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Microbiology and Technology of Fermented Foods PDF Free 12: A Practical and Theoretical Handbook on



The cleaner production of biomass into value-added products via microbial processes adds uniqueness in terms of food quality. The microbe-mediated traditional process for transforming biomass into food is a sustainable practice in Asian food industries. The 18 fermented fish products derived through this process as well as the associated micro-flora and nutritional composition have been focused. This review aims to update the process of green conversion biomass into value-added food products for a more sustainable future. Fish products are classified based on the substrate and source of the enzymes used in fermentation, which includes the three types of technology processing discussed. According to the findings, these fermented fish contain a plethora of beneficial microbiota, making them a valuable source of probiotics that may confer nutritional and health benefits. Bacillus (12 products), Lactobacillus (12 products), Micrococcus (9 products), and Staphylococcus (9 products) were the most common bacterial genera found in 18 fermented fish products. Consuming fermented fish products is beneficial to human health due to their high levels of carbohydrate, protein, fat, and lactic acid. However, biogenic amines, which are produced by certain bacteria as a by-product of their catabolic activity, are a significant potential hazard in traditionally fermented fish.




microbiology and technology of fermented foods pdf free 12




Fermentation is the microbial process of transforming food through the use of bacteria or fungus, as well as the enzymes produced by these microorganisms. This transformative ability of microbes has been utilized by people for production of fermented beverages and foods in order to preserve food and make the food more digestible with reduced harmfulness. Fermented foods involve controlling the microbial growth, which helps in the biotransformation of bioactive phenolics and volatile compounds into new edible forms with enhanced flavors and aromas [1, 2]. The microbial population in fermented food products deriving indigenously or from external 'starter cultures' causes chemical and textural changes to the food [3]. The microbial population in food can either cause spoilage of the food or produce a food product that is edible and safe for food, or there is a very thin line, determined by taste and flavor, between putrid and fermented food wherein the first one is undesirable, but the latter becomes a delicacy [4]. Fermented food has evolved with the development of human civilization since ancient times, partly sustaining the human population in the past and providing nutrition (calories, proteins, vitamins, minerals) at a reasonable cost. In particular, fermented fish is one of the most popular among the many different varieties of fermented food products. Although fermented food naturally contains live microorganisms (probiotics), the health benefits of their consumption are still uncertain [5].


Throughout history, different cultures have adopted a range of techniques to slow down the bacterial and enzymatic degradation of fish including salting, drying, smoking, and fermentation. Fermentation is one of the most ancient and significant traditional methods of food preservation. It entails the production of alcohol, lactic acid, and carbon dioxide from food sugars, primarily through the action of microorganisms and enzymes, resulting in foods with distinct quality characteristics such as aroma, taste, shelf life, texture, and nutritional value that differ significantly from the raw material [25]. Fish sauces and fish pastes are the most popular fermented fish products in many Asian countries and are regarded as indispensable condiments in these culinary cultures. Fish sauce is produced due to changes in physical and chemical characteristics brought about by microbial activity in high salt concentrations and low oxygen levels [26]. Another form of fermented fish product is one where the fish retains its solid form and does not get reduced to a paste or a liquid form. Based on the country and its traditional practices, fish sauce is made by combining fish and salt in a 2:1 to 6:1 ratio [14].


In Thailand, well-known fermented fish products are budu, kapi, and prala [36]. Budu is an intermediate between fish sauce and fermented fish paste and has a colloidal consistency, and prala is fermented fish paste where rice bran is added as a carbohydrate source [27]. Kapi, on the other hand, is a fermented shrimp paste using salt in a ratio of 5 (shrimp):1 (salt), that is then dried and compacted [37]. The technology used for the preparation of these products may be similar, but the additives are different depending on the product, with ingredients such as rice and fruits being used in many places. The use of an additive facilitates the growth of lactic acid bacteria, lowering the pH of the solution. Sometimes, similar products may also have diverse names in different localities of Thailand.


The fish curing industry has a large presence in India, but paradoxically, it is also one that lacks mainstream commercial visibility though it is popular as a local cottage industry in the northeastern and coastal parts of India [48]. Fermented fish products, again, are quite prevalent in North East India and West Bengal. It is interesting to note that many such products, like shidal and ngari, do not use salt [23]. Salt, which has a long and contentious colonial history in India, was introduced in the Northeastern region by the British people. In place of salt, sometimes a local alkali called khar is used, which helps in alkaline fermentation (napham, nichow and nakham ). The fermented fish pastes prepared in this region are pounded with various herbaceous plants like taro and allowed to age inside bamboo stems. Bamboo is abundant in this region, which has the highest diversity of bamboo species in India [49]. The use of bamboo stems and leaves in cooking is a widespread practice in Northeast Indian communities that finds its way even into aspects of folk cultures and studies of the region. Cooking food or processing it in bamboo stems imparts a unique flavor to the food. Thus, the fermented foods found in this region are unique and one-of-a-kind to a great extent due to the use of bamboo in their processing. Two types of fermented fish products have been reported in North East India: one that retains its solid form after fermentation and the other in a paste form. They are used as condiments or with other vegetables for their texture and flavor. The local people also associate these products with some health benefits. North East India's fermented fish products are diverse.


In the process of fish fermentation, biotransformation of proteins and fatty acids takes place as these are broken down into simpler compounds by microbes or the enzymes produced by them. The fish also contain indigenous enzymes that can bring about the breakdown of fish protein that cause the textural change in the final product. South Asian fermented fish products are alkaline [69]. In alkaline fish products, the hydrolysis of proteins into peptides and amino acids takes place naturally, releasing ammonia. The release of ammonia raises the final product's pH. The alkaline pH and ammonia in these products control the growth of a few dominant bacteria, which allows the anaerobic breakdown of proteins that release amine compounds. The high pH, free ammonia, and the rapid growth of essential microorganisms do not allow the sustenance of those bacteria that may spoil the product. Thus, the product is very well preserved and stable when dried [70, 71]. The majority of alkaline fermentations occur spontaneously in mixed bacterial cultures, with Bacillus subtilis predominating [70]. The physico-chemical characterization of various types of fermented fish is dependent on a variety of factors, including the type of processing fish used, the percentage of salt in the product, the number of days of fermentation, and the presence of microorganisms in the product. The biochemical characteristics of different fermented fish found in Asia are summarized in Table 2.


This review revealed that certain foods have a lasting cultural significance. South and Southeast Asian countries have diverse and rich food cultures centering on, among other things, fermented food, in particular, fermented fish. However, though Asian foodways have found a global platform, fermented fish figures less prominently in the global food map, precisely because its strong flavor and odoriferous quality usually repel Western sensibilities and taste. There is considerable politics in deciding which food cultures are acceptable for global consumption [8]. Taste itself entails a high degree of cultural politics. Steffan Igor Ayora-Diaz argues that the symbolic aspects of food, and whether it is deemed fit to be consumed, depend on several cultural markers as religion, political and communal ideology, ethnicity, gender, and society as well as transnational factors like the UN and its policies on food security and food safety [96]. For example, in the very recent context of the COVID-19 pandemic, China and the Chinese have received a severe backlash (primarily from people in America and Europe) and regarded as being morally reprehensible due to their food cultures, simply because the practice of consuming bats and pangolins exists in some Chinese communities [96]. In the light of such factors, fermented fish, despite its strong local and overseas base of consumption, has remained relatively obscure in literary and cultural studies. For example, in the realm of the literature, though food is a central theme in Asian diasporic literature, fermented fish by itself is not a central presence even within this framework, partly because these novels have a huge Western readership unfamiliar with this food category. Again, while there is, admittedly, a greater awareness of the health benefits of fermented foods, the same has not translated to its greater inclusion in food guides in many countries around the world [97]. This is not because they are harmful, but rather due to the possibility that they are not part of the food cultures in a particular nation (and therefore unfamiliar) or they are too limited in their production and consumption to become a wider trend or tradition [97]. Thus, there is a significant gap between the relatively limited scientific exploration of ethnic food (including fermented fish) and the embeddedness of fermented fish in the literature and culture of the local communities. Even within food studies, the technical aspects for fermented fish production are more highlighted, with only a few (notable among them being Ruddle, Ishige, Grainger, Tamang and Yankowski) actually connecting it to a larger socio-cultural context. This warrants more extensive research on the interconnections between the scientific and the cultural aspects of fermented fish in Asian foodways. 2ff7e9595c


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