eChapters

1. Introduction

Heat transfer from a hot surface is a general method or technique of heating liquids and slurry type of food materials. In such cases the heat can be generated either directly by a heating element or indirectly from a hot medium like steam or hot water via a heat exchanger (e.g. shell and tube, plate). Therefore, for the heat transfer during heating by these techniques a temperature gradient will be required, which usually causes the fouling on the surface of the heating element or heat exchanger. Afterwards the fouling not only reduces the heat transfer rate but also results in quality deterioration within the product which is being processed. 

1. Introduction

Thermal processing treatments are the conventional methods that have been broadly employed in the food industry to guarantee the microbiological safety of food materials at a minimal cost. However, these thermal treatments cause undesirable changes in flavor, nutritive value, texture, or color of the finished product that impact food quality (Pan et al., 2017). Growing the modern consumer’s demand towards the minimally processed and “fresh-like” taste foods has challenged the food industry to develop novel non-thermal preservation techniques as an alternative to thermal processing. 

1. Introduction

In recent years, consumers have been demanding convenient, healthy and safe foods which have ’fresh-like’ characteristics with a long shelf-life. These demands include important food quality such as appearance, texture, taste and nutritional content which are strongly impacted by the way it is processed. Another major concern among the consumers is food safety and quality. The shelf-life of the food products are mostly influenced due to the action of various harmful microorganisms and enzymes. The conventional food processing technologies, such as thermal treatments (pasteurisation and high temperature sterilisation), evaporation, drying, frying and baking can assure the microbiological safety and/or stability of processed food products, but affects the food quality and nutrients (heat sensitive vitamins, flavour and other bioactive compounds) (Zhang et al., 2019)

Eggs are considered as Nature’s original functional food because they are abundant source of nutrients like vitamins and minerals. It contains valuable nutrients from the high-quality protein to significant levels of beneficial vitamins, antioxidants and other healthful compounds. The protein of eggs is considered as highest quality protein as compared to other animal protein sources which is readily available and most inexpensive. Eggs are good source of all well balanced nutrients for persons of all age groups. Egg is a unique combination nutrient like it is rich in protein and low in calorie. The nutrients concentration in eggs is dependent on breed, strain, species, feed, age, season, storage and processing methods.

The nutritional value of eggs lies chiefly in their proteins of good biological value; an average-sized egg (60 g) provides approximately 7 g of proteins. These proteins are rich in essential amino acids with a very good balance between these amino acids. So the egg protein can be regarded as a reference protein. On comparison we can say that 2 eggs provide as much protein as 100 g of meat or 100 g of fish. The energy value for an average egg (60 g) is approximately 376 Kj (90 kcal). The lipid content is 7 g, most of these lipids being contained in the yolk. Among the total fatty acids 2/3^rd of these are unsaturated. Egg also contains 180 mg of cholesterol and rich in vitamins (A, D, E) and trace elements (iron and zinc).

Introduction

Nanotechnology is a rapidly expanding branch of science that has a critical role to play in raising the standard of living for people in the modern world. The global market for nanotechnology in food packaging is valued at 20 billion in 2023 and is expected to grow to 46.50 billion by 2031, with a compound annual growth rate (CAGR) of 11.32% from 2024 to 2031 (InsightAce Analytic, 2023). The rapid expansion of nanotechnology has paved the way for number of industrial areas, including food processing, food contact materials, and agricultural output (Mohammadi & Jafari, 2021). Nanotechnology is the fastest-growing field of science that significantly enhances the quality of life in today's world. This rapid advancement has opened up numerous industrial sectors, such as food processing, food contact materials, and agricultural production. A natural advancement is the integration of nanotechnology into food packaging. This includes enhanced packaging, active packaging, and a new category known as smart or intelligent packaging. Food contact materials, such as antimicrobial metals and oxides, biodegradable nanocomposites, and nanosensors, are utilized to create active and intelligent packaging. These materials enhance thermal and mechanical durability, increase safety and extend the shelf life of food, and facilitate the monitoring of packaged food (Kah et al., 2013). At the nanoscale, material properties change significantly, making it challenging to predict, identify, evaluate, and manage the health, safety, and environmental risks associated with nanomaterials. For example, nanoparticles (NPs) of 50 nm can enter cells, those of 70 nm can penetrate the lungs, and 30 nm NPs can cross blood-brain barriers.

Food preservation methods are important in order to avoid glut or shortage of food in the market. In addition it helps to increase the shelf life, maintain the nutritional and sensorial quality, facilitate transportation and improve the overall value of the commodity. Even though various methods of food preservation are available now. Most of the conventional methods are thermal preservation methods which may result in the loss of volatile nutrients and flavour, different sensorial modifications, microbial spread with or without gas production, damage to the microstructure, rupture of coating or packaging surfaces and microbial recontamination caused by non-hermetic closure.

Successful onion cultivation begins with vigorous, disease-free seedlings and their timely establishment in the field. Seed quality, nursery-bed preparation, growing medium, nutrition, irrigation, weed control and protection against pests and diseases determine seedling performance. This chapter explains conventional and modern nursery-management practices, including raised beds, plug trays, protected structures, soilless media, fertigation and climate-controlled production. It also discusses seedling selection, hardening, transplanting age, spacing and field establishment. Mechanized, robotic and precision transplanting systems are examined as solutions to labour shortages and uneven planting. Climate-resilient nurseries, sensors and automation can further improve transplant survival, resource efficiency, uniformity, productivity and sustainability.

8.1    Climatic Conditions
    
8.2    Water
    
8.3    Spacing
    
8.4    Crop Nutrition
    
8.5    Pests and Diseases
    
8.6    Bunch Covering
    
8.7    Maturity and Maturity Indices
    
8.8    Maturity vs Shelf life and Quality
    
8.9    Pre-Harvest Sprays
    
8.10    Harvesting

For a researcher, laboratory is another home where he/she spends much time every day. As we take care of cleanliness, safety, and design of our home, we must take care on these aspects of laboratory too. It is the responsibility of the laboratory personnel to ensure cleanliness/safety of the laboratory. Since every laboratory chemical and equipment have the potential to cause harms if not used with appropriate precautions. Hence, as a laboratory user, it is our responsibility to follow the basic safety/biosafety rules and regulations set up by the Principal Investigator of the laboratory, Institutional Biosafety Committee, as well as by other regulatory authorities, if any. We must be aware of the general/personal protective measures, cleanliness and laboratory waste disposal prior to joining a research laboratory. In this chapter we will briefly discuss about personal safety, chemical safety, cleanliness, waste disposal, etc.

A. Personal Safety

1. Personal Protective Equipment (PPE)

Personal protective equipment (PPE) is special arrangement to protect the worker from specific hazards because of using a hazardous substance. PPE does not reduce or eliminate the hazard, but protects the wearer from exposure to hazardous material. PPE should not be reused or brought outside the laboratory as these might increase the risk of spread hazardous material or contamination. Used PPE must be kept inside the laboratory in a designated waste storage area adjacent to the work area.

Processing extends onion availability and transforms perishable bulbs into stable, marketable products such as dehydrated flakes, powder, paste and pickles. Onion is also rich in phenolic acids, flavonols, anthocyanins and organosulphur compounds associated with antioxidant, antimicrobial, anti-inflammatory and cardioprotective properties. This chapter explains processing operations, quality preservation and the commercial importance of value-added onion products. It also addresses the large quantities of peels, outer scales and trimmings generated during processing. These residues contain quercetin, polyphenols, dietary fibre and other useful compounds that can be recovered for functional foods, nutraceuticals, natural antioxidants, biofuels and biodegradable materials, supporting waste reduction and a circular bioeconomy.

Abstract

The conventional methods of pathogen identification have often depended on identification of disease symptoms, isolation and culturing of the organisms, and identification by morphology and biochemical tests. The major limitations of these culture based morphological approaches, however, are the reliance on the ability of the organism to be cultured, the time consuming nature and requirement of extensive taxonomic expertise. Furthermore, diagnosis of plant diseases can be even more difficult with asymptomatically infected propagative materials such as tree grafting stocks or potato tubers. The use of molecular methods can circumvent many of these shortcomings. Accordingly, there have been significant developments in the area of molecular detection of plant pathogens in the last three decades. The polymerase chain reaction (PCR) which revolutionised molecular diagnostics and biological sciences. In the last decade the range of targets that can be diagnosed using diagnostic PCR have grown tremendously. The very flexibility and application specific variations in the basic theme of the system have allowed the development of many PCR variants adapted to wide range of applications. Furthermore, diagnostic PCR has been greatly improved by the introduction of the second generation PCR, known as the Real time PCR where closed-tube fluorescence detection and quantification during PCR amplification (in real time) is possible eliminating the need for laborious post-PCR sample processing steps which greatly reduces the risk of carryover contamination. Using Real Time PCR, it is possible not only to detect the presence or absence ofthe target pathogen, but it is also possible to quantify the amount present in the sample allowing the quantitative assessment of the number of the pathogen in the sample. Enumerating the pathogen upon detection is crucial to estimate the potential risks with respect to disease development and provides a useful basis for diseases management decisions. Crops can be attacked by many pathogens which, in addition, often occur in complexes. Therefore, many disease diagnostic applications require simultaneous detection and quantification of several targets. Methodological limitations, however, are in many cases the reason for developing simplex or assays designed for only few targets. The DNA Microarray technology, originally designed to study gene expression and generate single nucleotide polymorphism (SNP) profiles, is currently a new and emerging pathogen diagnostic technology, which in theory, offers a platform for unlimited multiplexing capability. It is viewed as a technology that fundamentally alters molecular diagnostics. The fast growing databases generated by genomics and biosystematics research provides unique opportunity for the design of more versatile, high-throughput, sensitive and specific molecular assays which will address the major limitations of the current technologies and benefit plant pathology.

Abstract

Health-conscious consumers are increasingly seeking functional foods in an effort to control their own health and well-being. The field of functional foods, however, is in its infancy. Claims about health benefits of functional foods must be based on sound scientific criteria. A number of factors complicate the establishment of a strong scientific foundation. These factors include the complexity of the food substance, effects on the food, compensatory metabolic changes that may occur with dietary changes, and, lack of surrogate markers of disease development. Additional research is necessary to substantiate the potential health benefits of those foods for which the diet-health relationships are not sufficiently scientifically validated. Research into functional foods will not advance public health unless the benefits of the foods are effectively communicated to the consumer. Finally, those foods whose health benefits are supported by sufficient scientific substantiation have the potential to be an increasingly important component of a healthy lifestyle and to be beneficial to the public and the food industry. Mounting evidence supports the observation that functional foods containing physiologically-active components, either from plant or animal sources, may enhance health. It should be stressed, however, that functional foods are not a magic bullet or universal panacea for poor health habits. There are no “good” or “bad” foods, but there are good or bad diets. Emphasis must be placed on over-all dietary pattern, which follows the current Dietary Guidelines, and is plant-based, high in fiber, low in animal fat, and contains 5-9 servings of fruits and vegetables per day.

3.0. Introduction

A hazard is any factor that may be present in the food or food products and can cause harm to the consumer either through injury or illness. Hazards may be biological, chemical and physical. It may be a biological, chemical or physical property or condition of food with the potential to cause an adverse health effect. Therefore, these hazards can be grouped into three broad categories (Fig 3.1). Further, various stages during which processing hazard can takes place in a food industry is illustrated through Fig. 3.2. Effect of different potential hazards on human health along with symptoms is presented in Annexure IV.

SYNOPSIS

India has been conspicuous as one of the most malnourished nations, as every child out of two is malnourished. Moreover, the levels of under nourishment is substantially high among tribal communities. The present investigation has been made to examine the levels of food insecurity at the micro level in four regions identified in the tribal dominated areas of Maharashtra on the basis of macro level indicators. A comparison of food insecurity between the two communities reveals a high incidence of food insecurity among the tribal as compared to that of non-tribal. The nutritional status of tribal children is much lower than that of their non-tribal counterparts.

Growing population has increased the demand on food supply. Providing safe and hygienic food to the population is an essential consideration. Food safety systems and tools need to be in place to assure safe food, until which the food businesses would not flourish or be able to build their reputation. Food safety systems and management tools are important as they assist food business organizations to build confidence in people regarding food safety.

Introduction

Spray drying process has been used for decades to encapsulate food ingredients such as flavors, lipids, and carotenoids. During this drying process, the evaporation of solvent, that is most often water, is rapid and the entrapment of the interest compound occurs quasi-instantaneously. This required property imposes a strict screening of the encapsulating materials to be used in addition to an optimization of the operating conditions. Likewise, if the encapsulated compound is of hydrophobic nature, the stability of the feed emulsion before drying should also be considered.

Abstract

There are several empirical models to describe deep bed drying dividing the domain into many thin layers. Empirical equations are seen as a resource that only serves to describe the thin layer drying kinetics of an agricultural product. Normally an empirical model is used to determine drying rate. The validity of following thin-layer drying models are accounted by coefficient of correlation (R2), standard error of estimated (SEE), root mean square error (RMSE). The properties of dried foods vary substantially depending upon the type of product, moisture content, drying type and ultimately drying conditions. To take care all above variables, a promising approach is to use Artificial Neural Network (ANN). In process control, the main objectives are food safety, high quality and yield at minimal costs. To obtain high quality products, on-line control techniques are required. Most food processes are highly nonlinear, with time varying dynamics, which complicates food automation. However, the recent developments in artificial intelligence based advanced control tools such as ANN to food processing have opened up novel possibilities for processing industries.

In most countries there is no legislative definition of the term drawing a border line between conventional and functional foods is challenging even for nutrition and food experts. Functional foods do not have a specific place in food law; consequently there is a great deal of confusion about what they are, could or should be. A common perception is that functional foods are foodstuffs either with one or more specific added ingredients (components), or certain substances of common ingredients (components) removed and which are claimed to have a positive influence on human health or well being. The term ‘functional foods’ for this group of products is considered to be an unfortunate one since all foodstuffs are or should be functional and a more appropriate term might be helpful.

Abstract

Fruit leather is a concentrated source of nutrient, energy and minerals processed from fruits in the form of sheet or leather. It is eaten as a desert or snack since ancient time. Fruit leathers have a greater benefit than fresh fruits if equilibrium ingredients are established and seasonal surplus of fruits are utilized and contributed to minimize post-harvest losses. The process of making fruit leathers involve making fruit puree and adding additives and preservatives for the purpose of enhancing taste and shelf-life. Drying, the key unit operation in making fruit leathers, is the most energy intensive and time consuming step in the process, modern drying techniques can be implemented to overcome the limitations. By novel means of processing technologies or enrichment could lead fruit leather to introduce high quality food product in the market. Continuous research and development can lead to a new era of production and development of fruit processing and overcome the obstacles during processing. In addition study on chemical and biochemical hazards involved in overall process will guide to ensure product safety. Market research tools e.g. quality function deployment method and other market analysis methods could be applied to understand the product trend, demand, consumer expectations and the scopes of improvement.

Abstract

Application of solar energy for drying of agricultural food products is one of the most attractive and cost-effective drying techniques. However, the intermittent nature of the solar energy is one of the major shortcomings of the solar drying system that can be alleviated by storing excess energy during the peak time and using it in off sun hours or when the direct availability of solar energy is inadequate. The use of sensible and latent heat storage systems in solar dryer is an effective way of storing thermal energy for drying purpose. This chapter will present information on different thermal energy storage (TES) materials, their advantages and disadvantages. The information available in the literature regarding the studies conducted on TES assisted solar drying systems is also covered in this chapter. In addition, some of the models that have been used by different researchers to test the performance of different TES materials are also reviewed.