Fermented and malted millet products in Africa: Expedition from traditional/ethnic foods to industrial value-added products

Application and functional properties of millet starch: Wet milling extraction process and different modification approaches

In the past decade, the demand and interest of consumers have expanded for using plant-based novel starch sources in different food and non-food processing. Therefore, millet-based value-added functional foods are acquired spare attention due to their excellent nutritional, medicinal, and therapeutic properties. Millet is mainly composed of starch (amylose and amylopectin), which is primary component of the millet grain and defines the quality of millet-based food products. Millet contains approximately 70 % starch of the total grain, which can be used as a, ingredient, thickening agent, binding agent, and stabilizer commercially due to its functional attributes. The physical, chemical, and enzymatic methods are used to extract starch from millet and other cereals. Numerous ways, such as non-thermal physical processes, including ultrasonication, HPP (High pressure processing) high-pressure, PEF (Pulsed electric field), and irradiation are used for modification of millet starch and improve functional properties compared to native starch. In the present review, different databases such as Scopus, Google Scholar, Research Gate, Science Direct, Web of Science, and PubMed were used to collect research articles, review articles, book chapters, reports, etc., for detailed study about millet starch, their extraction (wet milling process) and modification methods such as physical, chemical, biological. The impact of different modification approaches on the techno-functional properties of millet starch and their applications in different sectors have also been reviewed. The data and information created and aggregated in this study will give users the necessary knowledge to further utilize millet starch for value addition and new product development.

Phytochemical and biological studies of Panicum antidotale aerial parts ethanol extract supported by molecular docking study

Panicum antidotale has traditionally been used as a poultice to alleviate local inflammation and painful diseases. This study aimed to evaluate the anti-inflammatory, wound-healing, analgesic, and antipyretic potential of its ethanol extract (PAAPEE) in vivo for the first time. In vitro antioxidant assays of Panicum antidotale using a 2,2-diphenyl-1-picrylhydrazyl assay revealed that it showed IC50 of 62.50 ± 6.85 μg/mL in contrast to standard, ascorbic acid, that showed IC50 of 85.51 ± 0.38 μg/mL. Administration of PAAPEE at a dose of 500 mg/kg (PAAPEE-500) displayed 78.44% and 75.13% inhibition of paw edema in carrageenen and histamine-induced edema models. respectively, 6 h post-treatment compared to that of the untreated group. Furthermore, it showed 68.78% inhibition of Freund's complete adjuvant-induced edema 21 days after treatment. It reduced the animal's rectal temperature in the yeast-induced fever model to 99.45 during the fourth h post-treatment. It significantly inhibited abnormal writhing by 44% in the acetic acid-induced pain model. PAE-500 also showed enhancement in wound closure by 72.52% with respect to that of the untreated group on the 10th day post-treatment using the excision healing of wound model. Histopathological examination of skin samples confirmed this improvement, showing enhanced tissue architecture with minimal infiltration of inflammatory cells. High-performance liquid chromatography (HPLC) of PAAPEE revealed the presence of quercetin, gallic, p-coumaric, benzoic, chlorogenic, syringic, ferulic, cinnamic, and sinapic acids. Molecular docking of 5-lipoxygenase and glycogen synthase kinase-3 β protein indicated their potential interaction within the active sites of both enzymes. Thus, P. antidotale serves as an effective natural wound-healing, anti-inflammatory, analgesic, and antipyretic agent.

Developing a culturally acceptable peanut nutrition bar with smallholder women farmers in Kaffrine, Senegal using response surface methodology

To increase farm income and food security, a collaboration was made with smallholder women farmers in Kaffrine, Senegal to develop a culturally acceptable peanut nutrition bar using healthy indigenous and local ingredients and feasible manufacturing methods. This study aimed to use response surface methodology to optimize the bar's formulation and characterize the texture, nutrient profile, sensory qualities, and water activity. The bars were made by varying the ratio of cowpea flour to corn flour (w/w, d.b., 0/100, 25/75, 50/50, 75/25, and 100/0) and the percentage of baobab pulp powder in the cowpea-corn flour blend (w/w, d.b., 15%, 20%, 25%, and 30%) with a fixed amount of 13 g of peanut paste added to all formulations. The use of acacia gum as a binder increased the bars' cohesiveness. Increasing the ratio of cowpea flour to corn flour decreased the cohesiveness and increased protein, fiber, calcium, iron, and folate levels of the bars. Increasing the percentage of baobab pulp powder increased the hardness, fiber, and vitamin C levels, and decreased cohesiveness and water activity of the bars. The bar formulation optimized for sensory acceptance had a cowpea to corn ratio of 85.3:14.7, a baobab level of 9.95%, and 13 g of peanut paste. According to the research, the optimum formulation gave 38%, 32%, 36%, 50%, 11%, and 83% of the recommended dietary allowance of protein, fiber, calcium, iron, vitamin C, and folate, respectively, per serving for school-age children and featured culturally acceptable texture and desirable water activity for commercialization. This study provided critical foundations for the subsequent feasibility assessment of a commercial launch, projected to significantly increase the revenue and nutrient intake of the partnering communities. PRACTICAL APPLICATION: The commercialization of the peanut nutrition bar will serve as a source of new income for Senegalese smallholder women farmers, provide essential nutrients for school-age children and potentially reduce post-harvest loss. Response surface methodology used in this study can also be applied to food product development with indigenous communities to develop an accepted and community-feasible product formulation.

The Role of Amaranth, Quinoa, and Millets for the Development of Healthy, Sustainable Food Products-A Concise Review

The selection of sustainable crops adaptable to the rapidly changing environment, which also cater to the dietary needs of the growing population, is a primary challenge in meeting food security. Grains from ancient crops such as amaranth, quinoa, and millets are positioned to address this challenge and hence have gained dietary predominance among cereals and pseudocereals due to their nutritional value and energy efficiency. From a nutritional perspective, they are recognized for their complete protein, phenolic compounds and flavonoids, prebiotic fibers, and essential micronutrients, including minerals and vitamins. Bioactive peptides from their proteins have shown antihypertensive, antidiabetic, antioxidant, and anticancer properties. The nutritional diversity of these grains makes them a preferred choice over traditional cereals for developing healthy, sustainable food products such as plant-based dairy, vegan meats, and gluten-free products. With growing consumer awareness about sustainability and health, the categories mentioned above are transitioning from ‘emerging’ to ‘mainstream’; however, there is still a significant need to include such healthy grains to fulfill the nutritional gap. This review article emphasizes the health benefits of amaranth, quinoa, and millet grains and discusses the recent research progress in understanding their application in new sustainable food categories. The challenges associated with their incorporation into novel foods and future research directions are also provided.

A Review of the Potential Consequences of Pearl Millet (Pennisetum glaucum) for Diabetes Mellitus and Other Biomedical Applications

Diabetes mellitus has become a troublesome and increasingly widespread condition. Treatment strategies for diabetes prevention in high-risk as well as in affected individuals are largely attributed to improvements in lifestyle and dietary control. Therefore, it is important to understand the nutritional factors to be used in dietary intervention. A decreased risk of diabetes is associated with daily intake of millet-based foods. Pearl millet is a highly nutritious grain, nutritionally comparable and even superior in calories, protein, vitamins, and minerals to other large cereals, although its intake is confined to lower income segments of society. Pearl millet contains phenolic compounds which possess antidiabetic activity. Thus, it can be used to prepare a variety of food products for diabetes mellitus. Moreover, it also has many health benefits, including combating diabetes mellitus, cancer, cardiovascular conditions, decreasing tumour occurrence, lowering blood pressure, heart disease risk, cholesterol, and fat absorption rate. Therefore, the current review addresses the role of pearl millet in managing diabetes.

Biotechnological Application of Saccharomyces cerevisiae and Lactobacillus delbrueckii sp. bulgaricus for Protein Enrichment of Fermented Unmalted and Malted Sorghum (Sorghum bicolor (L.) Moench)

This study evaluated changes in protein contents of malted and unmalted sorghum, and their formulated blends, after fermentation for 10 days at 25°C with mono and cocultures of Saccharomyces cerevisiae and Lactobacillus delbrueckii sp. bulgaricus. Fermentation of unmalted and malted sorghum and their formulated blends of 1 : 1 (w/w), 3 : 1 (w/w), and 1 : 3 (w/w) by S. cerevisiae and L. bulgaricus could increase their protein contents. Thus, there was an increase in protein content of fermented, malted sorghum by 68.40% for S. cerevisiae, 34.98% for L. bulgaricus, and 76.59% for cocultures of S. cerevisiae and L. bulgaricus; protein contents of fermented, unmalted sorghum also increased by 58.20, 39.36, and 55.00% for monoculture of S. cerevisiae, monoculture of L. bulgaricus, and coculture of S. cerevisiae and L. bulgaricus, respectively. S. cerevisiae was more effective in enriching protein content of the 1 : 3 (w/w) formulated blend of unmalted-malted sorghum by 77.59%; L. bulgaricus was more effective in enriching protein content of the 3 : 1 (w/w) unmalted-malted sorghum blend by 60.00%; coculture of S. cerevisiae and L. bulgaricus enriched the protein content of 3 : 1 (w/w) unmalted-malted sorghum substrate by 44.54%. Significant (p ≤ 0.05) increases in fat with corresponding decreases in carbohydrate and fibre contents were consistently recorded in malted and unmalted sorghum. In the formulated blends of sorghum, fat, carbohydrate, and fibre contents either increased or decreased erratically after fermentation. There were significantly (p ≤ 0.05) higher protein contents in malted sorghum, compared to unmalted sorghum. These findings show that solid-state microbial fermentation technology, using S. cerevisiae and L. bulgaricus, either as mono- or coculture, could effectively enrich the protein contents of unmalted and malted sorghum and their formulated blends. The implications of the findings for infant and adult nutrition are discussed, and future work to augment findings is suggested.

Fermentation of Cereals and Legumes: Impact on Nutritional Constituents and Nutrient Bioavailability

Fermented food products, especially those derived from cereals and legumes are important contributors to diet diversity globally. These food items are vital to food security and significantly contribute to nutrition. Fermentation is a process that desirably modifies food constituents by increasing the palatability, organoleptic properties, bioavailability and alters nutritional constituents. This review focuses on deciphering possible mechanisms involved in the modification of nutritional constituents as well as nutrient bioavailability during the fermentation of cereals and legumes, especially those commonly consumed in developing countries. Although modifications in these constituents are dependent on inherent and available nutrients in the starting raw material, it was generally observed that fermentation increased these nutritive qualities (protein, amino acids, vitamins, fats, fatty acids, etc.) in cereals and legumes, while in a few instances, a reduction in these constituents was noted. A general reduction trend in antinutritional factors was also observed with a corresponding increase in the nutrient bioavailability and bioaccessibility. Notable mechanisms of modification include transamination or the synthesis of new compounds during the fermentation process, use of nutrients as energy sources, as well as the metabolic activity of microorganisms leading to a degradation or increase in the level of some constituents. A number of fermented products are yet to be studied and fully understood. Further research into these food products using both conventional and modern techniques are still required to provide insights into these important food groups, as well as for an overall improved food quality, enhanced nutrition and health, as well as other associated socioeconomic benefits.

Effects of Processing on Starch Structure, Textural, and Digestive Property of "Horisenbada", a Traditional Mongolian Food

Horisenbada, prepared by the soaking, steaming, and baking of millets, is a traditional Mongolian food and is characterized by its long shelf life, convenience, and nutrition. In this study, the effect of processing on the starch structure, textural, and digestive property of millets was investigated. Compared to the soaking treatment, steaming and baking significantly reduced the molecular size and crystallinity of the millet starch, while baking increased the proportion of long amylose chains, partially destroyed starch granules, and formed a closely packed granular structure. Soaking and steaming significantly reduced the hardness of the millets, while the hardness of baked millets is comparable to that of raw millet grains. By fitting digestive curves with a first-order model and logarithm of the slope (LOS) plot, it showed that the baking treatment significantly reduced the digestibility of millets, the steaming treatment increased the digestibility of millets, while the soaked millets displayed a similar digestive property with raw millets, in terms of both digestion rate and digestion degree. This study could improve the understanding of the effects of processing on the palatability and health benefits of Horisenbada.

Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R² = 0.45–0.96) and zero-order (R² = 0.20–0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R² = 0.46–0.69) and second-order (R² = 0.005–0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.

Efficacy of fermentation parameters on protein quality and microstructural properties of processed finger millet flour

The present study aims to explore the outcome of processing methods such as fermentation; treatments using lemon juice (T1), sodium chloride (T2), lemon juice followed by sodium chloride (T3) and fermentation followed by treatment-T3 on the quality characteristics of processed finger millet flour to develop a specialized low protein food supplement for a protein-related inborn error of metabolic disorders. The clean dirt-free finger millet grains were made into slurry subjected to treatment T1 (FMFT1), T2 (FMFT2), T3 (FMFT3), fermentation for 8-36 h with 4 h intervals using yoghurt as starter culture (FFMF) and fermentation (8-36 h) followed by treatment T3 (FFMFT3). The acidity of the finger millet slurry significantly increased with the increase in fermentation time when compared to control. The IVPD was found to be 89% in FFMF (20 h) sample which was significantly higher than the IVPD of control sample flour (27%). However, the crude protein content (%), the protein fractions and the IVPD of FFMFT3 (8-36 h) samples were found to be lesser than the FFMF (8-36 h) samples. The findings were further ensured by the results of scanning electron microscopic images and FT-IR spectra which showed the morphological and chemical modifications caused by the processing methods. The setback and breakdown viscosity of control (945 cP and 664 cP respectively) approximately reduced to two-third in FFMF (20 h) samples and one-third for FFMFT3 samples (303 cP and 286 cP respectively). From the study, it is evident that the processing method of fermentation followed by treatment-T3 could be utilized in the development of low protein food supplements.

Determination of volatile compounds during deterioration of African opaque beer using a stir bar sorptive extraction technique and gas chromatography-high resolution mass spectrometry

Opaque beer traditional to African communities undergoes quick deterioration and is consumed within 7 days of its production. The current study has utilized a stir bar sorptive extraction technique followed by GC-HRT determination to trace variations of 84 volatile compounds in four opaque beers commonly brewed in South Africa over the 7-day shelf life period. The major fruity esters were observed to increase up to Day 4 and eventually decreasing until Day 7 where their levels were finally lower than Day 1. Aldehydes reduced drastically and were less than 50% on Day 2 and becoming almost undetectable at Day 7. The common beer alcohols (phenylethyl alcohol and 3-methyl-1-butanol) decreased during beer shelf life while phenolics with undesirable medicinal tastes (creosol and p-cresol) increased up to 24-fold by Day 7. This study might open future research perspectives around opaque beer traditional to African rural communities.

•

84 volatiles in 4 opaque beers were traced over a 7-day shelf-life period.

•

A technique based on SBSE followed by GC-HRT was used.

•

Most fruity esters increased up to Day 4 eventually decreasing until Day 7.

•

Most aldehydes reduced drastically becoming almost undetectable at Day 7.

•

The study might open future research perspectives around traditional opaque beer.

Effects of fermentation and malt addition on the physicochemical properties of cereal based complementary foods in Ethiopia

Complementary foods (CFs) in Ethiopia are characterised by bulkiness, and poor nutrient density as these foods are primarily made of starchy staples. Meanwhile, several modification techniques are available to improve the quality of the starch-based CFs. The objective of this study was to examine the effect of fermentation time and malt concentration on cereal-based CFs in Ethiopia, intending to improve the nutrient density and reduce dietary bulkiness. Oats, barley and teff flours, with added malt at different concentrations (0, 2 and 5%), were spontaneously fermented for 0, 24 and 48 h. The physical, chemical and sensory properties of the fermented CFs flour were evaluated. The protein, fat, fibre, energy, phytate, tannin, bulk density, water absorption capacity (WAC) and viscosity ranged between 8.12–16.82%, 1.63–4.55%, 1.58–5.96%, 359.33–380.26kcal/100g, 18.63–175.07mg/100g, 0.84–42.89mg/100g, 0.66–0.99 g/ml, 61.33–143.12%, 235cP-1016.33cP, respectively. For all the three kinds of cereal, fermentation for 24 h resulted in a better sensory quality regardless of the malt concentration. Crude fibre, crude fat, total carbohydrate, phytate, tannin, bulk density and viscosity of the three kinds of cereal were significantly reduced due to the interaction of fermentation and addition of malt. Conversely, crude protein and calorific value were significantly increased by the interaction. Addition of 2% malt and fermentation of the cereal flours for 24 h increased energy density and palatability, reduced dietary bulkiness and viscosity of CFs, which in turn will increase food intake by infants and young children.

Fermented Edible Insects for Promoting Food Security in Africa

Efforts to attain sustainable nutritional diets in sub-Saharan Africa (SSA) are still below par. The continent is envisaged to face more impending food crises. This review presents an overview of common edible insects in Africa, their nutritional composition, health benefits and utilization in connection with fermentation to enrich the inherent composition of insect-based products and offer foods related to existing and generally preferred culinary practice. Attempts to explore fermentation treatments involving insects showed fermentation affected secondary metabolites to induce antimicrobial, nutritional and therapeutic properties. Available value-added fermented edible insect products like paste, powder, sauces, and insect containing fermented foods have been developed with potential for more. Novel fermented edible insect-based products could effectively fit in the continent's food mix and therefore mitigate ongoing food insecurity, as well as to balance nutrition with health risk concerns limiting edible insects' product acceptability in SSA.

African Sorghum-Based Fermented Foods: Past, Current and Future Prospects

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.

A Review of the Potential Health Benefits of Low Alcohol and Alcohol-Free Beer: Effects of Ingredients and Craft Brewing Processes on Potentially Bioactive Metabolites

Beer is a beverage of significant historical and cultural importance. Interest in the potential health effects of alcoholic beverages has largely focused on wine; however, there are a number of potentially beneficial bioactives that beer may contain that warrant further investigation. The challenge of considering any potential health benefits of beer are restricted by the negative consequences of its alcohol and energy content. There is potential to enhance the bioactive qualities of beer whilst reducing the alcohol and energy content through novel brewing approaches often used in craft brewing, in terms of ingredients, brewing methods and type of fermentation. Consumer demand to produce a greater variety of beer types, including alcohol-free beers, may also help to increase the number of beers which may have greater potential to improve health, with lower levels of alcohol, while still being tasty products. As low alcohol, prebiotic and bioactive containing beers are developed, it is important that their potential health benefits and risks are fully assessed.

Variation of Fungal Metabolites in Sorghum Malts Used to Prepare Namibian Traditional Fermented Beverages Omalodu and Otombo

Sorghum malts, which are important ingredients in traditional fermented beverages, are commonly infected by mycotoxigenic fungi and mycotoxins may transfer into the beverages, risking consumers’ health. Liquid chromatography–tandem mass spectrometry was used to determine variation of fungal metabolites in 81 sorghum malts processed for brewing of Namibian beverages, otombo (n = 45) and omalodu (n = 36). Co-occurrence of European Union (EU)-regulated mycotoxins, such as patulin, aflatoxins (B₁, B₂, and G₂), and fumonisins (B₁, B₂, and B₃) was detected in both malts with a prevalence range of 2–84%. Aflatoxin B₁ was quantified in omalodu (44%) and otombo malts (14%), with 20% of omalodu malts and 40% of otombo malts having levels above the EU allowable limit. Fumonisin B₁ was quantified in both omalodu (84%) and otombo (42%) malts. Emerging mycotoxins, aflatoxin precursors, and ergot alkaloids were quantified in both malts. Notably, 102 metabolites were quantified in both malts, with 96% in omalodu malts and 93% in otombo malts. An average of 48 metabolites were quantified in otombo malts while an average of 67 metabolites were quantified in omalodu malts. The study accentuates the need to monitor mycotoxins in sorghum malts intended for brewing and to determine their fate in the beverages.