eChapters

1. Preparation of Standard Sodium Hydroxide Solution

 Introduction

 When oxalic acid reacts sodium hydroxide, sodium oxalate and water are

form. Phenolphthalein indicator detects the end point by its characteristics

colour change.

 Apparatus

 Burettes, pipette, volumetric flask, beaker

 Reagents

 • Oxalic acid crystals

 • Sodium hydroxide – 0.1 N approximate

 • Phenolphthalein solution – 0.1 percent in ethyl alcohol

Procedure Preparation of 0.1 N oxalic acid solution 1. Weight accurately 1.575 g of oxalic acid into a 250 ml beaker using a weighing bottle. 2. Add some distilled water to the beaker and dissolve the oxalic acid with the help of glass rod. 3. Transfer the solution into a 250 ml volumetric flask through a funnel. 4. Wash the beaker 3- 4 times with small quantities of distilled water and transfer the washing into the flask. 5. Make up the volume up to the mark with distilled water and mix thoroughly. 6. Preparation of approximately 0.1 N sodium hydroxide solution 7. Weigh about 4.25 g of sodium hydroxide pellets and dissolve into 200 ml of distilled water.

Bacterial species vary greatly in the ability of their cultures to remain alive after the completion of growth. Some species such as Neisseria gonorrhoeae and Streptobacillus are poorly viable and their cultures usually die out within a few day, whether kept at 37°C at room temperature or at 4-5°C; thus, they must be sub cultivated every 2-4 days for maintenance in the laboratory. Other species are much hardier,. especially sporing species which may remain viable for many years. There are also many non - sporing species (enterobacteriaceae) whose cultures, under suitable conditions, commonly remain viable for many months and often for as much as 10-20 years.

Preservation of raw milk is essential to maintain its quality during storage and transportation before processing. One of the primary methods for extending its storage life is refrigeration, where milk is cooled to 2°C to 4°C immediately after milking. This significantly slows down the microbial growth and enzymatic activity. Bulk milk coolers (BMCs) are vital in achieving rapid cooling, especially in collection centres or dairy farms, where they ensure that milk remains fresh during storage and transportation. BMCs are particularly essential for regions with inadequate cold chain infrastructure, as they help maintain milk quality until it reaches processing facilities.
In addition to refrigeration, thermisation is another method used to preserve raw milk. Thermisation, a mild heat treatment, is widely used to extend the shelf life of raw milk, particularly when it needs to be transported over long distances. This process involves heating the milk to 57–68°C for 15 seconds, effectively reducing the microbial load while preserving the milk’s natural characteristics. Thermisation is typically followed by refrigerated storage, where milk is cooled to temperatures between 2° and 4°C to inhibit further microbial growth. The combination of thermisation and refrigeration ensures that milk retains its freshness and safety until it reaches processing facilities, even in regions with extended supply chains.
Raw milk also benefits from its natural inhibitors, such as lactoperoxidase, lactoferrin, and immunoglobulins, which exhibit antimicrobial properties and slow down bacterial growth. The lactoperoxidase system, for instance, can be activated by adding small amounts of hydrogen peroxide and thiocyanate to enhance milk’s preservation in the absence of refrigeration. The use of chemicals like hydrogen peroxide (H2O2) for milk preservation is not permitted in India due to safety and quality concerns. However, the FAO recommends its application under strict regulatory conditions in some countries as part of the lactoperoxidase system, particularly in regions where refrigeration is unavailable.

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.

There are potential beneficial medicinal uses of probiotics for which research is limited and only preliminary results are available. Recent research on the molecular biology and genomics of Lactobacillus has focused on the interaction with the immune system, anti-cancer potential, and potential as a biotherapeutic agent in case of antibiotic-associated diarrhoea, traveller‘s diarrhoea, pediatric diarrhoea, inflammatory bowel diseases and irritable bowel syndrome (Ljungh et al., 2009). Studies of some probiotics tested in vitro on human epithelial cell lines have shown that they could block the adhesion of shiga toxin producing E. coli (Sherman et al., 2005). These are claimed to be health promoting and/ or disease preventing beyond the basic function of supplying nutrients. Probiotic foods are emerging as an important category of food supplements. Earlier workers have shown the inhibition of diarrhea caused by E.coli using probiotic lactic acid bacteria and yeast (Yan and Polk, 2006). Ratledge et al. (2002) have studied the biochemistry and molecular biology of lipid accumulation in oleaginous microorganisms.

Abstract

Nutraceuticals have potential to be used as food supplement, preventive medicine and the growing evidence points in the direction that certain foods fight and or prevent against diseases. The development of next generation nutraceutical “super foods” or products consist of value-addition in the traditional natural diets.The word Nutraceuticals combine ‘nutrition’ and ‘pharmaceuticals’ to mean that they can be used as preventive drugs or food supplements. The increase in knowledge about the immune response unveils the fact that besides immunological disorders and infections the outcome of many other diseases like diabetes, hypercholesterolemia, rheumatoid arthritis, etc. can be modified by modulating Immune response. Hence, the efficient immunomodulators can be employed to prevent or cure the diseases as immunotherapeutic agents. The most acceptable alternative therapeutic agents are the edible sources. Hence the researchers shifted towards formation of nutraceuticals or foods acting as medicine, a concept which was given by Hippocrates long back.

Introduction

The term probiotic is derived from Greek and means ‘for life’ as opposed to antibiotics which means ‘against life’. The history of probiotics began with the consumption of fermented foods which was first observed in ancient Greeks and Romans [1]. The term, probiotic, as is used today was first used by Parker in 1974. Parker defined ‘probiotic’ as substances and organisms which contribute to intestinal microbial balance. In 1989, the term was modified further by Fuller. Thus, probiotic is a live microbial supplement which affects the host’s health positively by improving its intestinal microbial balance. This definition was broadened to include mono or mixed culture of live microorganisms which benefits animals or man by improving the properties of the indigenous microflora [2]. Some authors have interpreted probiotics as microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well-being of the host.

Introduction

Let food be thy medicine and medicine be thy food- the age-old quote by Hippocrates, is certainly the tenet of today. Microbial cultures have been used for millenniums in food and alcoholic fermentations and in the past century have undergone scientific scrutiny for their ability to prevent and cure a variety of diseases. Later it became popular in improving human and farm animal nutritive values and recently in aquaculture also. The growing interest in the understanding the role of food in human health has moved from its primary role as a source of energy to the subtle action of biologically active food components on human health. Henceforth functional foods or nutraceuticals are of great demand in present time. The growing scientific evidence suggests that the food supplements containing beneficial bacteria can provide an array of benefits to the host. Now a day’s probiotic fermented foods are in great demand due to the awareness of beneficial aspects of probiotics among people. Several industries focused on the improvement of conventional fermented foods scientifically in order to fetch good market for their products. Particularly, animal feed companies and researchers have been looking for alternative products and strategies that can help to maintain animal gut health in order to prevent or reduce the prevalence of pathogens in the food chain. After understanding the mechanism and beneficial aspects of probiotics in detail at molecular level in earlier chapters, now it is relevant to discuss the applied part of probiotics. In this chapter, commercial importance of probiotics and probiotics derived products at industrial level are emphasized.

Introduction

During the first 50 years of the 20th century, scientific focus was on the identification of essential elements and their role in the prevention of various dietary deficiency diseases. This emphasis on nutrient deficiencies or “undernutrition” shifted dramatically, however, during the 1970s when diseases linked to excess and “overnutrition” became a major public health concern. “Let food be thy medicine and medicine be thy food”, the age old quote by Hippocrates is the ideology of today’s health conscious population. Eli Metchnikoff, the Russian Nobel prize winner was the first one to recognize the beneficial role of selected bacteria on gastrointestinal tract of humans. Subsequently the “Theory of Longevity” by Metchnikoff was correlated with prolonged youth and a healthy old age, observed largely in Balkan peasants of those times, who used cultured milks in their diet (Kaufmann, 2008). Since then, the quest continues for understanding the role of wide range of food components and nutrients in enhancing health or preventing chronic diseases. The research in this field has resulted in a plethora of new labels for pro-, pre- and synbiotics.

Abstract

The gut microbiota, microbe population living in the human large intestine is generally associated with various metabolic functions and it influences health and well-being. Taking into account the major role gut microbiota play in the normal functioning of the body and the different functions it accomplishes, experts nowadays consider it as an “organ”. However, it is an “acquired” organ, as babies are born sterile; that is, intestine colonisation starts right after birth and evolves as we grow. Each of us has a unique microbiota, as the fingerprints, it always fullfils the same physiological functions and they have a direct impact on our health. Gut microbiota consists of a complex of microorganism species that live in the digestive tracts of animals and is the largest reservoir of microorganisms mutual to humans. Gut microorganisms benefit the host by gleaning the energy from thefermentation of undigested carbohydrates and the subsequent absorption of short-chain fatty acids. The most important of these fatty acids are butyrates, metabolised by the colonic epithelium; propionates by the liver; and acetates by the muscle tissue. The human body carries about 100 trillion microorganisms in its intestines, a number ten times greater than the total number of human cells in the body Guarner and Malagelada, 2003). Gut microbiota, particularly the probiotics, have beneficial effects on gastroenteritis resistance, blood lipids, antitumor properties, lactose tolerance and gastrointestinal immunity. Probiotics have role in reducing the risk of rotavirus-induced diarrhea and colon cancer. The survivability of any probiotic bacteria till a longer time in the gut can be enhanced by the supplementation of prebiotics. Prebiotics are non-digestible food ingredients that benefit the host by selectively stimulating the growth or activity of one or a limited number of bacteria in the colon. There are so many prebiotics which stimulate the growth and survivability of probiotic bacteria such as fructo-oligosaccharide (FOS), inulin, galacto-oligosaccharide (GOS), polydextrose (PDX), acacia gum (GUM), lactulose (LOS), lactitol etc. Many research studies have been done on above mentioned prebiotics. Mostly inulin-type fructans have been used as functional food ingredients. The prebiotics are known for reduction of disease risk such as constipation relief, suppression of diarrhea and reduction of the risks of osteoporosis, atherosclerotic cardiovascular disease associated with dyslipidemia and insulin resistance, obesity and possibly type-2 diabetes. Probiotics are beneficial microbes that confer a realistic health benefit on the host, which in combination with prebiotics, (indigestible dietary fibre/carbohydrate), also confer a health benefit on the host via products resulting from anaerobic fermentation. The combination of probiotics and prebiotics in a synbiotic might improve the survival of the bacteria crossing the upper part of the gastrointestinal tract, thereby enhancing their effects in the large bowel and immune-modulatory ability.

In 1907, the Russian Nobel laureate, Dr. Elie Metchnikoff, fascinated by the unusual longevity of Bulgarian farmers, consuming beneficial lactic acid bacteria by way of traditional fermented milk products, suggested that regular intake of friendly microbes could benefit human health. Although Dr. Metchnikoff ’s recommended bacteria for the purpose proved largely ineffective, the theory was carried forward with moderate success until the war on bacteria began because of the advent of sulfa drugs and antibiotics (Scott, 2012). However soon after their rampant use and the realization of the rapid spread of antimicrobial resistance, researchers turned yet again to ecological notions and the time was fertile for the advent of probiotics. By the 1980’s the term had stabilized both in medical and veterinary literature. The mid 1990’s witnessed a surge of exponential studies on probiotics, the definition of Probiotics emerged in 2001 and the years thereafter saw tremendous progress in the science of probiotics.

Almost simultaneous was the study on the study of the intestinal microbiota when Alfred Nissile demonstrated that transferring members of the human gut microbiota to healthy typhoid carriers helped in Salmonella being cleansed from their system (Nissle, 1916). It was then, that the importance of the gut microbes in prevention of infection became evident. What followed was the advent of culture independent, modern biotechnological tools for whole genome sequencing and the successful launch of two most ambitious projects - Human Microbiome project (Turnbaugh et al., 2007) and the Met Hit project (Metahit, 2009; Qin et al., 2010). They provided fascinating insights into the highly complex microbial ecosystem harboured by the human body. The term Microbiome (refers to the collective genome of our microbial inhabitants) had entered literature in 2001 and the concept of gut microbiota in maintaining overall health gained wider attention.

Introduction

Thermal processing is an important treatment for food preservation is, especially in the manufacture of shelf-stable foods with specific nutritional properties. It is also indispensable for determining the sensory properties, particularly, colour, flavour, and texture of fried, baked, and roasted products. As a result of heat treatment, chemical changes induced, and a plethora of new molecules are formed in foods, some of which have been claimed to be health-promoting antioxidants and anti-mutagens. However, reports suggest that thermal processing leads to the formation of certain toxic compounds, so-called process-induced contaminants in foods. The process-induced toxicants are certain compounds which are formed in food as a result of food processing, exert adverse toxicological effects, and cause potential health risks to humans. Acrylamide, furan, chloropropanols, heterocyclic aromatic amines, polycyclic aromatic hydrocarbons, and N-nitrosamines are some well-known examples of thermal process contaminants.

Abstract

Kulfi is a mixture of fat; sugar and milk solid not fat together with added flavour. So diabetics people on restricted diets cannot consume kulfi having normal ingredients. Now-a-days, consumers demand for low fat/calorie products has significantly raised in an attempt to limit health problems, to lose or stabilize their weight and to work within the frame of a healthier diet. The role of fat replacers and sugar substitutes in the successful manufacture of these products is crucial. Development of sugar free kulfi would certainly ensure diabetic/obese people to enjoy ice cream/ kulfi. The current study is to standardize the kulfi recipe with fat and calorie replacer. Basic formula mix consist of Whole milk 60 percent, SMP 12 percent, Sugar 13 percent, Cream 15 percent and Stabilizer 0.5 percent where the whole milk was replaced by skim milk, cream and sugar was replaced by maltodextrin as a bulking agent and aspartame respectively alongwith sodium alginate as a stabilizer. The replacers were incorporated at four different levels of 0, 25, 50, 75 and 100 percent to the basic formula mix. Freezing of above kulfi mix was done by traditional method and softy freezer method. Sensory evaluation was carried out by using 9-point hedonic scale through semi-trained judges and results were statistically analyzed. On the basis of sensory scores it was revealed that sugar could be replaced 100% by artificial sweetener, bulking agent (Maltodextrin). It was found from the sensory scores that the milk fat in kulfi can be replaced upto 75 percent by sodium caseinate thereafter increase in caseinate gives prominent flavour of casein and kulfi body becomes thick and hard. It was concluded from the results that 100 percent sugar replacement was found feasible in preparation of low fat and low calorie kulfi. Results of the low fat and low calorie kulfi mix indicated that there was 32.29 percent reduction in the calorific value of experimental kulfi as compared to the control sample (traditional). It was concluded from the results that the kulfi with 75 percent less fat and 100 percent sugar free can be prepared with low cost in comparison with control.

Introduction

India, with its unique agro climatic conditions is capable of producing a wide variety of fruits and vegetables. These highly perishable produce in both fresh and processed forms are of high demand in domestic as well as international market. Nowadays farming is becoming an enterprise and shifting towards consumer driven agriculture. Produce quality measurement is of utmost importance as consumers are more quality conscious and ready to pay higher for quality. Consumer preference is moving towards healthy food, minimally processed and, fresh cut fruits and vegetables, prepared salads, ready to cook, ready to eat and ready to drink health beverages. Hence health, nutrition, convenience, quality and safety of produce should be guaranteed to the consumers. Due to globalisation of production and trade, legislations and standards for markets are strict and product quality is the necessity for competitive markets.

Quality of a produce, based on subjective and objective measurement, is defined differently by consumers, wholesalers, retailers, processors or any other who is associated with it and varies with market either national or international. Quality of foods may be defined as the composite of those characteristics that differentiate individual units of a product, and have significance in determining the degree of acceptability of that unit to the user (Kramer, 1965). According to ISO (International Organisation of Standardisation), “Food quality is the totality of features and characteristics of a product that bear on its ability to satisfy stated or implied needs” and as per CAC (2003), “Food safety is the assurance that food will not cause harm to the consumer when it is prepared and/or consumed according to its intended use”. Food safety is the most important component of quality.

3.1. General Introduction

Value addition refers to the conversion of a raw commodity or commodities into a processed product through the use of raw materials, labour, time and technology, all mixed in a way that ensures increased economic return. Even if the amount of processing in a product is much less, for example, any canned fruit can be considered as a processed product. Value added processing of horticultural food crops, mainly involves actions which changes fresh fruits and vegetables to create a greater value-added product for human consumption, which mostly includes canned products, juices, soups, sauces and dehydrated fruits and vegetables (Sharan, 2018). It results in diversification of agricultural activities, improves value addition opportunities and creates surplus for export of processed agro products. Processing often goes with perishable products like meat, milk, poultry, fruits and vegetables, often termed as High Value Products (HVPs), are in greater demand of processing (Sanal & Krishna, 2017). The demands for processed products are particularly strong in developing countries like China and India; mainly due to increasing industrialization and rapid urbanization, followed by elevated income levels, greater diversity in diets, and affinity towards premium-branded products (Sharan, 2018).

Milk is a highly perishable commodity. The shelf life of raw milk is in hours. In order to harness its full potential for the well being of the humanity, it is essential to extend its shelf life not only in days but also in months and years. This can be achieved by judicious application of processing and preservation technologies.

Preservation is any purposeful treatment or processing of a food which prevents spoilage and extends the shelf life of raw material to a longer than its natural keeping quality.

During storage and distribution foods are exposed to a wide range of environmental conditions. Environmental factors such as temperature, humidity, oxygen and light can trigger several reactions that may lead to food deterioration. As a result foods may be altered to such an extent that they are either rejected by the consumer or are harmful to the person consuming them. It is, therefore, essential that the good knowledge of different reactions that cause food deterioration is gained prior to understanding the principles of food preservation.

The deterioration in foods may be caused either due to internal or external chemical or microbial reactions occurring in milk. The changes may be either latent to senses of consumer, or they may be discernible by the human senses. The consumer cannot perceive latent changes visually, olfactorily or otherwise, and laboratory measurements are the only method to detect them. Still the nutritional value of such materials may be seriously impaired. Such changes include fermentation, oxidation of lipids, loss of vitamins and changes in the contents and composition of nitrogenous substances.

Non-microbial changes in foods, perceptible to human senses, may often lead to serious deterioration noticeable to the average consumer. These include discolouration and changes in odor, taste and consistency. Microbial changes may result in alteration of original properties of milk making it unfit for further processing, deterioration in flavour quality, loss of nutrients and toxin production.

Yogurt is a fermented milk product that contains the characteristic bacterial cultures such as Lactobacillus bulgaricus and Streptococcus thermophilus. All yogurts must contain at least 8.25% solids not fat.

Introduction

Consumers are nowadays very much concerned about the food they purchase and consume. Consumer wants the food containing antioxidant properties or can say functional food in safe and stable forms, so that the availability of daily requirements of functional food ingredient must be ensured for normal growth and development of the body. The functional food that can provide a health benefit such as increased dietary fibre, vitamins or minerals to the body. The incorporation of antioxidant compounds acts as an efficient way to fight against reactive oxygen species (ROS) generated in our body. As it is already known that the ROS causes oxidative stress and acts as a main trigger for different life threatening chronic diseases like cancer, diabetes, cardiovascular disease, aging etc. Therefore, seeing the consumers’ demand for value added products with bioactive ingredients, all small and large scale food industries are taking initiatives to process different types of food (fruits, vegetables, dairy, sea food, animal, microbial products etc.) to extract and purify its active fraction of functional ingredients to valorize different value added products. Functional ingredients may also be derived from different food wastes generated during processing of food. This practice provides additional economic benefits to food businesses. Food industries are also giving importance to different processing methods to extract high quality of functional food ingredients in large quantity because processing method affects the concentration of extracted bioactive compounds. The simple addition of functional ingredients may cause an unwanted and negative change of sensory and texture of food. Therefore, using novel processing technologies such as microencapsulation, the negative changes could be minimized or avoided because these technologies could prevent the inactivation of bioactive ingredients.