eChapters

Rejuvenation of fruit trees is visionary approach to save the old senile declining trees for future sustainable quality fruit production through unique integration of invasive exhaustive operations in scientific manner and skilful management. Since unproductive and uneconomic orchards are in abundance, a large-scale uprooting and replacement with new plantations (rehabilitation) will be a long-term and expensive strategy. Therefore, research efforts have been initiated at various pioneer institutes/ SAUs to standardize. The technology for restoring the production potential of existing plantations by a technique called rejuvenation. Rejuvenation of old orchard is very vital under orchard management. Reiterative pruning and canopy re-building of perennial fruit trees is medium- term strategy requiring scientific skill and technique, for bringing back the youthful vigour with enhanced quantum of quality production in sustainable way within a time gap of three years for mango, litchi and cashew (Lal et al., 2000; Kumar, 2008), while two years for guava, aonla and pomegranate (Singh, 2007; Hiwale 2009) without any economic loss to growers. The old fruit orchards need to be rejuvenated since they show decline in yield and quality of produce. These trees/plants need to be rejuvenated which have attained a stage where they are no more profitable from the grower ’s point of view (Singh, 2007; Srivastava, 2007).

The low productivity of perennial fruits has been attributed to various factors, like small size of holdings, preponderance of old and senile trees and poor management of inputs such as water, nutrients and pesticides. Thickly-shaded mango orchards in Malihabad areas of Uttar Pradesh (Kalloo et al., 2005; Mishra, 2013), lanky as well as sick tall unproductive litchi orchards in Muzaffarpur and its adjoining areas in Bihar (Kumar, 2008), seedling orchards of guava and citrus fruits throughout the country, including disease-affected aonla and other perennial fruit plantations are commonly seen in large tracts in different parts of the country (Pandey et al., 2013; Singh 2007). In pomegranate, the old orchards become non- productive due to incidence of pests and diseases, and negligence (Hiwale, 2009).

The traditional trend of orcharding for most of the tropical and subtropical evergreen perennial fruit trees, in general, are regarded as not responsive to pruning. However, a number of observations made in recent decades have conclusively proved the effectiveness of this important operation in maintaining the sustained fruit yield and keeping the plant well within manageable limits. The efforts have been made to deal perennial fruits in quite details wherever deemed necessary. Climatic factors have been found to affect significantly on fruit bearing as a result of pruning treatments. Though, this aspect is one of the most misconceived and least understood when seen with shoot emergence and shoot physiology for perenation and phase change from vegetative to reproductive. Correct pruning may easily spell the difference between success and failure, yet many growers undertake infinite pains to get the best out of their trees but the neglect to give their consideration to important practice. It is obviously needless to mention here that their such efforts end in futility. For better understanding of principles and practices of pruning, it would be imperative to trace out its historical background. The present level of understanding about pruning has been developed through ages with the increased understanding of growth and developmental processes of fruit plants.

Today, our country is the second largest producer of fruits in the world, yet the per caput availability of fruits is below the recommended level (Chadha et al., 2013). The major reason for low availability of fruits is poor productivity. In addition, pressure of burgeoning population and ever increasing demand also result in reduced availability of fruits. The production of fruit crops is still nature dependent. The problem of low productivity of fruits is compounded by several environmental, genetic and conditional factors. At present, there exist a wide gap in between actual fruit yield and their potential yield in almost all tropical and subtropical fruit species, particularly in perennial and woody trees of fruits.

There is a great diversity in perennial fruit crops which permits considerable manipulation for various purposes and desirable outcome. For achieving even the average productivity in many fruit crops, the production constraints like lack of information regarding canopy management, non-adoption of appropriate agro-techniques and timely management practices are required, while the concern about existing a large number of old and senile orchards which has turned or are turning even unproductive needs attention (Hare Krishna, 2012). Though, the country’s fruit production status is showing an increase, but far below the potential production requires immediate attention to critically analyze the situation by revisiting the problems and its causes, identifying the gaps and development of need- based technologies in the present context.

India is endowed with abundant natural resources and diverse agroclimatic conditions, which are ideal for cultivation of a number of annual or perennial crops, in different areas. Meticulous planning, extraordinary scientific support, judicious use of inputs and focused policy thrust have led to manifold increase in production and productivity of fruit trees. The horticultural crops, particularly fruit crops, are high-value and technology- intensive crops. Appropriate technologies are gaining popularity in entire country in view of their high potential of productivity, land utilization and more income. Today, our country is producing different kinds of fruits, but quantum of total fruit production is unable to cope with the present day demand. Various constraints, biotic and abiotic in nature, pose hindrances to meet the fuel potential. The poor productivity of fruit trees is the main reason of low availability of fruits. The low productivity of fruits is compounded by several environmental, genetic and conditional factors. Besides, productivity and quality of perennial fruits continued to remain low and there exists a wide gap in between actual and potential production. Visualizing the problems of perennial commercial fruit production, the main reason comes in forefront/top is a large number of old and senile orchards turning even unproductive, due to lack of information regarding non-adoption of appropriate agro-techniques and canopy management (Hare Krishna, 2012). Though, we have made rapid strides in fruit production, the productivity is very low compared to developed countries. The present scenario of production in our country is still technology deficit and what so ever the technologies are available very poor in adoption level and the situation still go worse even in the era of climate change.

Present situation demands that new technologies are needed to push the yield frontiers further by utilizing inputs more efficiently, diversifying to more sustainable and yielding higher quantum of quality production, particularly by integration of invasive and non-invasive medium-term strategic technologies. There are still challenges ahead in the way of the research which require concerted efforts in organizing, conducting and developing the technology as well as the proper way they are transferred to growers. The new generation of technologies will have to be much more site-specific, based on high quality science and a heightened opportunity for end-users, participation/adoption in identification of targets and achieving the objectives. These must be not only aimed at increasing the growers/farmers technical knowledge and understanding of science-based timely operations. It will also need to take on challenges of integrating the socio-economic context and role of markets for profitability and economic viability.

Seed is the basic input in agriculture that acts as a catalyst for realising the full production potential of the high yielding/improved varieties. The role of quality seed in agriculture has been recognized since the ancient periods. It is a well established fact that among all the agricultural inputs, use of quality seed alone can enhance the crop production up to 15-20 per cent, depending upon the crop, and it can be further raised up to 45 per cent with efficient management of other inputs. If the seed sown is of inferior quality, the efforts of the plant breeders in developing and introducing improved varieties would be rendered futile. Modern agriculture lays great emphasis that each and every seed should germinate readily with full potential and produce vigorous seedlings to ensure high yields.

In Indian Agriculture pulses play an important role in maintaining soil fertility and supplying protein to the vegetarian population of the country. This is because they are endowed with unique property of fixing atmospheric nitrogen in their root nodules and improving soil physical property. Further, it is not only the high protein content of pulses for which they are important, but the amino acid profile of these proteins is such that the mixed diet of cereals and pulses has superior biological value than either of the components alone.

Pulse crops have a unique position in sustainable crop production as they provide proteinaceous food of high nutritive value and keep the soil alive and productive. India is the largest producer and consumer of pulses in the world which accounts for 32 per cent of global area and 28 per cent of world’s pulse production. But the yield levels of these pulse crops are not satisfactory as it is grown as a neglected crop. Besides, extensive damage caused by insect pests is another major constraint for low yield of pulse crops. On an average annually 2.5 to 3.0 million tonnes of pulses are lost (Rabindra et al., 2004) with a monetary value of nearly Rs.6,000 crores due to ravages of insect pest complex (Reddy, 2009 and Panda et al. 1998). About 250 insects have been recorded feeding on these pulse crops in different parts of India (Narang, 1990) of which maximum damage is caused by the pod borer complex along with some sucking pests and foliage feeders. Sap feeders viz., aphids, whitefly, leaf hopper, thrips ; defoliator viz., leaf roller, hairy caterpillars etc are major threats to the crop during vegetative stage whereas the pod borers and pod sucking bugs are of major concern during reproductive stage. About two dozen insect pests are very important and found occurring on one or the other pulse crop frequently causing variable degrees of damage. A list of the very common insect and mite pests infesting different pulse crops (Table 1) and the extent of loss caused by different insect pests to some important pulse crops documented by the IIPR, Kanpur (Table 2) are furnished below.

Abstract

The increasing interest in polyphenolic compounds in industries has led to the exploration and exploitation of rich bio-compounds from natural sources, essentially plants and their by-products. Solid-liquid extraction is mostly applied for the recovery of these valuable compounds from plants. Since the extraction process is often difficult in a fresh matrix, a drying operation is needed to reduce the moisture content, and preserve the targeted valuable compounds. An uncontrolled drying operation will lead to product damage and hence, loss in quality, reason why, several studies have been carried out to understand and control the drying process. The present chapter aims to present some data on drying for bioactive compound recovery from plants and their by-products, mainly polyphenolic compounds. Our main interest is the mathematical tools used to model the drying process.

Abstract

Design, operation and optimization of dryers demands the calculation of energy consumption, in most cases in the form of thermal energy, equipment sizing, temperature and moisture distribution of solids as well as temperature and humidity distribution of drying air. Energy calculations are very important as drying is a widespread process in a variety of industries and is highly energy demanding. In the energy analysis of the process the first step is the estimation of the minimum energy requirement followed by the estimation of energy rejection through solids stream and especially through drying air. Increase of thermal efficiency is always willing and the two most common ways for its achievement is the application of heat exchange between cold feeding air and relatively hot rejecting drying air and hot air recirculation. The later is also employed for the adjustment of air temperature and humidity gradient through the dryer. The combination of a heat pump with the dryer decreases considerably the thermal energy consumption but demands electricity and the method can be beneficial in cases of excess electricity production in the process plant, e.g. by cogeneration. Utilization of exhaust hot air from the main drying unit for the predrying of wet solids can also decrease the total energy requirement. The application of humidity adsorption from the feed air increases its drying potential, but regeneration of adsorbent is required. Grand composite curve of the process plant can reveal potential heat sources from different unit operations.

Abstract

Vitamin C is one of the most important phytochemicals and can be found in almost all fruits and vegetables. Since it covers almost all eventualities, being water solute and prone to leaching from cells, thermally labile (one of the most labile vitamins), pH-, metal ion-, light-sensitive, as well as readily oxidizable by ascorbic acid oxidase, vitamin C is selected as the most frequently measured nutrient to evaluate the nutrients loss during thermal processing. It is generally accepted that if vitamin C is well preserved, the other nutrients are also well retained. Higher retention of vitamin C in processed products is highly desired. Herein this chapter reviews the degradation mechanism and kinetics of vitamin C of fruits and vegetables during thermal processing, such as blanching, drying, cooking and frying. It starts with an overview of the functions of vitamin C in human’s health. Then the current status for understanding of the degradation kinetics of vitamin C during thermal processing was outlined, followed by the discussion of its degradation mechanism. At last, potential strategies or alternatives to keep vitamin C are identified and discussed.

Abstract

Mushrooms are the fruiting bodies of fungi, a group of organism that is different from fruits and vegetables. They are a rich source of good quality protein having more essential amino acids and vitamins with low calories. There are about six commonly known edible mushrooms throughout the world with button mushroom (Agaricus bisporous) being the most familiar and commercially important variety. Mushroom is a highly perishable product with a shelf life limiting to a few days. Soon after harvest, it starts to undergo physiological disorders like shriveling, wilting, liquefaction, browning, textural as well as weight losses and flavour changes. The main responsible factors for the quality deterioration after harvest are respiration rate, browning, bacterial spoilage of mushrooms, temperature and relative humidity. Because of its limited shelf life under ambient conditions of temperature and humidity, the preservation of mushrooms is a matter of concern. Various techniques have been involved in the extension of shelf life of mushrooms including chemical treatments, cooling, modified and controlled atmospheric storage, radiation, drying etc. Drying is one of the most accepted and effective methods for the long term storage of mushrooms. Mushrooms preserved by drying have a pleasant flavour and are used as an important ingredient in several food formulations including salads, instant soups, meats and rice dishes. Various drying processes like sun drying, hot air drying, freeze drying, vacuum drying etc. can be used for the long term storage of mushrooms. As mushrooms are sensitive to temperature, determining the right drying method is the key for the successful and effective operation of the system. The different operating conditions involved in various methods of drying affect product quality considerably. The effect of drying methods on the process and the quality of the dried mushroom is explained in detail in this chapter.

Abstract

Cocoa and coffee are highly sought after commodity crops in the market owing to the distinct flavor and aroma characteristics. Cocoa beans are mostly used in the manufacturing of chocolates and various types of confectioneries while coffee is mainly consumed in the form of beverages. Both cocoa and coffee need to be dried and roasted in order to produce the flavor precursors which further develop into the desired flavor and aroma in the finished products. This chapter aims to provide an overview of cocoa and coffee processing with particular emphasis on drying and roasting aspects and its impact on product quality.

Abstract

Application of ultrasound is one of the most promising uses of novel technologies in food processing. Use of ultrasound at various stages of drying has resulted in significant decrease in drying time and improvement in quality characteristics of dried products. The chapter discusses the principle behind use of ultrasound, general application in food industry with detailed description of various drying processes and equipments assisted by ultrasound.

Abstract

Foam Mat Drying (FMD) is an economical alternative to drum, spray and freeze-drying for the production of food powders. The raw material is converted into stable foam by adding foaming agent through beating or whipping in presence or not of foam stabilizers, and dehydrated by different classical airflow and thermal means. A high-quality food powder attributes can be obtained by the proper selection of foaming method, foaming agents, foam stabilizers, time taken for foaming, suitable drying method and temperature. FMD can be used for large production of food powders because of its suitability for all types of food materials, rapid drying at lower temperature, retention of nutritive value and bioactive compounds, good reconstitution characteristics and flowability and cost-effective for producing powders.

In this chapter, basics of foam and its structure, mechanisms of foaming, types of foaming agents and stabilizers for the production of stable foam have been discussed. The influence of foaming agents, foaming properties, thickness of foam and drying temperature on the drying characteristics of mat are also studied. This chapter analyzes the application of foam drying process for different food materials, the microstructure and whole quality attributes of obtained powder, and the energy consumption and costs of FMD as well.

Abstract

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

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

Abstract

Increasing global demand for ‘fresh-like’ processed food products has forced food industries to investigate into various minimal processing techniques. Food processing in general has been associated with thermal processing, alone or in various combination with chemical and mechanical preservation and processing methods. However, thermal processing methods are energy intensive in nature and tend to reduce product quality and freshness at the cost of shelf-life gain. Advance technique such as microwave, radio-frequency and freeze drying do maintain the product quality but their implementation at industrial scale involves high operational and maintenance cost. An ideal processing method therefore would be one that can process food products without losing its quality, is energy efficient and is easily scalable. In this chapter, we discuss about ‘Electrohydrodynamic (EHD) Drying’, which is can be classified as a minimal processing technique. The heat and mass transfer principles involved in EHD drying have been extensively discussed and so has been the key consideration for designing an EHD drying system.

Abstract

This chapter presents the principle of fluidisation and its use in drying of food materials. Being a convective drying process, capacity and kinetics are limited by process conditions and material properties. The influences are discussed as well as presenting the main equations that describe drying in fluidised beds. The main focus lies on hot gas drying, additionally superheated steam drying as well as atmospheric fluidised bed freeze drying and microwave-assisted fluidised bed drying are presented and discussed.

Abstract

Airflow drying persists as the main dehydration operation. Indeed, the high expense of freeze-drying in term of equipment cost and energy consumption considerably restricts its use and confines its applications to high added value products (pharmaceutical products, cosmetics, etc.). However, airflow drying undergoes fundamental problems such as low operation performance, poor product quality and short reliability of the equipment. The time of drying is long; particularly at the end of the operation, which implies crucial energy consumption. The poor quality of the end product is related to thermal degradation and in particular to the compactness of texture as a result of the phenomena of shrinkage and case hardening. Another main problem common to all drying operations, including freeze-drying, is the safety of the end products. Swell-drying is defined as an operation that combines optimized hot air drying with instant controlled pressure controlled texturing. The improvement of texture, the preservation of sensory and nutritional quality, the possibility of manufacturing expanded granule powders and the reduction of drying time and energy consumption allow considering swell-drying as the most relevant drying process.

1. Introduction

Conservation agriculture (CA) strategies and practices have been developed and promoted to reduce risk and improve natural resource conditions, as well as address the combination of low yields, production risks and poor natural resource conditions. According to the United Nations Food and Agriculture Organization (FAO), CA is an approach to managing agro-ecosystems for improved and sustained productivity, increased profits and food security while preserving and enhancing the resource base and the environment. It is based on enhancing natural biological and ecological processes above and below ground. Interventions such as mechanical soil tillage are reduced to an absolute minimum, and the use of external inputs such as agrochemicals and nutrients of mineral or organic origin are applied at an optimum level and in a way and quantity that does not interfere with or disrupt biological processes (FAO, 2008). 

Abstract

Agriculture is the major sector for the livelihood of the billions of people worldwide. Increasing population and decreasing arable lands are the major concern for the fulfillment of the desired food production. After green revolution more production in the crop is obtained by worldwide. Several insects and pests are responsible for the inhibition of desired production in agriculture. Therefore, pesticides play a major role in the control of destructive insects and pests. After ban of organochlorine pesticides, organophosphorus pesticides has been used vigorously. Beside the effective pest management in agriculture, residual organophosphorus pesticides are more lethal for human and other living creature. Monitoring of these compounds is very much essential in the food and agricultural samples. Chromatographic techniques are well adopted techniques for the hundreds of residual pesticides. Introduction of various analyzers in chromatographic techniques improve the monitoring of the residual pesticides from different samples. Therefore, recent advancement in residual pesticides isolation and chromatographic techniques has been discussed in this book chapter.