eChapters

1. Introduction

Membranes separation processes have gained widespread applications in food industry. High selectivity of membrane has been exploited for separating a particular component from complex liquid food mixture and for controlled release of active ingredients like preservatives or flavor compounds. Today, a number of chemical processes utilizing the unique properties of membrane have been developed for commercial application in food industry with specific advantage of low energy requirement. Membrane separation/molecular sieving is one among those food engineering principals which has found broad range of applications including concentration of heat labile compounds, recovery of solvent, downstream processing, flavor volatile recovery, deacidification, desalination, waste water treatment etc

1. Introduction

Foods available in nature and, in some cases, the products made from it thereof contain quite an amount of water. This water not only adds volume to the food products but also provides a sight for attack by the micro organisms. Also, removal of water becomes essential if this water interferes with the end product chracteristics. There are several processes in food industries which are designed to get rid of this excess water, such processes are called concentration processes. The processes which can remove water from food substances are,- evaporation, freeze concentration and membrane based processes. All these process have their limitations in rendering solid content to the final product (Fig. 1). Perhaps, these limitations can be overcome by combinig the processes.

The objectives that are fulfilled by the concentration processes can be enumerated as follows:

1. Introduction

To maintain good quality of product & shelf life, it is very important & essential to concentrate on Cleaning & Sanitization process at plant level & to follow the CIP process properly. An attempt is made in the current chapter to present details pertaining to cleaning in fluid milk and milk products manufacturing & processing plants. This chapter will be helpful the students of Food & Dairy Technology for better understanding the process milk plant cleaning & sanitation technology.

1. Introduction

Milk is a source of abundant nutrition has been a vital part of human civilization since prehistoric times. However, because of its perishable nature, it requires immediate processing to improve the shelf life and safe consumption .With the advancement of processing techniques in dairy and food processing, there is a widespread option being utilized to improve the milk shelf life byeither thermal technologies (pasteurization, sterilization, and ultra-high temperature) or nonthermal technologies (high pressure processing, high pressure homogenization, pulse electric field and ultra sonication). Still, pasteurization and sterilization are the two foremost process is used for milk industries. Pasteurization is the thermal inactivation of microorganisms at temperatures below100°C that enhance the safety and quality of milk and milk products and extends the shelf life to an extent. 

1. Introduction

Freezing is a method of food preservation that involves lowering the temperature below the freezing point of food generally -18 °C or below. During freezing of food the water present in them changes its state to form ice crystals. Human beings in the colder regions have used freezing as a means of preservation since they learnt hunting and gathering foods. The foundation of the modern frozen industry was laid in mid 1920 when Clarence Frank Birdseye, an American inventor used cold brine solution to chill packaged fish and extended it further for quick freezing of meat poultry fruit and vegetables. 

1. Introduction

Mixing is a fundamental and widely practiced operation in many fields, such as chemical, pharmaceutical, and food processing industries. The mixture’s primary aim is to increase the homogeneity of the material in bulk (Uhl and Gray, 1986; Patterson et al., 2004). Mixing means the random distribution of two or more ingredients throughout a system, which differs from the term’ agitation,’ which is defined as establishing a particular flow pattern with the liquid, especially in a circulatory motion within a container. Mixing is a necessary step in the context of food processing operations. 

1. Introduction

Raw milk is an emulsion. It is a mixture of milkfat globules, Solid Not Fat (SNF) and water. Over time, milkfat globule separate out from milk serum and comes to the surface of milk as a layer of cream due to the low density of milkfat or due to heating of milk. When milk is heated rapidly and continuously, some of the water in it evaporates from the surface. This exposes proteins and fat molecules, which bind and dry out and forms a skin like film on the surface. 

1. Introduction

Size reduction is applied to all the ways in which particles of the solids are cut or broken into smaller pieces. Size reduction operation of solids is referred to as 'Comminution", some of the common comminutive processes are - crushing, grinding, milling, mincing, and dicing. Breaking down of large sized particles of food substances into smaller particles is a common unit operation in many food processes, e.g. wheat flour, turmeric powder, spices, etc. are mostly used in powdered form. Some ofthe common objectives that are fulfilled by size reduction are:

1. Introduction

Cleaning and grading are the first and vital post harvest operations undertaken to remove foreign and undesirable materials such as crop seed, chaff, mud, stones, straws, immature grains, dust, husk and even iron and steel particles from grains as well as fruits and vegetables and to separate the products into various fractions. Generally, the hand threshing and the traditional handling used in most developing countries cause a larger percentage of foreign matter with these crops. Thus, more cleaning is required. Cleaning is essentially a separation process, in which some difference in physical properties of the contaminants and the food units is exploited. 

1. Introduction

Refrigeration may be defined as the process of achieving and maintaining a temperature below that of the surroundings. The aim being to cool some product or space to the required temperature. Refrigerated system or a room system is maintained at a temperature which is lower than the atmospheric temperature. Due to higher temperature of atmosphere, heat enters the system. To keep the temperature of the system constant, heat must be removed continuously from the system. Heat removed must be equal to the heat transferred to the system. One of the most important applications of refrigeration has been the preservation of perishable food products by storing them at low temperatures. Refrigeration systems are also used extensively for providing thermal comfort to human beings by means of air conditioning.

1. Introduction

Thermodynamics is science of energy and may be defined as “The branch of science which deals with the Interoction between the heat and work is referred as Thermodynamics

’Thermo’ means heat and ’dynamics’ means motion. It deals with energy interaction when work is converted into heat energy or vice versa. Precisely, thermodynamics may be defined as a science which deals with energy transformation from one form to another and dealing with relationship among the properties ofthe system. In power plants, internal combustion engines, boilers, nozzles, diffusers etc. are the example where heat is converted into work. In compressor, turbine, cooling of engines by water, application of brakes in a vehicle etc. are the examples where work is converted into heat.

1. Introduction

Psyohrometrio is the study thermal and physical properties of gas-vapour mixtures. Ambient air is the mixture of dry air and water vapour and some pollutants. The moisture and pollutant content vary from place to place. The amount of pollutant and water vapour decrease with increase in the altitude. The air is completely dry above 10 km altitude. In many unit operations moist air is required and properties of air changes with temperature and pressure. The pollutants has to be removed before using moist air as a process air either by filtration or circulation. So it is necessary to determine the amount of water present in the air and effect of different unit operation on thermal properties and change in the heat and moisture content of mixture.The International Joint Committee of psychrometric data have fixed the composition of dry by mole fraction as: Oxygen: 0.2095, Nitrogen: 0.7803, Argon: 0.0093, Carbon dioxide: 0.0003. The following are the properties of the dry air

Molecular weight    28.966

1. Introduction

Thermal energy is transferred in the form heat from one body to another through conduction, convection and radiation or in combination of these modes. Some of the examples of heat transfer that occur during various agricultural processing is drying and dehydration, sterilization, pasteurization, evaporation, distillation, to name a few.

The basic equation of conservation of heat can be written as:

Rate of heat in + rate of heat generation= rate of heat out+ rate of accumulation of heat

1. Introduction

Movement of fluids from one location to another is an important unit operation in food processing. Various types of systems are used to convey fluids based on their flow behaviour. Understanding fluid flow behaviour is therefore important for designing of fluid flow systems. The fundamental mechanism involved in fluid flow is the momentum transfer occurring in moving fluids during various unit operations (fluid flow, aeration, drying, fluidization, filtration, centrifugation, sedimentation, mixing, etc.). This chapter deals with the basic concepts of fluid flow, viscosity, pressure measurement, conservation of mass and energy, boundary layer, momentum and velocity profile of fluid flowing in a pipe, flow metering devices, and pumps.

1. Introduction

Packaging is the integral part and cornerstone of food processing industry. The development of food processing industry goes hand in hand with advancement of packaging technology. Packaging Institute International has defined packaging as “enclosure of products, items or packages in a wrapped pouch, bag, box, cup, tray, can, tube, bottle or other container form to perform one or more of the following functions: containment, protection, preservation, communication, utility and performance”. Lockhart has defined packaging as “a socio-scientific discipline that operates in society to ensure the delivery of goods to the ultimate consumer of those goods in the best condition intended for their use”. Food packaging technology has came a long way from use of anything in hand for wrapping up a product to becoming a key element in product development and design.

1. Introduction

In recent years, consumers have been demanding convenient, healthy and safe foods which have ’fresh-like’ characteristics with a long shelf-life. These demands include important food quality such as appearance, texture, taste and nutritional content which are strongly impacted by the way it is processed. Another major concern among the consumers is food safety and quality. The shelf-life of the food products are mostly influenced due to the action of various harmful microorganisms and enzymes. The conventional food processing technologies, such as thermal treatments (pasteurisation and high temperature sterilisation), evaporation, drying, frying and baking can assure the microbiological safety and/or stability of processed food products, but affects the food quality and nutrients (heat sensitive vitamins, flavour and other bioactive compounds) (Zhang et al., 2019)

1. Introduction

Drying is a thermo physical and physicochemical process, which involves removal of excess water from a solid, semi-solid or liquid food material by evaporating it into vapour phase on applying heat, to reduce growth of microorganism or to completely eliminate their growth. Hence, reducing the water activity increases shelf life of food products. Drying medium for carrying evaporated moisture can be air or steam. Benefits of drying include increase in shelf life, easy to transport, handle food material and reduce packaging cost as it reduces bulk weight. 

1. Introduction

Energy balance means keeping an account of how the flow of energy is taking place in and out of any system or process. It helps the engineers to estimate the total energy requirement and identify the area for conservation of energy in any process. In food processing the concept of energy balance is applicable in unit operation such as blanching, drying, evaporation, freezing, refrigeration, distillation, crystallization. The scopes of energy balance in food industry are:

i) Streamlining and reduction of energy consumption in the existing process.

ii) Selection and sizing of any equipment and process.

iii) Economic analysis of alternate process/technology.

iv) Designing new economically viable process/technology

1. Introduction

Law of conservation of mass says that material cannot be created nor destroyed, which is the basic fundamentals of physical science. Many engineering analyses involve material balances. These balances are simply accounting processes that account for all material in processes of interest. The material balance is one of the most useful tools fundamental in the “engineering approach” to design new process. The law of conservation of mass tells that the total mass of all material entering any process must equal the total mass of materials leaving plus the mass of any material accumulated in the process.

1. Proteins in solution absorb ultraviolet light with absorbance maxima at 280 and 200 nm. Amino acids with aromatic rings are the primary reason for the absorbance peak at 280 nm. Peptide bonds are primarily responsible for the peak at 200 nm.
2. Aromatic amino acids tyrosine and tryptophan give proteins their characteristic ultraviolet (UV) absorption at 280 nm, which is routinely used to estimate protein concentration. Phenylalanine and disulfide bonds also contribute to absorption at 280 nm, albeit slightly.

Safe Food means

• It is not injurious to health
• It does not contain any filthy, rotten, decomposed or diseased animal
• substance or vegetable substance
• It is produced undermost hygienic conditions to produce/manufacture it, inferior or cheaper ingredients/raw materials are not used
• Food additives/processing aids used are permitted and are within prescribed limits.
• It is not misbranded

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.

1. Natural Mineral Water- Food Safety & Standard Regulations - 2011 and IS 13428:2005 Reaff. 2009 requirements
2. Packaged Drinking Water other than Natural Mineral Water- Food Safety & Standard Regulations - 2011 and IS 14543:2004 Reaff. 2009 requirements
3. Water for processed Food Industry- IS 4251 : 1967 Reaff. 1992 requirements
4. Drinking water- IS 10500 : 2012

Food adulteration means anything adding or subtracting with food making it injurious to health. This adulteration may be done intentionally or unintentionally. Intentional adulteration is a criminal act and punishable offense. Or the process of lowering the nutritive value of food either by removing a vital component or by adding substances of inferior quality. Food Safety and Standards Act of India (FSSA) defined “adulterant” as any material which is or could be employed for making the food unsafe or sub-standard or mis-branded or containing extraneous matter”. According to Federal Food, Drug and Cosmetic Act (FFDCA), the primary food safety law administered by the Food and Drug Administration (FDA), food can be declared adulterated if:

1. a substance is added which is injurious to health
2. cheaper or inferior quality item added to food
3. any valuable constituent is extracted from main food article
4. quality of food is below the standards
5. any substance has been added to increase bulk or weight
6. to make it appear more valuable

The proximate system of analysis consists of the analytical determinations of water (moisture), ash, crude fat (ether extract), crude protein and crude fibre. Nitrogen-free extract (NFE), more or less representing sugars and starches, is calculated by difference rather than measured by analysis.

Water

1. Water constitutes about 70 percent of an adult’s body weight and water (moisture) is the predominant constituent in many foods.
2. All foods contain varying amounts of water in the range of 20 to 90%.
3. The hypothalamus is a brain center that controls activities such as maintenance of water balance, regulation of body temperature, and control of appetite.
4. Moisture content of some foods

1. Sample: One or more units selected from a population of units, or a portion of material selected from a larger quantity of material
2. The Standard Operating Procedures (SOPs) should contain full working instructions as well as information on applicability, expected performance, internal quality control (performance verification) requirements and calculation of results. It should also contain information on any hazards arising from the method, from standards or from reagents.
3. Analytical Samples: The quantity of the analytical sample to be used is usually indicated in tests and assays. Unless otherwise specified, the quantity used may deviate by 10% from that stated. All quantitative determinations should be conducted on triplicate test portions and in these cases, the amount actually taken should be accurately weighed or measured and the result of the analysis calculated on this exact quantity. When substances are to be “accurately weighed” in a test or assay, the weighing is to be performed in such manner as to limit the error to ± 0.1% or less. Quantities smaller than 100 mg should be weighed to the nearest 0.1 mg.

Procedure: Measurement of smoke point of given oils: Heat the given oils in a deep frying pan till fumes come out from oil. Record the temperature when the fumes come out and noted it as a ‘smoke point’. Cool the oil by keeping oil pan at room temperature. After cooling repeat the heating of same oils 2nd and 3rd time to measure the smoke point and record the observations

The RTS beverage was prepared by using freshly prepared carrot juice, sour orange juice, water and sugar as per FPO specification.

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

Pickling is the process of preserving or extending the shelf life of food by either anaerobic fermentation in brine or immersion in vinegar. The pickling procedure typically affects the food’s texture and flavor. The resulting food is called a pickle, or, to prevent ambiguity, prefaced with pickled. Foods that are pickled include vegetables, fruits, meats, fish, dairy and eggs.

Selection fresh fruits/frozen stored fruits/chilled fruits/fruit pulp/sulphited fruit. Wash them to remove the dairt, dust, stems, leaves, stalks, undesirable portions.

Drying is one of the oldest methods of preserving food. It is usually accomplished by the removal of water. Dried foods are preserved for long storage time because the available moisture is very low, so that the micro organisms cannot grow and enzyme activity is controlled. It is done by many methods. 1. Sun drying 2. Using mechanical dryers.

Formulation & method of bread making Baking is an exact science that requires precise measuring and accuracy. Accuracy is crucial in baking because most baked products are made from the same basic ingredients: flour, liquid, fat, sugar, salt etc. the difference between baked products are often the proportion of each ingredients in the formula. If the proportions are off, you will end up with a different product or an unacceptable product.

Sensitivity-Threshold tests Sensitivity tests are conducted to assess the ability of individuals to detect different tastes, odors and feel the presence of specific factors in.

Pure sugar when heated melts at about 160-1800c. at about 2100c sucrose loses water and becomes caramel.

Takes clean, washed and edible fish-50-100 g for each method of cooking. And cook the fish according to the methods given table and record the characteristics of cooked fish.

Poultry meat-50 g for each method
Cook the poultry meat according to the methods given in the table and record the cooking effects

(Ref: 1997-2016 American Meat Science Association)
The methods used for cooking meat can be divided into two groups:
1. Dry heat methods
2. Moist heat methods

In order to assess the quality characteristics of eggs the book reference values were taken for comparison

Ingredients; milk fat (cream)-12%, non-fat milk solids (skim milk powder)-11%, sugar-15%, stabilizer-0.2%, emulsifier-0.2%, flavors-a pinch Basic ice cream preparation: 1. Mix the ingredients 2. Pasteurization 3. Homogenization 4. Ageing (allowing to standby 24 hours at 4.440C) 5. Freezing (the mix is frozen at 5.5560c) 6. The freezing must be quick in order to prevent formation of large crystals. The ice cream is semi solid at this temperature. 7. The ice cream is finally frozen to a hard mass at about -30C.

Physical Properties of milk
Procedure: Collect different types of market milk samples and study the  properties of milk. Boil the milk and note down the properties given in table 1 and record the observations

Procedure: weigh vegetables 20 g (for each variation) Water: add sufficiently
1. Cook the vegetable in water in a pan according to the “cooking time” variations given in the table 1 and note down the color, texture and flavor changes takes place during cooking for each variation and record the observations

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.