The 3-deoxyanthocyanidins are natural pigments with (a) a narrow distribution in nature, (b) a high antioxidant activity, (c) resistance to bleaching agents, (d) resistance to ring openings during thermal treatments, (e) a better stability to pH-induced colour changes as compared to common anthocyanins and (f) properties that inhibit the growth of cancer cells. These properties of 3-deoxyanthocyanidins contribute to colour stability during food processing. Currently, the red sorghum biocolorant is applied in Benin in cereal-, legume-, tuber- and milk-based foods. Dyed fermented cereal porridge (koko) and dyed soft cheese (wagashi) are the most popular food applications of this red biocolorant in Benin and illustrate the potential as a new stable natural colorant from sorghum that can be used in food industry. The growing interest of consumers for natural food ingredients leads to a growing demand of the food industry for natural food colorants. However, to date limited data are available on the optimal extraction conditions for sorghum biocolorant and its properties in a wider range of food products. This thesis studies the extraction conditions of biocolorant from dye sorghum leaf sheaths, evaluates its bioactive properties, as well as its nutritional and sensorial impact on food products. The chapter 2 compares the colour and anthocyanin composition from various traditional extraction methods to determine options fo

A major drawback to the industrial application of many biocolorants is their instability to processing conditions, thereby limiting their use to replace artificial colorants. 3-Deoxyanthocyanidins have promising features to ensure colour stability in food processing conditions. This study evaluated the stability of apigeninidin, the main 3-deoxyanthocyanidin from sorghum leaf sheaths, to food processing conditions in watery extracts and in a maize porridge. Apigeninidin was not soluble at pH 5.04 ± 0.02. However, apigeninidin was soluble and stable at pH 6–10 with increased colour density and resistance to bleaching at alkaline pH. A heat treatment of 121 °C/30 min degraded 61% of the anthocyanins. At 65 °C, degradation rate of apigeninidin was four times lower at pH 9.03 ± 0.04 than 6.08 ± 0.02. Storage at room temperature promoted endothermic degradation reactions. Nevertheless, photodegradation of apigeninidin was not observed during storage. In the maize porridge, thermal stability of apigeninidin and redness were similar at pH 4–6 whereas they were higher at pH 9.03 ± 0.04. In summary, the watery extract of apigeninidin from sorghum leaf sheaths showed good stability regarding common industrial processes. Nevertheless, the biocolorant's precipitation at pH 5.04 ± 0.02 and degradation at pH 6.08 ± 0.02 and 9.03 ± 0.04 need further investigation to optimise its industrial applications.

In shea production zones in Sub-Saharan Africa, shea butter is mostly produced by women using traditional methods. Improvement of their practices would allow them to obtain better monetary returns for their activities. Roasting of crushed shea kernels is a processing step that has a major influence on the quantity and quality of extracted shea butter. Using a central composite face-centered design (CCFD), the effect of roasting, specifically roasting time and temperature was investigated. Both factors influenced fat content (44-53% dw) of the crushed kernels; colour characteristics and free fatty acid (FFA) content (0.5-3%) of the butter. In shea butter from differently roasted kernels, 58 volatile compounds were identified, of which 11 were quantitatively dominant, against 27 compounds in butter from unroasted kernels. The ideal practice according to the CCFD model is roasting at 171 ºC for 15 min, which resulted in a fat content of 49% dw of the kernels, a butter yield of 32%, a FFA of 1.2% of the butter, and a peroxide value of 3.2 meq O2/kg. This optimum roasting time is appreciably shorter than the current practice, suggesting that the use of firewood during traditional processing can be reduced.

Lupinus mutabilis has protein (32.0–52.6 g/100 g dry weight) and lipid (13.0–24.6 g/100 g dry weight) contents similar to soya bean (Glycine max). The Ω3, Ω6, and Ω9 contents are 1.9–3.0, 26.5–39.6, and 41.2–56.2 g/100 g lipid, respectively. Lupins can be used to fortify the protein content of pasta, bread, biscuits, salads, hamburgers, sausages, and can substitute milk and soya bean. Specific lupin protein concentrates or isolates display protein solubility (>90%), water-absorption capacity (4.5 g/g dry weight), oil-absorption capacity (3.98 g/g), emulsifying capacity (2000 mL of oil/g), emulsifying stability (100%, 60 hours), foaming capacity (2083%), foaming stability (78.8%, 36 hours), and least gelation concentration (6%), which are of industrial interest. Lupins contain bitter alkaloids. Preliminary studies on their toxicity suggest as lethal acute dose for infants and children 10 mg/kg bw and for adults 25 mg/kg bw. However, alkaloids can also have medical use for their hypocholesterolemic, antiarrhythmic, and immunosuppressive activity. Bitter lupins can be detoxified by biological, chemical, or aqueous processes. The shortest debittering process requires one hour. This review presents the nutritional composition of lupins, their uses (as food, medicine, and functional protein isolates), toxicology, and debittering process scenarios. It critically evaluates the data, infers conclusions, and makes suggestions for future research.

Mutandabota is a dairy product consumed as a major source of proteins and micronutrients in Southern Africa. In this study the microbial safety of traditional and a variant of mutandabota fermented with the probiotic Lactobacillus rhamnosus yoba (yoba mutandabota) was investigated by challenging the products with five important food pathogens: Listeria monocytogenes, Salmonella spp., Campylobacter jejuni, Escherichia coli O157:H7 and Bacillus cereus. Pasteurized full-fat cow's milk was used for producing traditional and yoba mutandabota, and was inoculated with a cocktail of strains of the pathogens at an inoculum level of 5.5 log cfu/mL. Survival of the pathogens was monitored over a potential consumption time of 24 h for traditional mutandabota, and over 24 h of fermentation followed by 24 h of potential consumption time for yoba mutandabota. In traditional mutandabota (pH 3.4 ± 0.1) no viable cells of B. cereus and C. jejuni were detected 3 h after inoculation, while L. monocytogenes, E. coli O157:H7 and Salmonella spp. significantly declined (P <0.05), but could still be detected (<3.5 log inactivation) at the end of the potential consumption time. This indicated that consumption of traditional mutandabota exposes consumers to the risk of food-borne microbial infections. In yoba mutandabota, L. rhamnosus yoba grew from 5.5 ± 0.1 log cfu/mL to 9.1 ± 0.4 log cfu/mL in the presence of pathogens. The pH of yoba mutandabota dropped from 4.2 ± 0.1 to 3.3 ± 0.1 after 24 h of fermentation, mainly due to organic acids produced during fermentation. Only Salmonella spp. was able to grow in yoba mutandabota during the first 9 h of fermentation, but then decreased in viable plate count. None of the tested pathogens were detected (> 3.5 log inactivation) after 3 h into potential consumption time of yoba mutandabota. Inactivation of pathogens in mutandabota is of public health significance because food-borne pathogens endanger public health upon consumption of contaminated foo

The objective of this study was to evaluate the presence of Aspergillus section Flavi and A. section Nigri in cashew nuts harvested in the Northern Guinea (NG) and Southern Sudanian (SS) agro-ecological zones of Benin. Also, the presence of aflatoxins was investigated. For detection of fungal contamination, a total of100 kernels/sample (with disinfection) and 40 kernels/sample (without disinfection) were plated. Seventy samples from fourteen villages were used. Aflatoxins occurrence was analysed on 84 samples by ultraehigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The average water content and the cashew nuts count were respectively 8.6% and 172 nuts/kg in NG and 8.7% and 174 nuts/kg in SS. Significant differences between villages in both zones were found for both water content and nuts count. In disinfected samples, strains of Aspergillus section Nigri were predominant, inNG and SS zones (90.2% and 87.2%) respectively. When non disinfected kernels were plated, A. section Nigri was predominant in both NG and SS zones, with percentages of 89.7% and 93.4%, respectively. None of the 84 nuts samples were positive for natural occurrence of aflatoxins with a detection limit of 0.05e0.2 mg/kg.

Mung bean (Vigna radiata (L.) R.Wilczek) has been intensively researched; scattered data are available on various properties. Data on physical, chemical, food processing, and nutritional properties were collected for whole mung bean grains and reviewed to assess the crop’s potential as food and to set research priorities. Results show that mung bean is a rich source of protein (14.6–33.0 g/100 g) and iron (5.9–7.6 mg/100 g). Grain color is correlated with compounds like polyphenols and carotenoids, while grain hardness is associated with fiber content. Physical properties like grain dimensions, sphericity, porosity, bulk, and true density are related to moisture content. Anti-nutrients are phytic acid, tannins, hemagglutinins, and polyphenols. Reported nutrient contents vary greatly, the causes of which are not well understood. Grain size and color have been associated with different regions and were used by plant breeders for selection purposes. Analytical methods require more accuracy and precision to distinguish biological variation from analytical variation. Research on nutrient digestibility, food processing properties, and bioavailability is needed. Furthermore, the effects of storage and processing on nutrients and food processing properties are required to enable optimization of processing steps, for better mung bean food quality and process efficiency.

Interrelationships between food processing conditions, consumer liking, purchase intent and willingness to pay can be studied and modeled as exemplified by this paper on lupin (Lupinus mutabilis). Lupin was debittered by 12 different aqueous treatments and evaluated by 99 consumers. First they scored the products on the basis of liking. Next, they were informed about the price of the products and asked to rank their purchase intent in relation to their liking scores and product price. Treatments with more processing (i.e. longer agitation times and/or more frequent changes of water) increased the product price but diminished liking. Consumers did not choose between liking and price; the purchase intent was the combined effect of both variables. Willingness to pay was inferred from the purchase intent plot. For example, at a purchase intent of 2, consumers would accept an increase in price of 0.3 $/kg if liking increased from ‘‘like slightly’’ to ‘‘like moderately’’. In the studied range, the effect of processing on liking and expected price, as well as their effect on purchase intent, could be described by first order regression equations.

Designing a food supply chain for a completely new product involves many stakeholders and knowledge from disciplines in natural and social sciences. This paper describes how Multi Criteria Decision Making (MCDM) facilitated designing a food supply chain in a case of Novel Protein Foods. It made the procedure transparent and aided the evaluation of alternatives. Two models, namely the Multi Attribute Value Theory (MAVT) and the Analytic Hierarchy Process (AHP), were used, due to the ease with which they handle a mix of quantitative and qualitative information, quantify the qualitative information and generate an overall value for each alternative. The resulting preference order differed mainly due to the manner in which criteria weights were elicited, alternatives scored and the use of scales in MAVT versus the pairwise comparison in AHP. However, the preference order of the top criteria with both methods was the same and weights were similar.

Consumption habits for mung bean foods were assessed by the free word association method and interview techniques. Four groups of closely related products and perceived quality were revealed. The largest group comprised sweets and snacks, which were associated with unhealthiness, expensiveness and sensory liking. Another group consisted of split dhals associated with convenience and healthiness. It appeared that under different circumstances food choices vary and are influenced more by socioeconomic restrictions then by consumer perception and preferences. Scenario analysis based on consumer perception, preferences, practices and nutritional value of products revealed dhals as the most promising food for innovation.