eChapters

1. The protein is derived from Greek word “Proteins” which means
   1. Principal
   2. Prime
   3. Holding the first place
   4. All of the above
2. The name protein to the group of organic compounds that are utmost important to life is suggested by
   1. Mulder
   2. Berzelius
   3. Kulim
   4. Sanger

Introduction

Proteins are the most abundant organic compounds constituting major part of the body. Chemically, proteins are nitrogen containing macromolecules and polymers of L α-amino acids, which serve a wide range of structural and biological functions in animal body. For example, connective tissue made up of collagen, metabolicenzymes, neuro transmitters,signal in gmolecules, structural components of cell membranes and cell organelles, etc. all are chemically proteins.

Before goinginto the details of protein metabolism, first, we need to understand that there are majorly two sources of proteins in our body: dietary protein and body protein. Dietary protein is taken in diet, while body protein indicates the protein and amino acids synthesized in animal body to fulfill the requirements for growth and development. The digestion of proteins will not be discussed here as it has been described in detail in chapter 12. Dietary protein is digested in presence of several enzymes such as trypsin, pepsin, chymotrypsin, aminopeptidases and carboxypeptidases and is converted into mono-, di- and oligopeptides in stomach and small intestine; and finally converted into amino acids. These amino acids are transported to the systemthrough intestinal mucosa via active transport, from where they enter into the cells for further metabolism. Therefore, ‘metabolismof proteins’ is more appropriatelylearnt as ‘metabolism of amino acids’.

1. INTRODUCTION

Proteins are polymers of amino acids. Twenty different types of amino acids occur naturally in proteins. Proteins differ from each other according to the type, number and sequence of amino acids that make up the polypeptide backbone. Proteins are the important constituents of foods for a number of reasons. They are a major source of energy, as well as containing essential amino-acids, like lysine, tryptophan, methionine, leucine, isoleucine and valine which are essential to human health, but which the body cannot synthesize. Proteins are also the major structural components of many natural foods, often determining their overall texture, e.g., tenderness of meat or fish products. Isolated proteins are often used in foods as ingredients because of their unique functional properties, i.e., their ability to provide desirable appearance, texture or stability.

Proteins are complex organic molecules made up of carbon, hydrogen, oxygen, and nitrogen. Most proteins also contain sulphur and phosphorus and also play an important role in food preparation. The final quality of many food products are influenced by how the proteins are treated while food is being prepared.

1.    The basic building block(s) of proteins is/are

(a) Amino acids

(b) Phenolics

(c) Carboxylic acids

(d) Fatty acids

2.    Alpha helix and ?- pleated sheet are characteristic of protein structure?

(a) Primary

(b) Secondary

(c) Tertiary

(d) Quaternary

Traditionally, Labour Laws have a protective function consisting of established standards both to protect workers in their workplace and to provide them a basic minimum level of living conditions. Alongwith this function, there also existed in most systems, a legal framework for the regulation of industrial relations between employers and workers. These functions had their impact on problems of development. The emphasis was more on labour legislation for its own sake, development being a separate proposition. This mutual lack of concern was perhaps due to historical factors. The most important aspect is the fact that in developed countries of the Western world, labour legislation followed the emergence of industrialization and in response to a demand for economic and social betterment of the workers, whereas in developing countries the emergence of labour laws preceded industrial growth.

5.1 Introduction

The medium used in various unit operations of food process engineering such as heating, cooling, drying, mixing and transport processes, is moist air, which is a mixture of two substances. One of these is dry air which itself is a mixture of number of gases and the other is water vapour which may exist in a saturated or superheated state. The properties of moist air are called psychrometric properties and the subject, which involves determination of thermodynamic properties of moist air, is known as psychrometry. Thus, psychrometry is that branch of engineering science, which deals with the study of moist air i.e. dry air mixed with water vapour or humidity. Knowledge of properties of moist air is imperative in design of systems such as air- conditioning equipment for storage of fresh produce, dryers for drying of cereal grains, and cooling towers in food processing plants. In this chapter, important thermodynamic properties used in psychrometric computations are defined. Psychrometric charts useful in determining such properties are presented. In addition, various psychrometric process used in food process engineering are discussed.

Abstract

Pulse combustors provide an advantageous superposition of unsteady gas flow and high intensity sound waves. Such a combination does not only accelerate drying rates because of increased heat and mass transfer but also allows processing of liquids, pastes and agglomerated solids in a dispersed state due to aerodynamic impact from the high intensity sound wave. Over last decades, applications of pulse combustion in drying have been exploited continuously and different pulse combustion dryers have been designed and fabricated. In pilot tests and technical reports on these dryers, short drying time, high energy efficiency and product quality are generally reported, which cause that pulse combustion drying is regarded as a technology of the future in convective drying.

This chapter attempt to introduce basic knowledge and state-of the art about this emerging technology and summarizes some recent studies in pulse combustion drying and equipment design. Following a concise description of pulse combustion and pulse combustor, the basic types of pulse-combustion dryers are presented, including spray dryers, fluidized bed dryers, impinging dryers, and dryers of special design. The existing commercial applications and pilot test projects are described and potential applications are identified.

1. Clean and wash the pulses, Mix the pulses with water, soak for 1 hour, 3 hours, 6hours, 9hours and overnight.
2. After soaking drain the water wash thoroughly and add fresh water keep it for boiling/cooking.
3. Study the effect of Acid and effect of Alkali on cooking time of pulses.

Abstract

Consumers increased response to new products with high sensory, organoleptic and nutritional potentials has impelled a search for new substitutes to processing methods. For several years, thermal processing was the main technology for producing safe products with long shelf lives, although in most cases losses of fresh flavors, vitamins, and some physicochemical characteristics were the price of safety and long-term stability. Pulsed electric field (PEF) processing as a non- thermal technique has been proven to inactivate microorganisms with minimal losses of flavor and food quality, possibly making it the answer to present-day consumer demands. In addition, the low processing temperatures used in this non- thermal technology allow the process to be nutrient preserving, energy efficient, which translates into lower costs and fewer environmental impacts. In this chapter, the the configuration of various PEF equipment, their electric configuration and recent application of this technique in processing of foods have been discussed in detail.

6.1 Introduction

Consumer demand, regulatory guidelines and economic power of the consumer as well as ascertained profitability stimulated the need of novel food processing techniques. The concept of “fresh”, “natural”, or “organic” food also led to the development of environmentally sound and resource efficient food processing technologies. Thermal processes have been used for food preservation since a long time. These are not very energy efficient and can change the phase of food from fresh to cooked as well as it can alter the nutritional and sensory qualities. Thus, the quest for energy conservation by the manufacturers to reduce carbon footprint of the processes involved in food processing and preservation as well as to fulfill consumers’ requirement for fresh-like quality food have given rise to the development of innovative non-thermal food processing technologies i.e. ionizing radiation, high-intensity light pulses, high isobaric pressure, electric or oscillating magnetic fields, as well as pulsed electric fields (PEF).

Application of electric energy in food processing started in the early 1900s. In the beginning, electrical pasteurization inactivated microorganisms by increasing the temperature of samples by means of an electrical resistance (ohmic heating). Milk was the first electrically pasteurized product. In the late 1940s, electric fields were used to increase the permeability of fruits to facilitate the subsequent extraction of juices. The PEF technology as a non-thermal process is very effective for inactivation of microorganisms, increasing the pressing efficiency, enhancing the juice extraction, and for intensification of the food dehydration and drying process. The main effect of PEF technology is based on the phenomena that biological membranes are punctured under the influence of external electrical impulses. This process is often referred as non-thermal, since the structural damage to membranes is implemented at very low temperature compared to the conventional heating process. The PEF process is considered to be energy efficient because the electric energy is released in short pulses, thus total energy requirement is much lower than other continuous preservation technologies. The microbial inactivation can be achieved at ambient or moderately elevated temperatures by the application of short-bursts of high intensity electric fields to liquid foods flowing between two electrodes or to semi-solid/ solid food between some specialized electrode and treatment systems. Due to chemical/physical properties and presence of electrical charge, the liquid foods (e.g. milk or fruit juices) had different conductivity, which results in variable flux of electrical current through the food systems.

1. Introduction

Thermal processing treatments are the conventional methods that have been broadly employed in the food industry to guarantee the microbiological safety of food materials at a minimal cost. However, these thermal treatments cause undesirable changes in flavor, nutritive value, texture, or color of the finished product that impact food quality (Pan et al., 2017). Growing the modern consumer’s demand towards the minimally processed and “fresh-like” taste foods has challenged the food industry to develop novel non-thermal preservation techniques as an alternative to thermal processing. 

INTRODUCTION

Pulses are edible fruits or seeds of food bearing plants belonging to the family of the leguminosae. The major pulses which find important place in our diet are redgram dhal, bengal gram dhal, black gram dhal, green gram dhal and masoor dhal. Some are used as whole grams cow pea, rajmah and dry peas also belong to leguminous family.

Legumes not only have dietary values but also play an important role in maintaining or even improving soil fertility through their ability to fix atomospheric nitrogen.

Introduction

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

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

Q10 value: The number of times a reaction rate change with a 10oC change in temperature is called Q10 value. If reaction rate doubles with 10oC change in temperature, Q10 = 2. It is also called temperature quotient.

Q-enzyme: It is a branching enzyme responsible for formation of 1-6 bonds in amylopectin.

QHV process: It stands for Quality Has Value Process.

QO2 : It is a unit for measurement of respiration. Or It is the oxygen uptake in microlitres per milligram on dry weight per hour.

Quailing: In this practice the oranges are kept in the baskets in which they are harvested to allow the fruit to loose little moisture. It is done for a couple of hours before transport to packhouse. This practice would allow the fruit to lose a little moisture which is called quailing. This operation is done for oranges to prevent Oleocellosis.

Qualitative measurement: It is a subjective / objective measurement of the quality of the product for presence of certain compound. It gives the idea of the presence or absence of the particular compound. It deals with the nature of the substance and not its amount or quantity.

The raw material of foremost importance in bakery product is the wheat flour. Bakery units prefer the flour obtained by milling in roller flourmill with 70– 72 percent extraction. Flour quality may be defined as the ability of the flour to produce an attractive end product at competitive cost, under conditions imposed by the end product manufacturing unit. The concept of quality differs from producer and consumer point of view. However, in general, the term quality may refer to fitness of a raw material or a product for a particular process or consumer. For a consumer, the following parameters are important criteria of a product quality.

The art of confectionery manufacture date back to over 3000 years as per Egyptian records. Traditionally honey, boiled and concentrated sugar cane juices have been used in confectioneries. In modern times, alternative sweeteners from sources like corn and starches constitute an integral part of confectionery manufacture.

Owing to the huge variation in finished products as well as raw materials in food sector, Quality control has an extremely important role to play. Quality control aims at controlling variation to within a tolerable level by taking corrective actions. Statistical and non-statistical techniques are employed to measure, analyze and control variation in food products. Statistical process control, acceptance sampling and visual inspection are widely used in food and allied sectors.

Maintenance of quality and manufacture of a standard confectionery should involve a very close control of raw materials, instrumentation, and statistical analysis of finished product. Statistical evaluation with respect to finished product includes weight control, sensory evaluation and packaging tests. The quality standards are set by the quality control departments. Chemists may undertake preliminary analysis through visual inspection. Visual inspection is usually combined with sampling. This gives an idea of variation, cleanliness, infestation etc. in the sample.

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 is a product of biological origin and is a suitable vehicle to accommodate any additive without apparent changes in its look. The quality of milk and its products depends upon quality of raw milk used in their manufacture, processing and handling conditions. It is therefore, necessary to check quality of raw milk to assess its suitability for processing, through various quick tests called “Platform Tests”

Raw milk quality assessment

(A) At collection center: - Milk from various suppliers is generally collected at dairy factory or privately owned collection centers located in marked area of milk sheds. The quantum of supply may vary from 2 – 100 Liters. As each supplier has to be paid in relation to quantity and quality of his produce, it is important to draw samples and ascertain its quality by performing quick tests for the purpose of acceptance or rejection.

Sampling procedures - The sampling procedure differs according to the nature of material and the purpose for which the sample is required. The sample collected for chemical analysis should be representative of the entire batch. Thorough mixing with proper instrument is essential to ensure representative sample. Samples for chemical analysis are to be delivered the same day for testing. If un-avoided, add small amount of preservative (Formaldehyde) to prevent deterioration and bear label to the effect.

Sample from single container – The procedure involved is thorough mixing of contents. If it is small container the contents should be poured from one vessel to another with swirling. In case of can the contents should be mixed with the help of plunger which should be moved up and down and sideways for about 10-15 times. The sample is then drawn with the help of dipper from different levels and collected in clean and dry sample bottles.

India has achieved a commendable position of being the highest milk producing country in the world. Nearly 110 million tons of milk per annum is contributed by small and marginal farmers having 2-3 milch animals which are scattered in lakhs of villages across the length and breath of India. The poor socio-economic conditions are serious constraints in producing raw milk of good quality. The quality of milk is further deteriorated during subsequent handling and transportation. Milk being a product of biological origin, is extremely vulnerable to attack by microbes. It is also a good vehicle for additives and adulterants without any apparent changes in its appearance. Thus, milk is susceptible to several post-secretion changes, some natural and some man-made.

Indian dairy industry faces a mammoth task to meet the world quality standards, particularly in the present context of globalization and increasing quality conscious consumers. In view of the highly perishable nature of milk soon after it is secreted, it is important to monitor its quality by having a firmly installed quality assurance programme along the entire production-to-supply chain. This can be possible with application of sensitive, accurate and rapid methodologies as a tool in quality assurance programmes.

Quality comprises of several attributes ranging from physical, chemical, technological and bacteriological through nutritional to aesthetic. All dairy plants have a quality assurance laboratory (Fig. 8.1) and usually follow chemical quality control with the intention of payments to contractors/producers, processing of milk and meeting mandatory requirements for end products. Quality is judged both by objective and subjective tests.

We all are familiar with the word “quality”. If we bring some fruits or vegetables from the market, the other family members will reflect on their quality by making observations such as: fresh or stale, good or bad quality or inferior product, etc. These observations are perceptions of consumers based on the sensory attributes of the fruit or vegetable colour, appearance, touch, smell or taste.

The quality characteristics of food that are acceptable to consumers are comprehended under the term “Food Quality. It includes external factors such as appearance (size, shape, colour, gloss, and consistency); internal factors (chemical, physical, microbiological) and characteristics/ specifications prescribed under the Government laws/standards. If consumer’s perceptions regarding quality of food are not positive he or she either will not purchase the material or will be paying less compared to when the consumer has positive perception about the quality.

The relationship between quality, profitability and market share has been well established. In the quest of quality, the dairy business is passing through revolutionary changes and the need for such changes has been very well realized. The leaders have initiated the process of setting vision and are working hard to provide the basic infrastructure with necessary resources. This has become a point of vital importance as the nation has now captured the first rank in milk production globally and is now ready and set to march ahead in the global race for dairy products market. Our country has great potential to export the dairy products such as cheese particularly Mozzarella, Feta, and indigenous products such as ghee, khoa, chhana, paneer, and array of sweets. Food items or dairy products to be traded in the international markets should be manufactured in accordance with global accepted norms and standards. In order to improve the quality of milk and milk products the Government of India is focusing on “Clean Milk Production”. As a dairy technologists and entrepreneurs, we must ensure production of quality products.