eChapters

Agriculture and Food Security

Food security refers to a situation when people gain physical and access to enough food to meet the dietary requirements for a healthy life for all times. A household can have food security when all the members lead a hunger free life. It is estimated that nearly 800 million people in the world go to bed hungry every night. Food security exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life (World Food Summit, 1996). This definition gives rise to four dimensions of food security: availability of food, accessibility (economically and physically), utilization (the way it is used and assimilated by the human body) and stability of these three dimensions.

Climatic Factors and Crop Growth

Crop growth depends on internal and external factors. Internal factors are mostly genetic or hereditary factors which include high yielding ability, resistance to lodging, tolerance to adverse conditions such as drought, flood and salinity, tolerance to insect pests and diseases, and grain quality. The external factors include climate, edaphic, biotic, physiographic and socio-economic factors.

Modern agriculture requires certain precise information on pattern of rainfall, temperature, occurrence of drought and flood etc. for formulating required strategy for crop production. It also requires knowledge about agro-climatic conditions of the region for deciding a planned cropping pattern. Therefore climatic classification and delineation of agro-climatic zones would be imperative for a country or state.

Climatic factors like increase in temperature, carbon dioxide (CO₂) concentration, moisture, and other factors directly or indirectly affect agriculture, which have been elaborately dealt in previous chapters. Climate change causes weather variability that may result in low production, hike in price of agricultural commodities including food grains, vegetables, fruits, meat, egg and milk. It is now realised that climate resilient agriculture (CRA) will be imperative to reduce the vulnerability of agriculture to the climate change.

Climate-smart Agriculture Practices and Indicators

Considering the three pillars of climate-smart agriculture such as productivity, adaptation and mitigation, different technologies and practices have been evolved.

The CSA practices are grouped under soil and land management, water management, crop management, livestock management, forestry, fishery & aquaculture and energy management. The World Bank Group (2016) has suggested broad indicators of CSA practices (Table 7.1; Chapter 7)

Services for CSA

Under the CSA projects and programmes, the services like supply of inputs and technology transfer through extension services are provided to the farmers. The inputs like seeds of crops are provided by the input dealers at the subsidized rate and seedlings of fruits and vegetables are provided by both private and government agencies to grow under general cultivation and poly-house cultivation technology. Similarly other services like soil testing facilities, issue of soil health cards, construction of micro-irrigation projects and rain harvesting structures are made available to farmers. Under insurance scheme, loanee farmers are supported to pay premium dues for availing crop insurance facilities. Other services like trainings at various levels, demonstrations, exposure visits, exhibitions, kisan melas, field days, monitoring and evaluation of all these activities under these programmes are provided to the farmers with collaboration of extension officers.

Climate and Agriculture

Soil, climate and water are three basic requirements of a crop to be grown in a particular region. Climate affects the temperature trends, seasons, length of the growing season, amount of sunlight and the seasonality of sunlight etc. A change in climate may cause recurrent droughts, floods and weather extremities that would affect the agricultural production, human livelihoods, health and biodiversity. The relationship between agriculture and climate is complex as it is dependent on climate and also plays a contributing role in emission of greenhouse gas (GHG). Greenhouse gases include carbon dioxide, nitrous oxide, methane, chlorofluorocarbons (CFCs), hydro-chlorofluorocarbons (HCFCs), hydro-fluorocarbons (HFCs), per fluorocarbons (PFCs) etc. , which play a significant role in climate change.

Electricity is one of the fundamental phenomena of nature. Electricity or electric current is caused due to the movement of charged particles i.e., electrons. Due to the potential difference between two points in a conductor, electron movement takes place. The potential difference between two points is caused due to the difference in charge density. Electron tends to flow from lower potential to higher potential which causes electricity to flow. In general, the electrons flow from cathode (negative) to anode (positive) but in a wire electricity, electrons flow from anode to cathode when connected to a battery or any electricity source.

Weather and climate have profound influence on agriculture of a region. There are some differences between these two terms. Weather describes the state of the lower atmosphere of a place with respect to temperature, precipitation, wind direction, wind speed, humidity, cloudiness and pressure etc. over a short period of time. The short term variations over minutes to days are indicated as weather of a location. It says whether the atmosphere is hot or cold, rainy or dry, sunny or cloudy, still or cyclonic and so on usually for period of 24 hours. The weather may vary from place to place and from time to time due to difference in temperature, cloudiness, humidity, rain and other events of atmosphere. It may be sunny at one locality, but rainy at another locality.

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. 

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

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

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.

Family : Euphorbiaceae

Flowering: July-September

Fruiting: September-December

Botanical description: The plant is a small erect herb, growing up to 60 cm or more. The ascending branches are angled and velvet-hairy. Leaves are broadly ovate, nearly triangular, rather coarsely toothed. Leaf stalks are as long as or longer than the 3-5 cm long blades. Flowers are stalkless, borne on erect axillary spikes longer than the leaves. Male flowers are minute, crowded distally. Female flowers are scattered along the inflorescence axis, each subtended by a conspicuous semicupular leaf-like toothed green bract nearly 7 mm long. Capsule is bristly and1 mm broad.

Ecology: It is mostly found in hot, low to medium altitude, sandy margins of rivers, seasonal water courses and pans, usually in shade of thickets, on rocky hillsides and often in disturbed ground and as a weed of cultivation.

Family : Amaranthaceae

Flowering : October-December

Fruiting : December-January

Botanical description

The plant is an erect, straggling or subscandant herb. The leaves are ovate, elliptic, obtuse, acute and finely attached to the stem on both sides. The flowers are greenish white in colour, bracteolate having membranous blade and seeds are reddish brown in colour, sub-cylindric at apex and rounded at the base.

Family : Rutaceae

Flowering: March-April

Fruiting: (Next Year) April-June

Botanical Description: The plant is a medium sized tree with spines of 1-2 cm long. The leaf is composed of three leaflets. The leaflets are oval, elliptic with 2.5-6.5 cm petiole, terminal one is larger. Flowers of the tree are white or greenish-white. The fruits are ovoid, hard and about 5-7.5 cm in diameter. The flowers appear during March-April and the tree bears fruits towards October, ripening in April.

Family : Amaranthaceae

Flowering: August-October

Fruiting: November-January

Botanical description: The plant is a perennial sub-erect, diffuse or prostrate herb, growing upto 0.3-2 meter high, branched from the base and often also from above. Stem and branches are densely woolly with whitish or yellowish, shaggy hairs. Leaves are alternately arranged, nearly circular to lanceo shaped-elliptic, wedge-shaped at the base, rounded to sharp at the tip. Flower spikes are stalkless, solitary or usually in clusters in leaf axils, silky white to creamy in colour, forming a long inflorescence leafy to the ultimate spikes.

Ecology: This plant is commonly found in open forests on mountain slopes, on waste and disturbed ground and coastal scrubs. The plant is widespread in drier parts of the tropics and subtropics.

Use: Leaves are collected, fried and then eaten

Family : Amaryllidaceae

Flowering: December-January

Fruiting: January-February

Botanical description: It is a herb. The leaves of the plants are cylindric, fistular and look like tubes. Flower of the plant is white or greenish white with a short pedicel.

Ecology: The plant is commonly cultivated along the river banks during winter season. The plant loves to grow in sandy and loamy soil.

Use: Young leaves and shoots are collected, fried then eaten. The leaves and the flowering stalks are used for various preparations and curries.

Family : Amaryllidaceae

Flowering: November-December

Fruiting: January-February

Botanical description: The plant is a herb. The leaves of the plants are flat, linear with sheaths, about half of their length. Flower of the plant is white or greenish white with a short pedicel. The plant is having bulbs with membranous outer scales in the axils of which do exist 10-12 lesser bulbs.

English Name: Node Flower Allmaina

Family: Amaranthaceae

Flowering: May-June

Fruiting: June-July

Botanical description: The plant is an annual herb. It is erect and rising, 10-50 cm tall. Stem is branched from or near the base. The Leaves are obovate, oblong, or linear with 1.5-6.5 mm long and 0.3-2.5 cm wide. Flowers of the plant are greenish or orange-red in colour with 3-7-flowered cymes. Seeds are single, black and shining with 1.5-2 mm in diam.

Ecology: The plant is a common weed widely distributed in forests and cultivated lands.