eChapters

Introduction

Fermented meat and fish products have been consumed all over the world since times immemorial and represent one of the most important groups of food. Meat offers its own natural microflora. Hence a wide variety of products have been prepared since ancient times by varying the mixture of meat and salt as well as by the addition of spices and seasonings. Thus, fermented meat products characterize a diversity of flavors and textures and are receiving increased interest from consumers all over the world. Most of these products still depend mainly on local, traditional manufacturing processes since little scientific information is available; but scientific knowledge is very important for consistent production of high quality and safe products.

Meat is an essential part of non-vegetarian diet. It is liked for its unique taste and is a rich source of nutrients like good quality animal proteins, essential amino acids and fatty acids, minerals, trace elements and particularly B-complex vitamins (Singh et al., 2013). The growing concern of consumers regarding health and safety issues has led to the development of functional meat products that promote health and well-being, beyond their nutritional benefits (Grasso, et al., 2014; Tyopponen et al., 2003). This has driven researches in the meat processing sector to increase their efforts in producing such functional meat products, which have incorporated functional ingredients, reduced salt, nitrates/nitrites, cholesterol and fat and modified product fatty acid profiles (Zhang et al., 2010). Fermentation of meat produces a wide range of physical, biochemical and microbial changes in the muscle-based product

Introduction

Food is the most vital prerequisite for sustenance of human life and provides adequate nutrients for the metabolism. Recently several hypothesis supports that, beyond meeting nutritional needs, they play beneficial roles in improving health, and minimize the risk of illnesses (Roberfroid, 2000a). In this way, a novel term “functional food” was introduced and plays an outstanding role in improving the overall conditions of the human body (e.g. pre- and probiotics), lessening the threat of some ailments (e.g. cholesterol-lowering products), and also as therapeutics for several diseases (Roberfroid, 2000a, Roberfroid, 2000b, Mollet and Rowland, 2002).

Recently throughout the world, an extensive array of functional foods were developed which includes prebiotics, probiotics, synbiotics, foods supplemented with anthocyanins, phytosterols, isoflavones, antioxidants, and fat, sugar and salt-reduced foods. Amongst them, probiotic functional food has exerted beneficial effects on the health and is comprised of both probiotic dairy foods and probiotic non-dairy foods. The demand for dairy probiotic foods are increasing as it attributes to the beneficial health effects on the host by improving the survival of gastrointestinal microflora, production of bioactive compounds and prevention of lactose intolerance. Consequently, production of these foods is a significant research importance for both food manufacturing units and research institutes.

Probiotics are the important ingredients for foods with a “healthy” image. It could be combined with other beneficial ingredients or simply used to supplement the natural functional qualities of whole foods. The amalgamation of probiotic bacteria with nutrient rich foods, like dairy products, will have the additional value of improving consumer nutrition.

Introduction

Over the past few decades, probiotics have become the most promising and emerging field in human nutrition and health across the world including India and other developing countries. The global profit generated from the probiotic market is expected to reach approximately 12,753.4 million US$ by the end of 2026 (Probiotic market report, 2018). The factor fueling the demand for probiotics is the growing awareness among consumers about their health benefits. The association of probiotics with health benefits stretches back to a time before microbes were discovered. However, the scientific evidence of the health benefits of probiotic microorganisms on the wellbeing of the host was firstly proposed by Russian Nobel laureate Ellie Metchnikoff in 1905. He reported that consumption of fermented milk containing Lactobacillus spp. is responsible for the healthy and long life of Bulgarian people (Anukam & Reid, 2007). Afterward, several of scientific progressions were made to reach the current status where probiotics are not only the subject of food and medical research but also the source of a multi-billion dollar global industry.

The term probiotic is derived from the Greek words, which means ‘for life’. According to the Food and Agriculture Association of the United Nations (FAO) and World Health Organization (WHO), probiotics are defined as “live microorganisms which when administered in adequate amount promote the health of the host” (Joint, FAO, 2002). In 2014, International Scientific Association for Probiotics and Prebiotics (IPPA) did minor correction in the definition given by FAO-WHO and defined them as “Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”

Introduction

One of the main properties of fermented foods whether alkaline or acidic is the presence and activity of beneficial organisms which themselves make these foods functional. These functional micro organisms have varied roles like conversion of the native constituents of raw materials to forms in which they are more bioavailable, formation of taste, colour and flavouring compounds thereby imparting pleasantness to foods, removal of anti-nutritive factors in food by converting them into much less harmful compounds or degrade certain native toxic elements present in food, formation of biopreservatives which will extend the shelf life of foods and provide microbial security, as pathogens and spoilage microorganisms fail to readily grow in such hostile conditions. These functional microorganisms also produce in foods certain health-promoting bioactive compounds like enzymes, vitamins, minerals or increase the digestibility which may not have been in the original food or raw material before fermentation. In other words they improve the nutrition profile of the foods or naturally fortify foods. Some of these beneficial effects may also lead to the formation of certain compounds which show antioxidant properties in foods. These very roles played by these functional micro-organisms form criteria in their selection for use in food fermentations when they are intentionally added to foods both to initiate and accomplish desired fermentations.

Introduction

Foods prepared by fermenting raw ingredients of plant or animal sources naturally or mixing it with the starter culture (s) containing functional micro flora is called fermented foods. The functional micro flora used in starter culture is responsible for biochemical and organoleptic alteration of the substrates into edible yields which are socially and culturally appropriate to consumers (Tamang et al., 2010a, Tamang et al., 2010b). Fermented food has its own characteristic microflora and this group of micro flora increases the nutritional value by increasing the levels of essential amino acids, vitamins, proteins, etc.

Fermented foods play a major role in meeting nutritional requirement and socio economic development of developing countries. They are important components of the diet as staples, adjuncts to staples, condiments and beverages. A wide variety of fermenting substrates are available such as cereals, pulses, soya beans, flowers, milk, fish, meat, etc. A wide majority of plants and their parts are often utilized in the preparation of starter culture (Deori et al., 2007, Deka and Sarma, 2010).

Introduction

Eradication of malnutrition and hunger (Sustainable Development Goal, SDG-2) are the major challenges to humanity. Availability of sufficient nutritionally balanced food is the prerequisite for ensuring global food security. Food security is also critical for achievement of SDG 1 (poverty eradication) and SDG 3 (health and well-being) (UNDP, 2019). Changing climatic conditions accompanied by global warming not only acts a major threat for achievement of SDGs but could actually lead to the reversal of the progress already made. The escalating global temperature has jeopardized the food security throughout the world. A great decrease in the global crop yield has been suspected even with a 2°C rise in temperature. On field, it is often associated with crop nutrient loss, less accumulation of micronutrients and low availability of micro-minerals like iron and zinc. Additionally, the effect of the rainfall and temperature has also been observed. The global food prices are projected to increase by 3–84% by 2050 due to the fluctuations in rainfall and temperature (Hoegh-Guldberg et al., 2018).

Millets are the small seeded grains which belong to family Grassacae/Poaceae. Traditionally, millets are used for the food and feed purpose and are among the oldest cultivated crops. The millet species of commercial importance are proso (Panicum miliaceum), foxtail (Setaria italica), barnyard (Echinochloa esculenta), finger (Eleusine coracana), little (Panicum sumatrense) and pearl (Pennisetum glaucum) in different regions of the world. In India, foxtail millet (priyangava), barnyard millet (aanava) and black finger millet (shyaamaka) have been mentioned even in the Yajurveda texts of 4500 BC (Morya et al., 2017). The records of consumption of foxtail and proso millet are as old as 2000 to 1000 BC in China. Cultivation of foxtail millet in Korean peninsula is documented around 3,500–2,000 BC. Foxtail millet is the oldest of all the cultivated millets and is believed to be originated in Southern Asia. From there, it was spread to Europian nations. In the west, cultivation of millets majorly started after 1850 (ICRISAT, 2019)

Introduction

Cereals are grown over 73% of the total world harvested area and contribute over 60% to the world food production providing dietary fibre, proteins, energy, minerals and vitamins required for human health. Cereals like rice, maize, wheat, barley, sorghum, and oats are chiefly used in the preparation of traditional fermented foods and beverages. However, the nutritional quality of cereals and the sensory properties of their products are sometimes inferior in comparison with dairy products. The reasons behind this the lower protein content, deficiency of certain essential amino acids, the presence of determined anti-nutrients (phytic acid, tanins and polyphenols) and the coarse nature.

Introduction

Fermentation of food dates back to ancient practice of wine making. Fermented foods reflect culture and tradition of folklore and emphasis their close association with nature. Various methods employed for fermenting foods aimed in food preservation to reduce wastage; however lactic acid fermentation enhanced nutrition content and improved organoleptic properties. Experimental evidences on benefits on health and wellness on consumption of fermented foods are being reported. Fermentation process used for preparation of indigenous or traditional foods often depend entirely on natural microflora on the surface of raw material and containers used; Practices of fermenting foods are passed on as traditional know how to generations as a legacy. The fermented food manufacturers rely on commercial starter cultures, and highly reliant on indigenous materials as microbial collections are unique and highly variable according to region and products. Therefore, isolation of novel organisms, development of newer products and interactions are being explored using variety of fermented foods obtained through traditional processes

Introduction

Fermentation has been an integral part of food processing throughout the history of mankind. In beginning, it was mainly preservation method, then it became key process in substantial sensory characteristic development and now it is utilized to improve overall properties of outcome from major industries like bakery, dairy, beverages, etc. The human understanding of controlled fermentation process changes its fundamental objective by exploring its success in development of rheological and texture characteristics.

The biochemical transformation of raw food due to fermentation affects the organoleptic as well as rheological properties of a product. The changes in rheological as well as sensory properties is related with the modification of major component by the action of microorganism. For example, transformation of polysaccharides in bread dough by action of yeast produce ethanol, CO₂ and other simple compound which modify sensory as well as rheology of dough. The major micro-structural, bio-compositional and bio-chemical changes are due to microbial action are frequently described to understand the effect of fermentation on rheological as well as sensory properties of food products. The rate and quality of these associated major changes mainly depends upon concentration of saccharides for growth of microorganism as well as nature and existing microflorae. Hence, a proper monitoring of changes in rheological and sensory properties is necessary to optimize the controlled fermentation as well as design of process parameters from engineering and consumer point of view.

The biochemical changes directly responsible for changes in basic rheological and sensory characteristic including flow behavior, consistency, viscoelastic properties, hardness, adhesiveness, color, aroma, flavor and mouthfeel. The food industry is so diverse and exploring new and possibilities to catch diverse consumer worldwide, a proper understanding of effect of fermentation on mentioned properties will be key to hold competitive market. Hence, the present chapter will cover the basics of rheology and its role in food industry, effect of fermentation on rheological and sensory attributes of major class of food.

Introduction

Fermented foods are those foods which have been subjected to the action of microorganisms or enzymes that cause desirable biochemical changes and significant modification of the food (Campbell-Piatt, 1994). Fermented foods are usually produced using ingredients of plants or animals in combination with bacteria or fungi. The bacteria or fungi are either sourced from cultures maintained by humans or from the environment. The origins of fermented foods go back many thousands of years, with early evidence of the alcoholic fermentations of barley to beer and grapes to wine. Evidence suggests that fermented foods were consumed 7,000 years ago in Babylon (Battcock and Azam-Ali, 1998).Throughout the world, the fermented foods are used by the people. It plays a major role in the diet in many developing countries. Several traditional fermented foods are prepared in rural areas of many countries.

Introduction

Fermentation is the process in which edible microorganisms invade food substrates and convert them into fermented foods including beverages, using their enzymatic and metabolic processes. These end products will have nontoxic flavors, aroma and texture which enhance the palatability. The word “fermentation” is originated from a Latin word fermentare, defined as “to leaven” (Frias et al., 2016). It is one of the oldest food processing technologies used by humans to preserve perishable food materials for long time, dated back to ancient human civilization (Hutkins, 2008). Globally, more than 5000 varieties of fermented foods are currently in use which includes traditionally fermented dairy products such as Dahi in India to industrial production of wines from fruits (Tamang, 2010) (Table 1 and Figure 1). Biochemically, fermentation is a metabolic process in which energy is derived from organic compounds without the involvement of an exogenous oxidizing agent. Fermentation may result in the production of many by-products such as carbon dioxide, alcohol, organic acids (lactic acid, acetic acid), vitamins, enzymes etc. which are now having more importance in food industries (Caplice and Fitzgerald 1999).

Introduction

Commonly available food materials especially dairy products, cereals and fruits are perishable and require processing for long term storage. The methods of food storage has been known from the pre historic times and was mostly based on processing the food into a more stable form with a longer shelf life. Such processes increases the time range of food availability and in many cases improves the taste thereby, cumulatively improving the food value. One of documented method of food preservation is by fermentation and is age old. Other commonly used methods include drying, refrigeration, salting and fermentation (Luck 1985, Paulus, 1985, Christensen et al., 2003, Martindale and Schiebel, 2017).

Flavour and appeal of food has been considered as one of the important factors contributing to the demand of the food. Originally the flavours were largely plant derived, current industrial practices largely utilise synthesis by chemical reactions and subsequent extraction to achieve a uniform quality (Weckerle et al., 2006, Davidovich-Rikanati et al., 2008, Sethupathy et al., 2018). These chemicals referred to as “flavourings” are defined as compounds that enhance the taste, appeal and palatability of food. They are naturally derived or artificially synthesised compounds. Considering that many artificially synthesised chemical flavours might affect the health adversely. Industrial food research has now shifted their focus on flavourings that are naturally available (Cohen et al., 2018). Such naturally occurring flavourings are referred to as bio-flavours (de Billerbeck 2015). The ease of producing bio active compounds from microbial culture extracts has played significant role in industrial food biotechnology (Verachtert et al., 2005).

Introduction

Fermentation is one of the oldest food preservation techniques that can be traced back thousands of years. Fermentation is referred as one of method of biopreservation as it leads to extending the shelf life of foods that involve the use of microorganisms and their metabolites. (Ross et al., 2002) For millennia, the fermentation of food by using micro organisms has been used as a technique for ensuring shelf life extension and improving the quality characteristics, texture and flavour of food products as well as to develop new innovative products. The major bacteria used in food fermentation worldwide are lactic acid bacteria (LAB). LAB is a multitude of genera including Lactobacillus, Lactococcus, Streptococcus, Leuconostoc, Pediococcus, and Enterococcus. Lactic acid bacteria constitutes a diverse group of bacteria that enjoys the status of “generally regarded as safe” (GRAS) and “qualified presumption of safety” (QPS) by the Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), respectively. In this respect, starter microorganisms are known to produce a wide array of antimicrobial and protein-acoustic compounds to inhibit the growth of undesirable flora in foodstuffs resulting in shelf life extension. (Hill et al., 2017).

Multipurpose trees and shrubs are defined as all woody perennials that are purposefully grown to provide more than one significant contribution to the production and/or service functions of a land-use system that they occupy. In agroforestry systems, different species of trees and shrubs can be planted with many types of crops in a variety of patterns. Thus, it is required to know about the methods of propagation and nursery raising, planting and other silvicultural management practices along with the diverse uses of multipurpose trees and shrubs of tropical and subtropical areas before their selection for forestry and agroforestry activities. It is important to select the most suitable tree species since it is not easy to replace them once they have been planted.

MANGIUM (Acacia mangium)

Acacia mangium is a single-stemmed evergreen tree that grows to 25-35 m in height and up to 60 cm in diameter. The bole is usually straight, often fluted near the base, free of branches for up to half its height. Mangium is native to Australia, Indonesia and Papua New Guinea. However, it tolerates varied site conditions and has adaptability to different planting objectives. Mangium shows most vigorous growth on well-drained, fertile soils in high rainfall areas in the humid tropics. It is valued for its rapid growth and has been planted throughout the humid tropics and is a major plantation species in the Asia-Pacific. Provenances from Papua New Guinea consistently show better growth in height and diameter.

Agricultural extension is a term that has long been used to describe a non-formal educational system aimed at improving the livelihood of farmers. Extension education aims at three main types of behavioural changes in relation to knowledge (things known), attitudes (things felt) and skills (how to implement the things). This can be achieved through persuasion and motivation for the changes. The core activities in extension are education and training. Extension is now being regarded as a much wider task of integrating indigenous and new skills and techniques, derived from study or research, into an overall framework of discussion and cooperation between the people and the extension organisation. The extension worker is primarily engaged in the ‘selling’ of ideas to bring about changes in the knowledge, attitudes and skills of the individual. Functions of extension in a broader sense include

Economic analysis provides a rational basis for making decisions in allocating scare resources among various options to achieve competing goals. If resources were not limiting, there would be no need for economic consideration. Some important basic principles of economic analysis are outlined below.

PRINCIPLES OF ECONOMIC ANALYSIS

Optimization criteria

The additional return obtained from using one additional unit of an input should be considered to optimize net income from several possible production options. If option ‘x’ gives a higher return to land than other options, then additional units of land should be allocated to option ‘x’.

Agroforestry systems are more complex than the agricultural systems. The long-term nature of trials involving woody species and the varying objectives of agroforestry trials demand that adequate caution be exercised in their design. Several characteristics of the trees like slow growth, long-term effects on their surroundings, long life, age of trees, the area over which the influence of trees extend, etc. complicate the issue of designing experiments for these systems. Agroforestry experiments are often established on marginal sites which include sloping lands, and sites with infertile and degraded soils. It is thus difficult to find homogeneous sites of such problem areas, especially sloping lands where plots along contour lines are long and linear. Germplasm of many agroforestry tree species are usually collected from different origins which lack uniformity. Therefore, experimental materials in an agroforestry experiment may not be of uniform quality.

There are several features of agroforestry systems that require some modification of the methods usually used in agricultural experiments. Important issues related to agroforestry experiments include

In agroforestry systems the various components like tree, crop and pasture exist in different proportions and orientations. It is difficult to find out which agroforestry system is the best suited for a given land situation. Similarly, it is to be decided which technologies are required for refinement and improvement of the existing agroforestry practices. But without sufficient knowledge of the existing system in a particular land situation, it is very difficult to set the research priorities for modification and development of this system.

Diagnosis and Design (D & D) is a systematic and objective methodology developed by International Centre for Research in Agroforestry (ICRAF) to initiate, monitor and evaluate agroforestry programmes. D & D is based on the philosophy that knowledge of the existing situation (diagnosis) is essential to plan and evaluate (design) meaningful and effective programmes in agroforestry research for development. The methodology plays a strategic role in all the phases of the agroforestry research process. D & D in agroforestry is unique and it has been specially developed for the following purposes.

Greenhouse gas emission is likely to rise by 25-90% by 2030 relative to 2000 and the earth could warm by 3° C at the end of this century. Even with a temperature rise of 1-2.5° C, the Intergovernmental Panel on Climate Change predict serious disastrous effects, including reduction in crop yields in tropical and subtropical areas leading to increased risk of food shortage, spread of climate responsive diseases such as malaria, and an increased risk of extinction of 20-30% of all biodiversity present on earth (IPCC, 2007). Carbon dioxide is the most important among all greenhouse gases. Carbon sequestration may be defined as the process of removing C from the atmosphere and depositing it in a reservoir. It entails the transfer of atmospheric carbon dioxide, and its secure storage in long-lived pools (UNFCCC, 2007).

From the agroforestry point of view, carbon sequestration involves primarily the uptake of atmospheric CO₂ during photosynthesis and transfer of fixed carbon into vegetation and soil pools for ‘secure’ storage. It occurs in two major segments of agroforestry systems; aboveground and belowground. The total amount sequestered in each part differs greatly depending on a number of factors including the region, the type of system, site quality, and previous land-use (Nair, 2012). On average, the soil and aboveground parts are estimated to hold major portions, roughly 60 and 30%, respectively, of the total carbon stored in tree-based land-use systems (Lal, 2010). Sequestering CO₂ from atmosphere through natural techniques such as afforestation, reforestation, natural regeneration of forests and the adaptive agriculture is more economically and ecologically sound in increasing the carbon storage capacity of the terrestrial ecosystems (Dhyani, 2014). Although carbon sequestration through afforestation and reforestation of degraded natural forests has long been considered useful in climate change mitigation, agroforestry offers some distinct advantages (Murthy et al., 2013). The carbon in the aboveground and belowground biomass in an agroforestry system is generally much higher than the equivalent land use without trees. An agroforestry system has higher carbon sequestration potential than pastures or field crops (Kirby and Potvin, 2007).

Human societies over the ages have depleted natural resources in different ways and degraded their local environments. Indiscriminate cutting down of trees and accelerating the construction works lead to global warming and climate change. Climate scientists believe that human-induced deforestation is responsible for 18-25% of climate change. Accumulation of greenhouse gases in the lower atmosphere is the main cause of global climate change. The concentration of these gases in the earth’s atmosphere is increasing, mainly due to deforestation and the combustion of fossil fuels which release carbon dioxide.

The earth receives heat energy constantly from the sun through radiation. Some of the heat is absorbed and some is reflected. Carbon dioxide works like an invisible blanket that wraps around the earth and traps the heat inside, similar to the function of a greenhouse. A greenhouse is a structure that is used in colder climates to grow plants. Even when outside temperatures drop below freezing point, greenhouses are still warm enough inside to grow plants. Greenhouses are made of glass, which allows solar radiation to enter. The heat is trapped inside the greenhouse, allowing plants to grow all the year round. Increasing concentrations of carbon dioxide in the earth’s atmosphere insulate it like a greenhouse, leading to a gradual warming of the earth’s atmosphere. Carbon dioxide is the major greenhouse gas, but there are others as well, including methane and nitrous oxide.

Mitigation means addressing the causes of climate change, while adaptation attempts to tackle its effects. The Intergovernmental Panel on Climate Change defines mitigation as an anthropogenic intervention to reduce the sources or enhance the sinks of greenhouse gases and adaptation as the adjustment in natural or human systems to a new or changing environment (IPCC, 2007).