eChapters

Butter is one of the leading milk product in developed countries of the world. It serves as a balance wheel of dairy industry. Surplus milk is generally converted into butter to be used during the times of scarcity. It is an article of commerce and a sign if wealth. Butter is a fat concentrate, which is obtained by churning cream, gathering the fat into a compact mass and then working it for proper distribution of moisture and salt. The art of butter making has a long history. The manufacture of butter was confined to colder regions where gravity creaming was successful. The milk was allowed to stand undisturbed for 10-12 hours until layer of cream collects at the top.

INTRODUCTION

Preservation of food by drying or chemical means as by alcohol or acid fermentation and that by the use of ice is long recorded in history. With the advancement of science and the knowledge governing various unit operations in food processing, these food preservation techniques employing thermal, radiation, or low temperature or a combination of these have only got further refined as regards their viability and commercial applications. Process foods of different genre and cuisine, which include frozen foods too, are increasingly becoming popular the world over for reasons of quality, safety and year round supply of nutritious foods to cater to different niche segments of human society. Increasing health consciousness is buoying those processed foods which are preserved and stabilized using non-thermal technologies as these ensure retention of food nutrients to a better definition. Interest in frozen food also stems from need to deliver safe and nutritious foods with extended shelf-lives.

Heat desiccated products represent khoa and khoa-based sweets, rabri, basundi, etc. These are important traditional dairy products. Traditional dairy products and a great assortment of sweets is an integral part of Indian heritage. These products are endowed with enormous value and enjoy tremendous mass appeal. Of great social, religious, cultural and economic importance these products have been developed over a long period of culinary skills and carry with them, the age-old wisdom and experience. Traditional dairy products have always played a pivotal role in preservation of precious milk nutrients and promotion of its consumption among masses. The increased availability of milk during the flush season coupled with lack of facilities to keep liquid milk fresh during transit from rural production areas to urban market has led to the conversion of milk into variety of traditional products. In addition to preservation of milk solids for longer duration, manufacture of traditional dairy products adds value to milk and also provides tremendous employment opportunity. It is estimated that about 50% of milk produced in India is converted into a variety of traditional products.

Traditional dairy products represent the most prolific segment of Indian dairy industry. These products not only have an established market in India but also have a great export potential because of strong presence of Indian diaspora in many parts of the world. In view of the growing awareness towards the safety aspects of milk-based sweets in India, the consumer shall prefer to buy these products from the organized sector. Despite the widespread popularity and acceptability of traditional milk products in the Indian market, the organized sector has so far not been able to tap into this market potential for many reasons such as lack of published literature on their technology, inadequacy of appropriate technologies for their commercial exploitation, inadequacy of appropriate packaging materials and labeling to take care of new pattern in consumer demand, low keeping quality and a lack of quality assurance systems.

Introduction

As the world population continues to grow, the global market for food products is expanding, together with an increased emphasis on food safety. Consumers have become more discerning in the type of foods they buy and how these foods affect their health and well being. Food safety is generally defined as the assurance that the food will not cause any harm to the consumer when it is prepared and/or eaten according to its intended use ( To achieve food safety, a management system has been developed which aims on preventing problems before they occur, rather than trying to detect failures through end product testing. It also places more responsibility for ensuring food safety on food manufacturers, who have to develop control and traceability of their products from ‘farm to plate’. The system requires the identification of specific hazards throughout the entire process of food production, concentrates on the points in the process that are critical to the safety of the product, and highlights measures for their control (Henson and Caswell, 1999).

4a. Intestinal Disorders
 
History of health claims
 
According to Bottazzi (1983) it was in 76 BC that the Roman historian Plinius recommended the use of fermented milk for treating gastroenteritis. Metchnikoff claimed that the intake of fermented milk containing Lactobacilli reduces the toxin producing bacteria, thereby increasing the longetivity of the host (Metchnikoff, 1908). Tissier (1905) showed that there was an increase in the Bifidobacteria in breast fed-infants, thus claiming that the administration of Bifidobacteria to infants suffering from diarrhea was very beneficial as they supersede the putrefactive bacteria that causes the disease. Intestinal beneficial microfloras are responsible to resist the disease (Bohnhoff et al., 1954).

2.1. The Story of Fermentation

Human progress depends on man’s tact to tame the forces of nature. It calls for knowledge. Prior to Age of Science, our fund of such knowledge was gained by a process of trial, error and accidental discovery. Progress was due not so much to man’s understanding as it was to his unquenchable spirit, miraculous ingenuity and indomitable persistence.

At last, in the utmost urgency of struggle for a longer, healthier and more satisfying existence, humanity taught itself the scientific method, which has changed the world, and will change it more in the coming years. This chapter deals with one of the most momentous and far reaching of all scientific achievements: the ability to harness microscopic living creatures in the service of mankind. Thanks to the wonders of fermentation technology and biochemical engineering developed by scientists and skilled technicians in industrial, governmental and university laboratories around the world, billions of microbes are now at work in industry, producing substances that give us better food $#x0026; drink, better clothing $#x0026; shelter and better medicines. Thus, the human race has entered a new era of health, comfort and longevity.

In the Beginning Art without Science: The cave man discovered that meat allowed to stand a few days was more pleasing to the taste than meat eaten soon after the kill. The cave man’s earliest descendants learned that intoxicating drinks could be made from grains and fruits.

Introduction

Recent advances in food technology have made our lives virtually easier and efficient. Changing lifestyle has led to the emergence of packaged food that provides convenience to the consumers. The authentic packaging of food implements consumers with the role of communication, containment, convenience, and protection. Any typical food package provides us with the information about the product and its nutritional fact, thus an efficient way of marketing/ branding. It protects the food product from the external environment and adulteration, thus keeps it safe. It allows the consumers to relish the food as per their convenience (reheating and direct consumption) and holds the product of any size, shape and restrains during handling and transportation (Robertson, 2006).

Food packages can be altered or modified according to one’s requirement with features like single-serving dishes and portability. However, traditional packaging is lacking adequacy to meet unending consumer demands and product intricacies. Therefore, a contemporary concept of packaging with higher proficiency is needed to meet various consumer requirements. For instance, a packaging that can - enhance product’s shelf-life with lesser or no preservatives, that maintains freshness, that meets permissible regulatory requisites and enables tracking throughout the product life-cycle. Emerging technologies like smart packaging have the expertise to invigilate a product and its milieu and pursue any modifications into these. Moreover, smart packaging helps in gaining global market recognition, and meets international food safety standards. In recent years, there has been rapid development in food packaging that includes active packaging, intelligent packaging, or smart packaging. These are the technologies that deal with the packaging of food, beverages, cosmetics, and pharmaceutical products. Moreover, these terminologies are apparently identical but, each has a different function to deal with and is as follows:

1. Guidelines on Analytical Terminology

    1.    Accuracy : The closeness of agreement between a test result or measurement result and a reference value.

    2.    Analyte : The chemical substance sought or determined in a sample. This definition does not apply to molecular biological analytical methods.

    3.    Applicability : The analytes, matrices, and concentrations for which a method of analysis may be used satisfactorily.

    4.    Bias : The difference between the expectation of the test result or measurement result and the true value. In practice conventional quantity value can be substituted for true value.

    5.    The bias of a measuring instrument is normally estimated by averaging the error of indication over the appropriate number of repeated measurements. The error of indication is the: “indication of a measuring instrument minus a true value of the corresponding input quantity”.

    6.    Calibration : Operation that, under specified conditions, in a first step, establishes a relation between the values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and in a second step uses this information to establish a relation for obtaining a measurement result from an indication.

    7.    Certified reference material (CRM) : Reference material accompanied by documentation issued by an authoritative body and providing one or more specified property values with associated uncertainties and traceability, using valid procedures.

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.

12.0. Introduction

The benefits of food laws to the consumers and the processing industries depend upon the efficacy with which the laws are implemented. The implementation of laws requires not only a well organized national infrastructure for inspection and quality control, but also requires reliable methods of analysis, that can be used to check the quality standards for improvement of the food product w.r.t. nutrition, safety and sensory attributes. Early and accurate analysis of food product prior to preservation, during preservation or post preservation is a crucial component for quality evaluation and their quality control. Quality control in food industries depends upon three principles viz. i) raw material control, ii) process control and iii) finished product inspection. Once a product has gone through the manufacturing process, little can be done to alter its quality or to overcome the faults. Examination of the finished product at the most represents analysis with respect to standards – to accept or reject. Effective control over the raw material and process minimizes the rejection of the products. The food spoilage can be managed most effectively, if control measures are introduced at an early stage of food preparation/contamination. Reliance on symptom is often not adequate because spoilage may occur before symptom appears. The spoilage of the food may affect sensory, physical, chemical or microbiological attributes. Therefore, now a day, food processors want to analyze their food samples quickly without any delay in shipment for which they have to depend on the different methods for their quality evaluation. The analysis and quality control of food products involve physical, chemical, microbiological and sensory methods. So, widely used standard procedures / methods for evaluation of quality of food prior to preservation, during preservation or post preservation has been given in this chapter for easy implementation.

With increasing food production, availability and accessibility the global agro-industrial food system has improved.However, malnutrition, biodiversity loss and climate change are newer challenges. The best solution to this is the utilization of indigenous and traditional crops which will bring a transformative change in the food system. There is a need to look into the development of smallholder producers. The agro-industrial food system has improved the food supply and has made way for significant trade-offs with agro-biodiversity, dietary diversity, environmental sustainability and socio-economic stability mainly amongst the rural poor. Now is the time to mainstream the underutilized indigenous and traditional crops into the food system. This will provide opportunities to develop a sustainable and healthy food system.It will also help towards the societal goals which include employment creation, wellbeing and environmental sustainability.

Introduction

Milk is regarded as the “ideal food” as it contains nutrients necessary for both newborns and adults (Azad & Ahmed, 2016). It is high in protein, fat, carbohydrates, vitamins, and minerals. Unfortunately, milk is easily adulterated all over the world for several reasons, including a gap between supply and demand, the inherent nature of milk which can imbibe many adulterants that are difficult to identify, the low purchasing power of consumers, an insufficient share of the organized sector in the dairy business, and, most importantly, a lack of efficient and rapid methods for detecting adulterants (Ellis et al., 2012; Moore et al., 2012).

Ice cream over the years has come to acquire an easy acceptance as a healthy, nutritious and hygienic food for the aged, sick, growing children and adults. Its popularity, as demonstrated on all types of occasions is growing fast and its potential appears to be unlimited.

Gone are the days when the word “Ice Cream” was synonymous with strawberry and vanilla flavours or the innocuous orange. Ice cream is available in many forms, flavours and packages. Today, there are exotic variations to titilate the palate, such as Jingle Bells, Goody goody Gum Drops, Champagne Snowballs, Mr. Frost, Tutty Fruity, Butter Scotch, etc, waiting to launch customers on a gastronomical voyage.

It is uncertain how long ice cream has been produced, however, the International Association of Ice cream Manufacturers (1966) traces the beginnings of ice cream and frozen desserts to iced drinks enjoyed by Alexander the Great in the fourth century B.C. down through the years Nero in the first century A. D., Marco Polo in the 13^th century through Italy and France to England in 1643-1649, and to America around 1700. From a very old writings it has been learnt that the Chinese liked a frozen product made by mixing fruit juices with snow, what we now call water ice. It is believed that ice cream evolved from iced beverages and water ices that were popular in the medieval period. This technique later spread to ancient Greece and Rome, where the wealthy, were partial to frozen desserts.

After disappearing for several centuries, ice creams in various forms reappeared in Italy in the Middle Ages, most probably as a result of Marco Polo returning to Italy in 1295 after a 16-17 year stay in China, where he had learnt to appreciate a frozen dessert based on milk. There is no gainsaying the fact that the true origin of ice cream cannot be proclaimed with a fair measure of certainty but, all the same, the Italians claim that Benaroo Bountalenti, a resident of Tuscany, invented ice cream in the early 1300s. From Italy ice cream spread over Europe during the 17^th century, and for long remained a luxury product for the royal courts. Italian ice cream was very popular in London around 1870.

Microscope

A microscope can be defined as an optical instrument consisting of a lens or a combination of lenses for getting magnified images of minute objects. A simple microscope is essentially an ordinary magnifying lens held on an adjustable stand. It can give magnification up to 20 times the size of the object.

A compound microscope consists of two separate lens system, the objective and eye piece (ocular) mounted on a holder known as body tube and with adjustment for illuminating the objects. It gives much greater magnification (100 to 1500 times) when compared to a simple microscope.

1. Ethyl alcohol content in alcoholic beverages is determined by Pyknometer Method or SG (Hydrometer) Method (after distillation). %Alcohol (v/v) = 8610.6 – (16584 x SG) + (7973.3 x SG 2)
2. 1 ml of 0.05N NaOH is equivalent to 0.00375 g of tartaric acid.
3. Volatile acidity of alcohol drinks is measured in terms of as acetic acid. 1 ml. of 0.05N NaOH is equivalent to 0.003g of acetic acid.
4. Esters in alcohol drinks is expressed as ethyl acetate gms. per 100 liters of abs. alcohol. 1 ml. of 0.1N NaOH is equivalent to 0.0088g of Ethyl acetate.
5. Esters in Higher alcohol drinks is expressed as Amyl alcohol gms. per 100 liters of abs. alcohol.1 ml of 0.1N NaOH is equivalent to 0.0088g of Amyl alcohol.
6. The concentration of Higher alcohol g/100L is determined by spectrophotometer method using p-dimethylaminobenzaldehyde solution by reading the % T or Absorbance (OD) of developed colour of samples and series of standards in spectrophotometer at 530/535 nm against reagent blank as reference.

Introduction

Organic substances consumed for nutritional purposes can be called as “food”. Food contains biomolecules, like, protein, lipid and carbohydrate, inorganic minerals as salts, and organic substances, such as, vitamins, emulsifiers, acids, antioxidants, pigments, polyphenols and flavour-producing compounds. They can be of plant or animal origin. Depending on the durability in terms of suitability of consumption, foods can be perishable, semi-perishable and non-perishable. Food spoilage occurs due to chemical, microbial, or physical actions. eventually affecting its nutritional values, colour, edibility and texture (M. Rahman, 2007).

Importance of Foods

The word “instant” has been used in widely different types of premixes to specify the products either as ready-to-eat food or semi processed foods. The instant premixes available in Indian market were classified as Indian products and Westernized or sophisticated products. The instant mixes included under Indian market products are spice mixes, snack mixes and desert and sweet meat mixes. The Westernized products (instant mixes) contained soup mixes, beverage mixes, desert mixes and soft drink mixes.

Convenience foods are gaining popularity in recent years as they are very easy to handle, require minimum storage space and are attractive. Convenience foods have emerged as a new set of products in the international market. Most of the traditional foods that are commercially available in our country are being prepared / processed by cottage industries and by some of the multinational companies. The various types of convenience foods/ instant mixes that are presently being processed, marketed and consumed all over the country. Supplementation with protein-rich sources and preparation of acceptable ready-to-eat snack foods would not only correct its nutritional inadequacies, but would also provide a variety.

Instant mixes were high in nutritive value especially needed for armed forces, light in weight, easy to carry and prepare. Rapid industrialization and urbanization and changes in eating habits of Indian people led to very high demand for ready-to-use snack foods. The convenience instant foods are meeting the urgent and exigency situations of offering hospitality to unexpected guests.

Changing life styles and values are at the root of considerable changes in eating habits over the last few years. Hand-in-hand with a strong demand for fast and take away foods, there has been a marked upturn in popularity for convenience foods in India. The major reasons for this trend are: the decline of the family meal time, growth in disposal incomes (only in cases of city dwellers), the desire for more leisure time and demand for “foreign” or “sophisticated” dishes inspired by the media and increased travel.

Dairy byproducts constitute an important segment of dairy industry. An important criterion in the economic choice of any process is the efficient utilization of byproduct that is produced along with the main product. The main byproducts of dairy industry are skim milk, buttermilk, whey and ghee residue. Each and every component of milk must be judiciously processed into edible form not only to improve the profitability of dairy industry but also to make best use of the unique nutritional value of the precious milk constituents on one hand, and to prevent environmental pollution, on the other. However, dairy plants, particularly in India, are usually confronted with the problem of byproduct utilization, especially that of whey and ghee residue in economical manner.

Skim milk is a byproduct obtained during the manufacture of cream. It is rich in solids-not-fat content and has high nutritional value. In dairy plants, it is mostly utilized either in standardization for the manufacture of main dairy products or preserved by removing moisture in milk powder form. The skim milk when utilized in either of these two forms or consumed as liquid, is not considered a byproduct. It is regarded as a byproduct only when it is either not economically utilized or utilized for derived byproducts, like casein and other related products, co-precipitates, protein hydrolyzates, etc.

Buttermilk is the byproduct obtained during butter manufacture. Sweet cream buttermilk resembles skim milk in gross chemical composition and is usually admixed with bulk of skim milk for further spray drying or even product manufacture in dairy plants. Desi buttermilk, on the other hand, has long been an important domestic beverage in India. It has high nutritive and therapeutic value. It also finds its way in the preparation of a host of culinary dishes such as kadhi, dhokla and idili. Also a number of federations and private plants sell salted and spiced buttermilk in 200 ml pouches.

12.1 Introduction

Man is the most beautiful of all God’s creations and like man, his environment too is beautiful with rivers to quench his thirst with sweet water, atmosphere to provide him oxygen, land and fire to provide him food. Primitive man ate uncooked food and lived in caves. Soon he learnt the use of firewood for cooking of raw meat and provided the first instance of ‘Pollution from food processing’ in history. As man shifted from one place to another, this sort of living never polluted the environment. But as the man ascended the ladder of civiliz ation, his needs grew in arithmeti c progression but corresponding pollution grew in geometric progression. With increase in agriculture produce, a need was felt to preserve the glut production in the form of processed foods giving rise to massive development of food processing industries all over the world. The rapid industrialization of agriculture and horticulture, increased the pollution load many folds especially the biodegradable waste from food industry [41].The wineries and distilleries (distill wine to make brandy) are no exception. Nevertheless, the waste is a precious source of several useful materials as such or after fermentation [1,31,46,86]. Thus, development and environment are two sides of the same coin.

From time immemorial, the biosphere is acting as a sink for all the waste products and recycles them to make good the loss so that every generation finds it the same as one before it. But, of late, this self-cleaning and equilibrium maintenance of biosphere is disastrously disturbed as the waste produced from man’s activities is continuously exceeding the capacity to purify herself. Consequently, our biosphere is becoming more and more poisonous and days are not far away when this planet will become inhabitable.

Introduction

About sixty percent of the world’s food intake comes from the three major crops, i.e., wheat, rice and maize (Thielecke and Nugent, 2018). Depending upon the country of utilization and consumption, the products made from cereals such as barley, wheat, maize, triticale, spelt, buckwheat, rice etc. can vary in the range of pasta, bread, pastries, soups, chapatti, cooked rice etc. World cereal utilization in 2021/22 is forecasted at 2,811 million tonnes and the worldwide production of cereals is expected to reach 2,818 million tonnes by 2025 (FAO, 2020).

    1.    Food : defined as something which is eaten / drunk by human beings or something we eat and which can be utilized by our body.

    2.    Milk and milk products like Dahi, yoghurt, paneer, cheese, Khoa etc these foods are rich sources of Vitamin A, Riboflavin and Calcium.

    3.    Meat, fish, poultry etc besides proteins these foods also provide Iron and B- complex Vitamins.

    4.    Eggs and egg products are also rich in Iron, Vitamin A and Riboflavin (B1).

    5.    Pulses, nuts and oil seeds are also a good source of thiamin, niacin, and Iron.

    6.    Strategies and measures for alleviating the world food problem require.

Introduction of Food Industry

India is one of the major food producers in the world. The food sector contributes to about 28% of India's GDP. India stands at 1st position in the world for production of cereals, milk, livestock, banana and Mango, 2nd in producing fruits and vegetables and ranks amongst top 5 in producing rice, wheat, groundnut, tea, coffee, tobacco, spices, sugar and oilseeds. India's share in global production of fruits is 10% and vegetables are 13.7%. The current consumption of fruits and vegetables is approx Rs.2 lakh crores at current prices with an estimated growth rate of 11% per annum. The growth rate is higher than cereals and milk and comparable to meet consumption

Status of Food Processing Industry

The food processing industry in India is still in a sorry state. The rural population comprising 70% including small cities, consume less than 10% of the processed foods and vegetables, whereas 60% of the processed food is consumed in four major metropolitan cities and 30% in the state capitals and big cities. Another fact is that 40% of the processed food and vegetables produced in the country in terms of value are bought by institutional buyers like Hotels, Restaurants and Defense etc. The highest growth in domestic market has been in fruit drinks, tomato ketch up and Jams.

There is another fact that India is the largest milk producer in the world, however, organized industry accounts for less than 15% of the milk produce in India. It is estimated that there may be a total production of 1100 million tons of production of food products mainly food grains, oilseeds, sugarcane and fruits/vegetables during 2011-12 and leaving marketable surplus of 870 million tons.

Experiment No.- 1
AIM
To determine the sucrose content in condensed or evaporated milk using the Lane-Eynon method.
Principle
The Lane-Eynon method is used to measure sucrose in condensed milk by utilizing the reducing properties of sugars. Sucrose, being a non-reducing sugar, is first hydrolyzed into glucose and fructose (reducing sugars). These reducing sugars then react with Fehling’s solution, producing a brick-red precipitate of cuprous oxide (Cu2O) when heated. This allows for the accurate determination of sucrose content after the hydrolysis (inversion) process.
Reactions
• Reaction of Fehling’s Solution
• CuSO4 + NaOH → Cu(OH)2 + Na2SO4
• Cu(OH)2 + Reducing Sugar (RCHO) → Cu2O (brick-red precipitate) + RCOOH
This reaction forms cuprous oxide (Cu2O), a brick-red precipitate. The intensity of this precipitate correlates with the concentration of reducing sugar in the sample, providing a way to determine sucrose content.

11.1 Introduction

Fermented foods are the result of the activity of a few specialized types of micro-organisms among the thousands of species known to mankind. Success of such processes is depended upon the control of environmental conditions ensuring the growth of the desired microbial species and inhibition of others. The fermentation can be broadly defined as the process in which the carbohydrate or like compounds are broken down, under anaerobic or aerobic conditions [171]. The basic role of micro-organisms is to breakdown the organic compounds to get energy for their metabolic activities. From ancient times, people all over the world have developed traditional processes for production of alcoholic beverages (wine) either from natural sugar such as in wine or by degrading the starchy materials (beer). Fruit wines referred to as ‘Soma’ in our ancient scriptures have been part of food of man and were used as medicine, might have originated accidentally (transformation of fruit juice beverages having exhilarating or stimulating properties). Wines are made principally from fruits like grape or extract of other fruits of various types (table wine, sparkling wine, dessert, aperitif or vermouth and pop wines) while the beers are prepared from grains like barley, rice and corn. The principal carbohydrate in grain is starch which can not be fermented directly. This process is brought about by starch splitting enzymes by germinating the grains followed by drying and storage until needed. Distillation of beer produces a variety of liquors (whisky, rum, gin, vodka), while that of wine produces the brandy. Besides, the improvement in the raw material selection, fermentation conditions and techniques, a lot of waste material is generated during fermentation process in the industries. Nevertheless, the food based industries are significant contributors to the economy of the many countries of the world (Fig 1). The global market value of food fermentation based industries is estimated to be around 250 million US dollars. Interestingly, more than 10% of this accounts for alcoholic beverages (Fig 2) with projected increase of US$ 27 billions in 1989 to 40 billions in 1990 [93,123,123,129].

Electrophoresis

The mobility of ions in an electric field is the basis for the separation method known as electrophoresis. Ions that are negatively charged move toward a positive electrode, while those that are positively charged move toward a negative electrode. Usually, one electrode is biased either positively or negatively, and the other is at the ground for safety reasons. Ions can be distinguished from one another based on their size, shape, and overall charge, which determine their migration rates.

Poly Acrylamide Gel Electrophoresis (PAGE)

Introduction

Electrophoresis is an electrochemical process in which substances with a net electric charge migrate under the influence of an electric current. This migration occurs in an agar gel or a liquid- filled buffered matrix such as cellulose acetate. Positively charged substances travel toward the cathode (negative electrode), while negatively charged substances go toward the anode (positive electrode). Different substances move at different rates depending on their charge. This movement is called electrophoretic mobility.

Proteins are charged molecules. They have a positive as well as a negative charge. Among proteins, particularly caseins, they have different contents. The charge density also varies depending on the molecular weight. Proteins have a net negative charge at a pH above 4.6, and hence they move towards the anode (positive electrode) when subjected to an electric field under alkaline conditions. Due to differences in the charge of individual protein fractions, their migration rates also differ and are hence separated into distinct bands. These bands are stained with the dye amido- black, destained with 7% acetic acid, and observed for the electrophoretic pattern.

The method of preserving various food stuffs by drying them, and thereby depriving microorganisms of the water necessary for their growth, has been known for centuries. According to Marco Polo’s accounts of his travel in Asia in 13^th century, soldiers of Kublai Khan carried dried milk on excursions. Before it was used, water was added to a portion of dried material. Mixing was accomplished by movement of the horse during riding on the trip. The recombined product was then consumed at the mealtime. The belief is that part of the fat was removed from the milk before drying and dehydration was accomplished by solar heating.

Drying is defined as the removal of the liquid, usually water, from a product by evaporation, leaving the solids in an essentially dry state. Today the production of dried milk and milk products has become important segment of dairy industry. Dry milk provides a means of preserving the excess milk supply during the flush season for use during the lean season. The value added dried dairy products like malted milk foods, infant food and infant formulae and dairy whiteners are convenient ready to use products having wide acceptance. The water content of milk powder ranges between 2.5 and 5%, and no microbial growth occurs at such low water content. Drying extends the shelf life of milk, simultaneously reducing its weight and volume. The main purpose of drying milk are: a) to improve the storage life of the product due to low moisture content, b) to reduce cost for storage and transportation of product due to reduced bulk, and c) to provide convenient product for utilization in many dairy and food preparations.

The production of dried milks to a great extent is now being governed by the market requirement and to some specialized use of such products. Considerable quantities of dried skim milk powders are being used extensively in the preparation of ‘Reconstituted and Recombined milks”. Milk powders are also used extensively in the manufacture of ice cream, bakery products, confectionary products, cottage cheese and in other cheese varieties. The greatest proportion of milk powder is utilized in confectioneries, such as milk chocolate, caramels, soft sweets, coatings, biscuits and cakes. In these products, milk powder has a special effect on the quality of particular products: it improves consistency, flavour as well as nutritional value and shelf life.

    1.    Microbial Risk Assessment (MRA) can be considered a tool for use in the management of the risks posed by food borne pathogens and in the elaboration of standards for food in international trade.

    2.    MRA comprises risk assessments of particular pathogen - commodity combinations

    3.    According to codex alimentarious commission (CAC) microbial risk assessment is defined as a scientifically based process consisting of 4 components.

        ·    Hazard identification
        ·    Exposure assessment
        ·    Hazard characterization
        ·    Risk characterization

India has emerged as the largest producer of milk in the World. This has boosted the confidence of producers, planners, dairy entrepreneurs and scientist alike. India has poised to play a major role in global dairy market in coming decade. The rapid growth of science and technology has positive impact on our life style and with strong trend of urbanization several demographic changes are likely to occur. There going to be ever increasing demand on the role of milk and milk products for human health. Accordingly, the demand for higher standards of milk products in terms of hygiene and safety of dairy products is to be followed. The competitiveness for the export of milk products among different dairy industry has increased in recent times due to GATT agreement. The biggest challenge before Indian dairy industry is the quality and safety of milk products indented for human consumption. Legal standards are made to have control over quality of food offered for sale and to safe guard the consumer form health hazards. It is therefore, imperative to determine different parameters that define product quality and safety. The purpose is to ensure production and distribution of products within well defined and accepted standards. This chapter deals with various parameters of product testing in order to maintain requisite prescribed standards.

Milk, on reception at the dairy factory is subjected to various unit operations on its way to product manufacture. Processing is applied as a means to convert liquid milk into products or to render the milk (and products) safe from harmful organisms. The basic processing operations to which milk is subjected at processing units have been described in this chapter. The common processing operations employed are depicted in Fig. 4.1. Several of these operations are routine compulsory processes common to all dairies, while certain others are undertaken for specialized purposes in some dairies.

4.1. Filtration and Clarification

At the time of milking various foreign materials such as dirt, feed, manure, dandruff, hair, flies, dust particles, worn out cells, cell debris and many other undesirable substances may find their way into milk. The process of removal of this extraneous matter (solid particles of higher density than that of milk) is called filtration or clarification. This can be achieved either by simple filtration through specially woven filter cloth or continuous process of centrifugal clarification that helps

Jay et al., (1995) and Joerger et al., (2003) have written the role of bacteriocins as an alternate to antibiotics. Bacteria produce bacteriocins which are proteinaceous in nature or peptidic toxins. These inhibit the growth of similar or closely related bacterial strain(s). There are different types of bacteriocins which are classified based on the producing strain, common resistance mechanisms and mechanism of killing. Ahmad et al., (2013) have isolated antifungal compound for food preservation. Martin et al., (2018) and Batish et al., (1997) found antibacterial compounds from fungus. Mahboubi et al., (2019) studied the potential of Zataria in IBS. There are bacteriocins from gram-positive bacteria known as the colicins, the microcins and the bacteriocins from Archaea (Cascales et al., 2007). The bacteriocins from E. coli are called colicins (formerly called ‘colicines,’ meaning ‘coli killers’). These have been studied widely. Earlier called colicin V and is now known as microcin V. It is very small and is produced and secreted in a different manner than the classic colicins. Adrienne et al., (2016) have studied the colicin resistance.

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.

1.1. General Discussion of Milk

“The cow is the foster mother of the human race. From the days of the ancient Hindoo to this time have the thoughts of men turned to this kindly and beneficent creature as one of the chief sustaining forces of human life”.

William Dempster Hoard (1836-1918)
Former Governor, State of Wisconsin, USA (1889-1891)
Founder of Hoard’s Dairyman (1885)

The oldest written records of the human race are in Sanskrit and are preserved in India. At the time these records began, about 6,000 years ago, milk had already become an important article of food. In fact, so important was the cow to these early people of South and Central Asia that wealth was measured in numbers of cattle, and the cow was in time made a sacred animal and is still so considered in India.

According to the best authorities, the domestication of cattle must have occurred somewhere between 6,000 and 10,000 years ago. The cow was worshipped in Babylonia, and in Egypt about 20,000 B.C. Over fifty references to cows and milk are found in Old Testament and the Promised Land was described as “a land flowing with milk and honey”.

Milk is the only food of the young mammal during the first period of its life. The substances in milk provide more energy and the building materials necessary for growth. Milk also contains antibodies which protect the young mammal against infection. A calf needs about 1000 litres of milk for growth, and that is the quantity which the primitive cow produces for each calf. There has been an enormous changes since man took the cow into his service. Selective breeding has resulted in dairy cows which yield more than 5,000 litres of milk per calf, i.e. five times as much as the primitive cow. Some cows can yield 10,000 litres or more.

Introduction

    1.    Food Science is the application of the physical, biological and behavioral science to the processing and marketing of foods (Margaret, 1968).

    2.    Technology can be defined as the science dealing with knowledge of doing things efficiently and effectively.

    3.    Food science helps us understand the theory example: what methods can best be used to store and preserve food to maintain quality and prevent spoilage.

    4.    Food technology demonstrates how the food is stored, preserved, processed and transported and has been responsible for development of new techniques for processing and preservation of food on a commercial scale and for packaging it in such a way that it can be sold conveniently.

    5.    Food science deals with the study of facts of the physical, chemical and biological sciences as they influence the processing and preservation of food.

    6.    Food technology deals with engineering and other scientific and technical problems involved in transforming edible raw materials and other ingredients into safe, nutritious and appetizing food products (Desrosier, 1977).

    7.    Food science is concerned with basic scientific facts about food, where as food technology concerned with the processing of raw materials into foods that meet human needs and wants.

    8.    Indian agriculture has undergone a sea change during the past half a century. Starting with the campaign for “grow more foods” in the forties, India reached self sufficiency during the eighties.

    1.    Wohler (1828) synthesized the first organic compound, urea from inorganic components.

    2.    Emil Fischer (1894) demonstrated the specificity of enzymes and the lock and key relationship between enzyme and substrate.

    3.    Michaelis and Menten (1913) developed kinetic theory of enzyme action

    4.    Watson and Crick (1953) Proposed the double-helical model for DNA structure

    5.    Ingo potrykus (1999) Golden rice- rich in b-carotene.

    6.    Glyoxysomes : Glyoxysomes are temporary in that they occur during transient periods in the life cycle of a plant such as in certain beans and nuts which store fats in their seeds as energy reserves. Glyoxysomes appear in the first few days after seed germination in endosperm cells and associate closely with lipid bodies. They disappear after the storage fats are broken down and converted into carbohydrate.

Fat-rich dairy products such as cream, makhan, butter, butter oil and ghee have played a pivotal role in growth and development of dairy industry in India as well as abroad from the time immemorial. The reference of makhan and ghee has been found in old Indian scriptures. Makhan was popularized by Lord Krishna about 5000 years before. In the traditional Indian dietary regimen, milk fat in the form of malai (cream), makhan (freshly churned butter) contributes significantly towards nourishment of people of almost all ages.

Indian dairy industry, over the years, has been converting surplus milk for the manufacture of fat-rich dairy products, especially ghee and butter with skimmilk as a byproduct because of technological and economic reasons. More than one-third of the total milk production is being utilized for the production of ghee and butter wherein milk lipids, the most expensive constituents of milk are conserved and preserved. Milk lipids play many diverse roles, some of which are essential for human health. Many of the desirable flavour and textural attributes of dairy products are due to their lipid components, consequently, butterfat has, traditionally, been highly valued. Significance of fat can also be realized from the fact that the consumer’s perception of food quality is largely based on the perceivable rich taste. Unfortunately, milk lipids are subject to chemical and enzymatic alterations which can cause flavour defects referred to as oxidative and hydrolytic rancidity, respectively. The storage stability of high-fat products is strongly influenced by these changes.

Obesity: A condition characterized by the excessive accumulation and storage of fat in the body. It is a physiological disorder having high body mass index (BMI), which can be expressed as a mathematical formula in which a person’s body weight in kilogram is divided by the square of his or her height in meters.

Objective Methods of quality evaluation: These are based on recognized standard scientific tests to any sample of the product without regard to its previous history. They represent the modern idea in quality control (QC) because the human element has been excluded. This method divided into three groups like physical, chemical and microbiological. The devices are used in this evaluation.

Obligate anaerobes: These microbes do no grow inthe presence of oxygen.

Obligate parasite: Obligate parasites is host specific and grows on living host only and attach limited range of host and are very difficult or impossible to grow on artificial culture/media.

Obligate thermophile: These microorganisms grow at a temperature between 38 80oC.

Oedema / edema: It is an abnormal infiltration and excess accumulation of serous f luid in connective tissue or in a serous cavity. Oedema meanswatery swelling of plant organs or parts. It is also called dropsy.

Cheese is a milk product of ancient origin and portrays the ethos of civilization and its cultural evolution. Cheese is one of the oldest foods of mankind. It is commonly believed that cheese evolved in the Fertile Crescent between the rivers Tigris and Euphrates in Iraq some 8000 years ago. The so-called Agricultural Revolution occurred here with the domestication of plants and animals.

It seems that the cheese originated accidentally as a result of the activities of nomadic tribes. Since animal skin bags were a convenient way of storing liquids for nomadic people, these were used for storing surplus milk. Fermentation of the milk sugars in the warm climate prevailing would cause the milk to curdle in the bags. The swaying animals would have broken up the acid curd during journeys, to produce curds and whey. The whey provided a refreshing drink on hot journeys, while the curds, preserved by the acid of fermentation and a handful of salt, became a source of high protein food supplementing the meager meat supply.

This activity gave rise to the assumption that cheese was evolved from fermented milks. It is perhaps more probable that the crude fermentations progressed in two ways. In one direction towards the production of liquid fermented milks such as dahi, yoghurt, laban, koumis and Kefir and in the other direction through the drainage of whey through a cloth or perforated bowls, to leave solid curds which when salted became cheese.

It was a prominent article of the Greek and Roman diet as much as 2500 years ago. It is referred to in the Old Testament several times.