eChapters

47.1. Aim

To conduct practical on preparation of pickle from different vegetables.

47.2. Theory

Pickles are good appetizers and add to the palatability of a meal. Pickles may be unfermented (mostly Indian pickles) and fermented (western pickles). Salt, vinegar, edible oil or acetic acid acts as preservative in pickle making. Mixed vegetable pickle from cauliflower, carrot and turnip is most common. Cucumber and olive pickles are examples of fermented pickles. The process of steeping vegetables/fruits in salt solution is also a common method used for preservation of mango and vegetable slices for longer duration storage for its later use in pickling.

Introduction

Vegetable crops are an important component of Indian Agriculture. They are known for their short cycle and high productivity per unit area providing a valuable source of income leading to improve livelihood. The prosperity and advancement of a nation largely depend on achieving nutritional security to its people. The vegetables play a vital role as major supplement to food and nutritional security of our people. They are important source of nutrients like b- carotene, vitamin B, C, E as well as folic acid, iron, magnesium, etc. and they also supply fair amounts of carbohydrate, protein, fiber, antioxidants and energy.

Abstract

Asurvey was conducted in wet temperate zone (Agro climatic Zone III) of Himachal Pradesh at an elevation of 1670-2290 m above mean sea level, falling in Kumarsain, Thanedhar, Jubbal and Kotkhai areas of Shimla district: a potential apple growing area. The average land holding size varies from 0.74 to 6.50 hectares with the predominance of small and marginal farmers. The area under apple increased with the increase in the size of holdings from 0.44ha to 2.10 ha in case of marginal and large farmers respectively. Average number of animals varied from 2.54 to 3.20 per house hold with Jersey cow component varying from 0.71 to 1.40. Grass availability was 13.18 per ha against their requirement of 49.05 for 200 days and 89.51 qt. for 365 days in an year and the carrying capacity was 0.36 and 0.20 respectively. Thus, there is a need to adopt improved horto-pastoral mode of agro forestry to sustain the present livestock population.

World Scenario

The world climatic conditions are divided into Tropical; Sub-Tropical and Temperate climates. Fruits and Vegetables suited to these climatic conditions are grown successfully. Considering the nutritional and economic importance of fruits and vegetables, there is tremendous increase in area and production of fruits and vegetables throughout the world. The present global scenario of fruit and vegetable crops (areas harvested, production and productivity (yield) has been given in Table 1. It shows that the fruits 865.88 million tones has been harvested from 65.24 million Ha land with productivity 13.27 t/ha (Table 1) where as vegetables produced 1075.20 million tonnes from area 57.00 million ha with yield 18.86 tonnes/ha (Table 1) during 2016.

Introduction

Beauty, purity, love and passion are some of the emotions symbolized by the flowers. The feelings of love, affection and joy are conveyed effectively with these non-speaking beauties of nature, for example a lotus conveys purity, rose love, pansy thoughts and narcissus egotism. Flowers have a definite role to play at almost all occasions of human affairs like birth, marriage, worship, adornments and death. Besides flowers, other ornamental plants also play an important role in environmental planning of urban and rural areas and from wasteland development to overcoming pollution. An important aspect of floriculture is that it is a good avenue to generate gainful employment for youth and women of peri-urban and rural areas.

Introduction

India (8^o-30^o N and 68-97.5^ºE) exhibits a wide range in topography and climate, which has a bearing on its vegetation and floristic composition. This subcontinent is one of the World’s 12 leading Biodiversity Centres, encompassing 16 different agro-climatic zones, 10 vegetation zones, 25 biotic provinces and about 426 habitats of specific species. It has been estimated that about 45,000 plant species (nearly 20% of the global species) occurs in the Indian Sub-continent. About 3,500 species of both higher and lower plant groups are of medicinal values. More than 80 per cent of medicinal and aromatic plants (MAPs) are collected from 17 million hectares of Indian forest land. However, many of these, due to over-exploitation have become rare (Rheum emodi, Aconitum deinorrhizum), threatened (Rauvolfia serpentina, Berberis artistata) or endangered ones (Sassurea lappa, Dioscorea deltoidea). Problems arising out of rapid genetic loss of medicinal plants forced the need for international co-operation and co-ordination to undertake programmes for conservation of medicinal plants to ensure that adequate quantities are available for future generations.

Sugar also acts as preservative at high concentration 70% or more in food products (fruit and vegetable products). High concentration of sugar in food materials create unfavourable conditions for microbial survival and prevent spoilage. Based on this principle of preservation, sugar based products are prepared from fruits and vegetables so that they can be preserved for long time. This method of preservation with high sugar concentration is principally based on the reduction in moisture content to arrest or stop microbial spoilage. Preparation of sugar based products is one of the most important aspects of home scale as well as industrial level processing of fruits and vegetables. Sugar based value added products include.

7.1. Introduction

Preservation of fruit and vegetables by application of heat is one of the important methods of food preservation as it not only imparts desirable effect in the eating quality of the food but also exerts a preservative effect on the foods by destruction of micro-organisms, enzymes, insects and parasites. Other advantages of heat processing include destruction of anti nutritional factors (e.g. trypsin inhibitor in some legumes), improvement in availability of some nutrients (eg improved digestibility of proteins, gelatinization of starches, and release of bound niacin), production of shelf-stable foods that do not require refrigeration and above all it offers a relatively simple control of processing conditions. The disadvantages of heat processing include alteration or destruction of sensory quality of foods like flavor, colour, taste and texture as a result the heat processed foods are perceived to have different quality as compared to fresh produce.

Introduction
Processing fruit and vegetables by applying heat is one of the most important methods of preservation as it exerts a positive preservative effect on the foods by destroying spoilage causing micro-organisms, enzymes, insects, parasites, etc. Heat processing also improves the availability of nutrients by improving digestibility, releasing vitamins like bound niacin, destroying anti-nutritional factors like trypsin inhibitor in some legumes including soybean, causing gelatinization of starches, and producing shelf-stable products. However, heating also causes some alteration or destruction of the sensory quality of fresh foods like changes in flavor, color, taste, and texture as a result, heatprocessed foods are perceived to have different sensory qualities than fresh produce.
Preservation by heat (thermal processing) involves heating foods in hermetically sealed containers for a specific time at a particular temperature to eliminate/kill/inactivate the microbial pathogens that endanger public health
and micro-organisms and enzymes that deteriorate food during storage. Most of the raw material used for canning is usually contaminated with different species and strains of bacteria, molds, and yeasts undergoing different stages of growth (lag phase, log phase, stationary phase, vegetative phase, sporulation phase, etc.,). Amongst these, bacterial spores are more difficult to inactivate. Thus, the criteria for heat processing chosen to inactivate the spores are also presumed to be capable of inactivating all other forms of microorganisms. Unlike fruits, most vegetables being low acid or even non-acid require a severe heat treatment to kill most bacteria. It is, therefore, necessary to work out the proper time and temperature combination for each category of food to ensure complete preservation.

Process of preservation of food stuffs such as fruits and vegetables whole or in pieces in sugar syrup or brine by heating them in hermetically sealed containers for long storage is known as canning. In other words canning is the process of sealing food stuffs hermetically in containers and sterilizing them by heat for long storage.

Introduction
The addition of sugar in foods acts as a preservative when its concentration is above 66%. It absorbs most of the available water and restricts the availability of moisture required for the growth of microorganisms. Sugar adds value to the product by imparting sweetness as well as body to these products. When sugar is boiled with acid and fruits, it is hydrolysed into glucose and fructose, the degree of inversion depending upon the pH and duration of boiling. Because of the inversion of sucrose, a mixture of sucrose, glucose and fructose is found in products like jam, jelly, marmalade, preserves and candies.
Jams, jellies and marmalades constitute an important class of fruit products preserved by using sugar as the method of preservation. Apple jam, mango jam, pineapple jam, strawberry jam and mixed fruit jam prepared by using the pulp of two or more fruits are quite common. Similarly, guava jelly and orange marmalade are also examples of such products.
A fruit preserve is made from properly matured fruit by cooking it whole or in the form of large pieces in heavy sugar syrup, till it becomes tender and transparent. A fruit impregnated with cane sugar and glucose, followed by subsequent draining and drying is called a candied fruit (Fruit candy) e.g. petha candy, ginger candy. While candied fruit covered or coated with a thin transparent coating of sugar, which imparts to it a glossy appearance is referred to as a glazed fruit. When candied fruit is coated with sugar crystals either by rolling it in powdered sugar or by allowing the sugar crystals from glucose syrup to deposit on it, it becomes a crystallized fruit (Crystallized Candy). The use of high concentrations of sugar in these products acts as a preservative. Products like Petha candy, aonla preserve, candied citrus peels, ginger candy, ginger in syrup, bael, pineapple and carrot preserve are the commercial products in this category.

6.1. Introduction

Chemical preservatives are those substances which minute organoleptic and physico-chemical properties . Preservation of food products with chemical preservatives is usually based on the combined or synergistic activity of several additives, intrinsic product parameters (e.g. composition, acidity, water activity) and extrinsic factors (e.g. processing and storage temperature).

Many chemical substances are added to the food for functional purposes and are called as additives and in many cases these are found to occur naturally in some foods. An additive is defined as a substance or mixture of substances other than basic food ingredient present in a food as a result of any aspect of production, processing or packaging.

Introduction
Many chemical substances are added to the food for functional purposes and in many cases, these are found to occur naturally in some foods. When these substances are added to the foods, they are known as food additives. An additive is defined as a substance or mixture of substances other than basic food ingredients that are present in a food as a result of any aspect of production, processing or packaging. Additives may be intentional as well as unintentional. Intentional additives are substances deliberately added to perform a specific function and to increase the shelf life of the products while unintentional additives have no intended function in the finished product but become part of that particular product. The food additives having significance in fruit and vegetable preservation and their mode of action are discussed as under:
Objectives of adding an additive
1. To reduce wastage and improve keeping quality e.g., the addition of potassium meta-bisulphite in squashes, benzoate in sauces, sodium propionate in bread and sorbic acids in cheese etc.,
2. To improve and maintain nutritive elements e.g., addition of vitamins for enrichment, addition of vitamin D to milk, addition of iodine to salt etc.
3. To enhance the quality and consumer acceptability of the product e.g., the addition of colouring agents, emulsifiers, thickeners etc.
4. To facilitate the preparation of foods e.g., the addition of acid to beverages, sugar in jams, jellies etc.

10.1. Introduction

Sugar acts as a preservative by osmosis and sugar is not a true poison fo micro organisms. It absorbs most of the available water and restricts the availability of water/moisture required for growth of micro-organism. The concentration of 68 70% sugar is used for preparation of jam and jellies. Sugar adds value to these products as it imparts sweetness as well as body to these products. When sugar is boiled with acid and fruits it is hydrolyzed into dextrose and fructose, the degree of inversion depending on the pH and duration of boiling. Because of inversion of sucrose, a mixture of sucrose, glucose and fructose are found in jams and jellies.

Jams, jellies and marmalades constitute an important class of preserved fruit products. Apple jam, pineapple jam, strawberry jam and mixed fruit jam prepared by using pulp of two or more fruits are quite common. Similarly, guava jelly and orange marmalade are also examples of such products.

11.1. Introduction

A fruit preserve is a product made from properly matured fruit by cooking it whole or in the form of large pieces in heavy sugar syrup, till it becomes tender and transparent. A fruit impregnated with cane sugar and glucose, followed by subsequent draining and drying is called a candied fruit e.g. petha candy, ginger candy. Further, candied fruit covered or coated with a thin transparent coating of sugar, which imparts a glossy appearance is referred to as a glaced fruit. When candied fruit is coated with sugar crystals either by rolling it in powdered sugar or by allowing the sugar crystals from glucose syrup to deposit on it, it becomes a crystallized fruit. The use of high concentration of sugar in these products acts as the preservative. The products like Petha candy, aonla preserve, apple rings; candied citrus peels, ginger candy, ginger in syrup; bael, pineapple and carrot preserve are the commercial products in this category.

1. INTRODUCTION

Fruits and vegetables represent highly perishable items of agricultural produce, mainly because of their high water content in the fresh form. Fruits and vegetables vary greatly in their protective covering, peel or rind, and also in shape, size, colour, texture and flavour. Their care starts from the field of harvest, including pre- harvest care to reduce postharvest infections and maintain quality. Because of the high rate of perishability in fresh form, fruits and vegetables are preserved by processing into several forms and choices, depending on the specific commodity to ensure reduction in mass, render storage stability for extension in storage life for both domestic and foreign trade over variable distance and time.

Food preservation can be defined as the science which deals with methods of prevention of decay or spoilage of food, thus allowing it to be stored in a fit condition for future use. In this chapter, food preservation and have been discussed in abroad way.

Thus, sugar serves as a preservative in jam and jelly, whereas salt is the major preservative for pickle. RTS (Ready-to-Serve) beverage under acidic conditions in pasteurized form can be stored at room temperature for approximately three months while dehydrated products with 5% residual moisture with suitable packages, depending on the low hygroscopicity can find storage life upto 12 months. Intermediate moisture product with 25% residual moisture is becoming popular to consume mango or papaya strips directly in ready-to-eat form. Storage quality of such forms assumes greater importance. The use of synthetic preservatives is highly questioned in the modern days. However, low concentrations of potassium meta-bisulfite and sodium benzoate are still in use. Formation of benzene under acidic conditions for example in products like RTS beverage by the use of sodium benzoate is said to be dangerous, as benzene is known to be carcinogenic. This takes us to a subject of food safety including hygiene and HACCP. Good manufacturing practices are practically the most useful form of product preparation to expect safety.

Vegetables consist of a large group of plants consumed as food. These represent complex commodities those include roots, stems, leaves, petioles, bulbs, tubers, corms, rhizomes, flowers buds, immature flowers, seedlings, immature and mature fruits and immature, partially mature and mature seeds of plants (Walker, 1988). Vegetables form an important part of human diet, providing essential minerals, vitamins, fibers and very special phytochemicals and they add a variety to the human diet (Singh, 2007). The consumption of vegetables has increased significantly since the consumers have now become more health-conscious (Cruess, 1958; Brackett, 1987a). Vegetables are cultivated in open fields, greenhouses and soil free hydroponic systems. In terms of retail, vegetables can be sold in a fresh or minimally processed form to provide a ready to eat product.

Vegetables are derived from various parts of plants, and it is sometimes useful to associate different vegetables with the parts of plant they represent. The vegetables based on their parts used as food are given below in Table 20.1.

Fermentation

The decomposition of carbohydrates by microorganisms and enzymes is known as fermentation. During fermentation process of food organic acids and alcohol etc are produced which act as preservatives and also provide fine flavor and aroma that increase the value of raw materials. Most fermented foods contain a complex mixture of carbohydrates, proteins and fats etc. Fermentation occurs when microorganisms consume susceptible organic substances as a part of their own metabolic processes. Natural fermentation is probably oldest form of food preservation.

13.1. Introduction

The preservation by using common salt, spices and vinegar is a common method for preparation of pickles, sauce and chutneys. Salt is mostly used as preservative in pickles in combination with acid. Minimum concentration of salt to act as preservative is about 12%. It inhibits enzymatic browning/discoloration by acting as an anti-oxidant. It exerts its preservative action by:

• Causing high osmotic pressure and thus suppress the microbial cells.

• Dehydrating food by tying up the moisture thus making it unavailable for the growth of microorganisms.

• Salt in the food affects the solubility of oxygen and thus growth of aerobic microorganisms is inhibited

• Chlorine in sodium chloride being good oxidizing agent is toxic to microorganisms

• Salt increases the permeability of the cell wall and thus cause changes in the permeability. Only the haloduric microorganisms can tolerate these effects while others are unable to survive.

• Similarly addition of acid to the food lowers the pH of the food which inhibits the growth of spoilage causing microorganisms.

• Addition of spices and edible oil in these products besides improving flavour and taste also help in preservation.

Introduction
Preservation by using common salt, spices and vinegar is a common method for the preparation of pickles, sauce and chutneys. Salt is mostly used as a preservative in pickles in combination with acid. Sodium chloride is used in brines and curing solutions or is applied directly to the food. The quantity of salt necessary to inhibit growth or harm the cells varies with the type of microorganisms. However, the minimum concentration of salt to act as a preservative is about 12%. Salt (sodium chloride) exerts its preservative action
by performing the following functions:
? Causing high osmotic pressure resulting in plasmolysis of the microbial cells.
? Dehydrating food by tying up the moisture thus making it unavailabl for the growth of microorganisms.
? Salt lowers the water activity and thus has adverse effects on microorganisms.
? Affecting the solubility of oxygen in the food and thus inhibiting the growth of aerobic microorganisms.
? Salt ionizes to yield chlorine ions, which is harmful to microorganisms.
? Chlorine in sodium chloride is a good oxidizing agent & is, therefore, toxic to microorganisms.