eChapters

Introduction In today’s environment, the greatest challenge for the food industry is to develop health promoting foods; it is determined by the raw materials used and its impact on consumer health. Furthermore, people lifestyle has changed greatly, resulting in a change in food eating patterns. In today’s world, people are moving towards eating foods that are nutrient base and tasty (Bonciu, 2018). of all the nutrient based products available in market, expanded snacks have become a popular snack all over the world because of its crunchy texture and low density making it consumer’s acceptance (Grasso, 2020). The basic idea for developing any expanded snacks is utilizing a starch-based material for a better crispy and crunchy product, but to make it more nutritious incorporation of protein and fibre rich raw materials is recommended (Gu et al., 2017). Along with the raw materials, the other important parameters for developing any extruded product is the particle of the flour, its physicochemical and rheological properties of the extrudates are much concentrated (Bouasla & Wójtowicz, 2021) Thereby, extruded snack is considering as functional food with major health benefits.

1. Introduction

Foods available in nature and, in some cases, the products made from it thereof contain quite an amount of water. This water not only adds volume to the food products but also provides a sight for attack by the micro organisms. Also, removal of water becomes essential if this water interferes with the end product chracteristics. There are several processes in food industries which are designed to get rid of this excess water, such processes are called concentration processes. The processes which can remove water from food substances are,- evaporation, freeze concentration and membrane based processes. All these process have their limitations in rendering solid content to the final product (Fig. 1). Perhaps, these limitations can be overcome by combinig the processes.

The objectives that are fulfilled by the concentration processes can be enumerated as follows:

7.1 Introduction

Evaporation is an unit operation which converts a liquid into a vapour, leaving behind a concentrated solution or a higher boiling liquid. In other words, the goal of evaporation is to vaporize most of the water from a solution containing a desired product. Heat is the main tool in evaporation, and the process occurs more readily at high temperature and low pressures. Removal of water from foods provides microbiological stability, reduces deteriorative chemical reactions, and reduces transportation and storage costs. Evaporation can be distinguished from some other drying methods in that the final product of evaporation is a concentrated liquid, not a solid. It also differs from distillation, since the vapours produced in the evaporator are not further divided into fractions.

Introduction

Baking is not a new concept to us. Baking process dates thousand years back since the Paleolithic age. During those days, the baking was done by simply grinding the grains, mixed with water and baked on the hot rocks. The bread produced that time was not leavened but flat. Ancient Egyptians have the credit for development of baking between 2600-1200 BC. Roman Empire also had the popularity of the art of baking and bakeries were in existence in Europe too during Middle Age. Baking was considered a highly respected profession under the Roman Empire. The art of baking has travelled a long journey since then. The bakery and confectionary has undergone a gradual evolution with time. Great technical progress stared in the nineteenth century. Development of automatic machines reduced the task of the manual labour and because of this development the bakers could perform many more tasks with the machines. Today’s baking has a dependency on the machines. All the work is performed by the automated machines whereas the bakers only control the machine operations. The baking process has become easier, the efficiency has increased and the quality of the products has improved because of these high-tech machines. The preparation of bakery products using traditional methods has also improved over the time to minimize the energy and time consumption. Today’s consumer is very much concerned about his/her health and look for the healthy options in baked products. The trend has led to various innovative formulations for the baked products so that the health benefits may also be provided not only the calories. This chapter will discuss various advancements and trends in different types of bakery and confectionary products.

Horticultural sector, which is contributing significantly for food and nutrition security, employment opportunity and poverty alleviation, got a real boost only in the early 1990s which coincided with liberalization of Indian economy. National area and production of horticultural crops are showing increasing trend over the years and production of horticultural crops has outpaced the production of food grain since 2012-13(Press Information Bureau, Govt. of India, Ministry of Finance, 2016). According to Economic Survey 2015-16, the share of horticultural output in agriculture is more than 33% over last decade and the sector contributes 30.4% to GDP of Agricultural sector. Horticulture sector accounts for 37% of total export of agricultural commodities at present and the exports have recorded sustained rising trend (Jha et al., 2019). The export status of APEDA (Agricultural and Processed Food Products Export Development Authority) products in the recent years shows 28.18% growth in value of horticultural products over the previous year. The investment in horticultural sector with focused attention has resulted in spectacular change in the horticultural scenario and production and productivity of horticultural crops.

5.1 Present Status

Export of pomegranate has decreased in quantity from 36,027.43 tons in 2012-13 to 20,997.02 tons in 2014-15, whereas in value term it show an increase trend during the same period. There is tremendous potential for exports of pomegranate from India and it is fact that India is largest producer of pomegranates in the world. Moreover, India produces finest edible quality of pomegranates which are available almost throughout the year. The major Markets of India’s pomegranate during the year 2014-15 were UAE, Nepal, Saudi Arabia, Kuwait and Netherland.

1. Introduction

India is a land of large varieties of fruits and vegetables due to its vast soil and climatic diversity. India is the second largest producer of fruits and vegetables in the world, with an annual production of fruits 45.5 Million tonnes and vegetables 90.8 Million tonnes. It contributes 10.23% and 14.45% of the total world production of fruits and vegetables (F&V) respectively (NHB, 2010). Though fruits and vegetables are grown only on 7–8% of gross cultivated area, these contribute more than 18.8% of the gross value of agricultural output and 52% export earnings from total agricultural produce. These have a high export potential of 20-30 times more foreign exchange per unit area than cereals due to higher yields and higher price available in the international market (Sen et al., 2012). According to estimates, the per capita consumption of fruits and vegetables in India is only around 46g and 130g which are far below the stipulation of a minimum of 92g and 300g respectively as recommended by the Indian Council of Medical Research and National Institute of Nutrition. The low availability is mainly due to considerably high post-harvest losses. About 15-20% of the fruits and vegetables are wasted every year in the country, due to poor post-harvest management and lack of infrastructural facilities for processing and storage, amounting to a revenue loss of over Rs. 625 billion.

The sensorial, nutritional, and organoleptic quality of fresh produce starts deteriorating after harvest as a result of soon after harvest the altered plant metabolism and microbial growth. The quality deterioration is the result of produce respiration and transpiration, senescence, ripening-associated processes, wound-initiated reactions, development of postharvest disorders, microbial proliferation leading to postharvest quality loss. Therefore, it is necessary to understand the respiration and ripening processes and the physiological and biochemical changes during ripening. The best way to reduce respiratory metabolism is to reduce the storage temperature. All biological processes proceed more slowly at lower temperature (Yahia, 2007). In general, O₂ levels must be reduced to less than 10 % to see a reduction in the rate of respiration. Respiration rate is temperature dependent; so, as the temperature reduces the amount of oxygen required also drops. Therefore, oxygen levels must be substantially reduced at low temperature for it to affect the rate of respiration. It must however, be ensured that O₂ levels do not fall below extinction point as anaerobic respiration and decay may occur. Tolerance to low O₂ varies between species and cultivars and is also time dependent. Commodities may be able to tolerate low O₂ for short periods of time. Low O₂ can also be tolerated when CO₂ is low.

Materials Required

Fruit, pulper, fruit mill, hydraulic press, screw type juice extractor, stainless steel pans, chemical preservatives, glass bottles, closures, crown corks, crown corking machine, plastic barrels.

Procedure

    1.    Select and weigh sound fruits/vegetables for extraction of juice/pulp.    
    2.    Wash and peel the fruits as required.
    3.    Extract the juice by hot or cold process.
    4.    Pasteurize the juice/pulp to inactivate the enzymes and partially kill microorganisms.
    5.    Preserve the juice/pulp by heat processing after hot filling and hermetic sealing or by addition of permissible quantities of suitable preservatives.
    6.    Label the bottles properly and keep them for storage

EXPERIMENT

TECHNOLOGY FOR EXTRACTION OF KERNEL OIL FROM STONE FRUITS

Apricot, peach, plum, cherries, nectarines etc are the important stone fruits belonging to the family Rosaceae. These fruits are known to contain stones/pits i.e., apricot (6.0-11.5%), peach (7.5-11.5%), plum (4.5-7.0%) and these stones are reported to contain kernels (%) apricot (28.0-32.0%), peach (5.7-5.9%), plum (10.0-20.8%), almond (28.0-30.0%). These kernels can yield an oil yield of (42.5-45.5%), (38.5-41.5%), (39.2-40.6%) and (52.0-58.9%), respectively. Thus, these stone fruit kernels can be utilized for extraction of kernel oil by using the improved technology developed for extraction of oil. The developed technology consists of mechanical decortication of stones by the use of mechanical decorticator, kernel separation by using specific gravity separation technique, oil extraction by using table oil expeller and oil filtration through oil filter press followed by packing in PET bottles and PE pouches.

Mechanical decorticator: The mechanical decorticator is a type of roller crusher consisting of two rollers moving in inward opposite directions with the help of 3 HP motor and is provided with a hopper and feeder assembly. The clearance between two rollers is adjusted according to the respective size of stones.

Table oil expeller: Oil expeller is a 24 patti screw type oil expeller driven by 7HP motor, in which the kernels are fed into the moving hopper at pre-determined flow rate, which are pressed in between rollers (worm) and side walls of the expeller. The kernels are then, passed through the expeller 3-4 times until a thin slice of press cake is obtained.

1. Algal Biomass

Algae is defined as heterogeneous assemblage of organisms that range in size from tiny cells to giant seaweeds, thus algae mostly are photosynthetic species which include eukaryotes and prokaryotic Cyanobacteria (blue-green algae) and live in aquatic habitats. They are ubiquitous in nature and are found in variety of environments ranging from soil, sand, marshes, brackish water, sea and fresh water. Most of them are capable of manufacturing their own food.

Microalgal research is offering wide potential in food biotechnology and is gaining more attention because of presence of wide range of bioactive and nutraceutical properties and added health benefits.The increasing population is one of the major growing concerns of today’s world. To meet the nutritional requirement of the rising population, researchers are looking for optional sources for food which are easy to cultivate, cost effective and produce large amount of bioactive compounds useful to prevent major diseases. Chlorella is unicellular green alga that is a potential source of nutrients like carotenoids, minerals, vitamins, and polyunsaturated fatty acids. Especially, omega-3 fatty acid and carotenoids have received considerable interests due to their roles in the prevention of chronic diseases. Lutein and zeaxanthin from Chlorella have been shown to be associated with eye health and function. Beta-carotene is known to reduce the risk of CVDs and certain cancers. Animal studies also demonstrated that Chlorella supplementation reduced the serum cholesterol levels.

Similarly, the blue green microalgae Spirulina, possesses diverse biological activities and nutritional significance. Regular consumption of Spirulina fortified food improves immune system by increasing phagocytic activity of macrophages, stimulating the production of antibodies and cytokines, increase accumulation of NK cells into tissue and activation and mobilization of T and B cells. Spirulina have also shown to perform regulatory role on lipid and carbohydrate metabolism by exhibiting glucose and lipid profile correcting activity in experimental animals and in diabetic patients. They were also found to be active against several enveloped viruses including herpes virus, cytomegalovirus, influenza virus and HIV. They are capable to inhibit carcinogenesis due to antioxidant properties.

Food extrusion technology is a popular means of preparing snacks and ready-to-prepare food items. It is a method of size enlargement in which tiny granular food or powdered particles are strengthened into bigger parts with various forms, texture, color, etc. Extrusion cooking or thermoplastic extrusion is a common extrusion technology considered to be a process of HTST (high temperature, short time). It allows the manufacturing of a wide range of food products with little or no alteration of the fundamental equipment and adequate process control. Extrusion cooking is used for starchy and protein substances to make nutritious foods. Generally, such products are rich in calories and incorporation of protein rich fish improves its nutritional value. Most of the cereal-based extruded snacks were primarily made from maize, wheat and rice. However, these cereals (e.g. rice) have comparatively low protein content (6 - 8 g/100 g db) and an elevated amino acid profile in glutamic and aspartic acid, whereas lysine is the restricting amino acid. Therefore, it is recommended that protein food ingredient (e.g. fish) be added to the extruded snack products to develop nutrient rich diets.

Fish is considered to be great sources of protein of high dietary importance with a balanced profile of essential amino acids and lipids containing omega-3 fatty acids, in particular essential fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively. EPA and DHA are very essential to normal growth and development. To avoid or moderate coronary artery disease, hypertension, diabetes, arthritis, other inflammatory and autoimmune illnesses, these vital fatty acids are discovered. The benefits of fish-based extruded products will assist in providing a big population in the nation like India with nutritious and balanced diets.

Extrusion cooking is an emerging technology having advantages of low production cost, capable of producing end products in various shapes and sizes, from a variety of food materials with easy digestibility, maintaining hygiene and high product quality and leaving no effluents or hazardous materials. Minimal energy consumption and processing costs and possibility of flavour addition are the added advantages of technology. The process/technique has the versality and ability to constituently produce a given product in continuity at a given set of pre – determined specifications. It destroys fat splitting enzymes to avoid rancidity and thus extends the shelf life of products considerably. Microorganisms present in food materials are destroyed. It can be effectively utilized to develop functional and designer foods by using several locally available under-utilized food materials. However, it leads to increased package cost as puffed or expanded food products have low bulk density. R & D studies are further needed for co – extrusion of variety of cereals with high fibre content foods and micronutrients.

1.1 Introduction and Background

In present scenario, the word “extrusion” refers to a process by which dry or semi-moist ingredients with varying in-barrel moisture are forced through varying barrel temperature, screw speed and screw configuration through a die opening of the desired cross section. In other words, extrusion is predominantly a thermo-mechanical processing operation that combines several unit operations, including mixing, coating, kneading, venting, shearing, heating, forming, partial drying or puffing, depending on the material and equipment used.

The origins of extrusion are in the metallurgical industry, where in 1797 Joseph Bramah patented the first extrusion process, wherein a piston driven device was used for making seamless lead pipes. The present understanding of extrusion technology and the developments or improvements in machine design are largely due to research carried out by the plastics industry. In food industry, this technology is in use since 1930 and its popularity is increasing continuously due to its efficiency, continuity and sustainability. In beginning, sausage extruders were developed in the nineteenth century as simple forming machines. One of the original developments which laid the foundation of the food extrusion was the use of pasta press termed as “cold extruder” in mid 1930s. Furthermore, in the late 1930s, General Mills, Incorporation., Minneapolis, MN, USA, first used a single screw extruder in the manufacture of ready-to-eat (RTE) cereals. Later in 1970s, twin screw extruders were used for the manufacture of moist pet-foods. Twin screw extruders were also adapted from polymer industry, as rising food quality and limitations of single screw extruders were demanding a more versatile process for the newer and higher quality products. After 1970s, the extrusion processing with simultaneous use of heat was popularized as a versatile and highly energy efficient with negligible wastage process. In all these years, number of changes has been noted in the extruder design such as changes in screw design, barrel design and also material used for the manufacture of these materials. Barrel liners availability along with already available segmented screws could further add more economics to the process and increased equipment lifetime. For better wearing characteristics, a number of screw elements of different materials are being used in addition to standard nitrided steel for customized processing needs, such as corrosion and wear resistant surface coated steels, stainless steel, satellite welded and bimetallic HIP (Hot Isostatic Press). JBL Feedscrews Limited, a UK based company recently introduced tungsten carbide coated screw in conjunction with a compatible bimetallic barrel. Likewise, a number of options for barrel metallurgy are available to withstand the higher internal pressure and temperature. Barrels lined with hard cobalt based alloy, typically Xaloy, to give abrasion and chemical resistance are also in use, although, the most common material is carbon steel with a nitride interior. Similarly, steam heated or jacketed barrels were used earlier for cooking purpose which gradually replaced by the electric induction heating elements. These HTST cooking extruders are versatile, highly productive and energy efficient processing machines. They can use a wide variety of raw materials and formulations to produce products with increased shelf-life and convenience.

F0 value: It is used to express F-value when z =10oC / 18oF and the temperature is 121.1oC. It is the number of minutes at a specific temperature (250oC) required to destroy or kill a stated number of microorganisms and has specific z-value. It is also called reference value.

Facing or lining board: The layer of the paper on which the flute is embedded is called facing or lining board (Plate 258).

Facultative anaerobic: Organisms that grow either with or without oxygen.

Facultative parasites: Facultative parasites can adapt to live on dead organic matter and often have a wide host range and can easily be cultured on artificial media. These organisms may be aerobic or anaerobic but under changed conditions, they changes to anaerobic or aerobic.

Falling rate period: It is that part of the drying process during which the drying rate varies with time and the instantaneous drying rate per unit surface or weight of dry material continuously decreases. Falling rate takes place when most of the moisture has been evaporated during constant rate period. The falling rate period during dehydration take place in the final stage of dehydration when the food commodities have large amount of free water available for evaporation. Here, rate of removal of the moisture from the food to the surrounding is continuously decreasing / falling per unit time.

    1.    Wohler (1828) synthesized the first organic compound, urea from inorganic components.

    2.    Emil Fischer (1894) demonstrated the specificity of enzymes and the lock and key relationship between enzyme and substrate.

    3.    Michaelis and Menten (1913) developed kinetic theory of enzyme action

    4.    Watson and Crick (1953) Proposed the double-helical model for DNA structure

    5.    Ingo potrykus (1999) Golden rice- rich in b-carotene.

    6.    Glyoxysomes : Glyoxysomes are temporary in that they occur during transient periods in the life cycle of a plant such as in certain beans and nuts which store fats in their seeds as energy reserves. Glyoxysomes appear in the first few days after seed germination in endosperm cells and associate closely with lipid bodies. They disappear after the storage fats are broken down and converted into carbohydrate.

Fats are obtained from both animal and vegetable sources. The principal animal fats are cream, butter, egg yolk, the fat of beef, mutton, pork, bone marrow, chicken fat, and codliver oil. Vegetable fats are those derived from fruits and seeds of plant, as olive oil, cottonsed oil, corn oil, peanut oil, soyabean oil and nut oils.

COMPOSITION AND NUTRITIVE VALUE OF FATS

Fats and oils, the most concentrated of fuel foods, were the first of the organic compounds or foods to have their composition determined. They are made up of same three elements which go to produce the carbohydrates, but the oxygen is less in proportion to the carbon. This explains the fact that fat yields more energy per gram than carbohydrates do.

Lipids are a class of compounds that are defined by how they are isolated, rather than by their composition. Lipids are molecules that can be extracted from plants and animals by low polarity solvents such as ether, chloroform, or even acetone. They are not appreciably soluble in water. Fats and the fatty acids from which they are made belong to this group as do oils, waxes and steroids. Hydrolyzable lipids are those that contain a functional group that will react with water. The functional group is usually an ester and the list of compounds includes neutral fats, waxes, phospholipids, and glycolipids. Non- hydrolyzable lipids lack such functional groups and include steroids and fat-soluble vitamins (e.g. A, D, E, and K).

Fats and oils are composed of triacylglycerols. These are compounds prepared by the union of glycerol (1,2, 3-tri- hydroxypropane) and 3 fatty acids to form a triester. Fats and oils belong to a group of biological substances called lipids. Lipids are biological chemicals that do not dissolve in water. They serve a variety of functions in organisms, such as regulatory messengers (hormones), structural components of membranes, and as energy storehouses. Fats and oils generally function in the latter capacity. Fats differ from oils only in that they are solid at room temperature, while oils are liquid. Fats and oils share a common molecular structure. The fats and oils contain three ester functional groups. Fats and oils are esters of the tri- alcohol, glycerol (or glycerine). Therefore, fats and oils are commonly called triglycerides, although a more accurate name is triacylglycerols. Triglyceride molecules contain mostly carbon and hydrogen atoms, with only six oxygen atoms per molecule. This means that fats and oils are highly reduced (un-oxidized). Oils are particularly common in seeds, where the stored energy helps seedlings during germination, until they can exploit solar energy through photosynthesis. Fatty acids contain an even number of carbon atoms, from 4 to 36, bonded in an unbranched chain. Most of the bonds between carbon atoms are single bonds. If all of these bonds are single bonds, the fatty acid is said to be saturated, because the number of atoms attached to each carbon atom is the maximum of four. If some of the bonds between carbon atoms are double bonds, then the fatty acid is unsaturated. When there is only one double bond, it is usually between the 9th and 10th carbon atom in the chain, where the carbon atom attached to the oxygen atoms is counted as the first carbon atom. If there is a second double bond, it usually occurs between the 12th and 13th carbon atoms, while a third is usually between the 15th and 16th.

Introduction India is a country of festivals and celebrations. Indian sweets enjoy a legendary reputation across the world. India is home to a number of delicious sweets that play a vital role in every Indian celebration. While gulab jamuns, rasgullas and kaju katlis may be the most popular sweets in the country (Pal Sanchari, 2016). Functions and events in India are celebrated with intake of sweets. Also, it is customary to sweeten the mouth in social gathering like marriage, birthday, poojas, etc. (Gulati and Misra, 2014). In the past few years, guidelines are formulated based on analyses of all published scientific studies on the consumption of sugars. In view of the rising prevalence of overweight, obesity and related disorders globally, in 2002, the WHO recommended that sugar should be less than 10 percent of daily calories. The consensus dietary guidelines for Indians in 2011 recommend less than 10% of total calories from free sugars per day. In May 2014, the expert panel of WHO recently recommended decreasing sugar intake to 5% of total calorie intake to combat obesity. A high intake of added sugars is a primary risk factor for diabetes. It is these added sugars in sweets that makes them palatable, but also does the physical damage. (Willet Brian, 2011). People have developed taste towards food in which fat and sugar contents are high.

Fermentation was known to mankind from time immemorial. But, development of biochemical principles of  fermentation  was originated by  Lavoisier in France in 1789 by way of analysing chemical composition of  sugar and its fermentation products such as ethanol, carbon dioxide and  acetic acid. Many products are produced by fermentation process. In fermentation, controlled action of selected microorganisms is used to alter  texture of foods, preserve foods by production of acids or alcohol or to produce fine flavours and aromas which increase value of raw materials.

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).