eChapters

1. INTRODUCTION

Fruits and Vegetables are heighly perishable crops and have to be handled carefully after harvest. Postharvest handling of these perishables is essential to prevent the post harvest losses and maintain the quality of the fruits and vegetables. Various treatments (chemical, physical and biological agents) have been standardised and used for retaining the storage quality of different horticultural commodities. All these aspects have been discussed in this chapter.

1. INTRODUCTION

In the changing global scenario, food nutrition, health care and livelihood security are the matter of great concern to human, social and economic development. Fruits and vegetables is one of the most important and fast growing sub-sectors as they form an indispensable part of healthy diet. The current trend shows that dietary habits are changing with increasing income, from cereal based diet to nutritious diet. Resultantly, there is a growing demand for horticultural produce.

World production of vegetables amounts to 1169.45 million tonnes, while that of fruits is 689.39 million tonnes (NHB, 2017). India is the second major producer of fruits and vegetables in the world and ranks next to China. India produces 92.85 million tonnes of fruits from an area of 6.5 million hectares and 175.00 millions tonns of vegetables from an area of 9.2 million hectares annually. The productivity of vegetables in India is 17.6 tonnes per hectare. Potato (28.9%), tomato (11.3%), onion (10.3%) and brinjal (8.1%) are the 4 major vegetables contributing 58.6% of total vegetable production in our country. Other important vegetables are cabbage (5.4%), cauliflower (4.6%), okra (3.9%) and peas (2.4%)

Abstract

Water, the most important component of common foods, is considered to be desirable as well as undesirable in the different food systems. Water-solid interaction in food systems controls various biological, biochemical and biophysical reactions affecting their acceptability. The retention or release of water from solid has been quantified in the terms of sorption isotherm. Sorption isotherm techniques have been used to characterize and identify the type of water-solid interaction in different food products. Sorption isotherm provides various information useful in designing and optimization of drying, storage, packaging, predicting quality and shelf life of the product.

1. INTRODUCTION

Juices and pulps are produced from a wide variety of fruits and vegetables around the world, while some medicinal plants and herbs are also used for preparation of extract of beneficial bioactive compounds. These juices and extracts contain very high proportions (upto 75-90%) of water. Due to their seasonal nature, these products can not be produced round the year in various parts of the world. Preservation, storage, transportation and marketing of single strength juices, pulps and extracts is not at all economical due to the presence of large quantities of water. Under these circumstances, the technology of concentration offers many advantages.

In chemistry, concentration, as a state, may be defined as “the abundance of a constituent divided by the total volume of a mixture” and can be mathematically explained in four types i.e. mass concentration, volume concentration, molar concentration and number concentration. Generally, the term concentration can be applied to any mixture (solid or liquid) but most frequently it refers to the presence of solutes in solvents. Mass concentration is defined as mass/volume (m/V) of mixture and represented in kg/m³, volume concentration as volume of a constituent divided by the volume of all constituents of the mixture (v/V) and represented in m³/m³, molar concentration as moles of a constituent divided by the volume of all constituents of the mixture (n/V) and represented in mol/m³, while, number concentration is defined as the number of entities of a constituent in a mixture divided by the volume of the mixture (N/V) represented in 1/m³.

In food technology or fruit juice industry in particular, concentration refers to a process of separation of water (or any other solvent) from the solids of the pulp, juice, extract by making use of any of the three basic methods i.e. evaporation, freezing and membrane technology. Pulps, juices and extracts are the basic material used for preparation of various types of processed products. But due to their bulk and presence of large quantities of water they are difficult to store and transport. Concentration of juices, not only provides microbial stability, but also reduces the costs of packaging, transportation and storage by reducing the bulk of the material. Concentrated juice, contains far less water than normal, or “not-from-concentrate” forms of juice.

Introduction

Fermentation is one of the oldest food preservation techniques that can be traced back thousands of years. Fermentation is referred as one of method of biopreservation as it leads to extending the shelf life of foods that involve the use of microorganisms and their metabolites. (Ross et al., 2002) For millennia, the fermentation of food by using micro organisms has been used as a technique for ensuring shelf life extension and improving the quality characteristics, texture and flavour of food products as well as to develop new innovative products. The major bacteria used in food fermentation worldwide are lactic acid bacteria (LAB). LAB is a multitude of genera including Lactobacillus, Lactococcus, Streptococcus, Leuconostoc, Pediococcus, and Enterococcus. Lactic acid bacteria constitutes a diverse group of bacteria that enjoys the status of “generally regarded as safe” (GRAS) and “qualified presumption of safety” (QPS) by the Food and Drug Administration (FDA) and European Food Safety Authority (EFSA), respectively. In this respect, starter microorganisms are known to produce a wide array of antimicrobial and protein-acoustic compounds to inhibit the growth of undesirable flora in foodstuffs resulting in shelf life extension. (Hill et al., 2017).

Netting yarns for the fabrication of fishing gear are either of textile or non-textile origin. Textile materials compose of netting, twine and rope while non-textile origin materials constitute floats, sinkers, hooks etc. Raw material for fish netting consists of fibres which can be distinguished into two groups: natural fibres and man-made fibres. Different kinds of fibres originating from plant and animal body parts have been used for production of textiles and other products and are termed as natural fibres. Natural fibres such as cotton, manila, sisal, jute and coir were the materials exclusively used in earlier days for fishing gear fabrication.

Later, the invention of polymers resulted in synthetic fibres the use of which revolutionalized the fishing industry. In recent decades advances have taken place in fiber technology, along with the introduction of other modern materials. With the introduction of man-made synthetic fibers in India in the late 1950s, natural fibers used for the fishing gears have been substituted by these synthetic materials due to their high breaking strength, low maintenance cost, long service life and better uniformity in characteristics. Most important synthetic fibres used in fisheries are polyamide (PA), polyester (PES), polyethylene (PE) and polypropylene (PP). Other synthetic fibres, which are less widely used and generally restricted to Japanese fisheries, are polyvinyl alcohol (PVA), polyvinyl chloride (PVC) and polyvinylidene chloride (PVD). Earlier, netting used to be fabricated manually, which is laborious and time consuming while the introduction of synthetic fibres paved way for machine made nettings which are almost exclusively used in fishing net fabrication.

Modern fruit and vegetable processing industry is by and large, employing sophisticated machinery and equipment and efficient technique of production. There is still a scope for expansion of the industry by developing and exporting value-added products and on more foreign exchange. The choice of products to be manufactured will depend on the readily availability of raw materials in the area where the Processing Unit is supposed to be set up and the consumer preference in the neighbouring market. Preservation of food has to be established in the developing countries for other reasons also such as to generate both rural and urban employment, improve farmers nutrition by allowing them to consume their own processed fruits and vegetables during the off- season, stimulate agricultural production by obtaining marketable products, reduction of imports and meeting of export demand and to develop new value-added products. The food processing industry has now become more of a necessity than being a luxury. It plays an important role in the conservation and better utilisation of fruits and vegetables. To avoid the glut and utilise the surplus during the season, it is necessary to employ modern methods to extend storage life for better distribution and processing techniques to preserve them for utilisation in the off season on both large scale and small scale. Fruit and vegetable processing was first started in an organised manner in 1857, mainly to make pickles and chutneys with a view to meeting the export requirement.
Mango Processing Technologies
Mangoes are processed at two stages of maturity. Green fruit is used to make chutney, pickles, curries and dehydrated products. The green fruit should be freshly picked from the tree. Fruit that is bruised, damaged, or that has prematurely fallen to the ground should not be used.

Introduction

One of the main properties of fermented foods whether alkaline or acidic is the presence and activity of beneficial organisms which themselves make these foods functional. These functional micro organisms have varied roles like conversion of the native constituents of raw materials to forms in which they are more bioavailable, formation of taste, colour and flavouring compounds thereby imparting pleasantness to foods, removal of anti-nutritive factors in food by converting them into much less harmful compounds or degrade certain native toxic elements present in food, formation of biopreservatives which will extend the shelf life of foods and provide microbial security, as pathogens and spoilage microorganisms fail to readily grow in such hostile conditions. These functional microorganisms also produce in foods certain health-promoting bioactive compounds like enzymes, vitamins, minerals or increase the digestibility which may not have been in the original food or raw material before fermentation. In other words they improve the nutrition profile of the foods or naturally fortify foods. Some of these beneficial effects may also lead to the formation of certain compounds which show antioxidant properties in foods. These very roles played by these functional micro-organisms form criteria in their selection for use in food fermentations when they are intentionally added to foods both to initiate and accomplish desired fermentations.

Introduction

Over the past few decades, probiotics have become the most promising and emerging field in human nutrition and health across the world including India and other developing countries. The global profit generated from the probiotic market is expected to reach approximately 12,753.4 million US$ by the end of 2026 (Probiotic market report, 2018). The factor fueling the demand for probiotics is the growing awareness among consumers about their health benefits. The association of probiotics with health benefits stretches back to a time before microbes were discovered. However, the scientific evidence of the health benefits of probiotic microorganisms on the wellbeing of the host was firstly proposed by Russian Nobel laureate Ellie Metchnikoff in 1905. He reported that consumption of fermented milk containing Lactobacillus spp. is responsible for the healthy and long life of Bulgarian people (Anukam & Reid, 2007). Afterward, several of scientific progressions were made to reach the current status where probiotics are not only the subject of food and medical research but also the source of a multi-billion dollar global industry.

The term probiotic is derived from the Greek words, which means ‘for life’. According to the Food and Agriculture Association of the United Nations (FAO) and World Health Organization (WHO), probiotics are defined as “live microorganisms which when administered in adequate amount promote the health of the host” (Joint, FAO, 2002). In 2014, International Scientific Association for Probiotics and Prebiotics (IPPA) did minor correction in the definition given by FAO-WHO and defined them as “Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host”

1. INTRODUCTION

Food additives have been used for centuries in food processing practices such as smoking and salting of meat. Prior to the advent of refrigeration, food grown in the summer had to be preserved for the winter. Salt, sugar, and vinegar were commonly used preservatives. Additives serve many roles and their common uses includes maintaining product consistency and palatability, providing leavening or controlling pH, enhancing flavour and imparting colour. A food additive can be defined in many ways. The Codex Alimentarius Commission, which develops international regulatory guidelines for food additives, provides the following definition of a food additive:

"Any substance not normally consumed as a food by itself, and not normally used as a typical ingredient of the food, whether or not it has nutritive value, the intentional addition of which to food for a technological (including organoleptic) purpose in the manufacture, processing, preparation, treatment, packing, packaging, transport or holding of such food results, or may reasonably be expected to result, (directly or indirectly), in it or its by-products becoming a component of or otherwise affecting the characteristics of such food. The term does not include contaminants or substances added to food for maintaining or improving nutritional qualities".

F.A.O and W.H.O in 1956 defines food additives as non-nutritive substances added intentionally to food, generally in small quantities, to improve its appearance, flavour, or storage properties. The definition did not include vitamins and minerals. Food Safety and Standard Authority of India (FASSI) in 2011 defines food additives “as any substances which is added to food for a technological (including organoleptic) purpose in the manufacture, processing, preparation or treatment of such food and affects the characteristics of such food, but does” not include contaminats or any substance(s) added to the food maintaining or improving the nutritional values. Food additives are those added intentionally to foods and are not naturally a part of a food but can be a part of food unintentionally.

1. INTRODUCTION

Enzymes are proteins with highly specialized catalytic functions responsible for many essential biochemical reactions in microorganisms, plants, animals and human beings. Enzymes play an important role in many aspects of life since the dawn of civilization that have used enzymes for thousands of years without understanding what they were or how they work. Food processing through the use of biological agents/enzymes is historically a well-established approach. The earliest applications go back to 6000 BC or earlier, with the brewing of beer, bread baking, cheese and wine making. Whereas the first purposeful microbial oxidation dates back 2000 BC, with vinegar production. In the late 19^thcentury, Christian Hansen reported the use of rennet for cheese making and production of bacterial amylases was started at Takamine (latter became part of Genencor). Pectinases have been used for juice clarification in the 1930s and during World War II, invertase was also employed the production of invert sugar syrup in a process that pioneered the use of immobilized enzymes in the sugar industry. Still, the large-scale application of enzymes could only be really established in the 1960s, when the traditional acid hydrolysis of starch was replaced by an approach based in the use of amylases and amyloglucosidases (glucoamylases) and glucose (xylose) isomerase. From then onward, the trend for the design and implementation of processes and production of products by the use of enzymes has steadily increased.

Food and beverages and household care industries represent the largest application areas of enzymes, followed by animal feed, biofuels, textile and other technical industries. Recently, several new developments have taken place in the application of enzymes in fruit and vegetable processing. Fruits and vegetables are consumed as fresh or processed into different type of products. Commercial enzyme preparations are used as processing aids in fruit and vegetable processing to improve the process efficiency and product quality, because enzymes show activity on specific substrates under mild processing conditions. Therefore, there has been a striking growth in the enzyme market for applications in the fruit and vegetable industry.

Nutrients are organic and inorganic complexes contained in the food and it is essential for all living organisms for their normal body development. Macronutrients are the key biopolymers such as proteins, carbohydrates and lipids, which are needed in hefty quantities to provide the bulk of the energy while micronutrients (vitamins and minerals) are required in minor levels in the body; however, are indispensable for proper growth and development of living organisms. Food that cannot provide the right blend of energy including high-quality protein, essential fats, and carbohydrates as well as vitamins and minerals definitely impair growth and development, increase the risk of death from common childhood illness, or result in life-long health consequences. Fish and fishery products form a substantial part of human diet, both of poor and wealthy. Seafood is an excellent resource for proteins, vitamins, trace elements and polyunsaturated fat (omega-3 fatty acids). Profiling of nutrients is very much essential due to the ever-increasing awareness about healthy food which finds more acceptance towards the consumption of fish and fish products owing to its special nutritional qualities.

MAC: It stands for modified atmospheric coating.

Macaroni wheat: It is tetraploid wheat and is preferred for making macaroni, vermicelli etc.

Macaroni: Pasta made from semolina and shaped in the form of slender tubes (Plate 230).

Macaroon: A small cookie composed chiefly of egg whites, sugar, and ground almonds or coconut (Plate 231).

Mace: An aromatic spice consisting of the dried external fibrous covering of a nutmeg (Plate 232).

Mach number: It is a number representing the ratio of the speed of a body (flow velocity) to the speed of sound (sonic velocity) in a surrounding medium (as air).

Macro economics: Studies of economics in terms of whole systems esp. with reference to general levels of output and income and to the inter-relations among sectors of the economy.

1. INTRODUCTION

Packaging waste forms a significant part of solid waste and has caused increasing environmental concerns, resulting in strengthening of various regulations aimed at reducing the amounts generated. A wide range of oil-based polymers is currently used for packaging of various products by different industries including the food industry. These are virtually non-biodegradable and some are difficult to recycle or re-use as they are complex composites having varying levels of contaminants and pose serious health concerns. In the recent years, the use of bio-based and biodegradable products as packaging material has generated a lot of interest amongst researchers as they bring out a significant contribution to sustainable development with a wider range of disposal options.

Bioplastics are polymers that are capable of undergoing decomposition into CO₂, H₂O and inorganic compounds or biomass through predominantly the enzymatic action of microorganisms. Some of these polymers can also be compostable, which leads to their decomposition in a compost site at a rate consistent with known compostable materials. The market for these environmentally friendly materials is expanding rapidly, at the rate of 10–20 per cent per year. The global market for biodegradable polymers exceeds 114 million pounds and is expected to rise at an average annual growth rate of 12.6 per cent to 206 million pounds by 2020.

Bio-based packaging materials are mostly used to pack short shelf-life products, like fresh fruits and vegetables, and long shelf-life products, like pasta and chips, which do not require very high oxygen and/or water barrier properties. However, the inventory of films shows a wide variety in properties, which could make them applicable as a packaging material for other food products with stricter conditions, like MAP packaging. One of the challenges faced by the food packaging industry in its efforts to produce bio-based primary packaging, is to match the durability of the packaging with product shelf-life. The bio-based material offers great potential for the packaging industry. However, it is important to realize that a thorough evaluation of the functional properties of a bio-based material is essential before it can be used as an alternative for the traditional film materials.

1. INTRODUCTION

Sensory science is the fundamental physiological and psychological underpinnings of sensory evaluation and includes our basic understanding of the mechanisms of taste and odour, kinesthetic and the various techniques of scaling and statistical analysis, whereas, sensory evaluation could unfold the application of this knowledge and the development of specific methods for the evaluation of the discriminative, descriptive and affective nature of products, in a problem-solving situation. When the Quantitative Descriptive Analysis (QDA) methodology was first described, it represented a decade of experimentation and study of the issue that were perceived at the time to be the impediments in solving “the problem of flavour characterization” Further, new developments and knowledge about sensory evaluation were beginning to have a positive effect on its acceptance by the food industry, but much more needed in be done if it is to contribute in a meaningful way. Today, it is indisputable that flavour is an important attribute affecting consumer acceptance of food and it is taste plus odour. The perception of taste is merely the detection of non-volatile tastants by the tongue while in other words, the perception of odour is the detection of odoriferous volatile aroma compounds by the olfactory nerves ending in the nose. The combination of all the possible flavour stimuli that could be encountered is as vast as the galaxy.

T A Spoilage: The spoilage of low and medium acid canned foods by Clostridium thermosacharolyticum which breaks sugars and form acid and gas (moisture of H2 and CO2 ) resulted in swelling and in severe cases even bursting of can may occur and the spoiled food usually has a sour odour.

T cell: It is one of the lymphocytes (helper T cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (regulation of T and B cell maturation and proliferation) and others that lyses antigen-bearing cells. It is also called T lymphocyte.

Table cream: It is also called coffee cream, single cream or homogenized cream. It is used in coffee and tests about 20% butter fat.

Table oil expeller: It is a type of the machine that is used for extraction of the oil from the oil seeds (Plate 313).

Table ready meat: Cooked and smoked sausages are called table ready meats.

Table wine: Table wine is a dry wine with low alcohol content. Dessert wines certified sweet wine.

Dahi: It is the product obtained from pasteurized or boiled milk by souring, natural or by harmless lactic acid or other bacterial culture. It is also called Curd (Plate 209).

Dairy: It is a room, building, or establishment where milk is kept and butter / cheese is made or it is the department of farming / farm that is concerned with the production of milk, butter, and cheese or an establishment for the sale / and distribution of milk and milk products.

Dairy husbandry: It deals with care, breeding, feeding, milking of the diary cattle and the production and sale of the milk. It is the economical management of a dairy, including looking after the dairy cattle breeding and proper disposal or sale of milk and milk products.

Dairy products: These are the milk preparation, including butter, cream, cheese, ghee, yoghurt, pasteurized milk, tonned milk, butter milk etc processed and prepared in dairy. Ice cream and kulfi or sweets are not included in this.

Damage: Damage is a physical spoilage, often a partial deterioration, are subjectively judge and very difficult to measure and usually reported as per cent damage.

Daminozide: It is a growth regulator which is used for red colour development in apple.

E numbers: Each food additive used in the food industry has been given a specific number code for their identification. These numbers are called as E numbers. These E numbers are used within the European Union. The word prefix “E” stands for Europe. They are commonly used on the food label through out the European Union. These are not used in Australia and New Zealand. The different food additives are given different E numbers depending upon the type of food additive like E100-E199 (food colours), E200-E299 (preservative), E300-E399 (antioxidants), E400-E499 (thickners, stabilizers, emulsifier), E500- E599 (pH regulator, anticaking agent), E600- E699 (flavour enhancers), E700-E799 (antibiotics), E900-E999 (miscellaneous like waxes, synthetic glazes, packaging gases, sweetners, foaming agents), and E1000-E1099 (additional chemicals).

Earling: The young lamb of one to two years’ age is called earling or yearling.

Ebullioscopic constant: The boiling point elevation is expressed by Dtb = Km, where m is molality of the solution and K is ebullioscopic constant. It is also called as molal boiling point elevation constant. The unit of an ebullioscopic constant is K Kg mol-1.

Seafood has grown in consumption as it has become an important part of a diet. Simultaneously their safety is a rising concern for human health. However, seafood may contain harmful chemicals as well as biological agents that could pose health risks to consumers. Fishes are harvested from waters that are contaminated by varying amounts of industrial chemicals, heavy metals, pesticides and antibiotics. These contaminants may accumulate in fish at levels that can cause human health problems (e.g. carcinogenic and mutagenic effects).The seafood may also get contaminated with various pathogenic bacteria due to unhygienic handling practices, cross contamination of raw foods with cooked or ready-to eat foods, and lack of proper temperature control. Pathogenic bacteria can cause illness in human, either by infection or intoxication. Food borne infections are caused by swallowing live pathogens that grow within the body, usually in the intestinal tract. Intoxication is a condition caused by swallowing preformed toxins i.e. toxins produced by microorganisms in the food before it is eaten. Food can become contaminated at any point during production, distribution and preparation. Everyone along the production chain, from producer to consumer, has a role to ensure the safety of seafood.

Galactometer: It is an instrument used for recording the specific gravity of the milk (Plate 306).

Galactose: It is an aldohexose sugar obtained by hydrolysis of lactose. Galactose is a monosaccharide and has the same chemical formula as glucose, i.e., C6 H12 O6 . It is similar to glucose in its structure, differing only in the position of one hydroxyl group. Due to this difference galactose possess different biochemical properties to glucose (Plate 307).

Galactosidase: An enzyme (actase) that hydrolyzes a galactoside. β-Galactosidase, commonly known as lactase, is an enzyme responsible to hydrolyze lactose (Plate 308).

Galactoside: A glycoside that yields galactose on hydrolysis. A galactoside is a glycoside containing galactose. The H of the OH group on carbon-1 of galactose is replaced by an organic moiety (Plate 309).

Galactosyl: A glycosyl radical C6 H11 O5 that is derived from galactose.