eChapters

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.

Carbohydrates are polyhydroxy derivatives of aldehydes or ketones and undergo all the organic reactions common to the carbonyl groups and hydroxyl groups. The principal milk carbohydrate is lactose. It is a disaccharide. Hydrolysis of lactose with enzyme β-galactosidase yields glucose and galactose.

Lactose is the major carbohydrate present in all types of milk. The first record of isolation of lactose was in 1663, by Bartolettus by evaporation of whey. Milk contains only trace amounts of other sugars, including glucose, fructose, glucosamine, galactosamine, neuraminic acid, and neutral and acidic oligosaccharides.

Lactose plays a significant role in milk and milk products that are

• It plays a major role in the production of fermented dairy products.

• It contributes to the nutritive value of milk and milk products

• It affects the texture of certain concentrated and frozen products;

• It is involved in heat-induced changes in the color and flavor of highly heated milk products.

Status of Lactose

Lactose content varies extensively in the milk of different species. Breed of animal, individuality factors, udder infection, and especially the stage of lactation regulates the lactose content in milk. The lactose concentration in milk decreases gradually and significantly during lactation; this behavior contrasts with the lactational trends for lipids and proteins, which, after a decrease during early lactation, increase significantly during the second half of lactation. Lactose synthesis is hampered during mastitis. Lactose, along with sodium, potassium, and chloride ions, plays the principal role in controlling the osmotic pressure of the mammary system. Thus, any change in lactose content is compensated by a change in the soluble salt constituents. The osmotic relationship between lactose and soluble salts during the secretion of milk partly explains the presence of high lactose in milk with a reduced ash content and vice versa (Table 1).

Types of Enazymes in milk

1. Endogenous and 2. Exogenous.

Three sources of enzyme in milk:

1. The blood via defective mammary cells.

2. Secretory cell cytoplasm. Some of which are occasionally entrapped with fat globules by the encircling MFGM.

3. The outer layer of MFGM is probably the principal source of endogenous enzymes in milk. The outer layer of MFGM is derived from the apical membrane of the secretory cell which in turn originates from the Golgi membrane and acts as the principal source of enzyme in milk.

General Characteristics of Milk Enzymes

1. Deteriorative character e.g. lipase (commercially most important enzyme in milk), proteinase, acid phosphatase, xanthine oxidase.

2. Preservative enzymes. e.g. superoxide dismutase, sulfhydryl oxidase.

3. As an indicator of the thermal treatment history of milk. Related enzymes are alkaline phosphatase, ϒ glutamyl transpeptidase, and lactoperoxidase.

4. Mastitis infection indicator. Related enzymes are catalase, n-Acetyl-β D-glucosaminidase, and acid phosphatase.

5. Antimicrobial activity.

6. Commercial source of ribonuclease and lactoperoxidase

Common Milk Enzymes and their Role in Dairy Industry

Abstract

Vitamin D or “sunshine vitamin” is an essential fat soluble vitamin required for healthy bones. It is responsible for enhancing intestinal absorption of calcium and phosphate. Its deficiency leads to osteoporosis and osteomalacia in adults and rickets and other bone deformities in children. Vitamin D deficiency is being reported to be quite common these days due to modernization accompanied with changes in lifestyle and environmental pollution which limit sun exposure for several individuals. Inadequate sun exposure results in reduced vitamin D synthesis and ultimately poor vitamin D status necessitating compensation through dietary intake. Dietary vitamin D intake is very low in India because of low consumption of vitamin D rich foods, absence of fortification and little use of supplements. It is becoming a major public health problem, needing immediate attention. Fortification of milk and milk products is the safe and effective approach to deal with widespread vitamin D deficiency as milk is consumed and liked equally by all age groups. This paper highlights the importance, sources, recommended allowances and other relevant issues related to vitamin D fortification and its health effects.

The first use of milk in a solid chocolate product is commonly attributed to Daniel Peter in 1875. Milk chocolate is the most popular type of chocolate, and milk ingredients are critical in delivering the highly desired properties and taste profile to consumers. Milk ingredients also have a significant effect on chocolate processing.

Milk is one of the most complex raw materials used by the food industry. A typical bovine whole milk has a solids content of about 13.5%, comprising about 3.4% protein, 4.6% fat, 4.7% lactose and 0.7% minerals.

Milk proteins can be classified as either caseins or whey proteins - typically found in milk

Introduction

There are manypeople all over the world who have a certain level of sensitivity or intolerance towards milk and milk products. The reactions to milk which involve the immune systemare termed as milkallergy, whereas, difficulty in the digestion of the milk and milk products is known as milk intolerance. Milk intolerance occurs due to malabsorption of milk sugar (lactose) in intestine, a condition in which lactose is not digested into its monomers (galactose and glucose) due to lower activity or insufficiency of lactase enzyme. Inability to digest lactose, which is a disaccharide present only in milk, is specifically known as lactose intolerance. However, hypersensitivity involves the adverse immune reaction(allergic reaction) inthe body causeddue to the ingestion of milk proteins. Milk and milk products are major source of basic as well as essential nutrients and cannot be skipped from the diet of the individual. It is a rich source of calcium,which is essential for the growth and reformationof bones. The decline in calcium may lead to thin, fragile bones that break easily, a condition called osteomalacia or osteoporosis in women. Thus, it is a matter of concern for both children andadults whoare allergic or intolerant towards milk and milk products and not getting enough calcium and other nutrients in diet. This chapter would provide more insight about milk intolerance and milk allergy/hypersensitivity and how to deal with it.

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.

Introduction

The milling machine is one of the maximum flexible conventional system equipment with a huge variety of steel-reducing capabilities. Many complex operations along with indexing, multi-milling and saddle milling, etc. may be completed on a milling system. A milling device is a tool that cuts steel at the same time as the workpiece is fed closer to a rotating multi-element milling cutter. This machine can also contain one or greater knives at a time. That is why a milling device has extensive utility in production work. It’s better for other machines when it comes to precision and a better surface finish. It is also designed to perform a variety of jobs in the tool room.

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.

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.

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

Materials and reagents

Material : Fresh cauliflower, glass jars, polythene pouches

Reagents: 15% sodium chloride

1. Introduction

Antheraea assamensis is lepidopteron insects of Assam which is commercially utilized for the heritage golden silk “muga”. Rearing of muga silkworm is one of the most significant traditional handloom industries restricted only to the North Eastern Region of India (N.E. India) and plays a major role in the rural economy.  Considering the ecological conditions, food plant distribution, presence of eco-types and species of diverse nature in co-existence, it is speculated that this region is a possible home of origin of Antharaea, from where radiations would have occurred (Neog et. al., 2010). Despite the fact that N.E. India is the original home of muga, earlier studies have shown that the population is declining due to depletion in genetic variability (www.cdfd.org.in/wildsilkbase/info_moths.php).

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).