B-vitamins and heat processed fermented starchy and vegetable foods in sub-Saharan Africa: A review.

Micronutrient deficiency still occurs in sub-Saharan Africa (SSA) despite the availability of several food resources, particularly fermented foods and vegetables, with high nutritional potential. Fermentation enhances the quality of food in several aspects. Organoleptically, certain taste, aroma, and textures are developed. Health and safety are improved by inhibiting the growth of several foodborne pathogens and removing harmful toxic compounds. Furthermore, nutrition is enhanced by improving micronutrient contents and bioavailability from the food, especially vitamin B content. However, during processing and before final consumption, many fermented foods are heat treated (drying, pasteurization, cooking, etc.) to make the food digestible and safe for consumption. Heat treatment improves the bioavailability of B-vitamins in some foods. In other foods, heating decreases the nutritional value because some B-vitamins are degraded. In SSA, cooked starchy foods are often associated with vegetables in household meals. This paper reviews studies that have focused fermented starchy foods and vegetable foods in SSA with the potential to provide B-vitamins to consumers. The review also describes the process of the preparation of these foods for final consumption, and techniques that can prevent or lessen B-vitamin loss, or enrich B-vitamins prior to consumption.

Rheological and textural properties of lafun, a stiff dough, from improved cassava varieties.

We studied the textural and rheological (viscoelastic) properties of fresh lafun dough, a fermented cassava product, and their changes during storage at 45 °C for 5 and 24 h, in order to determine after-cooking storability. Lafun flours were produced from three types of cassava varieties: seven improved white-fleshed varieties, seven improved provitamin A carotenoids (pVAC) varieties and two local white-fleshed varieties; and processed into lafun doughs. Pasting properties of the flours were assessed. Flours from local varieties had pasting profiles with highest viscosities, while pVAC flours had the lowest. The three types of cassava varieties varied significantly in most of their pasting properties. Four promising improved varieties were identified, based on high peak viscosity (55.8-61.5 P) and stiffer texture than local varieties during storage. Undesirable varieties were also found, which softened during storage instead of hardening. Optimum texture of lafun dough was obtained after 5 h of storage.

Occurrence of lactic acid bacteria and yeasts at species and strain level during spontaneous fermentation of mawè, a cereal dough produced in West Africa.

Mawè is a West African spontaneous fermented cereal-based dough. Different types of mawè exist varying in type of cereal and/or production condition, with fermentations lasting 24-48 h. With the aim of obtaining a comprehensive understanding of the microbial ecology of mawè processing, a microbiological characterisation was performed for four mawè types, produced at eight sites in Benin. At the onset of the fermentations lactic acid bacteria (LAB) and yeast counts were on average 7.5 ±â€¯1.03 and 4.8 ±â€¯0.79 Log10 cfu/g, which increased to 9.2 ±â€¯0.38 and 7.4 ±â€¯0.42 Log10 cfu/g, respectively, at the end of the fermentations. LAB (n = 321) and yeasts (n = 298), isolated during the fermentations, were identified. The predominant LAB and yeast species were Lactobacillus fermentum and Pichia kudriavzevii, respectively, followed by Kluyveromyces marxianus, all present throughout the mawè fermentations. Further, microbial successions took place with Weissella confusa occurring mostly at the onset, while Pediococcus acidilactici and Saccharomyces cerevisiae were mainly associated with the end of the fermentations. Species diversity was influenced both by type of cereal and production condition. The dominating strain clusters of L. fermentum and P. kudriavzevii were ubiquitous and strain diversities were influenced by type of cereal and production site.

Weissella beninensis sp. nov., a motile lactic acid bacterium from submerged cassava fermentations, and emended description of the genus Weissella.

Four Gram-positive, catalase-negative, short rod-shaped or coccoid, heterofermentative lactic acid bacterial strains (2L24P13(T), 1L48P15, 1L24P31 and 1L24P34) with unusual phenotypic and genotypic properties were isolated from submerged fermenting cassava on MRS agar. All strains were motile, grew at 15 degrees C, produced dl-lactic acid from glucose with gas formation and produced ammonia from arginine. Acid was produced from d-fructose, d-galactose, d-glucose, lactose, maltose, d-mannose, melibiose, d-raffinose, sucrose, N-acetylglucosamine and d-mannitol, but not from d-arabinose or xylose. 16S rRNA gene sequence analysis revealed that the strains belonged to the genus Weissella and were most closely related to Weissella ghanensis LMG 24286(T). Low DNA-DNA reassociation values were obtained between the isolates and W. ghanensis DSM 19935(T). Based on the genetic and phenotypic results, the strains are considered to represent a novel species, for which the name Weissella beninensis sp. nov. is proposed. The type strain is 2L24P13(T) (=DSM 22752(T)=LMG 25373(T)).