Fermentation: A Broader Perspective

Abstract

Fermentation is as old as man. It is a technology where growth and metabolic activities of microbes are used to preserve foods. The global increase in population and scarcity of food necessitated actions that will lead to increased and efficient food production, improved storage and transportation. Bacteria, fungi and yeast are capable of converting substrates of different kinds such as cereals, legumes, milk, meat, vegetables, palm sap, tubers and roots to produce variety of fermented foods consumed and enjoyed globally such as koji, kununzaki, yogurt, cheese, sauerkraut, peperoni, palmwine, fufu, Kefir, ogi, chhurpi and many others. Submerged and solid-state fermentation techniques are employed to produce fermented products which have applications in the food and non-food industries. Fermentation improves the, nutrition, enhances the shelf life and preserves of foods, baked foods production, produces biofuels and biopolymers as well as improves health.

1. Introduction

Fermentation is an ancient technique for preserving food and drinks that has been practiced since long before the days of refrigeration. During fermentation, microorganisms like bacteria, yeast or fungi convert organic compounds like sugars and starch into alcohol [1]. Yeasts like Saccharomyces cerevisiae and their close relatives are dominant in many niches because of their high sugar consumption, ethanol production and their ability to survive anaerobic conditions, though aerobic which are the winning characteristics attributed to their competitive outcome as good brewers [2]. Lactic acid act to reduce bacterial load and improve sensory characteristics [3]. Many fungi are desirable in food applications and fermentation processes such as Aspergillus, Penicillium and many others [4].

2. Categories of fermentation

Solid state fermentation occurs in aerobic conditions on solid state substrate with minimal moisture content, commonly used in traditional food production like Indonesian tempeh and bread [5]. Solid State fermentation is disadvantageous for some microorganisms, especially bacteria is greatly explored using fungal species because fungi grow on solid substrates such as wood, roots, stem, dry parts of animal skin and low moisture fecal matter [6]. Going down the history of fermentation technology, solid state fermentation process was almost completely sidelined in western countries after 1940s due to adaptation of submerged fermentation [7]. Patents and publications later came up on the use of solid-state fermentation, development of bioreactors, production of food and feeds, microbial metabolites, bio processes such as bioleaching, biopulping, bioremediation and so on [8, 9, 10, 11, 12, 13, 14]. Food, pharmaceuticals, energy and chemical sectors use solid state fermentation [15]. Though solid-State fermentation is important and acceptable, fermentation time is key to achieving this type of fermentation and has been employed in the production of biopesticide and biostimulant using green waste [16].

Submerged fermentation take place in liquid media, promoting anaerobic growth of microorganisms and is widely used in industries like sucrose laven, enzymes, and pigment production [17, 18]. Submerged fermentation is advantageous because it takes shorter fermentation time, large volume processing, low labour intensity and widely applied in industrial biotechnological processes [19, 20]. During submerged fermentation dispersed fungal mycelia, clumped aggregates and mycelial pellets are observed [21, 22]. Fungal metabolites such as antibiotics, hormones, enzymes which are not needed for their growth are used in the food and drug industry [23, 24].

2.1 Fermentation in food processing

The growing global population poses a threat to food security [25] which has necessitated actions that will lead to increased and efficient food production, improved storage and transportation [26]. Food fermentation utilizes the growth and metabolic activity of microorganisms which improve organoleptic and general value addition associated with fermented foods [27]. Fermentation is also employed in modern food processing for food preservation and improvement of its quality from the time of manufacture to the time of consumption [28].

The discovery of the role of microorganisms as fermenting agents began from the time pasteurization was discovered in 1861 AD [28] which led to an industrial revolution in the production of fermented foods and beverages using yeast and lactic acid bacteria for the production of beer, spirits, wines as well as fermented diary, vegetable and meat products respectively [28]. Depending on the type of microorganisms, the substrate, the environmental conditions and the processing methods, fermentation can result in various food products that may be peculiar to a region of the world such as yogurt, cheese, bread, kunun- zaki, masa, ogi, wine, beer, burukutu, and many more. An overview of some fermented foods produced worldwide is represented in Table 1.

Substrate	Fermented food product	Country of origin
Milk	Airag	Mongolia
Milk	Amasi	South Africa, Zimbabwe
Milk	Cheese	Global
Milk	Chhu	India, Nepal, Bhutan, China (Tibet)
Milk	Chhurpi	India, Nepal, Bhutan, China (Tibet)
Milk	Dhadi	Indonesia
Milk	Kefir, Koumiss	Russia
Milk	Laban rayeb	Egypt
Milk	Leben	North, East, Central Africa
Milk	Dahi	India, Nepal, Sri Lanka, Bangladesh, Pakistan
Milk	Nunu	Ghana
Milk	Philu	India, Nepal, Bhutan, China (Tibet)
Milk	Yogurt	Europe, America, Australia
Milk	Viili	Finland
Milk, sugar, starter	Sua chua	Vietnam
Maize, Sorghum, Millet	Kunu-zaki	Nigeria
Sorghum, Maize, Rice, Millet	Masa	Nigeria
Sorghum	Kisra	Sudan
Maize, Sorghum	Pito	West Africa
Maize, Sorghum, Millet	Ogi	Nigeria
Rye, Wheat	Sourdough	Europe, America, Australia
Maize, Sorghum, Millet, Cassava flour	Uji	Kenya, Tanzania, Uganda
Maize	Pozol	Mexico
Maize	Poto Poto	Congo
Soybean	Miso	Japan
Soybean	Meju	Korea
Melon seeds, Castor oil seeds, Sesame, Pumpkin bean	Ogiri/Ogili	West, East, Central Africa
Soybean	Tempe	Indonesia, The Netherlands, Japan. USA
Soybean	Thua nao	Thailand
Locust bean	Soumbala	Burkina Faso
Soybean	Shoyu	Japan, Korea, China
Pork, Beef	Peperoni	USA, Europe, Australia
Pork or Beef meat, Fat, NaCl, Spices	Salchichan	Spain
Chopped pork meat, Spices, NaCl	Salsiccia	Italy
Pork, Salt, Cooked rice	Nem-chua	Vietnam
Pork, Salt, Sugar, Potassium nitrate	Tocino	Philippines
Fish	Sidra	India
Small sardine, salt	Myulchijeot	Korea
Horse mackerel, salt	Kusaya	Japan
Marne Fish	Nuoc mam	Vietnam
Shrimp	Saeoo Jeot	Korea
Cucumbers	Cucumbers	Europe, Canada, USA
Cupers	Cupers	Spain
Mustard	Burong mustala	Philippines
Bamboo shoots	Naw-mai-dong	Thailand
Bamboo shoot	Mesu	India, Nepal, Bhutan
Cassava	Tapai Ubi	Malaysia
Cassava	Garri, Fufu, Lafun	West Africa
Cassava	Tapé	Indonesia
Cassava	Chikwangue	Central Africa, Zaire
Cassava	Chingwada	East and Central Africa
Maize	Mangisi	Zimbabwe
Palm sap	Palm wine	Palm growing regions
Molasses	Rum	World wide
Sugar cane	Koji	Japan
Grapes	Sparkling wine	Worldwide
Molasses	Rum	Worldwide
Barley	Whisky	Worldwide
Grapes	Wine	Worldwide
Potato	Vodka	Russia, Finland, Poland

Table 1.

Geographical distribution of fermented foods.

Source: [29, 30, 31, 32, 33, 34, 35, 36, 37, 38].

Fermented foods are produced and enjoyed all over the world [29, 34, 35, 36, 37, 39, 40] using different raw materials such as cereals, legumes, tubers, roots, milk, fish and meat [41].

2.2 Benefits of fermentation

2.2.1 Baking industries (e.g. Bread)

Sourdough is produced by the use of lactic acid bacteria and yeast mixed in water and flour [42, 43, 44]. A good sourdough is dependent on parameters such as temperature, enzymatic composition of the flour, redox potential, water content, fermentation time [44]. The use of sourdough results in a better characteristic of bread and specific LAB strains delay staling in bread [45].

2.2.2 Energy production (e.g. Biofuel)

Although it may sound ridiculous, bacteria are often used to produce biofuels. The global demand for non-renewable fossil fuel is increasingly becoming unsustainable, therefore the need to seek alternative fuel sources such as biofuels [46]. The genus Clostridium have been studied and shown to have the ability to degrade sugars, starches, and other complex substrates to produce biofuel [47]. The production of biofuel is through alcoholic fermentation which has been reported in Clostridium sp. on Casava waste residue [48].

2.2.3 Synthesis of biopolymers

Fermentation plays an essential role in the production of biopolymers. Biopolymers are made of gelatin, xanthan gum cellulose, collagen and other related substances gotten from agri-food waste [49] which have been studied to have food and pharmaceutical uses [49]. Many genera of microorganisms produce polymers like cellulose, xanthan, alginate, cellulose and so on which are completely broken down into carbondioxide, methane, water and biomass [50]. Azobacter, Pseudomonas, Bacillus, Rhizopus, are among the numerous genera of microorganisms capable of producing biopolymers with various duration of degradation [51, 52, 53, 54].

2.2.4 Food preservation and shelf-life extension

Fermentation is a traditional method that extends the usability of foods by months, preventing spoilage. This process transforms perishable items like cabbage into long-lasting sauerkraut, enhancing food safety and reducing waste [51].

2.2.5 Toxin mitigation and nutritional enhancement

Fermentation not only mitigates harmful substances but also enriches foods with essential nutrients. Through fermentation, natural compounds like phytic acid in legumes are broken down, improving the availability of vitamins and minerals for better absorption. This process also removes anti-nutrients, making nutrients more accessible and boosting the health potential of the food [51]. Bacteria, yeast, algae and fungi are microorganisms that can be relied on for the protein need of man. Microbial based protein known as bioprotein can be multicellular [55]. Microbial protein can be obtained from environmental waste by microbial activity, thereby reducing environmental pollutants and addition of value-added feed and food as high nutritional biomass [56]. Oleaginous yeast such as Yarrowia lipolytica and Candida spp. clean up the environment and are capable of growing on biofuel waste, alkanes, petroleum bye-products, natural gas, glycerol as well as waste products from pants and animals [55, 57, 58, 59, 60, 61, 62]. Filamentous fungi such as Aspergillus, Penicillium, Rhizopus, and Fusarium are regarded as highly nutritious because of their ability to provide variety of essential nutrients and bioactive compounds which contribute to healthy diet, including protein, carbohydrates, fatty acids, minerals, vitamins and antioxidants and hence used in a wide range of fermented food technologies [4, 63, 64, 65, 66, 67]. Lactic acid bacteria (LAB) play an important role in degrading harmful substances in food. Lactic Acid Bacteria has been used in reduction of aflatoxin [68], breakdown of ethyl carbamate [69], decomposition of phytic acid [70] and hydrolysis of bitter peptides in cheese production [71].

3. Conclusions

Fermentation is an ancient preserving technique adopted by man. Bacteria, yeast or fungi convert fermentable organic compounds like sugars and starch into alcohol. Fermentation can be categorized into solid state fermentation and submerged fermentation. Solid state fermentation occurs in aerobic conditions on solid state substrate with minimal moisture content which is commonly employed in traditional food production like Indonesian tempeh and bread. Submerged fermentation take place in liquid media, promoting anaerobic growth of microorganism and is widely employed in industries like sucrose laven, enzymes, and pigment production. Food fermentation utilizes the growth and metabolic activity of microorganisms which improve organoleptic and general value addition associated with fermented foods. Many fermented foods such as yogurt, cheese, bread, kunun- zaki, masa, ogi, and wines are produced as a result of fermentation of different substrates. Fermented foods are produced and enjoyed all over the world. Fermentation is beneficial to both food and nonfood industries especially in the production of bread with better characteristic using specific LAB strains, production of biofuel through alcoholic fermentation which has been reported in Clostridium sp. on Casava waste residue, production of biopolymers, extension of shelf life as well as food preservation especially in perishable items like cabbage which is transformed to long-lasting sauerkraut, enhancing food safety and reducing waste. Fermentation not only mitigates harmful substances but also enriches foods with essential nutrients. Microbial protein can be obtained from waste obtained from the environment by microbial action, thereby reducing environmental pollutants and addition of value to feed and food as high nutritional biomass. Harmful aflatoxins are degraded and reduced in foods by lactic acid bacteria.

Acknowledgments

We appreciate intechopen for giving us the opportunity for contributing to this chapter. We also appreciate in anticipation, the sponsorship by Australian Society for Microbiology, World Bank Group, Akwa Ibom State University, Australian Commission on Safety and Quality in Health Care, Society for General Microbiology, Third World Organization for Women in Science, Academy of Science Research and Technology, AAIR Charity, Thrivent Financial Foundation and Abu Dhabi National Oil Company.

Conflict of interest

The authors declare no conflict of interest.

Notes/thanks/other declarations

Thanks to the authors whose rich contribution to science was used to write this piece of chapter and to intechopen, we are grateful for the opportunity to contribute to your book.