eChapters

Introduction

A wide range of agricultural pesticides is currently being used in India. In the financial year of 2015, the size of the crop protection market in India was of about $4.5 billion (FICCI, 2016). A large number of these pesticides are also being used in considerable quantity on horticultural crops, including fruit crops. In general, judicious application of a pesticide following Good Agricultural Practices (GAP) does not leave its residues in crop produces above unacceptable limit. But the GAP recommendations are not available for all crop-pesticide combinations. The usage pattern of pesticides also sometimes gets modified at farm level due to sudden climate changes, and under such situations, the indiscriminate use of pesticides to combat disease and insect complex might result in the contamination of pesticides in fruits.

Waste is defined as anything that doesn’t add value to their operations. To the average person, waste is simply stuff that’s unwanted or useless. But from a scientific perspective, there’s really no such thing as waste. Nearly all the things we throw away can be transformed or processed in ways that make them useful again.

Waste comes in various forms, ranging from household trash to industrial byproducts. These include domestic waste, factory waste, e-waste, construction waste, agricultural waste, and more. We can categorize waste into different types:

Solid waste: This includes organic materials like vegetable and kitchen waste, as well as general household waste.

E-waste: Discarded electronic devices such as computers, TVs, and music systems fall into this category.

Liquid waste: This comprises water used in various industries, as well as waste from tanneries, distilleries, and thermal power plants.

Plastic waste: Items like plastic bags, bottles, and containers make up this category.

Introduction

The horticulture sector is contributing over 30 per cent share in agricultural GDP of the country. Presently, India producing about 351.92 million tons of horticultural produce from 28.04 million hectare which has surpassed the food grain production for last five consecutive years (Anonymous, 2023). Horticulture sector has been identified by Government of India also identified horticulture as one of the vital sector for entrepreneurship development, employment generation, livelihood and nutritional security, doubling farmer’s income, achieving SDGs of the United Nations.

Fruits and vegetables have become part of a modern healthy lifestyle as they possess high amounts of minerals, especially electrolytes, dietary fiber, phytochemicals, especially antioxidants, and vitamins (Yahia et al., 2019; Krishnan Kesavan et al., 2023). In consumption, the qualities of products play a critical role in consumers’ choices, which are directly related to health problems (Tian, and Xu, 2022). Bioactive compounds are phytochemical substances present in small quantities in plant materials that can provide biological activity, being generally associated with health benefits, including hepatoprotective, anti-inflammatory, antioxidant, antithrombotic, anticarcinogenic, antidiabetic and prevention of cardiovascular and degenerative diseases (Campoli et al., 2018). Therefore, maintaining high-quality fruits and vegetables is very important for the fruit and vegetable industry. This requires some methods to evaluate the quality of fresh fruits and vegetables during their post-harvest manipulation and storage and before their industrial processing as well (Tian and Xu, 2022).

Introduction

India is bestowed with varied agro-climatic conditions. Thus, horticultural crops have lot of potential in the country. India has witnessed voluminous increase in horticulture production over the last few years, which has undoubtedly doubled the income of farmers. As a result, the country has emerged as the 2nd largest producer of fruits (102.48 million tonnes) after China during 2020-21 (Anonymous, 2023). The abundance of fruits ranging from tropical delights like mango, banana, guava and papaya to temperate fruits such as apple, peach, plum, apricot and pear, have laid a robust foundation for the growth of the fruit processing industry. This chapter delves into the dynamics of fruit processed products in both local and international markets, exploring the challenges, opportunities and strategies for sustained success. Fruit processing plays a crucial role in adding value to horticultural produce, enhancing shelf-life and meeting the diverse demands of local and international markets. In India, a country blessed with abundant fruit varieties, the processed fruit industry has been witnessing significant growth, catering not only to the domestic market but also making strides in the global arena. The processing of these fruits into various products such as juices, pulps, concentrates, jams and dried fruits has emerged as a thriving industry. This chapter will provide insights into the current state of fruit processed products in India, their importance for both local consumption and export markets, challenges faced by the industry and potential avenues for the future growth.

Introduction

Perishable nature of horticultural produce is a major factor contributing in high post-harvest losses. The metabolic processes such as respiration, transpiration, and ethylene production remain active after the harvesting of produce, which drive ripening and senescence Fig. 1. Thus, an effective post-harvest handling is crucial to delay these changes. The rate of these processes depends on the produce’s physiological characteristics, composition, and storage conditions like temperature and humidity. Low-temperature storage is the simplest and most efficient method to slow down deterioration Escobedo-Avellaneda and Welti-Chanes, 2016. Combining low temperatures with methods that limit oxygen exposure, which fuels many enzymatic reactions, further extends shelf life and maintains food quality. Reduced oxygen levels decrease respiration and the activity of enzymes like polyphenol oxidase and peroxidase.

Introduction

The cold chain is a meticulously managed series of actions using specialized equipment to ensure products remain within a specific low-temperature range from production to consumption (ASHRAE, 2024; IIR, 2024). This unbroken sequence encompasses refrigerated production, storage, and distribution activities, safeguarding the safety and quality of perishable and thermo-sensitive goods like agricultural commodities (such as fresh produce, meat, dairy, seafood, chemicals, pharmaceuticals, flowers, wine, etc.), processed foods and pharmaceuticals (Aung and Chang, 2014; Awan, 2023). For climacteric fruits like bananas, custard apples, apples, pears, tomatoes, mangoes, and avocados, cold storage facilitates controlled ripening, extending the time between harvest and consumption. Cold chain management, integral to the overall supply chain, requires expertise in maintaining temperature, air quality, and adherence to regulatory standards. Any disruption in this process can lead to product spoilage and financial implications (FAO, 2019). The management of the cold chain system is crucial for preserving the freshness, taste, and nutritional value of fruits from harvest to consumption (Kader, 2003).

Fruits and vegetables are perishables and the post-harvest losses from the point of production at the farm gate till it reaches the consumers is estimated as 30-35 per cent which constitute a major economic drain of more than 33 billion USD equivalent to Rs 2,40,000 crores annually. In order to reduce the losses at various stages, nanotechnologies have come as potential strategies to minimize the losses while improving the marketability and profitability of perishables. One of the plants derived natural compounds “hexanal” which is known to extend the shelf-life of fruits when it is used as a pre-harvest spray or post-harvest dip as a nano-emulsion. Since, it is a highly volatile compound, efforts were undertaken to entrap the compound in the polymer-based nano f ibres (as nano stickers) or as a cyclodextrin inclusion complex (as nano pellets) in order to preserve the perishables. Further, hexanal vapour was also evaluated to preserve fruits. In this book chapter, various nanotechnologies tested, evaluated and technologies developed over the years are elucidated. Overall, the literature review suggests that use of any of the nanotechnologies delivered as pre-harvest spray, post-harvest dip, nano-stickers, nano-pellets and vapour singly or in combination found to reduce the infestation of post harvest diseases, minimize the losses and extended shelf-life by 2-3 weeks that help the farmers to get lucrative prices due to the late arrival in the market besides significantly improve the productivity and profitability of orchards.

Fruits, the vivid and delightful offerings of the nature, undergo remarkable transformations as they travel from the orchard to our dining tables. These changes indicate the significance of post-harvest physiology, which is the scientific study that reveals the secrets of how fruits behave after they are picked, including the mechanisms that affect fruit quality and how long it may be stored. The next section provides definitions of the various stages and key players involved in the processes of fruit maturity, ripening, and post harvest physiology. These topics will be further explored in the subsequent sub-sections of this chapter.

Fruit developmental physiology

The life cycle of horticultural commodities (fruits and vegetables) can be effectively categorized into three primary physiological stages after fruit set or initiation, namely growth, maturation, and senescence. Still, a lack of obvious differentiation exists among the several stages. Growth encompasses the process of cell division followed by cell enlargement, which determines the ultimate size of the product. Maturation typically begins prior to the cessation of growth and involves various activities across different commodities. The stages of growth and maturity are commonly denoted as the developmental phase. Senescence can be described as the phase in which anabolic biochemical processes transition into catabolic processes, resulting in the ageing and eventual demise of the tissue. Ripening, a term specifically used for fruit, is typically regarded as the initial phase of senescence that occurs during the later phases of development. Defining the transition from growth to senescence is rather straightforward.

Calcium, anti-oxidants and certain enzymes are reported to play vital role in extending the shelf-life of harvested produce of many horticultural crops especially fruits. They help in maintenance of cell wall structure. Being an important constituent of cell wall, in the form of calcium pectate, it helps in maintenance of cell wall structure. Antioxidants are highly beneficial in extending the shelf-life of fruits besides maintaining the quality. Similarly, some enzymes play a key role in preserving the fruit quality and prolonging its market life. As some fruits are catergorized under ‘Low volume high value fruits’, it is essential to extend their shel-flife for reducing the post-harvest losses of fruits and also to reap better remuneration. Thus, it becomes indispensable to review the role of Ca, anti-oxidants and enzymes which are beneficial in keeping the harvested produce afresh for a relatively longer period.

Fruit ripening is a phenomena during which horticulture produce undergoes a series of complex physical and biochemical changes initiated through a series of hormones (Ethylene, auxin, abscisic acid (ABA), gibberellins, jasmonic acid, etc.) to attain maximum physiological maturity and favourable organoleptic properties. These changes lead to alterations in colour, texture, aroma, flavour and nutrient composition. In a nut shell, ripening involves increase in pulp to peel ratio, solubilisation of pectic substances, degradation of complex carbohydrates, organic acids and chlorophyll, accumulation sugars, flavour volatiles, polyphenolic compounds and pigments (carotenoids, xanthophylls and anthocynanins). The extent of these changes guide harvesting, readiness for processing and consumption decisions, with physic-chemical alterations serving as indicators of optimum ripeness. Respiration rate, ethylene and ABA are key regulators of fruit ripening in climacteric and non-climacteric fruits, respectively. In climacteric fruits, ABA interacts with ethylene, influencing the synthesis of ethylene itself. Although there is ample documentation on the involvement of hormones in fruit development and ripening, our understanding of the functions of various hormones throughout growth, maturation, and specific ripening processes remains incomplete.

Plant hormone ethylene is involved in a number of physiological activities within the plant system, ranging from seed germination to fruit development. Ethylene acts as a key player in accelerating fruit ripening by regulating the activities of different enzymes, and is responsible for shortening the shelf life and associated post-harvest losses during the storage of fruit crops. However, all fruit crops have different ethylene production capacities and vary in their response to ethylene. Hence, effective management of post-harvest ethylene is imperative for addressing the global challenge of reducing fruit losses after harvesting. In recent periods, numerous technologies and compounds have been developed for the suppression of ethylene and for enhancing in-situ oxidation of ethylene or inhibiting its production at a receptor level. Among these emerging techniques, the use of sachets, fumigating agents, catalysis and composite films embedded with nanoparticles has been found to be trending, but the use of some of compounds has been limited due to health risks or consumer unacceptance. However, most of these technologies are very costly and are not affordable for marginal farmers and developing nations. In order to address these issues, long term breeding approaches for shelf-life improvement, targeting the tfs, ERFs have been involved. This manuscript fills the knowledge gap by encompassing all the recent progress made in enhancing the shelf life of fruits by managing ethylene during storage.

56.1. Aim

To determine quality characteristics of dried and dehydrated fruits and vegetables.

56.2. Theory

The quality of dried/dehydrated products can be measured by estimating moisture contents, preservatives level, acid insoluble ash contents and most importantly enzyme reactions.

56.3. Estimation of Acid insoluble ash

1. To total ash add 25 ml of dilute HCl (10% w/w)

2. Cover with a watch glass and boil gently over a low flame for 5 minutes

3. Filter and wash the filter paper thoroughly with hot water

4. Return the paper to the original dish, ignite, cool and weigh the insoluble ash

55.1. Aim

To determine dietary fibres in given samples.

55.2. Theory

Fibres can be classified into four categories like crude fibre (cellulose); acid detergent fibre (cellulose + lignin); neutral detergent fibre (cellulose + lignin + hemicelluloses) and total dietary fibre.

55.3. Procedure for estimation of dietary fibre

55.3.1. Acid detergent fibre (ADF)

Reagents: Cetyl tri-methyl ammonium bromide (CTAB) reagent and Acetone

Apparatus: Digestion apparatus vacuum pump, oven, desiccator and sintered glass crucible.

54.1. Aim

To determine crude fibre in given samples.

54.2. Theory

Fibres can be classified into four categories like crude fibre (cellulose); acid detergent fibre (cellulose + lignin); neutral detergent fibre (cellulose + lignin + hemicelluloses) and total dietary fibre (Cellulose + lignin + hemicelluloses + pectic substances). Crude fibre is the organic residue of a sample. A fat free sample is treated with boiling sulphuric acid and subsequently with sodium hydroxide. The residue after subtraction of ash is regarded as crude fibre.

54.3. Reagents/ Apparatus/Glassware

1. 0.255 N Sulphuric acid solution

2. 0.313 N Sodium hydroxide solution

3. 10% Potassium sulphate solution

4. Ethanol

53.1. Aim

To conduct practical on freezing of vegetables

53.2. Theory

Freezing is often considered the simplest and most natural way of preservation for vegetables. Frozen vegetables and potatoes form a significant proportion of the market in terms of frozen food consumption. The quality of frozen vegetables depends on the quality of fresh products, since freezing does not improve product quality. Pre-process handling, from the time vegetables are picked until ready to eat, is the important factor affecting quality of finished product. The process variables for freezing of different vegetables and flow chart are shown in Table 54.1 and Fig 54.1. Generally fruits after preliminary treatments are packed in sugar syrup and frozen in freezer.

52.1. Aim

To conduct practical on freezing of fruits.

52.2. Theory

Freezing is a method of preservation in which the food temperature is reduced below freezing point and a proportion of water changes in to ice-crystals. Immobilization of water to ice and the resulting concentration of dissolved solutes in unfrozen water cause lowering of water activity in the food. Thus, reduction in water activity and use of low temperature coupled with some pre-treatments is the basis for food preservation by freezing. The method for freezing of fruits depends upon the intended use. The process variables for freezing of different fruits and flow chart are shown in Table 52.1 and Fig 52.1. Generally fruits after preliminary treatments are packed in sugar syrup and frozen in freezer. The fruits are frozen to an internal temperature of -18oC or lower and kept at 18oC or lower throughout transport and storage.

51.1. Aim

To prepare products from tomato fruits.

51.2. Theory

Commercial products from tomatoes include ketchup, soup, cocktail, chutney, canned and dehydrated tomatoes. Processing of tomato is now practiced from home scale level to a large scale enterprise. Both puree and paste are used for preparation of different finished products like ketchup, canned and dehydrated products, soup etc. The method for preparation of these products are well standardized, however, some modification with respect to recipes are made in the processing plants owing to variation in the quality of the raw material. The method for preparation and recipe of different tomato products are as under:

51.3. Raw material, ingredients and utensils required

1. Tomatoes, sugar, salt, sodium benzoate etc.

2. Stainless steel knives, utensils, juicer, pulper, glass bottles, corking machine, crown corks, muslin cloth, boiler/gas bhatti, etc.

50.1. Aim

To prepare products from tomato fruits.

50.2. Theory

Commercial products from tomatoes include juice, puree and paste. Processing of tomato is now practiced from home scale level to a large scale enterprise. As a semi finished product, tomato puree is prepared on a small scale while at large scale tomato paste has gained commercial significance. Both puree and paste are used for preparation of different finished products like ketchup, juice, soup etc. The method for preparation of these products are well standardized, however, some modification with respect to recipes are made in the processing plants owing to variation in the quality of the raw material. The method for preparation and recipe of different tomato products are as under:

50.3. Raw material, ingredients and utensils required

1. Tomatoes.

2. Stainless steel knives, utensils, juicer, pulper, glass bottles, corking machine, crown corks, muslin cloth, boiler/gas bhatti, etc.

49.1. Aim

To perform practical on drying/dehydration of different vegetables.

49.2. Theory

Drying refers to the method of removal of moisture content from the food to a level at which the activities of food spoilage and food poisoning micro-organism are inhibited. Therefore, reduction in water activity of the food is the main principal of preservation by drying. In the dehydrator initial temperature is generally kept at 43oC which is then gradually increased to 60-66oC for vegetables. The product shall be prepared from wholesome vegetables free from blight, insect infestation and fungal discoloration. Only edible portion of the vegetables shall be used and it shall be free from stalks, peels, stems, and extraneous matter. The dried/dehydrated vegetable may contain permitted preservative. The finished product shall be of good edible quality and shall reasonably reconstitute to its original shape and quality on boiling for 15 minutes to an hour. The finished product shall be free from visible mould, insect or larvae. Kind of dry vegetable shall be declared on the label. Acid insoluble ash shall not be more than 0.5%.

48.1. Aim

To conduct practical on drying of fruits

48.2. Theory

Drying generally refers to the method of removal of moisture from the food under natural condition such as sunlight and wind for example open sun drying, shade drying etc. Dehydration refers to a process of removal of moisture by application of artificial heat under controlled conditions of temperatures humidity and air flow. It also represents drying of agricultural commodity to dry state. For drying, single thin layer of fruit and vegetables, either whole or sliced after primary pre-treatments is spread on the trays which are then placed inside the dehydrator or in the open sun for drying. In the dehydrator initial temperature is generally kept at 43oC which is then gradually increased to 66-71oC for fruits.