eChapters

Introduction

Vast proportions of the population of the world are dependent on plants as their principal source of food either directly or indirectly. Recent decades have also seen increased numbers of people turning to alternative medical therapy based upon traditional folk medicine or food as a form of medicine. These alternative therapies emphasise the importance of a ‘good diet’ in maintaining and restoring health. Under these circumstances, vast majority of population may see diet therapy, dietary supplements and non-invasive alternative therapies as a safer, less technological and more natural way of maintaining health and treating and preventing individuals from illness. These alternatives may be seen as empowering the consumer and shifting the locus of control away from the medical establishment. This chapter covers many crucial topics to understand the chemistry and bioactivity of the active compounds of plant origin. It also aims to cover the latest research on the bioactive compounds.

Introduction

The tenet “Let food be thy medicine and medicine be thy food,” said by Hippocrates nearly 2,500 years ago, is receiving renewed interest. In particular, there has been an explosion of consumer interest in the health enhancing role of specific foods or physiologically active food components called as functional foods [1]. Clearly, all foods are functional, as they provide taste, aroma, or nutritive value. Within the last decade, however, the term functional as it applies to food has adopted a different meaning - that of providing an additional physiological benefit beyond that of meeting basic nutritional needs.

Tomato (Solanum lycopersicum L.) is one of the most important vegetable crops cultivated in the world. It is used as raw in salads and also used as cooked vegetable in the preparation of curries. Processed items such as tomato puree, ketchup, pickle, chutney, whole peeled tomatoes and tomato powder are also consumed considerably. It is a rich source of Vitamins A & C. Lycopene and other flavonoids in tomato serve as good source of antioxidants. Tomato occupies 5 million hectares with a productivity of 34t/ha. in the world. In India it is cultivated in an area of 0.88 million hectares with productivity of 21 t/ha.

Mango (Mangifera indica L), the king of fruits, is cultivated throughout a wide range of frost-free climates (Litz 1998). It is commercially the most important fruit crop of India, accounting for more than 54% of the total mango production worldwide. The fruit of mango (Mangifera indica L.) is exceptional for its juicy, succulent, thick fruit pulp and nutrient abundance in terms of wide range of amino acids, sugars, organic acids, minerals including Ca, P, Fe, and K and vitamins. Out of several diseases which attack mango crop, mango malformation disease is a serious threat to its cultivation since it causes gross deformation of the vegetative and floral tissues (Ploetz et al., 2002; Kumar et al., 2011). Floral malformation is a major problem in mango, rendering mango cultivation unproductive in northern India and other regions of the world (Pandey et al., 1977; Ram, 1991).

Methylene-cyclo-propyl-glycine (MCPG), is a cyclopropyl derivative, grouped into the amino acids that have been isolated from the higher plants (Fowden, 1960). MCPG was identified to be closely related to two other cyclopropyl derivatives (Fig. 1), 1-aminocyclopropane – 1 – carboxylic acid from Vacciniumvitis-idaea and perry pears (Vahatalo and Viertanen, 1957; Burroughs, 1957) and â- methylenecyclopropyl alanine (MCPA or Hypoglycin A) from Blighia sapida (Hassall and Rayle, 1955; Anderson et al., 1958; Ellington, Hassall and Plimmer, 1958).

The orchids are commercially important group of flowering plants and their flowers are affluent in uniqueness in their shape, size and colour, exquisitely attractive, remain fresh condition for long period of time in comparison to other flowers. Orchidaceae is the second largest family among floriculture; about 25000 to 35000 species of orchids have been reported over the world (Rampal and Nagrare, 2006). India accounts for nearly 7 per cent of world’s orchids genetic diversity contributed 1300 species under 184 genera (Arora, 1983; Rampal and Nagrare, 2006) and 1150 species belonging to 164 genera (Satish Kumar, 1994) of which about 800 species are found in the North Eastern region of the country (Nagaraju et al., 2006) and many more are discovered year after year because of the prevailing congenial climatic conditions, diverse terrain and altitudinal variations, which provide suitable habitat for orchids.

The word Cymbidium has been derived from a Greek word ‘Kumbos’ meaning ‘hole or cavity’ referring to the structure of the base of the lip. The genus consists of 44 known evergreen species in the family Orchidaceae, subfamily Vandoideae, tribe Cymbidieae and sub-tribe Cryptopodiinae. It is distributed from northwestern India to China, Japan, south through the Malay Archipelago to the north and east Australia. (DuPuy and Cribb, 1988). Cymbidiums have been for over hundred years one of the most famous orchids in commerce.

Mango (Mangifera indica L.) is one of the most important tropical fruits of the world and is commonly known as the ‘King of fruits’ for its high quality fruits which are very popular among the Indians (Sharma et al., 2008). It is the oldest and extensively cultivated fruit crop in India having high socio-economic significance. India is the home of more than 1000 mango varieties, which originated in the Indo-Burma region (Mukherjee, 1958). India is the largest producer of mango, grown in about 2.3 million hectares with an annual production of 15.02 million tones. However, its productivity is only 6.5 tones per ha against 30 tones per ha in Israel (Bijay Jumar, 2010). Improvement of productivity in mango continues to be the foremost issue in mango production (Sauco, 1993). Of late, all the mango importing countries are considering the India as a source of quality mangoes due to its varietal wealth and availability. Hence, it is imperative to improve the productivity and quality of Indian mangoes to meet the global need (Balamohan et al., 2014).

Spices play important roles in daily life and India is a rich repository of spices. Various biotechnological approaches like micropropagation, somaclonal variation, in vitro conservation, synseed technology, protoplast fusion, production of flavor and coloring components, and development of novel transgenics have great significance in conservation, utilization and increasing the production and productivity of spices. Protocols for micropropagation and production of disease free planting materials are available for many spices. Efficient plant regeneration protocols are also available for exploiting somaclonal variation ,where the available natural variability is relatively low. Technologies for isolation and culture of protoplasts were reported in a few spices. Development of transgenics for disease resistance is gaining momentum. Synseed and Micro-rhizome technology are also available for many spices for safe propagation, conservation, movement, and exchange of germplasm. In vitro and cryo preservation technologies for conservation of spices germplasm are available for many spices.

Centuries before Greece and Rome were discovered, sailing ships carried Indian spices, perfumes and textiles to Mesopotamia, Arabia and Egypt. It was the lure of these that brought many seafarers to the shores of India. Emperors, kings, senators and the aristocracy transformed spices into the mostly highly prized commodities of ancient trade routes The story of Indian Spices is more than 7000 years old. By the 1400s, when navigational equipment had improved to the point that long-haul sailing became possible, European rulers set out to change the balance of world trade by funding spice-hunting missions of their own. Christopher Columbus who, in searching for a quick route to India, reached the Americas. Vasco de Gama was the first to surround Africa, and with a crew led by Ferdinand Magellan, fully circumnavigated the globe.

Soybean, a source of 40 per cent good quality protein, 20 per cent oil and other nutrients has great potential in meeting nutritional requirements and extending health benefits through soy based food products to Indian population. Soy foods are nutritious, economical and good for health. Regular food use of about 10 per cent processed soybean flour with cereal flours or 25-30 g properly processed soybean per day in a diet entitles the consumer to derive maximum nutritional and health benefits at a relatively low-price. Soy food products like fullfatsoyflour, soy-based bakery products and dairy analogs (soy milk, soy paneer (tofu), curd (dahi), soyshrikhand, soy amrakhand), being the products of acceptable type to Indian population, have good scope. Different organizations have given input in R&D work on soybean processing. SPU Centre at ICAR-CIAE, Bhopal has been involved in development of number of soybased food products, technology and equipment for preparation of those. To make available the properly processed soy food products to our population, the centre is actively engaged in capacity building of upcoming entrepreneurs and entreprise development for soybean processing for food uses. Around 500 cottage scale soy food enterprises have been established in different states of the country.

Pesticides are an undeniable part of modern life, used to protect everything from flower gardens to agricultural crops from specific pests. Pesticides have contributed significantly to improving quality of life and safeguarding the environment. Some 20 to 40 percent of the world’s potential crop production is already lost annually because of the effects of weeds, pests and diseases (according to the FAO reports) (www.CropLifeAmerica.mht). In addition to increasing crop yields, crop protection products used in stored products can also prolong the viable life of products, prevent huge post-harvest losses from pests and diseases and protect food safety for eating.

The vegetables and fruits are largely consumed fresh and day by day, their market demand is increasing due to nutritious quality. However, market supply is not sufficient to meet public demand throughout the year as production is inadequate because crop production has not increased substantially in recent years due to climatic changes. Another important reason for low production is the economic losses incurred due to damages of insect pests and plant diseases.

Since ancient times, reduction in pest and disease incidence is sought by spraying of pesticides including conventional preparations such as tobacco decoction, Bordeaux mixture, neem leaf extract etc. During the green revolution years, the synthetic pesticides were greatly recommended for pest and disease control and thereby increasing crop yields many-fold. Having experienced the spectacular improvement in both yield and quality of marketable produce, farmers were solely dependent on synthetics and ultimately abandoned other control measures.

Labour is one of the biggest input costs for vegetable growers. Vegetable farming is labor intensive and time consuming. Frequently, it is associated with low yield and poor quality production. The constraints are high labor requirements for land clearing, ploughing, bed forming, mulch laying, seeding, transplanting, harvesting and transporting. Mechanization is interjection of improved tools, implements, machines and other equipments between man and materials (soil, water, environment, seed, fertilizer, pesticides, growth regulators, irrigation water, agricultural produce and by-products such as fruits, vegetables, and seeds, etc.)

Every research in agriculture aims at developing a promising new technology or refines an age old technology that can help addressing the improvement in crop yield. This is a worldwide scenario to meet up with the food needs of the growing population and reducing agricultural land resources. Many traditions in the world are associated with vast knowledge of cultivating the food crops, vegetables, fruits etc using selected methods that are modified based on the needs, climatic conditions and the resources available in the place of settlements. Soil based agriculture is the most popular method of growing plants since soil is considered as the main source of nutrients and water required for the healthy growth of crops. Generally it includes 3 major steps, ploughing, sowing and harvesting.

“Standards are to Industry as Culture is to Society” said Shri C. Rajagopalachari, the first Governor General of India. Shri C. Rajagopalachari was inaugurating a conference on Standardization and Quality Control in February 1948. The great statesman has beautifully summed up the importance of standardization.

The basic principles on which procedures and practices are based had their origin in the United Kingdom, where the first national standardization movement started as early as 1901. Thereafter, procedures have been continuously developed, modified and improved till considerable similarity is achieved.

The scientific community working in the field of crop protection is experiencing an increasing academic and industrial interest in the discovery and development of new bio-insecticides as environmentally friendly pest control tools to be integrated, in combination or rotation, with chemicals in pest management programmes. In this context, Entomopathogenic nematodes (EPNs) as a bio-control agent have proven successful and are now commercially mass produced in six of the seven continents to treat pest problem in agriculture, horticulture and forest crops. They actively search for the host, including those in cryptic habitat stages of insect pests in soil environment. They can be considered as good candidates for integrated pest management in ustainable agriculture due to plants and mammals which are not adversely affected and have ease of mass production. We present a general overview on the current state of knowledge of EPN and their mutualistically associated bacteria and their utilization as biological control agent against insect pests in world and India are briefly presented in this chapter.

Endophytic Microorganisms

Endophytes (‘endo’, inside; ‘phyte’, plant) include microorganisms that thrive inside the plant tissues without any obvious adverse effects on the host, and they include mainly bacteria and fungi (Hallmann et al., 1997; Bacon et al., 2002; Hardoim, 2015). Endophytic microorganisms share an intimate association with the host adding essential and functional capabilities. Therefore, plant may be considered as a superorganism composed of an amalgam of both selected symbiont microbiota and host cells (Hardoim, 2015) with the new concept of holobiome, i.e., plant together with the associated microorganisms collectively governing the plant activities (Hardoim et al., 2015; Vandenkoornhuys et al., 2015).

The shift from vegetative to reproductive phase in plants is the result of multiple gene cascades in response to photoperiodic and temperature dependent pathways, gibberellic acid pathway, vernalization pathway and autonomous pathway. The environmental cues are initially detected in the leaves and the mRNA of the flowering signal integrator FT gene, moving to the shoot apical meristem, acts as a long-distance signal for floral meristem identity. At SAM, FT-FD protein complex, based on signals from above said pathways in association with the signals from age-dependent and miRNA pathways, leads to the activation of master regulator gene of flowering AP1. The activation of genes involved in ABCDE model of floral organ differentiation, based on the directions of various cadastral genes lead to the development of floral organs. Thus, the sequential action of floral meristem identity genes, floral organ developmental genes, floral meristem size and organ number genes, floral organ pattern genes and cadastral genes leads to the flower development. This chapter sums up the gene interactions happening in leaf and SAM, leading to the development of a complete flower.

Today it has been understood that yeasts have great potentials as novel probiotics (Nayak, 2011). They have been found to be safe for human consumption in traditional fermented foods (Jakobsen and Narvhus 1996). Yeasts have a great physiological importance inside the gastrointestinal (GI) tract (Czerucka et al., 2007; Gatesoupe, 2007). Jespersen (2003) has mentioned the role of consuming fermented foods and the health benefits attributed with it.Yeasts are known for prevention of table olive (Arroyo lopez et al., 2012). Bonatsau et al. (2015) have shown multi-functional property of yeast as starters.

In spite of the problems with dosage and viability of probiotic strains, a lot more work is required for industry standardization and safety issues. However, it is noted that probiotics have considerable potential against many pathogenic and other diseases. A wide range of clinical trials are still needed to standardize and optimize the conditions. Ongoing basic research will continue to identify and characterize existing strains of probiotics, identifying strain-specific outcomes, determine optimal doses needed for certain results and assess their stability through processing and digestion.

What new research is needed, what trials and how will the ultimate consumer and Industry benefit?
 
In Brazil, the sales of functional foods amounts to US $ 500 million per year representing about 1% of the total sale of the Brazilian food processing industry. According to a report the interests are mainly for dairy products, nutraceuticals and soy-based products. ABIA forecasts a substantial growth of 4.5-5% for this segment of the market (Stanton et al., 2001). In order to exert the health benefits beyond inherent basic nutrition, it is necessary that the activity of the probiotic culture should be maintained at very high levels during the shelf life of the product.

Probiotics are measured in colony forming units (cfu). CFUs are generally measured in the millions or billions per serving. Probiotics are most commonly beneficial bacteria, but can also be friendly fungal or other organisms, that are typically freeze dried to stabilize them in an inert state during storage and production. Then their continued stability and viability, as measured by CFU counts when cultured, is dependent on limiting their exposure to stimulating environmental conditions such as temperature and moisture. Besides refrigeration, this protection can be done by packaging in glass or by adding freshness packets that helps to absorb and reduce moisture in the package.

Antibiotic Resistance and Gene transfer
 
It is important that probiotic strains should be assessed for their phenotypical antibiotic resistance and potential to transfer resistance gene as otherwise they cannot be used in food (BgVV, 2000; Vankerckhoven et al., 2008). It is vital to do research on characterization of acquired resistance mechanisms and transferability of resistance genes and on methods for determining transferability.

Probiotic Fermented food products
 
An individual requires adequate nutrients like proteins, carbohydrates, vitamins, and minerals to maintain diet. There has been an explosion of the consumer interest in the role of enhancing the health by some specific foods or physiologically active food components, so called functional foods (Hasler, 1998). The concept of functional foods evolved in the year 1990 in Japan.

The lack of mechanistic understanding of probiotic activity is a major drawback for the prediction of safety of probiotic intervention. The complex gut-associated microbial ecosystem and nutritionally related factors are the most important environmental triggers for the development and modification of chronic degenerative diseases including immune and metabolic pathologies. In fact, the interaction between the gut microbial ecosystem and the host is considered to be a critical factor in overall health or disease. Whether probiotics will exert protective, harmful, immune-stimulating or immune-suppressing effects on a host is dependent on the interaction between the microbial signals, the genetic make-up of the host and the effects by the environment. Many studies have revealed that certain probiotic bacteria stimulate immune cell proliferation and activity as evidenced by the production of cytokines and antibodies, thereby enhancing the effectiveness of the immune response against pathogens. Ng et al. (2009)

4a. Intestinal Disorders
 
History of health claims
 
According to Bottazzi (1983) it was in 76 BC that the Roman historian Plinius recommended the use of fermented milk for treating gastroenteritis. Metchnikoff claimed that the intake of fermented milk containing Lactobacilli reduces the toxin producing bacteria, thereby increasing the longetivity of the host (Metchnikoff, 1908). Tissier (1905) showed that there was an increase in the Bifidobacteria in breast fed-infants, thus claiming that the administration of Bifidobacteria to infants suffering from diarrhea was very beneficial as they supersede the putrefactive bacteria that causes the disease. Intestinal beneficial microfloras are responsible to resist the disease (Bohnhoff et al., 1954).

LAB constitutes a group of gram positive bacteria. They are nonsporulating, nonrespiring but aerotolerant cocci or rods, which produce lactic acid as one of the main fermentation products of carbohydrates, they do not have cytochromes. They belong to the phylum Firmicuttes, class Bacilli and order Lactobacillaceae. The group includes several genera such as Lactobacillus, Lactococcus, Bifidobacterium, Pediococcus, Enterobacter, Corynebacterium, Streptococcus, Leuconostoc etc.

There are potential beneficial medicinal uses of probiotics for which research is limited and only preliminary results are available. Recent research on the molecular biology and genomics of Lactobacillus has focused on the interaction with the immune system, anti-cancer potential, and potential as a biotherapeutic agent in case of antibiotic-associated diarrhoea, traveller‘s diarrhoea, pediatric diarrhoea, inflammatory bowel diseases and irritable bowel syndrome (Ljungh et al., 2009). Studies of some probiotics tested in vitro on human epithelial cell lines have shown that they could block the adhesion of shiga toxin producing E. coli (Sherman et al., 2005). These are claimed to be health promoting and/ or disease preventing beyond the basic function of supplying nutrients. Probiotic foods are emerging as an important category of food supplements. Earlier workers have shown the inhibition of diarrhea caused by E.coli using probiotic lactic acid bacteria and yeast (Yan and Polk, 2006). Ratledge et al. (2002) have studied the biochemistry and molecular biology of lipid accumulation in oleaginous microorganisms.

Newer technologies involve fermentation by specific strains of lactic acid bacteria which bring specific fermentation under controlled conditions to a specific fermented product with enhanced organoleptic, nutritional and therapeutic qualities. Today health is of primary concern. It is important to have nutritionally balanced food with good bacteria. For this, probiotic foods top the list. The functional food concept was initially developed in Japan in 1990‘s as there were many side effects of allopathic medicines. A regulatory system has been initiated by the ministry of health and welfare to approve certain foods to improve health. These are now recognized as Foods for specialized health use (FOSHU). According to American dietic association (ADA) these foods are potential healthful food or food ingredients that may provide health benefits beyond the traditional nutrients. Probiotics are beneficial microorganisms. Probiotic foods as yogurt and sauerkraut are very well known. Fermentation increases the nutrient content and taste with the shelf life.

Quality is an increasingly important factor in the production and marketing of biological products. Consumers are becoming more discerning as their affluence increases, and would be suppliers of products must meet these demands if they are to maintain or increase market share. The term ‘quality’ is one of the most defined terms in use in food industry today. Quality may be defined as ‘The totality of features and characteristics of a product that bear on its ability to satisfy a given need’. The first part, ‘The totality of features and characteristics of a product…..’ concerns objective factors related to the product.  The second part, ‘…… to satisfy a given need’, concerns subjective factors related to user or consumer of goods.

Transportation and distribution of fruits and vegetables are important stages   of post-harvest loss. In India,  transportation of perishable commodities is in the most precarious stage. For local market, the produce is brought either by bullock cart or tractor trollies. The long distance transportation is mainly by rails and trucks, which is very costly. The basic reason for preference to road transportation is that it takes short transit period.

Packaging is an integral part of fruit and vegetable processing. It has  major influence on storage life and on marketability of fresh as well as processed products. Packaging fulfills several functions including containment, facilitating transportation, protection of fruit/vegetable from further damage, protection of environment from contents of package (for example, if the contents are dirty), marketing, product advertising, and stock control.

Minimally processed fruits and vegetables are products that have the attributes of convenience and fresh like quality. Their forms vary widely, depending on nature of unprocessed commodity and how it is normally consumed. In many cases, minimally processed product is raw and cells of tissues are alive, but these characteristics are  not regarded as essential. It is important that products have fresh-like character, regardless of   state of cells.  Minimally processed products for both retail and food service applications have increasingly appeared in market place recently.  In coming years, it is commonly perceived that this industry will have unprecedented growth.

Fermentation was known to mankind from time immemorial. But, development of biochemical principles of  fermentation  was originated by  Lavoisier in France in 1789 by way of analysing chemical composition of  sugar and its fermentation products such as ethanol, carbon dioxide and  acetic acid. Many products are produced by fermentation process. In fermentation, controlled action of selected microorganisms is used to alter  texture of foods, preserve foods by production of acids or alcohol or to produce fine flavours and aromas which increase value of raw materials.

Fruit beverages

Fruit beverages are highly refreshing, thirst quenching, appetizing, easily digestible and nutritionally far superior to synthetic drinks. The fruit beverages includes natural and sweetened juices, squash, syrup, cordial, nectar, Ready to Serve (RTS) beverages, fruit juice concentrate and citrus juice barley water. Fruits most commonly used to prepare beverages are oranges, lime, pineapple, grapes, cashew fruit, mango, jack fruit, apple etc. To prepare fruit beverages select fresh, fully ripe, tart, juicy and seasonal fruits.

The technique of preserving fruit by the use of low temperature dates from the eighteenth century with the first use of ice house in 1750. Later in 1800s commercial cold storages have come up for the storage of perishables like meat, dairy and fruit products.  The main change took place in the cold store in recent years has been the introduction of multi temperature chambers with humidity control for specific products. Cold preservation can be either refrigeration or freezing. Household refrigerators usually run at 4-7^ºC. Chilling or cold storage usually uses a slightly lower temperature on the basis of the food to be refrigerated. In freezing a temperature of -18^ºC or below is used. Chilling will preserve perishable foods for days or weeks and freezing will preserve foods for months or even years.

Drying is the oldest known method of preserving food. Drying or dehydration is removal of majority of water contained in fruit or vegetable. Although preservation is the primary reason for dehydration, it also lowers cost of packaging, storing and transportation by reducing both weight and volume of final product. In addition, dried foods add variety to our diets. In the process of drying, sufficient moisture is removed to protect product  from  spoilage. Processing should be done in such a way that food value, natural flavour and characteristic cooking quality of fresh material are retained after drying.

Processing of fruits  and vegetables into various products which could be preserved for a long time and add to value of product using proper cost effective technology will be a viable tool for improving   economic status of  farmer as well as our country. Modern methods of fruit and vegetable preservation are  broadly classified as follows:

Storage is one of the most important aspects of post harvest handling of fruits and vegetables. The main objective of storage is to extend storage life of fruits and vegetables and increase their period of availability. A substantial quantity of fruits go waste in India due to lack of proper storage facilities. Storage of fruits and vegetables is practiced for various reasons. Proper post harvest handling of fresh horticultural produce helps in extending  period of availability of wide range of  fruits and vegetables round the year, prevention of seasonal market gluts, orderly marketing, better return to grower and  preservation of  nutritional qualities. The   long  term  storage  of  fruits  and  vegetables is expensive and requires high level of technical  knowledge of crop. However, an orderly marketing reduces storage period considerably. 

Various systems were developed to take produce from field to consumer and selection of a particular method depends on several factors, including perishability and value of crop.  One method is to harvest the crop and take it to a packhouse for various unit operations like grading, cleaning, post-grading treatments, and packing for transport and marketing. When deciding upon where to locate a packinghouse, access to field and market point, adequate space for vehicles to enter and leave  packinghouse and ease of access to labor will all be considered.
 
In the simplest packinghouse, produce is delivered in picking containers, immediately after harvest, directly to packers.  Packers then sort, grade, size and pack the produce directly into appropriate transport containers. In this case, each worker must be aware of produce defects, grade and size requirements, and packing methods.

Maturity at harvest is the most important determinant of storage life and final fruit quality. Maturity indices are determined for many fruit, vegetable and floral crops. Harvesting crops at proper maturity allows handlers to begin their work with the best possible quality produce. Produce harvested too early may lack flavour and may not ripen properly, while produce harvested too late may be fibrous or over ripe.
 
Almost all fruits reach their best eating quality when allowed to ripen on the tree or plant (exceptions e.g., pears, avocados, and bananas). In general, fruits become sweeter, more colourful, and softer as they mature. A few fruits are usually picked mature but unripe so that they withstand post harvest handling system when shipped long distances.  Most of  currently used maturity evaluation is based on a compromise between those methods that would ensure the best eating quality and those that provide flexibility in transportation and marketing.  Optimum harvesting stage depends upon type of fruit or vegetable and their final use. Such a division is usually based on their classification according to physiology, environmental conditions, ripening bahaviour and nutritional aspect. Some of the classifications, important for their harvesting and storage are briefed in  subsequent sections.

Structure

Structural unit of edible portion of most fruits and vegetables is the parenchyma cells and makes up bulk of cells. A parenchyma cell is rather thin walled and may be polygonal or cubical in shape.  Walls of parenchyma cells in young plants are composed almost entirely of fibrils of cellulose. In parenchyma cells of plants actively metabolising protoplast portion represents only about 5% of total cell volume. This protoplast is rather film like and is pressed against cell wall by large water filled central vacuole.  Protoplast has inner and outer semi permeable membrane layers between which is confined cytoplasm and its nucleus. 

Fruits and vegetables are very important food commodities. India has become the largest producer of fruits and the second largest producer of vegetables. Though the production of fruits and vegetables make us believe in our strength for self-sufficiency, a significant qualitative and quantitative loss occur in the produce from harvest till consumption.  For self sufficiency and also for processing, export and to meet additional requirements, a lot of emphasis need to be given to reduce post harvest losses, besides increasing  production and productivity of horticultural produces. Processing plays an important role in  conservation and effective utilisation of these perishable commodities. However, only less than 2% of total production of fruits and vegetables are processed.  The new industrial policy has placed this sector in the list of high priority areas.

6.1 Strength of India
    ·    In India, pomegranate is cultivated over 1.31 lakh ha with a production of 13.46 lakh tonnes and a productivity of 10.27 t/ha. 
    ·    India is the largest producer of pomegranates in the world.
    ·    Pomegranate is currently ranked 10th in terms of fruit consumed annually in the world. India is the only country in the world where pomegranate is available throughout the year i.e. From January to December. It is cultivated in 3 seasons (Ambia bahar, Mrig bahar and hasth bahar) in Deccan plateau of India. 
    ·    India is endowed with wide agro climatic conditions that offer immense scope for cultivation of various kinds of fruit crops. This provides an excellent platform for the country to emerge as a leading producer of fruit crop. 

5.1 Present Status

Export of pomegranate has decreased in quantity from 36,027.43 tons in 2012-13 to 20,997.02 tons in 2014-15, whereas in value term it show an increase trend during the same period. There is tremendous potential for exports of pomegranate from India and it is fact that India is largest producer of pomegranates in the world. Moreover, India produces finest edible quality of pomegranates which are available almost throughout the year. The major Markets of India’s pomegranate during the year 2014-15 were UAE, Nepal, Saudi Arabia, Kuwait and Netherland.

4.1 Harvesting

Pomegranate being non-climacteric fruits should be picked when fully ripe. Its fruits become ready for picking 120-130 days after fruit set. Mature fruits should be immediately removed from the plants as delay in harvesting leads to fruit cracking. Fruits harvested at a premature stage have poor keeping quality and are prone to damage during handling and transport. The fruits are harvested when outer rind becomes yellowish and the fruit when tapped produces a metallic sound. The round fruits become flattened from all the sides and basal beak shaped portion shrinks at the time of maturity. Fruits are harvested with the help of secateurs by retaining 1 cm stalk with the fruit. All the fruits should be harvested in 2-3 pickings within a span of one month.

3.1 Integrated Insect Pests Management

1. Anar butterfly [Deudorix (Virachola) isocrates Fabricus]

Pomegranate fruit borer or pomegranate butterfly is the most widespread, polyphagous and destructive pest distributed all over India and common in Asia. Peak incidence is during the month of August in monsoon season, while it is more during November/December in winter crop. Infestation from flowering to button stage causing loss up to 50 per cent of the fruit. Adult bluish brown butterfly, female with V shaped patch on forewing. Full-grown larvae are dark brown with short hair and white patches all over the body and measures about 16 to 20mm long. The larvae bore into the pomegranate fruits soon after hatching. Once inside the fruit, larvae (approx 2cm length) feed on the flesh and seeds.  The bored hole is plugged by the last abdominal segment of the larva. When fully grown, the larva comes out by boring through the hard shell and spins a web, which ties the fruit, stalk to the main branch. Offensive smell and excreta of caterpillars coming out of the entry holes with excreta stuck around the holes. The fruits rot and drop off. The holes ultimately expose the rest of the fruit to disease, and typically rot off the tree.

2.1 Soil and Climate

Pomegranate grows well in sandy-loam and well-drained soils having a pH of 7.5. It can also be grown on light soils. Quality and colour development in light soils is good but poor in heavy soils. It tolerates salinity up to 9.00 EC/mm and sodicity 6.78 ESP. Even it can be grown well in slightly saline soils as it is considered a saline-tolerant plant (Patil and Waghmare 1983; Rao and Khandelwal 2001; Ram Asrey et al., 2002). Accumulation of salts, in excess of 0.5% of the soil mass causes dying off of growing roots. Interestingly, application of Paclobutrazol (250 ppm) was reported to reduce salinity damage (Saeed 2005). The presence of water-soluble salts like sulphates and chlorides and ex- changeable sodium negatively affect root formation.

1.1 Introduction

Pomegranate (Punica granatum L.) is a well-known table fruit of tropical and subtropical regions of the world. The Romans received it from Carthage, hence the name of the genus Punica. Some botanists place it in the family Lythraceae, of the peculiar type of fruit, called as balausta, most authorities make it the only genus in the family Punicaceae. It belongs to genera Punica and family Punicaceae (Chatterjee & Randhawa, 1952; Joshi, 1956). It is a small tree, measuring less than 4 m when cultivated, although it can reach 7 m in the wild. Recent research findings corroborate traditional use of pomegranate as a medical remedy as all parts of this plant have several bioactive metabolites (Holland et al. 2009). Consequently, its demand has increased tremendously not only in the western world but also in other parts of the globe.