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Functional foods contain health-promoting ingredients, which make them beneficial to humans and potentially help in disease prevention or treatment. The demand for functional foods is growing not just in the developed regions, but also in the developing regions of the world such as in Africa due to heightened consumer awareness on the role of foods in human health. African functional foods are foods of African origin that possess various characteristics like prebiotic, probiotic, satiety, immune modulation, stress-reduction, improved memory, and cardiovascular benefits. Traditionally fermented functional foods prepared from cereals like maize, millet, or sorghum abound in many African countries. Traditional fermentation, often spontaneous, utilizes a mixed culture of microorganisms mostly belonging to the lactic acid bacteria and yeast groups. The present review corroborated these pieces of information into the famous African functional foods and beverages, their sources, and quality attributes. Furthermore, functional foods were explained in very clear terms while evaluating the relationship between functional foods and African consumer's health benefits. The study peaked at future work and further considerations on the potential of common functional foods from Africa, which are cheap and readily available to the people. [ABSTRACT FROM AUTHOR]

Background: Antimicrobial resistance (AMR) is one of the biggest threats to public health. The food chain has been recognised as a vehicle for transmitting AMR bacteria. However, information about resistant strains isolated from African traditional fermented foods remains limited. Nono is a traditional, naturally fermented milk product consumed by many pastoral communities across West Africa. The main aim of this study was to investigate and determine the AMR patterns of lactic acid bacteria (LAB) involved in the traditional fermentation of milk for Nono production, and the presence of transferable AMR determinants. Methods: One hundred (100) LAB isolates from Nono identified in a previous study as Limosilactobacillus fermentum, Lactobacillus delbrueckii, Streptococcus thermophilus, Streptococcus infantarius, Lentilactobacillus senioris, Leuconostoc pseudomesenteriodes, and Enterococcus thailandicus were investigated. The minimum inhibitory concentration (MIC) was determined for 18 antimicrobials using the micro-broth dilution method. In addition, LAB isolates were screened for 28 antimicrobial resistance genes using PCR. The ability of LAB isolates to transfer tetracycline and streptomycin resistance genes to Enterococcus faecalis was also investigated. Results: The experiments revealed variable antimicrobial susceptibility according to the LAB isolate and the antimicrobial tested. The tetracycline resistance genes tet(S) and tet(M) were detected in isolates Ent. thailandicus 52 and S. infantarius 10. Additionally, aad(E) encoding resistance to streptomycin was detected in Ent. thailandicus 52. The conjugation experiments suggested that the tet(S) and aad(E) genes were transferable in vitro from isolate Ent. thailandicus 52 to Ent. faecalis JH2-2. Significance and Impact: Traditional fermented foods play a significant role in the diet of millions of people in Africa, yet their contribution to the burden of AMR is largely unknown. This study highlights that LAB involved in traditionally fermented foods could be potential reservoirs of AMR. It also underscores the relevant safety issues of Ent. thailandicus 52 and S. infantarius 10 for use as starter cultures as they carry transferable AMR genes. Starter cultures are an essential aspect of improving the safety and quality attributes of African fermented foods. However, AMR monitoring is an important safety aspect in the selection of starter cultures for improving traditional fermentation technologies. [ABSTRACT FROM AUTHOR]

The benefits derived from fermented foods and beverages have placed great value on their acceptability worldwide. Food fermentation technologies have been employed for thousands of years and are considered essential processes for the production and preservation of foods, with the critical roles played by the autochthonous fermenting food-grade microorganisms in ensuring food security and safety, increased shelf life, and enhanced livelihoods of many people in Africa, particularly the marginalized and vulnerable groups. Many indigenous fermented foods and beverages of Africa are of plant origin. In this review, the predominance, fermentative activities, and biopreservative role of Lactobacillus spp. during production of indigenous foods and beverages, the potential health benefit of probiotics, and the impact of these food-grade microorganisms on food safety and prolonged shelf life are discussed. During production of African indigenous foods (with emphasis on cereals and cassava-based food products), fermentation occurs in succession; the first group of microorganisms to colonize the fermenting substrates are lactic acid bacteria (LAB) with the diversity and dominance of Lactobacillus spp. The Lactobacillus spp. multiply rapidly in the fermentation matrix, by taking up nutrients from the surrounding environments, and cause rapid acidification in the fermenting system via the production of organic compounds that convert fermentable sugars into mainly lactic acid. Production of these compounds in food systems inhibits spoilage microorganisms, which has a direct effect on food quality and safety. The knowledge of microbial interaction and succession during food fermentation will assist the food industry in producing functional foods and beverages with improved nutritional profiling and technological attributes, as Lactobacillus strains isolated during fermentation of several African indigenous foods have demonstrated desirable characteristics that make them safe for use as probiotic microorganisms and even as a starter culture in small- and large-scale/industrial food production processes. [ABSTRACT FROM AUTHOR]

The use of insects as food and feed is widespread worldwide due to their attractive nutritional profile comparable to that of conventional livestock. In particular, edible grasshoppers act as a food source to many tribes in East and Central Africa but still harvested from their natural habitats. In this perspective, the health hazards associated with consumption of grasshoppers ought to be investigated. The present review assesses the risks (microbiological and heavy metals hazards) of wild-harvested Ruspolia differens (Serville) (Orthoptera: Tettigonidae) and compares with the levels recommended for minced meat as an indicator of food safety for edible insects. In addition, the effect of common processing methods in reducing the risks is stated. Due to the scarcity of the data, other edible grasshoppers within the order Orthoptera have been included in the review. The risks identified as main hazards include: (1) high total viable counts; (2) high counts of Enterobacteriaceae and lactic acid bacteria; (3) high counts of yeasts and moulds; and (4) accumulation of lead and other heavy metals. Conventional processing methods are effective in reducing microbiological hazards except for bacterial endospores. Important data gaps regarding edible grasshoppers and their safety include: (1) lack of data on bacterial communities (raw and processed); (2) fungal communities and mycotoxins-producing fungi; (3) studies on shelf life of processed edible grasshoppers; (4) limited data on heavy metals on whole grasshoppers and derived products; and (5) lack of data on parasites, viruses, antimicrobial resistance and veterinary medicinal products. Future aspect should focus on sustainable farming of grasshoppers using different diets in controlled environments and risks profiling. The present review explores food safety risks related to consumption of edible grasshoppers, from wild collections to consumption. [ABSTRACT FROM AUTHOR]

• Raphia hookeri (RH) is an underutilized palm crop native to Africa. • Its ethnomedicinal, phytochemistry and biotechnological applications are appraised. • RH's metabolites could support its inherent industrial and therapeutic significance. • "-omics" could provide supportive data on its safety and health benefits. • The study provided baseline information that will inspire further investigations on RH. Raphia hookeri G. Mann & H. Wendl (Arecaceae), commonly known as 'Raffia Palm' is an underutilized plant native to Africa. Like other palms, it is a good source of medicine with diverse ethnomedicinal and industrial applications. Despite these discernible therapeutic and economic benefits of R. hookeri , the plant remains underutilized, albeit some achievement has been made in this area. Hence, this review highlights the existing scope and knowledge gaps regarding its folkloric uses and phytochemistry with a view to lending credence to its pharmacological properties, particularly in the treatment of diabetes. Information are also provided on its biotechnological applications. Despite the pharmacological significance and ethnomedicinal uses of R. hookeri , a major challenge that persists is the lack of comprehensive data on its phytochemical characterization as well as inadequate information on its pharmacokinetics and pharmacodynamics. In view of this, the concepts of molecular dynamics and "-omics" (genomics, proteomics, metabolomics, and transcriptomics etc.) as currently being embraced as modern strategies enhancing translational studies, could find relevance and may provide more comprehensive data supporting the safety profile and therapeutic efficacy of R. hookeri against markers implicated in the pathogenesis and physiological perturbations associated with diseases. These strategies are proposed for adoption in future studies seeking to provide evidence-based data on the therapeutic scope and overall economic benefits of R. hookeri. [ABSTRACT FROM AUTHOR]

Wheat and sorghum are the main dieter cereals for millions of people in Africa and Asia. Their nutritive value in wheat and sorghum is limited due to presence of several anti-nutritional substances such as tannins, phytic acid, proteinase inhibitors and cyanogenic glycosides. Phytic acid (PA) or myo-inositol hexakisphosphate (IP6) in salt form known as phytate is the principal storage form of phosphorus in plant tissues, typically accounting for 60-90% of total seed phosphorous. Phytase enzyme catalyses the hydrolysis of phytate and releases the phosphate for absorption. This study explains the use of different methods for the reduction of PA content in wheat and sorghum such as soaking, cooking, roasting and fermentation using lactic acid bacteria (LAB). Among all the methods, fermentation using LAB was found to be effective in reduction of PA. LAB was isolated from the curd sample and fermentation of wheat and sorghum flour was carried out to reduce the PA content. The effect of different fermentation conditions such as pH, temperature and incubation time was also carried out. The results have shown that the optimal fermentation conditions for reduction of PA in wheat and sorghum flour using LAB were; pH- 6 (wheat) and 6.5 (sorghum), temperature 32 °C (wheat) and 37 °C (sorghum) and fermentation time of 4 to 6 h for both wheat and sorghum. The percentage of reduction of PA using fermentation process was compared with the other methods such as soaking, cooking and roasting process. [ABSTRACT FROM AUTHOR]

Objective: To effectively utilize crop by-product resources to address the shortage of animal feed during the dry season in Africa, the community of natural lactic acid bacteria (LAB) of corn stover and sugarcane tops and fermentation characteristics of silage were studied in Mozambique. Methods: Corn stover and sugarcane tops were obtained from agricultural field in Mozambique. Silage was prepared with LAB inoculant and cellulase enzyme and their fermentation quality and microbial population were analyzed. Results: Aerobic bacteria were the dominant population with 107 colony-forming unit/g of fresh matter in both crops prior to ensiling, while 104 to 107 LAB became the dominant bacteria during ensiling. Lactobacillus plantarum was more than 76.30% of total isolates which dominated silage fermentation in the LAB-treated sugarcane top silages or all corn stover silages. Fresh corn stover and sugarcane tops contain 65.05% to 76.10% neutral detergent fiber (NDF) and 6.52% to 6.77% crude protein (CP) on a dry matter basis, and these nutrients did not change greatly during ensiling. Corn stover exhibits higher LAB counts and watersoluble carbohydrates content than sugarcane top, which are naturally suited for ensiling. Meanwhile, sugarcane tops require LAB or cellulase additives for high quality of silage making. Conclusion: This study confirms that both crop by-products contain certain nutrients of CP and NDF that could be well-preserved in silage, and that they are potential roughage resources that could cover livestock feed shortages during the dry season in Africa. [ABSTRACT FROM AUTHOR]

Sesotho is an indigenous cereal-based fermented drink traditionally produced in the mountain kingdom of Lesotho, Southern Africa. The present study sought to examine the microbial (bacterial and fungal) community composition of Sesotho at five fermentation stages in five different locations. Using culture-independent (Illumina sequencing) techniques it was found that the bacterial communities followed similar successional patterns during the fermentation processes, regardless of geographical location and recipe variation between breweries. The most abundant bacterial taxa belonged to the phyla Firmicutes (66.2% of the reads on average) and Proteobacteria (22.1%); the families Lactobacillaceae (54.9%), Enterobacteriaceae (14.4%) and Leoconostrocaceae (8.1%); and the genera Lactobacillus (54%), Leuconostoc (10.7%), Leptotrichia (8.5%), and Weissella (5.5%). Most fungal taxa were from the phyla Ascomycota (60.7%) and Mucoromycota (25.3%); the families Rhizopodaceae (25.3%), Nectriaceae (24.2%), Saccharomycetaceae (16%) and Aspergillaceae (6.7%); and the genera Rhizopus (25.3%), Saccharomyces (9.6%), and Aspergillus (2.5%). Lactic acid bacteria (LAB) such as Enterococcus , Pediococcus , Lactobacillus , Leuconostoc , and Wiesella ; as well as yeasts belonging to the genus Saccharomyces , were dominant in all breweries during the production of Sesotho. Several pathogenic and food spoilage microorganisms (e.g., Escherichia , Shigella , Klebsiella , etc.) were also present, but the study demonstrated the safety potential of the Sesotho fermentation process, as these microbial groups decline throughout Sesotho production. The functional profiles of the different brewing steps showed that the process is dominated by chemoheterotrophic and fermentative metabolisms. This study reveals, for the first time, the complex microbial dynamics that occur during Sesotho production. [ABSTRACT FROM AUTHOR]

Fermented cereals are part of the main traditional diets of many people in Africa, usually obtained from artisanal production. The intensification of their manufacturing, responding to the consumers demand, requires a better control to ensure their sanitary, nutritional, and taste qualities, hence, the need of selecting accurate and safe starter cultures. In the present study, 48 lactic acid bacteria (LAB) strains, previously isolated from Algerian fermented wheat lemzeiet, were analyzed for different technological properties. 14 LAB strains, belonging to Pediococcus pentosaceus, Enterococcus faecium, Lactobacillus curvatus, Lactobacillus brevis, and Leuconostoc mesenteroides species, decreased rapidly the pH of the flour extract broth close to 4 or below. 91% of strains showed extracellular protease activity, but only 12% were amylolytics. 18 LAB strains inhibited or postponed the growth of three fungal targets Rhodotorula mucilaginosa UBOCC-A-216004, Penicillium verrucosum UBOCC-A-109221, and Aspergillus flavus UBOCC-A-106028. The strains belonging to Lactobacillus spp., Leuconostoc fallax, L. mesenteroides, and Weissella paramesenteroides were the most antifungal ones. Multiplex PCR for biogenic amines' production did not reveal any of the genes involved in the production of putrescine, histamine, and tyramine for 17 of the 48 strains. The obtained results provided several candidates for use as starter culture in the future production of lemzeiet. [ABSTRACT FROM AUTHOR]

Fermented foods are an integral part of the diet for many communities in Africa. The fermentation of maize is characterized by an improved nutrient content/bioavailability and the presence of bioactive compounds which are largely attributed to the activity of the microbial population mainly lactic acid bacteria (LAB) and yeasts. The role of LAB in maize and other cereal fermentations has been extensively studied. However, limited literature is available on the role of yeasts in maize fermentations and resultant nutritional and health promoting properties. This review explores the contribution of yeasts to the nutritional and health properties of fermented maize and other cereal products. Additionally, the proliferation and growth characteristics of dominant yeasts and their derived metabolites are discussed. It is particularly important to comprehend the processes and type of yeasts involved in maize fermentation as an essential step in maize product development. This will facilitate the development of yeast-based starter culture, improve maize fermentation process and provide better understanding of associated nutrition and bioactive properties. [ABSTRACT FROM AUTHOR]

Diverse African traditional fermented foods and beverages, produced using different types of fermentation, have been used since antiquity because of their numerous nutritional values. Lactic acid bacteria (LAB) isolated from these products have emerged as a welcome source of antimicrobials and therapeutics, and are accepted as probiotics. Probiotics are defined as live microbial food supplements which beneficially affect the host by improving the intestinal microbial balance. Currently, popular probiotics are derived from fermented milk products. However, with the growing number of consumers with lactose intolerance that are affected by dietary cholesterol from milk products, there is a growing global interest in probiotics from other food sources. The focus of this review is to provide an overview of recent developments on the applications of probiotic LAB globally, and to specifically highlight the suitability of African fermented foods and beverages as a viable source of novel probiotics. [ABSTRACT FROM AUTHOR]

Fungal deterioration is a barrier to the wide acceptance of fermented cereal foods from Africa. The use of protective cultures is a natural approach to controlling fungi in foods that also complies with a clean label strategy. This study aims to select antifungal lactic acid bacteria (LAB) previously isolated from kunu-zaki to bio-control deterioration in this cereal-based Nigerian fermented beverage. Strains of Leuconostoc citreum (1), Limosilactobacillus fermentum (6), and Weissella confusa (3) were the most active against seven test mold species, with average inhibition score of 2.25–2.88, after screening 220 LAB strains using agar overlay on millet-sorghum flour hydrolysate (MSFH) agar. The MSFH agar diffusion method revealed that antifungal activity against the seven target molds was retained in cell-free supernatants (CFSs) of selected LABs, with the strongest inhibition against A. flavus F008BA and P. citrinum 3AS1 demonstrated by L. fermentum 5KJEU5 (9.06%) and W. confusa YKDIA1 (24.55%), respectively. The antifungal activity of CFSs was mainly due to the occurrence of acidic compounds, with the most abundant compounds being acetic (0.30–1.96 mg/mL) and lactic (1.80–3.23 mg/mL) acids. Other compounds such as hydroxycaffeic (0.16–6.72 μg/mL), 3-(4-hydroxyphenyl) propionic (1.40–6.36 μg/mL), 3-phenyllactic (1.28–24.48 μg/mL), and hydroxyferulic acids (12.25 μg/mL) occurred at lower concentrations. In challenged kunu-zaki , L. fermentum 5KJEU5 prevented the growth of A. flavus F008BA and P. citrinum 3AS1 beyond 8 day at ambient temperature (25 °C). In this study, LAB from kunu-zaki displayed strong antifungal activity, showing great potential as a protective culture to prevent fungal growth and mycotoxin accumulation in cereal foods. • A millet-sorghum flour hydrolysate medium was used to simulate conditions in kunu-zaki , a cereal-based indigenously fermented Nigerian beverage. • Strong and broad-spectrum antifungal activity was found in strains of Limosilactobacillus fermentum, Leuconostoc citreum , and Weissella confusa. • Cell-free culture supernatant (CFS) of antifungal LAB retained antifungal activity due to organic acid metabolites. • Eight antifungal molecules were detected in the CFS of antifungal LAB strains. • Limosilactobacillus fermentum 5KJEU5 demonstrated an antifungal effect in a kunu-zaki model. [ABSTRACT FROM AUTHOR]

Background: Indigenous fermented food products play an essential role in the diet of millions of Africans. Lactic acid bacteria (LAB) are among the predominant microbial species in African indigenous fermented food products and are used for different applications in the food and biotechnology industries. Numerous studies have described antimicrobial susceptibility profiles of LAB from different parts of the world. However, there is limited information on antimicrobial resistance profiles of LAB from Africa. The aim of this study was to characterize 33 LAB previously isolated from three different African indigenous fermented food products using (GTG)5-based rep-PCR, sequencing of the 16S rRNA gene and species-specific PCR techniques for differentiation of closely related species and further evaluate their antibiotic resistance profiles by the broth microdilution method and their haemolytic activity on sheep blood agar plates as indicators of safety traits among these bacteria. Results: Using molecular biology based methods and selected phenotypic tests such as catalase reaction, CO2 production from glucose, colonies and cells morphology, the isolates were identified as Lactobacillus delbrueckii, Lactobacillus fermentum, Lactobacillus ghanensis, Lactobacillus plantarum, Lactobacillus salivarius, Leuconostoc pseudomesenteroides, Pediococcus acidilactici, Pediococcus pentosaceus and Weissella confusa. The bacteria were susceptible to ampicillin, chloramphenicol, clindamycin and erythromycin but resistant to vancomycin, kanamycin and streptomycin. Variable sensitivity profiles to tetracycline and gentamicin was observed among the isolates with Lb. plantarum, Lb. salivarius, W. confusa (except strain SK9-5) and Lb. fermentum strains being susceptible to tetracycline whereas Pediococcus strains and Lb. ghanensis strains were resistant. For gentamicin, Leuc. pseudomesenteroides, Lb. ghanensis and Ped. acidilactici strains were resistant to 64 mg/L whereas some W. confusa and Lb. plantarum strains had a MIC value of 16 mg/L and 32 mg/L respectively. No β-haemolytic activity was observed, however, α-haemolytic activity was observed in 27% (9) of the strains comprising Lb. salivarius (6), W. confusa (2) and Lb. delbrueckii (1) isolates. Conclusions: The resistance to kanamycin and vancomycin is probably an intrinsic feature since similar observations were reported in the literature for LAB. Low prevalence of pathogenicity indicator traits were observed among the isolates especially with the presence of poor haemolytic activities and they could therefore be considered as interesting candidates for selection of starter cultures or probiotics for different applications. [ABSTRACT FROM AUTHOR]

Aims: To select appropriate micro-organisms to be used as starter culture for reliable and reproducible fermentation of Lafun. Methods and Results: A total of 22 cultures consisting of yeast, lactic acid bacteria (LAB) and Bacillus cereus strains predominant in traditionally fermented cassava during Lafun processing were tested as potential starter cultures. In an initial screening, Saccharomyces cerevisiae 2Y48P22, Lactobacillus fermentum 2L48P21, Lactobacillus plantarum 1L48P35 and B.  cereus 2B24P31 were found to be the most promising of the cultures and were subsequently tested in different combinations as mixed starter cultures to ferment submerged cassava roots. Saccharomyces cerevisiae, inoculated singly or combined with B. cereus, gave the softest cassava root after 48 h of fermentation according to determination of compression profile and stress at fracture. Overall, sensory quality testing showed that Lafun obtained from S. cerevisiae-fermented cassava gave the most preferred stiff porridge. Saccharomyces cerevisiae 2Y48P22 showed pectinase production in a model system. Conclusions: The results suggest that S. cerevisiae 2Y48P22 is the most efficient organism for cassava softening during the fermentation. Therefore, it could be combined with LAB and used as starter for Lafun processing. Significance and Impact of the Study: Starter cultures are made available for controlled fermentation of Lafun. [ABSTRACT FROM AUTHOR]

AbstractAfrican traditional fermented foods remain the main source of nutrition for many rural communities in Africa. Although lactic acid bacteria are integral to many of these foods, little is known about the specific health benefits they confer or the properties of their strains. This mini-review explores the history of some African fermented foods and their microbial content and properties within the context of probiotic characteristics. Given the recent upsurge in probiotic research, recommendations are made on studies that could be performed with African fermented foods and their strains, with a view to improving the health of people in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

Abstract: Cereal fermentations in Africa and Asia involve mainly the processing of maize, rice, sorghum and the millets. Lactic acid bacteria (Lactobacillus, Pediococcus), Enterobacter spp., yeasts (Candida, Debaryomyces, Endomycopsis, Hansenula, Pichia, Saccharomyces and Trichosporon spp.) and filamentous fungi (Amylomyces, Aspergillus, Mucor, and Rhizopus spp.) contribute to desirable modifications of taste, flavour, acidity, digestibility, and texture in non-alcoholic beverages (e.g., uji, and ben-saalga), porridges (e.g., mawè) and cooked gels (e.g., kenkey, idli, and mifen). In addition, alcoholic beverages (beers such as tchoukoutou and jnard; and spirits e.g. jiu) are obtained using malt, or using amylolytic mixed microbial starter cultures as generators of fermentable substrates. Wet processing, marketing of multi-purpose intermediate products, co-fermentation for texture and nutrition, and mixed culture fermentations as practiced in indigenous fermentation processes are of interest for industrial innovation and for better control of natural mixed culture fermentation systems. On the other hand, the nutritional properties of traditional cereal fermented products can be enhanced by increasing their nutrient and energy density, as well as by increasing their mineral status by combining mineral fortification and dephytinization. [Copyright &y& Elsevier]

Abstract: Probiotic bacteria and starter cultures of Lactobacillus, Weissella and Bifidobacterium of African and European origins were studied and compared for their susceptibility to antimicrobials. The study included, for all isolates, determination of MICs (Minimal Inhibitory Concentration) for 24 antimicrobials, detection of resistance genes by PCR reactions using specific primers and sequencing of positive amplicons. The ability of Lb. reuteri from Africa to transfer the erythromycin resistance gene erm(B) to closely related bacteria was investigated by conjugation. Variations were observed and high levels of intrinsic resistance were found among the tested species. Positive amplicons were obtained for resistance genes encoding aminoglycoside (aph(3′)-III, aadA, aadE) and tetracycline (tet(S)) from isolates from Europe and macrolide (erm(B)) from an isolate from Africa. However, only the erm(B) gene found in Lb. reuteri L4: 12002 from Africa contained a homologous sequence to previously published sequences. This gene could be transferred in vitro to enterococci. Higher prevalence of phenotypic resistance for aminoglycoside was found in isolates from Europe. [Copyright &y& Elsevier]

In a programme to develop starter cultures for improving the safety and quality of traditional fermented foods in Africa, a study was conducted on lactic acid bacterial (LAB) strains isolated from the traditional selected Nigerian fermented foods kunun-zaki, wara, nono, iru. The LAB strains representing the dominating population of each product, were identified as Enterococcux faecalis (1), Pediococcus pentosaceus (4), and Lactobacillus fermentum (19). All the strains grew at 450°C, an observation which could be attributed to the tropical environment of the fermented foods. They produced a moderate spectrum of enzymes of relevance to food processing, and exhibited similar patterns of enzymatic activity between species, but generally showed weak esterase and lipase activities as compared with peptidases. While no proteinase activity was detected, most strains showed high galactosidase activity. Two strains showed ability to degrade phytic acid. None of the strains produced any detectable bacteriocins or biogenic amines under the test conditions used, and all were unable to hydrolyse bile salt. Eleven (45.8%) of the strains coagulated skim milk at 30°C within 24-36 h, and at 37°C within 12-20 h together with a moderate drop in pH. The results are discussed to highlight the relevance of technological features of starter cultures in food processing in the African environment. [ABSTRACT FROM AUTHOR]

Indigenous fermented foods (IFFs) have a long history in Africa and are embedded in cultural norms and practices. Typically, these foods are produced at small or household scale using indigenous processing technologies. In addition, limited knowledge of good manufacturing and handling practices can lead to production under unhygienic conditions. This results in variations in the quality and safety attributes of IFFs, as spoilage and pathogenic bacteria can be introduced at any stage of the value chain. These foods have an important role in the African diet and can contribute to food security by increasing the availability of cheap, nutritious food and supporting livelihoods. However, the presence of foodborne pathogens and antibiotic-resistant bacteria in IFFs may constitute a health risk to consumers. Therefore, this review presents an overview of the microorganisms associated with IFFs from Africa, focusing on microbial food safety hazards. African indigenous fermented foods offer a vast genetic potential of undiscovered strains that possess valuable technical characteristics. However, IFFs may also serve as vehicles of pathogenic and antibiotic-resistant bacteria and genetic determinants. Significant research and data gaps exist regarding the microbiological safety of these food products, which warrant urgent attention. We propose practical solutions for improving the safety of African IFFs requiring action and collaboration from all stakeholders, including researchers, producers, governmental regulatory bodies, and consumers. [ABSTRACT FROM AUTHOR]

Indigenous grains for food production have the potential to combat food insecurity and poverty in Africa. The aim of the study was to determine the effect of sourdough fermentation on the acidity, microbiological quality, microbial diversity and rheological properties of three underutilized African cereals. The sourdoughs had pH ranging from 3.9 to 4.1. Finger millet and pearl millet sourdoughs had LAB counts >7 log cfu g−1 indicating they are suitable for use as starter culture(s). Microbial diversity was determined using culture dependent techniques and the identity of isolates was established using 16S rRNA gene sequencing. This showed the presence of Bacillus , Brevibacillus , Acinetobacter and Pediococcus species in the sourdoughs. An occurrence of Candida glabrata was observed in finger millet sourdough. Sourdough fermentation resulted in significant increases (p < 0.05) in the peak, trough and final viscosity of pearl millet and sorghum. A lower setback in the three samples indicated improved shelf-life. Starter culture(s) were identified that might be used in the production of gluten-free baked foods as a result of sourdough fermentation. [ABSTRACT FROM AUTHOR]

Ting is a traditional fermented sorghum product mostly eaten in Southern Africa, generally believed to be highly nutritious and rich in health beneficial properties. Although refined grains are mostly used for fermented foods, the use of whole grains (WGs) in fermented products is gradually gaining prominence due to their benefits. In this study, Lactobacillus fermentum strains were used singly and in combination for the fermentation of WG- ting from WG-sorghum and all possible metabolites profiled using gas chromatography-high resolution time of flight-mass spectrometry. 198 compounds were observed in the experimented samples, classified into different metabolic groups, with varying proportions: esters (23%), ketones (10%), fatty acids methyl esters (7%), and hydrocarbons (6%). Other important metabolites include vitamins, terpenes and terpenoids, phytosterols, phenols, and alcohols. Although similar lactic acid bacteria were used, differences were observed in levels of the metabolites and in some instances, the types of metabolites obtained differ. Much of the differences were attributed to varying fermentation behaviours of the strains, which could be related to their inherent genes. The correlation between metabolites from raw sorghum and the fermented product may assist in developing processing methods to retain the desired metabolites and enhance their functional potentials toward product improvement and for health benefits. Image 1 • Gas chromatography mass spectrometry was utilized to profile the metabolites in whole grain (WG) sorghum and WG- ting. • Strains of starter culture and mode of fermentation (spontaneous or controlled) influenced the metabolites detected. • Difference in metabolism of the fermenting strains and inherent genes could have influenced the profiled metabolites. • Nutritionally important and health beneficial metabolites were detected in both WG-sorghum and WG- ting samples. [ABSTRACT FROM AUTHOR]

Fermented foods and beverages are mainly consumed by the indigenous people of Africa and other developing countries. Traditional fermentation is an age-long means of preserving perishable foods especially when other methods of preservation are not available and/or not consistent. The main beneficial microorganisms that are responsible for the fermentation of African indigenous fermented foods and beverages are lactic acid bacteria and yeasts which may be present as microflora on the substrates or added as starter cultures. The understanding of the synergistic interaction between these microorganisms in the fermented food matrices result in improved nutrient availability, food quality, palatability, organoleptic properties, increased shelf life, safety, digestibility and also play beneficial roles in modulating host immune system thereby minimizing the risk of certain diseases. [ABSTRACT FROM AUTHOR]

Sorghum ( Sorghum bicolor ) is a well-known drought and climate resistant crop with vast food use for the inhabitants of Africa and other developing countries. The importance of this crop is well reflected in its embedded benefits and use as a staple food, with fermentation playing a significant role in transforming this crop into an edible form. Although the majority of these fermented food products evolve from ethnic groups and rural communities, industrialization and the application of improved food processing techniques have led to the commercial success and viability of derived products. While some of these sorghum-based fermented food products still continue to bask in this success, much more still needs to be done to further explore evolving techniques, technologies and processes. The addition of other affordable nutrient sources in sorghum-based fermented foods is equally important, as this will effectively augment the intake of a nutritionally balanced product.

Milk is a major source of nutrients, but can also be a vehicle for zoonotic foodborne diseases, especially when raw milk is consumed. In Africa, poor processing and storage conditions contribute to contamination, outgrowth and transmission of pathogens, which lead to spoilage, reduced food safety and security. Fermentation helps mitigate the impact of poor handling and storage conditions by enhancing shelf life and food safety. Traditionally-fermented sour milk products are culturally accepted and widely distributed in Africa, and rely on product-specific microbiota responsible for aroma, flavor and texture. Knowledge of microbiota and predominant, technologically important microorganisms is critical in developing products with enhanced quality and safety, as well as sustainable interventions for these products, including Africa-specific starter culture development. This narrative review summarizes current knowledge of technologically-important microorganisms of African fermented dairy products (FDP) and raw milk, taking into consideration novel findings and taxonomy when re-analyzing data of 29 publications covering 25 products from 17 African countries. Technologically-important lactic acid bacteria such as Lactococcus lactis and Streptococcus infantarius subsp. infantarius (Sii), Lactobacillus spp. and yeasts predominated in raw milk and FDP across Africa. Re-analysis of data also suggests a much wider distribution of Sii and thus a potentially longer history of use than previously expected. Therefore, evaluating the role and safety of African Sii lineages is important when developing interventions and starter cultures for FDP in Africa to enhance food safety and food security. In-depth functional genomics, epidemiologic investigations and latest identification approaches coupled with stakeholder involvement will be required to evaluate the possibility of African Sii lineages as novel food-grade Streptococcus lineage., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)