**1. Introduction**

Human nutrition begins with milk. Fermented milk products have been recognized as healthy foods since ancient times. Fermentation processes and products are believed to have been developed 9000 years ago in order to preserve food for times of deficiency, improve flavor, and reduce poisonous effects. Recommendations for the consumption of certain nutritious foods date back to the Hippocratic Corpus of Ancient Greece [1]. Thousands of different fermented foods and beverages are still unknown outside the native area in which they have been produced for centuries, many going back even before recorded history [2]. Fermented foods and beverages pass through a process of lacto fermentation in which natural bacteria or yeasts feed on the sugar and starch in the food creating lactic acid.

The list of fermented products is extremely vast and the diversity derives from the heterogeneity of traditions found in the world, the cultural preference, different geographical areas where they are produced and the staple and/or by-products used for fermentation. The most popular involve beverages such as wine, beer, cider and foods such as yoghurt, cheese, soya, beans, fish, meat, cabbages, among others. In many instances, it is highly likely that the methods of production were unknown

and came about by chance, and were passed down by cultural traditional values to subsequent generations [3].

Modern food is submitted to many processing methods such as pasteurization, affecting its nutritional value by reducing vitamins, fiber, minerals, essential fatty acids and amino acids. Food security can be enhanced in poor rural areas with fermented products, generating income in a small-scale family farm in developing countries [4]. The importance of fermentation is reflected by the amount and variety of foods and beverages traded not only for the benefits on nutrition and health-promoting effects but also for preservation, safety, and their peculiar appreciated sensory attributes [5].

The exploration of the microbial communities and enzymes of fermented products has been extensively reviewed [6]. At the genus level, *Lactobacillus* is usually the most abundant genus, followed by *Lactococcus*, *Enterococcus*, *Vibrio*, *Weissella*, *Pediococcus*, *Enterobacter*, *Salinivibrio*, *Acinetobacter*, *Macrococcus*, *Kluyvera* and *Clostridium*.

A better knowledge of microorganisms and fermentation at a molecular level is still required to support and develop the production of sustainable fermented food with high nutritional characteristics. A metagenomic approach has enabled identification of novel microbiome profiles and exploration of microbial compositions in a range of traditional fermented foods while bypassing the need for cultivation, allowing the identification of a vast array of microorganisms never previously isolated in culture [7].

## **2. Sustainable Development and Fermented Food Hygiene in Africa**

Food preservation increases the range of raw materials and by-products that can be used to produce edible food products and remove anti-nutritional factors, rendering food safe to eat by humans and animals. Fermentation is a cheap way of preserving perishable raw materials, accessible to even the most marginalized people. Utilizing small-scale fermentation contributes to economic and social benefits and sustainable development of families and communities [8]. Poor hygiene or improper post-handling fermentation limits shelf-life and becomes dependent on information from developed countries and technology transfer [9].

Regulators will only be convinced on causal relationships existing between fermented foods/beverages and health benefit or eventual risk, through the development of scientific dossiers, which is only feasible by industrialized producers [10].

Fermented foods may be recommended for improving the health and nutritional quality of traditional African foods and regular inclusion of fermented products as part of the daily diet would be desirable. However, lack of knowledge and understanding toward fermented food preparation may limit their usage.

Hazard Analysis and Critical Control Point (HACCP) studies in Africa of some fermented products have demonstrated that, depending on the process and the hygienic conditions observed during preparation, some fermented foods, e.g., *togwa*—fermented cereals prepared in Tanzania—may pose a safety risk [11].

Accidents may occur. For example, in 2015, at least 75 people died and some 180 fell ill, including a toddler, in the north-west of Mozambique, from apparent poisoning after consuming during a wedding party traditional fermented beer (made of sorghum, bran, corn, sugar, with *Schizosaccharomyces pombe* yeast, which belongs to the division Ascomycota, which represents the largest and most diverse group of fungi) known as "*pombe*" (Swahili word for beer). The exact cause of the contamination was later connected with bacterium *Burkholderia gladioli* and two produced toxins, bongkrekic acid and toxoflavin [12].

These safety concerns relating to pathogenic bacteria or chemical intoxicants produced by contaminating microorganisms, yeasts or moulds on a fermented food were also demonstrated by the deaths and risks of esophageal cancer reported by the consumption of fermented milk products from

Kenya including *Mursik* (a cow or goat´s milk fermented in a calabash gourd), *Kule naoto*, *Amabere amaruranu* and *Suusa* [13–15].
