eChapters

1. INTRODUCTION

Fruits and vegetables are increasing in popularity in the daily diet of people of both the developed and developing countries. Product quality and quality evaluation methods are extremely important. The decisions concerning harvesting, maturity, ripeness and quality are based mostly on subjective and visual inspection of the external appearance of the fruits. The quality of fruits and vegetable is mostly based on size, shape, colour, gloss, flavour, firmness, texture, taste and freedom from external and internal defect. Many techniques for evaluating the external quality parameters are now available commercially. Internal quality parameters such as sugar content, acidity, oil content and internal defects however, are difficult to evaluate. Methods are needed to predict the internal quality of fruits and vegetable better without destroying them. Recently, there have been an increasing interest in non-destructive method of quality evaluation and a considerable amount of efforts has been made in this direction. The development of science and technology, especially of information technology has made available many non-destructive methods of analysis of materials which can also be applied to fruits and vegetables. The fruit industry needs non-destructive techniques for online sorting and certifying high quality fruit.

Non-destructive method can be classified according to the principle used to detect fruit properties; mechanical, acoustic, optical and Nuclear Magnetic Resonance (MRI) Techniques.

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.

1. INTRODUCTION AND IMPORTANCE

Sensory evaluation is one of the important methods of evaluation of the quality of food. Without the sensory evaluation of a product whether it is fresh or processed, it cannot be launched in the market. All the other methods like physical, chemical and microbiological fails for the product development if sensory evaluation is ignored as the final acceptance can come from the sensory evaluation only. So sensory evaluation has got an upper edge as compared to the other methods of food quality evaluation. However, a collective approach of quality evaluation of a product that includes the physical, chemical, microbiological and sensory evaluation is the most acceptable approach today.

In the past, human sensory perception had been the only mean of assessment of product quality as illustrated by the classical examples of cooks who knew how to mask the off-notes long before the microbial assessment of quality came into existence. Everybody relied on the sensory evaluation of food as a criterion of quality assessment. In the past, even the kings depended upon “tasters” to assure that the food was suitable for their consumption in the past. The role of sensory organs in sensory evaluation of food is shown in Table 1. But later on, with the development of instrumentation, sensory analysis was overlooked and the instrumental methods were preferred as they were supposed to provide absolute measures of quality. Consequently, the product quality was traditionally determined by physical, chemical and microbiological criteria with the assumption that the products meeting the prescribed specifications in the above parameters would automatically meet the desired sensory quality. However, soon it was realized that without sensory evaluation, the acceptability of a product cannot be determined.

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

Food processing involves the use of wide range of unit operations and technologies to transform the raw, bulky and perishable food into more shelf-stable, palatable and marketable food products. Food processing is one of the most effective solution to reduce the wastages, improves the quality and safety aspects of food products, increase the food availability and marketability. Fruits and vegetables are considered as an integral part of any dietary system as these are rich sources of vitamins, minerals and dietary fibres. India is the second largest producer of fruits and vegetables after Brazil and China which contributes 10 % of world fruit production and 14 % of world vegetable production. Fruits and vegetables are more prone to spoilage as compared to cereals due to their nature and composition. The spoilage can be occurr at the time of harvesting, handling transportation, storage, marketing and processing that results in lot of wastage in the form of seeds, pulps, peels etc. Efficient management of these wastes can help in preserving vital nutrients of fruits and vegetables, and bringing down the cost of production of processed foods, besides minimizing pollution hazards. In India, processing of fruits and vegetables is extremely low as compared to the developed countries.

Biotechnology can help in the bio-processing of fruits and vegetables for the production of novel products having better sensory and nutritional qualities, improved shelf life. Bio-processes involve the use of different micro-organisms and enzymes along with modern biotechnological techniques like genetic engineering.

1. INTRODUCTION

Flavour is a distinctive property of a substance affecting the gustatory sense. It may be defined as “The sum of those characteristics of any material taken in the mouth, perceived principally by the senses of taste and smell, and interpreted by the brain.” Flavour perception is a complex process which requires the particles to be mixed with saliva and salivary enzymes to promote the release of flavour. Flavour molecules are very diverse in nature. More than 5000 compounds in food have been identified as flavour components which can be detected at very low concentration and are thus, used in products at very low levels. Hexenols and hexenals, characteristic of green taste of fresh fruits and vegetables, can be perceived at a concentration of about 1 part per million (ppm). Naturally occuring flavour compounds are present at a very low concentration ranging from parts per trillions (ppt) to parts per millions (ppm) level. Majority of these compounds are volatile, with boiling points in the range of 20-300 °C. Most of these compounds are lipophilic and possess a great diversity of chemical group and structure with molecular weight ranging between 50-250 g/mol.

Flavour and fragrance compounds are a part of expanding industry with an estimated cost of nearly $27 billion. These comprise of diverse molecules with unique structures and functional groups that contribute to varied aroma and flavour, ranging from floral to fruity notes. The processing operations modify the equilibrium between the different components in raw food that might weaken the original flavour, which require subsequent supplementation. These flavour supplements can be natural or chemically synthesized. Of all the available flavour compounds, around 80% are produced by chemical synthesis whose use is limited due to formation of racemic mixtures and lack of substrate specificity. The growing awareness of consumers towards chemicals supplemented to food has led to the development of the flavouring compounds of biological origin referred to as natural flavours or bioflavours. The first major source of flavour compounds was primarily from plants. Identification of microbes producing vital food flavourants paved the way for alternative low cost, efficient and flexible method for the commercial production of flavour compounds.

1. INTRODUCTION

Colour affects every moments of our lives, strongly influencing the cloths we wear, the furnishing in our house and garden, and the appeal of foods. Not only this, colour aids the recognition of food and also has psychological appeal on the enjoyment of food. It is also one of the first characteristic perceived by our senses and help in determining acceptability, judging the quality and basic aesthetic value of food. Addition of colour to the food ensures the uniformity and intensifies the naturally occurring pigments in our food. To achieve this, historically natural or bio-colours have been used extensively till the end of 19^th century, when synthetic colours called ‘coal tar dyes’ were developed that acquired a widespread acceptability. But unfortunately, these are not totally safe for human consumption; for example high levels of erythrosine intake causes thyroid tumors, while Ponceau 4R, tartrazine and sunset yellow were found to be allergic. Many dyes used as colourant have been proved to be carcinogenic. The consumer wants to see the food looking natural as the synthetic colours have been proved to be carcinogenic to humans. Thus, increasing consumer awareness for natural products with almost no chemical additive and certified dyes (which was earlier considered safe) has necessitated the need to exploit food colourants of natural origin. Natural colours are generally extracted from materials of biological origin like fruits, vegetables, seeds, roots and microorganisms, and are often called as ‘Biocolours’. Microorganisms like Rhodotorula, Sarcina, Chromobacter have been proved to be a good source of biocolour.Colour has also been successfully produced from microorganisms using apple pomace as a base for the growth medium of biocolour producing microorganisms.

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.

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

Stone fruits belonging to family Rosaceae (sub family-Prunoideae) include several important fruit crops like peach, plum, apricot, cherries, nectarines etc. The World production of these stone fruits is approximately 45.49 million tones; out of which 39.61 million tones stone fruits are grown in Asia and India contributes 6.67 million tones of stone fruits annually. Among all the stone fruits Peach, Plum and Apricot production in world is 24.98, 12.05 and 4.11 million tones, respectively whereas India alone produces 287778, 261903 and 17862 metric tones of peach, plum and apricot, respectively (Table 1). These stone fruits are grown extensively in USA, Spain, France, Italy, Turkey, Morocco, Iran, Africa and Australia. In India, these are grown in J&K, Himachal Pradesh sub-mountainous tracts of Punjab, Uttarakhand, North East States and to the limited extent in the Nilgiris hills. Primarily, these stone fruits are used for table purposes or processed to prepare various types of value added products like jam, jelly, marmalades, preserves, baby foods, nectar, juices, squashes, concentrates, ready-to-serve beverages, wines and also processed into dried products.

1. INTRODUCTION

With diverse agro-climatic conditions, India produces a wide variety of horticultural crops and out of these crops and out of these apple (Malus x domestica Borkh.) occupies a prominent position in India. It is processed into different products like juice, concentrates, wine, cider, canned slices etc. Apple processing is one of the major industries in countries of the world including India, where it is processed in different states like H.P, Jammu and Kashmir and Uttarakhand. Apple pomace is a left-over residue after juice extraction containing peel, seeds and remaining solid parts and represents about 25-35% of the weight of the fresh apple processed. At prasent, it is a waste and its disposal is a major environmental problem (Plate 1). Being precious natural resources its utilization is a challenge and opportunity to the scientists and technologists. It may be a good substrate for the pectin esterase enzyme, animal feed, citric acid, ethanol and biocolour production. It could be a good substrate for the production of microbial colours under SSF which otherwise require a costlier medium for its production. Different products using solid state fermentation of apple pomace forms the subject matter of this chapter. Here the efforts made to utilize apple pomace especially to explore the possibility of making value added products using Solid State Fermentation (SSF) have been summarized.

1. INTRODUCTION

Food processing industries are engaged in production of different types of processed products and generate various types of wastes. These wastes, whether solid or liquid, on one hand are a direct loss to the producer or manufacturer and on the other hand create environmental pollution, if not disposed properly. Therefore, the processors would always like to minimize these wastes. The generation of wastes not only cause economic losses but would also require additional cost for their management and disposal. As a matter of fact, it is often estimated that proper use of efficient machinery and careful handling during various operations can lead to more than 50% reduction in losses.

In general, the wastes from the food processing industries are either not utilized or primarily utilized as animal feed, fertilizer and in preparation of by-products on a limited extent. Many of the wastes such as cuttings and shreds from the fruit and vegetable processing industry can be used as animal feed. Fruit and vegetables wastes can also be used for extraction of starch, pectin, natural colouring matter, fat, essential oils etc. Wheat and maize bran alongwith palm kernel are used for the production of feed for chickens. Various oils and oleoresins having enormous pharmaceutical properties can be obtained from the spice processing industry.

Fermentation is a cheap and energy efficient means of preserving perishable raw materials. It commonly does not require any sophisticated equipment, neither is the storage of fermented products a big issue. Fermented foods play an important role in providing food security, enhancing livelihoods and improving the nutrition and social well being of millions of people around the world, particularly the marginalised and vulnerable population across the developing countries.

1. INTRODUCTION

Wine is an ancient fermented product as revealed by the wine jugs recovered (Plate 1) during excavation from different places. Wine is made all over the world and wine produced in each region from different parts of the world has different characteristics. Development and implementation of practices and policies for sustainable growth of grapes and other fruits is the most essential component for the growth and development of wine industry. The science dealing with wine production, evaluation and consumption is known as 'Oenology'. For the introduction of wine, several aspects influence the wine quality are style, the consumer perception and finally, the marketing are taken in account. Factors related with fruit growing, ripening, micro organisms and other verification factors need to be considered in wine production.

1. INTRODUCTION

Wild fruits are highly nutritious and contain vitamins, carbohydrates, protein and minerals in higher quantity than majority of other common cultivated fruits. They are also a rich source of several bioactive substances, compared to the cultivated fruits. In India,these wild fruit trees grow abundantly across an altitudinal gradient of Himalaya and the majority of them bear fruits during summer. Fruit varieties are consumed by the local inhabitants of the region. At the same time, there are numerous under exploited species of wild fruits having high potential for exploitation viz., Bael (Aegle marmelos CL.), Berberis asiatica DC, Seabuckthorn (Hippophae sp.,) Rubus sp., Prunus armeniaca L., Karonda (Carissa carandas L.) Bitter Almond (Prunus amygdalus Batsch Smith), Feijoa sp. Among the wild fruits, Hippophae sp.was found to be economically efficient, followed by Aegle marmelos, Rubus ellipticus Smith, respectively. Wild apricot (Prunus armeniaca L.), a semi-domesticated and less utilized fruit of the higher Himalaya, provides better economic returns on an annual basis. Attempts have been made to utilize these wild fruits as a source of income, particularly for poor rural inhabitants and unemployed youths of the region by making a variety of edible products such as jam, jelly, juice, squash, sauce, wine etc. Here in this article, production of wine, vermouth and brandy from wild fruits would be focused. But before discussing preparation of wine and brandy in detail, we shall be describing the general process of wine and brandy making first, then the products from the specific wild fruits.

1. INTRODUCTION

Wine is the alcoholic product obtained by fermentation of fruits like grape, plum, peach, pear, apple and apricot (see chapter 25). Different types of wine which can be made from various fruits are:

• Table wines
• Fortified wines
• Sparkling wines

In preparation of table, fortified and sparkling wine many steps are common. It is out of scope of this text to discuss these specialized wines. But the general steps involved to in wine making are described here.

1. INTRODUCTION

Admitably except for water and milk, no other beverage has earned such universal acceptance and esteem throughout the ages as wine. The aesthetic postures of wine can be gauged by the quotations like ‘wine is the most healthful and the most hygienic beverage (Louis Pasteur)’, ‘wine is a chemical symphony (Amerine). Man has been preparing and consuming since time immemorial a large variety of alcoholic beverages, ranging from mild stimulants to highly intoxicants liquors. Amongst the mild stimulants are the wines which have long association with human artistic, cultural and religious activities.

Grapes and wines are of immense importance to us and their sheer magnitude of production and associated investment, employment, enjoyment, tax revenue collected and the economic contribution is a justifiable. These play a major role in economics of major wine producing countries like Italy and France. Wine and brandy refer to the fermented by-products of grapes, member of genus Vitis notably the cultivars of V.vinifera L. as per the European definition. However, here these terms may also refer to the fermented by-products from any fleshy fruit or flower. Compared to the grapes, industry producing wine from other fruits is very small. Do these have any role to play especially in nutrition, health and economy of the horticulturally developed countries or are simply mild intoxicants consumed? Such queries at one or the other time may baffle the thinking of an inquisive reader. An attempt has been made here to discuss briefly the historical aspects, role of wine in the context of nutritive and therapeutic value, present status of Indian Wine Industry, research status and future strategies. Emphasis on its role in developing the horticultural industry would also be laid.

1. INTRODUCTION

Vegetables occupy a prominent position in our diet especially to tone up our digestive system and provide nourishment. Regular use of vegetables, supply many essential health building and protective substances, such as vitamins and minerals. India ranks second in vegetable production in the world. The abundant production of vegetables during the season, results in a glut. Consequently, a large quantity of vegetables gets spoiled resulting in a considerable loss of natural resources. Therefore, preservation is the best way to save the wastage of vegetables and make them available even in the off-season (Plate 1).

1. INTRODUCTION

Fermentation is an age old technology. It has been used by man since antiquity. It has been employed to produce a number of fermented products such as wine, beer, curd, vinegar, pickles and several others. Fermentation was discovered quite early and by chance but the underlying principles were discovered very late. Primarly fermentation was used as a method of shelf-life extension of the produce in the time of glut production, though the final product had modified sensory qualities. Thus, fermentation and drying were the main methods of preservation. With the discovery of new methods of preservation, fermentation as a method of preservation has gone into background and as technique of flavour development and product with modified sensory quality came into practice. In this chapter, fermentation as a method of preservation has been described.

1. INTRODUCTION

Food fermentation is the oldest method of food preservation and have originated several million years ago. It plays an important role in ensuring the food security of millions of people around the world particularly marginalized and vulnerable groups. It is relatively efficient, low energy consuming process which needs no refrigeration or other energy intensive food preservation technologies but increases the shelf-life of foods. Fermentation ensures not only increased shelf-life and microbiological safety of food but may also make some foods more digestible and lower or eliminate the toxicity of substrate like cassava.

The food fermentation technology utilizes the ability of growth of microorganisms on various substrates for the production of a variety of fermented foods, beverages and pickles like bread, beer, cheese, idli, tempeh, miso, sauerkraut, fermented sausages, etc. Fermented foods are popular throughout the world since antiquity and in some regions these are the major component of the diet of millions of individuals. Indigenous fermented foods such as bread, cheese and wine have been prepared and consumed since ages and have occupied important place in culture, religion and tradition of people all over the world.

1. INTRODUCTION

Since vedic times, importance of fermented milk and its products was known but the major attention to probiotic and its health related benefits was gained after Eli Metchnikoff’s publication entitled “The prolongation of life” in 1908. Due to the awareness of the role of nutrition in health and well-being, improved knowledge of diet-related diseases, consumer demand for probiotic and prebiotic products has been increased in recent years. The link between diet and health is flourishing the market for health-embracing population and opens an opportunity for Food and Dairy Industries meet the demand of this market. Probiotics, constituting live micro organisms, have been incorporated into drinks, food products, supplements (tablets, capsules and freeze–dried preparations) and prebiotic products. Milk, milk based products, fruits and vegetables are rich in functional food components such as minerals, vitamins, dietary fibers, and antioxidants (phytochemicals). Application of probiotic bacteria in such products further enhances the nutritional value of the food product. Probiotic juices produced from fruits and vegetables have also been in consideration in recent years. The food market is being getting captured by pro- and prebiotic food products day-by-day. Even the agro-industrial by-products such as whey, wheat straw, rice straw, sugarcane bagasse, etc. are being explored for the economical and cost effective production of prebiotic molecules. Thus, this chapter gives a comprehensive overview of pro- and prebiotics and their market potential.