eChapters

Introduction

A sheet metal shop is a kind of workshop where different types of materials are used to make sheet metal and then it is flattened into thin sheets of desired shape and size. Sheet metals are used for the production of automobile bodies, utensils, almirah and cabinet appliances, etc.Sheet metal parts have many advantages, like they are less expensive, lighter in weight and can be modified into versatile shapes. Low-carbon steel is commonly used. The use of casting and machining is being replaced by metal stamping. The stamping press is a kind of machine tool in which most of the operations occur, and the sheet metal products which are obtained by the machine are called stampings.

Study of Carpentry Hand Tool

Introduction

The process of making the wooden components is called carpentry. Carpentry deals with the mechanical work of making wood components such as making beds, roofs, wardrobes, tables, cases, utensils, floors, etc. It manages the structure work, furniture, cabinet making and so on joinery, i.e., preparation of joints is one of the significant activities in all wood works.

The products produced are used in making furniture, musical instruments, and building constructions like doors, windows, desks, chairs, cupboards, etc., of a place utilizing a specific kind of wood with the help of tools known as carpentry tools. Different wooden pieces are connected to make a useful product. Wood is used to make furniture, boxes, doors, windows, industrial floors, stairs, pencils etc.

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. 

1. Introduction

Heat transfer from a hot surface is a general method or technique of heating liquids and slurry type of food materials. In such cases the heat can be generated either directly by a heating element or indirectly from a hot medium like steam or hot water via a heat exchanger (e.g. shell and tube, plate). Therefore, for the heat transfer during heating by these techniques a temperature gradient will be required, which usually causes the fouling on the surface of the heating element or heat exchanger. Afterwards the fouling not only reduces the heat transfer rate but also results in quality deterioration within the product which is being processed. 

1. Introduction

Thermal processing used extensively in the food industry for preservation and shelf life extension of the products (Arnoldi 2001). Heat treatments remain most important in food processing unit operations, not only to achieve desirable changes in eating quality but also for preservative effect by inactivation of microorganisms, destruction of enzymes and insects.Heat is applied in various unit operations through adifferent mode of heat transfer such as conduction, convection, and radiations. 

1. Introduction

Extrusion of foods is an emerging technology for the food industries to process and market a large number of products of varying size, shape, texture and taste. Extrusion cooking of cereals is becoming more adaptive due to its various advantages over the traditional food processing techniques (White, 1994). Nowadays the extrusion of food is of major importance in the food-processing sector and it is the only process, which covers a wide range of food products such as ready to eat (RTE) breakfast cereals, snack foods, baby foods etc. Elaborate scientific research, technological development and engineering design, which have been done in this field so far, have led to large-scale industrial production. 

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.

22.1 Introduction

Rhubarb is a less popular winter vegetable grown in India and originated from colder parts of Asia. It is cultivated for its large, thick leaf stalks or petioles which are used for sauces and pies. The plant is a herbaceous cool season perennial with large fleshy underground rhizome having a fibrous root system. It is sufficiently rich in vitamin C and contains traces of vitamins A and B₂. It is grown in cooler climatic conditions and is resistant to cold and dry conditions. It is propagated by divisions of crown. Rhubarb is a native of the cooler areas of Asia, probably Siberia but it is grown in Europe and England for its large, thick leafstalks or petioles which are used for sauces. 

21.1 Introduction

Globe artichoke, commonly known as artichoke, is a perennial crop grown for its flower buds. It has thistle like plants. The above ground portion dies each year during winter and again emerges in spring. It is generally propagated by means of suckers or off shoots from the old root stocks and also by dividing the old crown into pieces with a portion of the stem. The buds are harvested before they become loose and fibrous. It is very nutritious as it contains appreciable quantities of proteins, carbohydrates and minerals. It is a herbaceous perennial in which the globular immature flower heads or buds and the edible bracts are used as vegetable. 

20.1 Introduction

Asparagus is a herbaceous perennial plant with an erect branched stem growing to 1-3 m height and is grown in large areas in countries like USA, Germany, Spain and France, while India’s contribution is meagre. The tender shoots called ‘spears’ are used as vegetable and in preparation of soup. It is also eaten as salad. The canned and frozen spears are also used as processed foods. Once asparagus starts producing, it continues to give economic yield for 10-15 years. The tender shoots contain a white crystalline substance, asparagine, which is used in medicine as diuretic in cardiac dropsy and chronic gout. It has good potential as fresh vegetable.

19.1 Introduction

Traditionally spinach or vilayati palak is classified as a pot herb. The word ‘spinach’ has been derived from a Spanish word Hispania. However, the Latin meaning of ‘spina’ is spiny fruit and oleracea means herbaceous garden herb. The edible part of spinach is a compact rosette of leaves which is normally consumed as a cooked vegetable. Sometimes, it is also used as salad along with lettuce and other vegetables. Spinach is highly suitable for hydroponics. 

18.1 Introduction

It is a rich source of vitamin A as compared to spinach and carrot. It also contains high quantity of ascorbic acid, manganese and iron. A 100 g of leaves supplies as much essential amino acids as 100 g of any non-vegetarian food like meat and fish. Its succulent leaves and stems make nutritious dish after cooking. The herbaceous annual plants are mildly laxative besides other medicinal values. This is annual for leaf production and biennial for seed production. 

17.1 Introduction

Lettuce is one of the most important vegetable crops in temperate countries. However, it occupies an important position for its cultivation in tropical and subtropical countries also. In the world, the largest consumer and producer is USA. Lettuce is also grown on large areas in South Eastern Australia, Japan, China, Israel, Northern Mexico, Chile, Argentina, Brazil and Peru. Probable ancestor of lettuce is Lactuca serriola L. The crop was spread throughout the 

16.1 Introduction

The broad bean is a hardy plant and can withstand sufficiently cold temperatures. It is cultivated on a small scale in India but widely cultivated in Latin America. This is the only bean which is sown in autumn and is grown as a winter crop (in temperate countries). Broad bean is used as green, shelled and dry beans and as a feed for livestock. Plants have distinguishing features like square and erect growing stems which grow up to 30 cm (dwarf cultivars) to 100 cm (tall cultivars). 

15.1 Introduction

It is an important vegetable grown since long and used as fresh vegetable. It is an important legume vegetable rich in proteins. The crop is usually grown for its green pods which contains immature seed and are cooked as vegetable, alone or mixed with others. It prefers cool weather and it does not grow well during intense heat of the summer season, especially the wrinkled seeded cultivars which are tender, sweet and of much better quality than the smooth cultivars. 

14.1 Introduction

Turnip is quick growing root vegetable. It is a herbaceous biennial for seed production and an annual for use as a vegetable. Both roots and leaves are edible in turnip. Turnip produces napiform types of roots. Turnip is a popular root vegetable of North India grown during winter months. In young stage, it can be cooked but when it is mature, it may become fibrous and hard. It can be eaten raw but, for making palatable pickles, only desi types are the best. European cultivars of turnip are sweeter than Indian ones. The turnip greens are rich in vitamin A and C and contain appreciable amount of vitamin B, and also good source of Ca, P and Fe. 

13.1 Introduction

Beet root or garden beet or table beet is an important home and market garden crop of India grown during winter season for its fleshy enlarged roots. It can be eaten raw as salad, and cooked with other vegetables. Beet root is rich in minerals and vitamin C. The garden beet, sugar beet, swiss chard, mangel and palak, all belong to the same genus and species Beta vulgaris. Beet root (Chukandar) is not so popular vegetable crop in India. Its root contains high percentage of sugar.

12.1 Introduction

Carrot is valued as a nutritive food mainly because of high carotene content. The edible part of carrot is modified root (conical form, i.e., enlarged fleshy taproot). Although carrot is a biennial crop but it is grown as an annual for its root. Black carrots (Asiatic carrot root) are used for the preparation of a soft beverage called Kanji, which is supposed to be a good appetizer. Red type is good for preparing various types of sweets especially Gajar Halwa in northern India. Carrot seed oil is used for flavouring liquors and commercially used in France. The taste of carrot is due to the presence of glutamic acid. In carrot roots sucrose is the most abundant than glucose and fructose. Maximum concentration of carotene is found 85-100 days after planting. Carrot seeds contain germination inhibitor named as carrotal. 

11.1 Introduction

The word Raphanus has been originated from Greek, meaning quick appearing, refers to its very rapid germination and growth characteristics. It is grown chiefly for its succulent and fleshy edible taproot eaten raw as salad or cooked. The leafy tops are very rich in vitamins A, B and C, and minerals particularly calcium and iron. Major sugar present in radish is glucose. It is a short duration crop and highly productive, so preferred as intercrop or in relay and sequential cropping. 

10.1 Introduction

Leek is a non-bulb forming tetraploid plant of onion family. It belongs to monocotyledons group like onion and garlic, and has white narrow bulbs with broad leaves and etiolated pseudostem formed by the leaf sheaths. Except large size it looks like green onion. Its cultivation is not commercial in India and grown only in kitchen garden. Recently, its cultivation has been noticed in temperate regions of north India and the Niligiri hills of South India. Leek is cultivated for blanched stems and leaves. It is a hardy biennial plant, consumed as salad and used in flavouring the soups. It has flattened leaf blades rather than the radial, and it is bigger than onion. As compared to onion, it has milder and more delicate flavour. 

9.1 Introduction

Garlic (Allium sativum L.) is one of the important bulb crops grown and used as a spice or condiment throughout India. It is derived from two words gar meaning spear and lic meaning herb. It is also important foreign exchange earner for the country. Garlic has higher nutritive value than other bulb crops. It is rich in proteins, phosphorous, potassium, calcium, magnesium and carbohydrates. Healthy garlic bulbs contain allicin, a colourless, odourless and water-soluble amino acid. On crushing the garlic bulbs, the enzyme allinase breaks down into allin to produce allicin of which the principal ingredient is odoriferous diallyl disulfide. Garlic contains about 0.1% volatile oil. 

6.1 Introduction

It is an important vegetable in European countries. It got its name from the capital city of Belgium since it has been grown around Brussels for hundreds of years. From Belgium it has been introduced to England (1810). Some parts of Long Island in New York are also well known for Brussels Sprout production. In India, it is widely grown in Kodai kanal and Nilgiris hills of Tamil Nadu and Maharashtra. Exact statistics regarding area, production and productivity are not available. It is a cool, moisture loving and frost resistant biennial, with axillary buds produced in the leaf axils during the first year of growth and a seed head is produced in the second year of growth. Edible part is swollen axillary bud (sprouts or buttons or mini cabbage). 

8.1 Introduction

Common onion, Allium cepa L., is a vegetable that is the most widely cultivated species of the genus Allium. It has been cultivated for more than 5000 years. However, its wild species do not exist. Allium is a Greek word. Onion is native of Central Asia. According to Vavilov onion originated in Pakistan, however, others opined it to have domesticated in the mountainous regions of Central Asia comprising Turkmenistan, Uzbekistan, Tajikistan, Afghanistan, Pakistan and north Iran. Jones and Mann proposed the area comprising Pakistan and Iran or South East Asia as the centre of origin. Onion is very important in cookery. 

7.1 Introduction

Chinese cabbage appears to be native of China. It is known to have arisen from a cross between Pak choi (Brassica rapa var. chinensis, non-heading Chinese cabbage) from south China and turnip (Brassica rapa var. rapifera) from north China when they were grown together in the city of Young-chou. Artificial crosses between these species have proved this hypothesis. Its chromosome number 2n=20 distinguishes it from cole crops. It is not a member of cole group but regarded as very closely allied crop due to similarity in breeding systems, cultivation practices, season of growing and other features besides being like a member of Brassica vegetables. In general Pe-tsai cabbage, i.e., heading type (B. rapa subsp. pekinensis or B. pekinensis) and pak-choi cabbage, i.e., leafy type (B. rapa subsp. 

5.1 Introduction

Sprouting broccoli is believed to be the first to be originated from wild cabbage (Brassica oleracea var. sylvestris) or wild cliff cabbage which is found growing wild in southern Europe and along the eastern Mediterranean Sea. It is also known by several other names such as Calabrese or Italian Green because it was cultivated first in Italy by the ancient Romans and spread to other countries only from sixteenth century onwards. In India, it was introduced during the second half of the 20th century. The word broccoli is derived from the Latin word Brachium meaning an arm or branch. Broccoli contains higher amount of protein, vitamin A and C and appreciable quantities of thiamine, riboflavin, niacin, calcium and iron. 

Common Name: Ganth gobhi or kadam

4.1 Introduction

Knol khol or kohlrabi is not very widely grown in our country except in Kashmir, West Bengal and some of the South Indian states. Kohlrabi is a herbaceous biennial grown for its edible stem. The edible part in kohlrabi is the tuber formed by the thickening of stem tissue above the cotyledons, i.e., swollen stem called knob or tuber. 

3.1 Introduction

Cauliflower is a cruciferous vegetable that is naturally high in fibre and B-vitamins. It is said that the cauliflower has originated around the Mediterranean Sea. Ancestor of cauliflower is Brassica cretica which has been descended from the wild cliff cabbage, Brassica oleracea var. sylvestris, a native of coastal region of Europe and Africa. Cauliflower is cultivated worldwide in different climatic conditions ranging from temperate to tropics during most of the cropping seasons and is available round the year. Curd is the economic part of cauliflower and is an intermediate stage between vegetative and reproductive stage. It was introduced in India during the Mughal period. In 1822 a botanist Dr Jemson, In-charge of Company Bagh, Saharanpur, U.P introduced it in India from Kew Garden London. 

2.1 Introduction

Cabbage is consumed in the raw state as well as in cooked. The word cabbage has been derived from the French word Cobache, meaning head which is best described as single large terminal bud comprised of tightly overlapped numerous leaves attached to an unbranched short stem. It is known for its rich source of vitamin A and C. It is an effective curative against scurvy disease. Cabbage leaves are low in calories (24 %), fat (0.2 %) and carbohydrates (5.4 %). It is a good source of protein (1.3 %). Cabbage is an excellent source of minerals such as calcium, iron, magnesium, sodium, potassium and phosphorus. It contains good amount of ascorbic acid. Cabbage is used mainly as a vegetable and nice pickle (sauerkraut) is prepared from it. It is also used as salads. Cabbage is well known for its medicinal properties. 

1.1 Introduction

Horticulture is defined as “The science and art of growing vegetables, fruits, flowers, ornamental plants and landscaping of gardens and surroundings in small and commercial gardens”. The Latin word “horticulture” comprises two parts: “hortus” (which means “garden”) and “cultura” (which means “cultivation”). In other words, horticulture is the nurturing of gardens. Pomology, olericulture, floriculture, and landscaping are the main aspects of horticulture. Horticulture is becoming more and more important since it produces greater output per unit of land and provides humans with nourishing food, improving their quality of life and enhancing the visual beauty of nature. Regarding the worth of the goods, one of the main branches of horticulture is vegetable growing.

Technically speaking, every component of a vegetable is edible. However, the phrase is typically used to refer to edible plants that include reserves of food in the form of roots, tubers, bulbs, stems, petioles, leaves, buds, flowers, fruits, and seeds that can be consumed either cooked or raw. Growing vegetables is crucial not only for supplying food that is protective but also for serving as a substantial auxiliary food that contributes more significantly to food consumption. They are vital parts of a balanced diet since they are nutrient-rich.

Plant breeding or crop plant improvement is one of the oldest accomplishments of man. It began when he domesticated plants by growing them under controlled conditions and selecting those types that suited to his food requirements, about 10,000 years ago. As settlements improved, men could find time to innovate agricultural practices and to have better selections. Thus, domestication of plants and animals marked one of the most important phases in man’s progress from a nomadic and highly individualistic life to the organized and cooperative society. All our food crops as we know them now are the direct results of this primitive agriculture. This early phase of plant breeding was haphazard and slow based on selection of desirable types from the availability variability and it largely remained an art and not a science until Mendel’s laws were rediscovered in 1900 and applied to plant breeding at the beginning of 19^th century. 

Plant abiotic stresses are external and nonliving factors that have harmful effects on plants. A non-living factor must exert influence on the normal range of environmental variation to adversely and significantly affect the plant performance or the physiology of the organism. Abiotic stresses are the most harmful factors affecting the growth and productivity of crops worldwide, resulting in a yield reduction ranging from 10% to 100%. They are most harmful when occurring together with other abiotic stresses and their effect in yield will only worsen with the climatic changes experienced now and expected to be more severe in the future.