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India

Milk legislation and regulations are designed to prevent fraud and adulteration. But they now cover many factors that affect sanitation and public health. Milk generally is classified into grades according to the care with which it is produced.

Milk lipids or milk fats exist as an emulsion of small spherical droplets called milk fat globules. These globules are very small in size but very large in number. The diameter of the milk fat globules ranges between 0.1 and 22 µm and the number varies between 1.5 and 3.0 billion globules/mL. The average size of milk fat globules ranges from 2 to 5 µm. The average fat globule size in cow and buffalo milk are 3.4 and 4.5 µm, respectively. The surface of the milk fat globules is coated with an adsorbed layer of material known as the milk fat globule membrane (MFGM). MFGM contains phospholipids and proteins in a complex form. MFGM has two main functions (a) fat globule stabilization and (b) preservation of the fat globule’s identity.

General Composition

Triacylglycerols (triglycerides) represent 97–98% of the total lipids in the milk of most species. The diglycerides probably represent incompletely synthesized lipids in most cases. Although phospholipids represent less than 1% of total lipids, they play an important role in being present mainly in the MFGM and other membranous material in milk. The principal phospholipids are phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin. Trace amounts of other polar lipids, including ceramides, cerebrosides, and gangliosides, are also present. Phospholipids represent a considerable percentage of the total lipid of buttermilk and skim milk reflecting the presence of proportionately larger amounts of membrane material in these products.

The primary objective of dairy plant hygiene is to ensure the consistent daily turn-out of safe and clean products which comply with pure-food and public health laws. A secondary and commercially important aim is to preserve the keeping quality of dairy products and so enhance consumer confidence in them. An integral part of a dairy is the quality control laboratory. Continuous testing is necessary for many purposes, including equipment hygiene. Bacteriological standards of dairy products can be maintained only if the raw product is of good bacteriological quality and is protected against contamination from the equipment with which it comes in contact during all stages of processing. 
Many factors may influence the maintenance of dairy equipment in a hygienic condition; the most important are the dairy buildings, the materials and construction of the equipment, personnel, water supply, cleaning procedures, and laboratory control. It is quite impossible to place these points in order of importance, efficient control of dairy plant hygiene being dependent on proper attention to all factors.

10.1 Introduction

Milk is a unique substance in that it is both consumed, as fluid milk with minimal processing and it is the raw material used to manufacture a wide variety of products. From the nutrition point of view, milk is an almost ideal food and considered to be perfect food. The human body needs more than thirty distinct materials in its food supply. No single food stuff supplies all of them but milk supplies nearly all. Since milk by its nature is perishable and an ideal product for bacterial growth, so it must be carefully handled, both during production and while processing. This chapter focuses on the technological (processing) aspects of the transformation of milk into its various consumer products, including beverages, fermented products, concentrated and dried products, butter and ice cream.

Milk production in India is a subsidiary activity of agriculture in contrast to the organized dairy sector in the western countries. Farmers and landless labour maintain one to five milch animals. As a result, small quantities of milk are produced in a scattered manner. Due to this reason, milk procurement models from western countries, such as bulk cooling and bulk transportation are not applicable under Indian conditions. Collection of small amounts of milk is scattered over long distances and, therefore, poses a formidable challenge in maintaining the quality attributes and keeping costs down.

3.1. Rural Milk Collection

A systematic approach to rural milk collection suitable for the tropical climate and techno-economic conditions prevailing in India has been developed, based on the indigenous experience gained over the past few decades. In the first phase, extensive surveys are undertaken in the milkshed areas, where the milk plant is to be established. The second phase involves ‘route planning’ taking into account, availability of quantities of milk, access to roads for plying vehicles and distance from the site of dairy plant. Then zones are identified, representing equal costs of collection and transportation. In the third phase, planning is done for locating the primary collection centres as well as chilling centres, where, milk can be cooled to 4ºC before transporting to the milk plant. Milk may be collected from individual producers either by the contractor or by forming village level cooperative societies.

Bovine milk contains an average of 3.5% protein. The concentration of protein changes significantly during lactation. The first few days of lactation exhibit the main change in protein concentration. The main changes occur in whey protein fraction.

Distribution of Protein in Milk

80% casein and 20% whey protein (β lactoglobulin- 10%, α- lactalbumin- 5%, serum albumin, and immunoglobulin- 5%).

Fractionation of Milk Proteins Fractionation of milk protein is mainly done by acidification at pH 4.6 around 30 °C.

Almost 80% of the bovine milk protein precipitates at pH4.6, and this fraction yielded by precipitation is called casein.

The remaining soluble part of the protein is referred to as whey protein/serum protein/ non- casein protein. Wide variation is observed in the casein- whey protein ratio in different types of milk(protein synthesis is independent of animal diet)

Significant Difference Between Casein and Whey Protein

1. Casein precipitates at pH 4.6 but does not precipitate whey protein at that pH. This property of milk protein is commercially exploited for the preparation of industrial casein and certain varieties of cheese.

2. Chymosin or other proteolytic enzymes produce specific changes in casein resulting in coagulation in the presence of calcium. Whey protein does not undergo this type of coagulation.

3. Casein is very stable to high temperatures. They can withstand heating up to 140 °C for 20 minutes but whey protein is relatively heat labile. They are completely denatured by heating at 90 °C for 10 min.

4. Casein is a phosphoprotein containing an average of 0.85% phosphorous while whey protein does not contain any phosphorous. The phosphate of casein is an important contributor to remarkably high heat stability and calcium- induced coagulation of rennet- altered casein.

5. Casein contains very low sulfur (0.8%) whereas whey protein is relatively rich in sulfur (1%). The principle casein contains only methionine but whey protein contains a significant amount of cystine, cysteine, and methionine. These sulfur- containing amino acids are responsible for many changes in milk on heating.

6. Casein is synthesized only in the mammary gland and no other sources in nature. Some of the whey proteins β lactoglobulin, and α- lactalbumin are synthesized in the mammary gland but bovine serum albumin and immunoglobulin are not synthesized in the mammary gland but derived from blood.

7. The whey protein is dispersed in solution and has a simple quaternary structure. Casein has a complex quaternary structure and exists in milk as large colloidal aggregates.

The salts of the milk include those constituents that are present as ions or in equilibrium with ions. The main salts of milk are phosphates, citrates, chlorides, sulfates, carbonates, and bicarbonates of sodium, potassium, calcium, and magnesium. Approximately 20 other elements are found in milk in trace quantities including copper, iron, lead, boron, manganese, zinc, iodine, etc. These ions are more or less associated with themselves and with proteins. Some metals act as catalysts in the oxidation of milk fat leading to oxidative rancidity and certain metals like Ca, P, Mg, Mo, Co, Fe, etc. are components of metalloproteins such as lactoferrin, lactoperoxidase, xanthine oxidase, and parts of phospholipids.

Distribution of Salts Between Casein Micelles and Serum

The phosphorus is present as orthophosphate, but part of it is bound to organic components like serine and threonine residues of casein, molecules of hexoses and glycerol, phospholipids, etc. Phosphorus is also found in the hydroxyapatite structure of the colloidal calcium phosphate in the micellar structure of casein. The sulfur content of milk is about 0.36 g/kg, but most of it is in the amino acid residues methionine and cysteine of the proteins. About 10% is present as inorganic sulfate.

Physical Equilibria Among Salts

Milk contains several elements but all of them are not entirely in a soluble state. Some minerals exist in colloidal and ionic states at the normal pH of milk. The compounds that are in soluble condition play an important role in keeping various milk constituents in stable condition. A balance exists between the components that are in a soluble state and those which are in colloidal state.

Milk

Importance

Milk contains approximately 86% water, 4.7% sugar (lactose), 4.1% fat, 4.2% protein and 1% minerals. It supports the growth of micro-organisms and thus is prone to contamination. The purpose of milking a dairy cow is to obtain milk that is fit for human consumption. Milk from the udder of a healthy cow contains very few bacteria and to ensure that it remains fresh for long it should be handled under conditions of good hygiene. Unclean milk can be a source of disease to the consumer, rejected at the market and so is a loss to the farmer, does not keep for long and is not good for processing.

Millets or nutri-cereals are the ancient grains which have now regained the interest of the scientific community as the super grains. These exhibit excellent nutritional and technobiofunctional profile apart from exhibiting tolerance to biotic and abiotic stresses. The millets are gluten free and show high in vitro protein digestibility, resistant starch content, antioxidant and prebiotic potential providing health benefits for all age groups ranging from paediatrics to geriatrics. The presence of certain anti-nutritional factors can lower the bioavailability of proteins and minerals. Processing enhances the nutritional and functional properties by increasing the antioxidant content and lowering the antinutrients. Different value added products can be prepared by incorporating millets thereby enhancing the nutritional and functional attributes. It is necessary to bring millets into regular consumption by the food industry in the interest of nutritionally and health-conscious consumer.

1. Introduction Millets, also known as “smart crops” or “miracle grains,” are a group of small-seeded, hardy cereal crops that have been cultivated for millennia. They are used as a staple food in many of the countries particularly located in arid and semi-arid regions. Millets have been overshadowed for quite a long time by commonly consumed cereals like wheat, rice, and maize. Nevertheless, they have made a remarkable comeback in our cuisines owing to the growing awareness and recognition of the numerous benefits at individual and environmental level. These small, drought-resistant grains play a pivotal role in addressing some of the most pressing global issues like food security, malnutrition and climate change.

Millets are a type of minor cereals found in the Poaceae family. Millets are often described as “Nutri-Cereals” since they contain more nutrients than commonly produced main cereals. They are an important part of human’s diet in the world. These are foods with a high nutritional content, gluten-free and have nutraceutical qualities. The adequate amount of protein (essential amino acid), micronutrients and phytochemicals are found in millets. The phytochemicals found in millet grains enhance human health by lowering cholesterol and phytates in the body. Millets are full of antioxidants, minerals including dietary fibre, iron, calcium and magnesium that are vital for battling a variety of diseases. These are beneficial to include in our daily diet because the grain is healthy and nutritious. They decrease blood pressure, prevent cancer and lessen the chance of tumour growth. The rich nutrient content in millet has many health advantages such as cancer, obesity, lower risk of cardiovascular disease, gastrointestinal issues, migraines and asthma. People utilise millet-based products to fight a variety of nutritional deficiencies and diseases.

Millets which are also known as “Shree Anna” are a type of grass with small seeds that belongs to the Poaceae family and are widely grown throughout the world. Millets have high levels of proteins, minerals, vitamins, and antioxidants that why they are known to be climate-change-resilient crops. Proteins are essential amino acids that the body cannot synthesize and are used as a nitrogen source during embryo development following germination. Millets are high in dietary fibre and are important staple crop in many parts of the world. They are versatile grains that can be used to make a variety of food products, including millet flour. Millets are good for cardiac health, weight management, antioxidant activity, and may have anti-cancerous properties. They are nutrient- dense, provide sustained energy, and contain antioxidants such as polyphenols and flavonoids. Millets are considered safe and have a variety of health benefits. Surprisingly, millets perform major non-millet cereals in terms of nutrition. They are particularly high in dietary fibres, minerals, antioxidants, phytochemicals, and polyphenols, all of which have broad-spectrum positive effects on human health.

INTRODUCTION

Fruits and vegetables are historically important constituents of human diet and the growing awareness of consumers about the beneficial effects of these commodities could result in enhancement of global trade involving fresh and processed fruits and vegetables. Emergence of postharvest handling of fresh fruits and vegetables facilitated global trade of these commodities. The developed countries started realizing the export potential of these commodities by development of adequate value addition in terms of pretreatments, shelf life extension and packaging besides grading and other associated packing house operations. However, the trade concerning fresh fruits and vegetables could never come out completely from problems related to pesticidal residues, spoilage, bulkiness of the commodities involving transportation of inedible portions and excessive packaging costs arising out of bulkiness. The other problems associated with fresh produce include mandatory requirement of specific storage temperatures with refrigeration as the primary means of regulation of metabolic rate.

Introduction

In this modern era, educated and health-conscious people are increasingly demanding such food products that preserve their nutritional value, retain a natural and fresh colour, flavour and texture, and free from chemical preservatives. Besides, urbanization has extensively affected the life-style of people all over the world. Competition has made their life extremely busy and time has become a very important factor. Hence, recently there has been increase in demand for ready-to-cook or ready-to-use fresh food products of fruits and vegetables along with convenience and safety. This new demand by consumers has opened a new avenue of food preservation known as minimal processing. The products prepared by this processing method are known as fresh cut or pre-pared products. Minimally processed products are also known as lightly processed, partially processed, fresh processed, fresh cut, and pre prepared. It can be defined in many ways for example as "least possible treatment to achieve a purpose". A more specific definition is as the method that "preserve foods but also retain to a greater extent their nutritional quality and sensory characteristics by reducing the reliance on heat as the main preservative action. In a broader way it can also be defined as the processed foods have been slightly altered for the main purpose of preservation but which does not substantially change the nutritional content of the food. Generally minimal processing involves cleaning, washing, trimming, coring, slicing, shredding before packaging and storage at specific temperature. Some of the examples of minimally processed fruits and vegetables include sliced mango cheeks/melons/papaya/apple, pieces of pomelo segments, peeled and cored pineapple, chilled peach, pomegranate arils dressing, shredded lettuce, shelled peas, cauliflower florets, peeled sliced potatoes, diced onion etc. Minimally processed products are important to food service industry such as eateries and catering companies as they offer many advantages over traditional products, with respect to convenience, expense, labor, and hygiene. Even if it is very much liked by people, the production of minimal processed products is limited due to rapid deterioration and short shelf life. Whereas most food processing methods stabilize the products and prolong their shelf-life, minimal processing of fruits and vegetables increases their perishability.

Minimally processed fruits and vegetables are products that have the attributes of convenience and fresh like quality. Their forms vary widely, depending on nature of unprocessed commodity and how it is normally consumed. In many cases, minimally processed product is raw and cells of tissues are alive, but these characteristics are  not regarded as essential. It is important that products have fresh-like character, regardless of   state of cells.  Minimally processed products for both retail and food service applications have increasingly appeared in market place recently.  In coming years, it is commonly perceived that this industry will have unprecedented growth.

1. INTRODUCTION

In recent years, fruit and vegetable consumption has grown rapidly. Today’s society is characterized by an increasing health consciousness and growing interest in the role of food for maintaining and improving human well-being and consumer health. Due to consumer’s profile being ‘‘rich in cash/poor in time’’, there is a demand for ready-to-eat products As a result of changes in consumer attitudes, the market of minimally processed (MP) fruits and vegetables has grown rapidly. In addition to their nutritional and sensory properties, foods are currently recognized as active and protective agents. Among the others, minimally processed products stand out as convenient novel foods that fit the many needs of a modern lifestyle as they combine technical content with an innovative food concept. Fresh fruits and vegetables are an essential component of a healthy diet, able to decrease the risk of cardiovascular diseases and cancer. Their consumption has continued to grow rapidly, linked to the increased public awareness of their health benefits.

Minimal Processing’ (MP) is a concept describing approaches to food safety and preservation that are designed to retain the natural and as-fresh properties of foods. Minimally processed fruits are new forms of product marketing, intended to meet the consumers’ desires for convenience and fresh-like quality. Minimally processed fruits and vegetables, also called ready-to-use, fresh-cut or pre-cut produce, are raw fruits and vegetables that have been washed, peeled, sliced, chopped or shredded into 100% usable product that is bagged or packaged to offer to the consumers high nutrition, convenience, and flavour while still maintaining its freshness.

Minimal processing of fruits and vegetables
The technological development and modernization during recent years have resulted in in organisation coupled with Lifestyle modification and changes in dietary habits. This development and Organisation have made it easier to meet the requirement of processed food. Processing of fruits and vegetables effects shelf life providing ready to eat food with similarities to fresh product. Before the food Industries shoulder a bigger responsibility of utilising a novel technology to produce safe food without detrimental effects on quality. The industries need to who built biological (enzymatic / fomentation and biopreservation and Engineering solutions like non-thermal high-pressure treatment, cook chill, microencapsulation, vacuum impregnation etc. For the adoption of de - constructive culinary techniques such as 3D food printing and Molecular gastronomy as well as developments in nutrigenomics and digital technologies may facilitate novel product format, personalization, and access to niche market. Concretely, e - operating movement from Naresh mint to health improvement in present conditions demand or shift from defensive market oriented offensive market developing strategies including collaborative networks with Research Organization.
It is also defined as any fruit and vegetable that has been subjected to different processing steps (e.g. peeling, trimming, cutting, washing, disinfection rinsing etc.).

EXPERIMENT: MINIMAL PROCESSING OF CAULIFLOWER (FREEZING PRESERVATION AND STEEPING PRESERVATION)

Materials and reagents

Material : Fresh cauliflower, glass jars, polythene pouches

Reagents: 15% sodium chloride

Tamarind (Tamarindus Indica)

Introduction

The fruit of tamarind a pod 5 to 15 cm long, 3 to 10 seeds surrounded with edible pulp which is principal souring agent for sauces, chutney, in beverages and in general cooking. Pulp is carminative, laxative, given as infusion in biliousness and febrile conditions. It is also used in dyring and tanning and for polishing and cleaning metal ware. The tartaric acid is extracted from unripe fruits. The polysaccharide (jellose) is extracted from seeds, which is used as a sizing material in the cotton and jute industries. Besides, polyose obtained from the seed is good substitute for fruit pectin in the preparation of jam, jelly or marmalade. The bark and leaves are used for tanning. Tamarind balls are prepared after taking out seeds from the fruit. Tamarind paste and tamarind juice concentrate are the other commercial products.

The fruits, flattish, bean-like, irregulary curved and bulged pods, are born in great abundance along the new branches and usually vary from 2 to 7 in long and from 3/4 to 1 1/4 in (2-3.2 cm) in diameter. Exceptionally large tamarinds have been found on individual trees. The pods may be cinnamon-brown or grayish-brown externally and, at first, are tender-skinned with green, highly acid flesh and soft, whitish, under-developed seeds. As they mature, the pods fill out somewhat and the juicy, acidulous pulp turns brown or reddish-brown.

New Technique of Food Preservation

1. High Pressure Processing (HPP)

High Pressure Processing (HPP) is a method of food processing where food is subjected to elevated pressures (up to 87,000 pounds per square inch or approximately 6,000 atmospheres), with or without the addition of heat, to achieve microbial inactivation or to alter the food attributes in order to achieve consumer-desired qualities. Pressure inactivates most vegetative bacteria at pressures above 60,000 pounds per square inch. HPP retains food quality, maintains natural freshness, and extends microbiological shelf life. The process is also known as high hydrostatic pressure processing (HHP) and ultra high-pressure processing (UHP).