eChapters

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.

———————— is a thornless and seedless selection from Kagzi lime.

A. Pramalini            B. Vikram

C. Chakradhar        D. Jai devi

The storage life of fresh lemon at 10ºC is

A. 6-10 weeks           B. 10-15 weeks

C. 12-20 weeks        D. 12-16 weeks

Where is the Central Institute for Medicinal & Aromatic Plants situated at?

A. Srinagar        B. Bengaluru

C. Anand           D. Lucknow

The products of the plants which are used as food adjuncts to add taste only is called

A. Spices                   B. Medicinal plants

C. Aromatic plants     D. Condiments

The scientific horticulture consists of the following divisions. Among them, which division has impact on environment aesthetically and functionally

A. Fruits         B. Flowers

C. Spices       D. Plantations

India ranks ___________ in area and production of vegetables in the world.

A. First           B. Second

C. Third         D. Fourth

The practice of smoking the trees to induce off-season crops in mango is

A. Smudging      B. Bending

C. Ringing         D. Notching

Organic soils contain _____ % or more of organic matter.

A. 10       B. 15

C. 20      D. 30

Plant propagation by means of seed is called ________ propagation.

A. Sexual          B. Parthenocarpy

C. Asexual        D. Apomixis

The response of a plant to the relative length of day and night is called as

A. Photosynthesis      B. Phytochrome

C. Photoperiodism     D. Photo respiration

‘Hydroponics’ technique was first developed on commercial scale as early as in 1930 by

A. De. Condole             B. J.D. Hooker

C. W.F. Greicke            D. Hugo De Vries

The United States of America (USA), European Union (EU), Brazil and China are four of the largest agricultural producers and users of agricultural pesticides in the world. Comparing the inclination and ability of different regulatory agencies to ban or eliminate pesticides that have the most potential for harm to humans and the environment can provide a glimpse into the effectiveness of each nation’s pesticide regulatory laws and oversight.

Biological control or biocontrol is a method of controlling pests such as insects, mites, weeds and plant diseases using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also involves an active human management role. It can be an important component of integrated pest management (IPM) programs.

Weeds can be defined as plants which are undesirable, persistent, damaging and interfere with growth of other crop plants thus affecting agriculture, natural resources and economy of the country. These plants influence the produce of farmers in several ways.

A number of plant substances have been considered for use as insect antifeedants or repellents, but apart from some natural mosquito repellents, little commercial success has ensued for plant substances that modify arthropod behavior. Several factors appear to limit the success of botanicals, most notably regulatory barriers and the availability of competing products that are cost-effective and relatively safe compared with their predecessors.

Many chemical and visual lures attract insects and therefore can be used as attractants to monitor or directly catch and reduce insect populations. These attractants are used in ways that do not injure other animals or humans or result in residues on foods or feeds, and can be used in an environmentally sound manner in pest management programs.

The application of insecticide to control a particular crop pest should have options of the pesticides, as some may be less effective than other due to various reasons.

Slugs and snails occasionally cause serious damage to seedlings, tender, lowgrowing leafy vegetables; or ripening fruit that are on the ground. Feeding damage, hollowed-out areas, can be found anywhere on fruit, but is usually concentrated near the stem. Slugs leave a tell tale slime trail (silvery trail) behind on the surface of fruit or leaves.

Nereistoxin (NTX) was originated from a marine annelid worm Lumbriconereis heteropoda and its analogue pesticides (table 51) including cartap, bensultap, thiocyclam and thiobensultap have been commonly used in agriculture, because of their low toxicity and high insecticidal activity.

Pyrethrum is the most widely used botanical insecticide. The active ingredient, pyrethrin, is extracted from a chrysanthemum plant, grown primarily in Kenya, Rwanda, Tanzania and Ecuador. Pyrethrum is the powdered, dried flower head of the pyrethrum daisy, Chrysanthemum cinerariaefolium.

Medicines used for controlling insect pests are known as Pesicides which have assumed great importance in today’s high yielding and intensive agricultural system as well as public health programme, all over the world. The term pesticide is an all-inclusive word meaning killer of pests and includes substances used for controlling, preventing, destroying, repelling or mitigating any pest.

Sixteen chemical elements are known to be important for a plant growth, their metabolic activities and survival. These can be divided in to two main groups

Fruit drop just before harvest is a serious problem for various crop varieties. The severity of fruit drop is influenced by several factors but plant stress and premature ethylene production is at the basis of true physiological drop. Stress factors such as late season heat, primary and secondary pest infestation, and nutrient imbalance or deficiency, and heavy summer pruning, all can contribute to drop.

The use of flower inducers stimulates flower growth during the resting year so the tree produces annually. Flower inducers can also increase the number of viable blooms during the natural fruit producing year, for an increase in production. These can also be used on varieties that provide a crop every year, to boost harvest.

Anti-transpirants are usually foliar sprays, although they may sometimes be used more conveniently as dips for immersing the above ground plant parts. Foliar sprays may reduce transpiration in three different ways

Plant growth regulators or phytohormones are organic substances produced naturally in higher plants, controlling growth or other physiological functions at a site remote from its place of production and active in minute amounts. Thimmann in1948 proposed the term Phytohormone as these hormones are synthesized in plants (Thimmann, 1963).

Proper selection of plant health medicines like fungicide, bactericide, antibiotics, algaecide, viricide, nematicide, weedicide, plant harmones and auxins and its application at the correct dose and the proper time are highly essential for the management of plant health. The basic requirement of an application method is that it delivers the chemical to the site where the active compound will prevent the pathogen/pest damaging the plant. 

Seed is a basic input to raise the crop plants. Healthy seeds produces the healthy crop. However, the seed carries different pathogens either externally or sometimes internally in the seed to affect the seed emergence and healthy seedling growth. Therefore, the seed treatment with fungicides/bactericides, based on the infection of the pathogen, is highly essential to counter the attack and infection of these pathogens to the germinating seedlings.

Protozoan parasites are Trypanosomatids of the class Kinetoplastida predominately restricted to invertebrate hosts (i.e. possess a monoxenous lifecycle). However, several genera are pathogenic to humans, animals and plants, and have an invertebrate vector that facilitates their transmission (i.e. possess a dixenous life-cycle).

The algae associated with the plants belongs to the Order Trentepohliales (Ulvophyceae, Chlorophyta). These are filamentous green algae parasitic to higher plants, generally causing minor diseases characterized by negligible leaf spots, but on certain crops, in moist environments, these algal diseases can cause economic injury to plant leaves, fruits, and stems (Nelson, 2008).

Nematodes are multicellular, unsegmented, bilaterally symmetrical roundworms belonging to pseudocoelomates class of creatures. Many of them are parasites of plants. Different crops species are susceptible to several species of plant parasitic nematodes which limits the yield and quality of the food harvest. Root-knot nematodes (Meloidogyne spp.), foliar nematodes (Aphelenchoides spp.), root-lesion nematodes (Pratylenchus spp.) reniform nematodes (Rotylenchulus spp.) and other ectoparasitic nematodes are the important nematodes species to infect the crop plants.

Plant viruses cause severe crop losses worldwide. Conventional control strategies, such as cultural methods and biocide applications have limited success at mitigating the impact of plant viruses.

It is used in the control of bacterial leaf spots, blights, and cankers mostly on fruits crops and ornamentals. The Bordeaux mixture, however, can cause burning of leaves or russeting of fruit such as apples when applied in cool, wet weather. The phytotoxicity of Bordeaux is reduced by increasing the ratio of hydrated lime to copper sulfate. Copper is the only ingredient in the Bordeaux mixture that is toxic to pathogens and, sometimes, to plants, whereas the role of lime is primarily that of a “safener.”

A same active ingredient are available in the market with different trade name and are the product of different companies. These may also differ in their formulation and hazard class (table 7), the knowledge of which is necessary in the plant disease management in view of their effect on the pathogen, ecosystem and environment.

Development of fungicide resistance in a fungal disease pathogen is a major concern for some of the important diseases in their management. This can be overcome by designing of fungicide use strategies to manage the threat of fungicide resistance.

There are several fungicidal molecules available in the market, some of which are specific for certain diseases/pathogens while others are broad spectrum and can be used against a range of diseases. However, for proper control measures a knowledge of disease specific fungicide are very important. Ready-Reckoner for disease specific fungicide (Table 4) makes available the option for selection of alternative fungicide in the management of specific disease.

Actino-IronOG (Streptomyces lydicus WYEC)

Biological soil and seed treatment for Fusarium, Rhizoctonia, Pythium, and Phytophthora with added iron.