eChapters

6.0. Introduction

Food is the basic need of all living organisms and hence, its quality should be given top priority. Food processing involves number of unit operations for material handling and there are always chances that the food may be contaminated or adulterated. The food is said to be contaminated if food is injurious to health and contain filthy, putrid rotten odour of insect pests etc. and can affect a large number of the populations at a time and hazards may occur. However, a food is said to be adulterated if it contains any other substance which affects the nature and quality product or substance is substituted with cheaper substance. So, it is essential to set the minimum limits of the desirable characteristics required and the maximum limits of the undesirable components that the food should contain. This helps to set common standards for commodities and to prevent confusion among the consumers.

5.0. Introduction

Quality control is generally defined as the regulation by law of food manufacture, distribution and sale in order to prevent health hazards and fraud to the consumers. Thus, it becomes a criminal offence to sell adulterated, filthy or contaminated foods. Quality control is the scientific control of production. There are certain basic fundamentals which are required for successful running of the food processing industry. So, for successful quality control in an industry / organization certain management systems are needed. Depending upon consumer requirement and satisfaction, quality management system is based on four important pillars like management responsibility, resource management, product / service realization and measurement, analysis & improvement. This management system is also important for ISO certification in an organization / industry.

4.0. Introduction

Quality is a measure of the degree of excellence or degree of acceptability by the consumer. By quality, one can differentiate the individual unit of a product from the other units and can determined the degree of acceptability of the individual unit by the consumer. The quality may also be defined in term of end use and may vary depending upon consumer’s perception and need. According to USDA Marketing Workshop Report (1951) “quality is the combination of attributes or characteristics of a product that have significance in determining the degree of acceptability of the product to the user”. For industry, quality is a measure of purity, strength, flavour, colour, size, maturity, workmanship and conditions or any other distinctive attributes of the product.

According to Code of Federal Regulations “Quality is the inherent properties of any processed product which determine the relative degree of excellence of such product and includes the effect of preparation and processing and may or may not include the effects of packaging or added ingredients/ additives”.

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.

2.0. Introduction

Before dealing with the various processes involved in the processing of fruit and vegetables or any food commodity on commercial scale, it is necessary to consider certain important factors such as investment, site, building, water supply, staff, labour etc. which are essential for the successful running of the food processing plant. Processing plant is the premises, buildings, structure and equipment used in the preparation, processing, handling, transportation and storage of any food commodity / fruits and vegetables / the processed products. The design and layout of the food processing plant is of great importance, besides other important factors. The food processing plant may be single storeyed or multi-storeyed depending upon capacity of production and viability of the plant e.g. if the production of the plant is assumed to be small and processing plant have to run only for short duration during the year then single storeyed processing plant can serve the purpose. Plant layout, product layout and process layout are the most important components for setting up of food processing industry and can determine the working efficiency of unit. Sanitary requirements in food processing plant are also important for marketing of the prepared product in national and international market. Sanitary requirement is as important in food processing plant as is the treatment of the effluent waste. For setting up of the food processing plant certain guidelines have been laid out by FPO, 1955.

1.0. Introduction

Any commodity, produce or harvest in organic or inorganic form to be fit to eat by a particular society, and contributes materially towards growth and repair of tissue is known as food. Food processing is application of techniques in a systematic manner for preventing losses through preservation, processing, packaging, storage and distribution to ensure greater availability of a wide variety of foods. It is a set of methods and techniques used to transform raw ingredients into food for consumption by humans or animals.

The early stages of food processing were largely confined to primary processing of food crops, commodities and produce whereby all these rendered fit for consumption or sale in the markets. Processing of rice and oil seeds were the necessities of that time for living. Later on, World War II gave a fillip to some of other food processing industries to meet the demand of the defence forces of the country. Fruits and vegetables processing; wheat and sugar milling drew support and sustenance from the exigencies created by war. Post war situation almost merged into the post-independence scenario. However, food processing industry received its first major impulse after independence. During this time, all the primary food processing industries received top most priority and all necessary support from the Governments in the country.

Abstract

The increasing interest in polyphenolic compounds in industries has led to the exploration and exploitation of rich bio-compounds from natural sources, essentially plants and their by-products. Solid-liquid extraction is mostly applied for the recovery of these valuable compounds from plants. Since the extraction process is often difficult in a fresh matrix, a drying operation is needed to reduce the moisture content, and preserve the targeted valuable compounds. An uncontrolled drying operation will lead to product damage and hence, loss in quality, reason why, several studies have been carried out to understand and control the drying process. The present chapter aims to present some data on drying for bioactive compound recovery from plants and their by-products, mainly polyphenolic compounds. Our main interest is the mathematical tools used to model the drying process.

Abstract

Design, operation and optimization of dryers demands the calculation of energy consumption, in most cases in the form of thermal energy, equipment sizing, temperature and moisture distribution of solids as well as temperature and humidity distribution of drying air. Energy calculations are very important as drying is a widespread process in a variety of industries and is highly energy demanding. In the energy analysis of the process the first step is the estimation of the minimum energy requirement followed by the estimation of energy rejection through solids stream and especially through drying air. Increase of thermal efficiency is always willing and the two most common ways for its achievement is the application of heat exchange between cold feeding air and relatively hot rejecting drying air and hot air recirculation. The later is also employed for the adjustment of air temperature and humidity gradient through the dryer. The combination of a heat pump with the dryer decreases considerably the thermal energy consumption but demands electricity and the method can be beneficial in cases of excess electricity production in the process plant, e.g. by cogeneration. Utilization of exhaust hot air from the main drying unit for the predrying of wet solids can also decrease the total energy requirement. The application of humidity adsorption from the feed air increases its drying potential, but regeneration of adsorbent is required. Grand composite curve of the process plant can reveal potential heat sources from different unit operations.

Abstract

Vitamin C is one of the most important phytochemicals and can be found in almost all fruits and vegetables. Since it covers almost all eventualities, being water solute and prone to leaching from cells, thermally labile (one of the most labile vitamins), pH-, metal ion-, light-sensitive, as well as readily oxidizable by ascorbic acid oxidase, vitamin C is selected as the most frequently measured nutrient to evaluate the nutrients loss during thermal processing. It is generally accepted that if vitamin C is well preserved, the other nutrients are also well retained. Higher retention of vitamin C in processed products is highly desired. Herein this chapter reviews the degradation mechanism and kinetics of vitamin C of fruits and vegetables during thermal processing, such as blanching, drying, cooking and frying. It starts with an overview of the functions of vitamin C in human’s health. Then the current status for understanding of the degradation kinetics of vitamin C during thermal processing was outlined, followed by the discussion of its degradation mechanism. At last, potential strategies or alternatives to keep vitamin C are identified and discussed.

Abstract

Mushrooms are the fruiting bodies of fungi, a group of organism that is different from fruits and vegetables. They are a rich source of good quality protein having more essential amino acids and vitamins with low calories. There are about six commonly known edible mushrooms throughout the world with button mushroom (Agaricus bisporous) being the most familiar and commercially important variety. Mushroom is a highly perishable product with a shelf life limiting to a few days. Soon after harvest, it starts to undergo physiological disorders like shriveling, wilting, liquefaction, browning, textural as well as weight losses and flavour changes. The main responsible factors for the quality deterioration after harvest are respiration rate, browning, bacterial spoilage of mushrooms, temperature and relative humidity. Because of its limited shelf life under ambient conditions of temperature and humidity, the preservation of mushrooms is a matter of concern. Various techniques have been involved in the extension of shelf life of mushrooms including chemical treatments, cooling, modified and controlled atmospheric storage, radiation, drying etc. Drying is one of the most accepted and effective methods for the long term storage of mushrooms. Mushrooms preserved by drying have a pleasant flavour and are used as an important ingredient in several food formulations including salads, instant soups, meats and rice dishes. Various drying processes like sun drying, hot air drying, freeze drying, vacuum drying etc. can be used for the long term storage of mushrooms. As mushrooms are sensitive to temperature, determining the right drying method is the key for the successful and effective operation of the system. The different operating conditions involved in various methods of drying affect product quality considerably. The effect of drying methods on the process and the quality of the dried mushroom is explained in detail in this chapter.

Abstract

Cocoa and coffee are highly sought after commodity crops in the market owing to the distinct flavor and aroma characteristics. Cocoa beans are mostly used in the manufacturing of chocolates and various types of confectioneries while coffee is mainly consumed in the form of beverages. Both cocoa and coffee need to be dried and roasted in order to produce the flavor precursors which further develop into the desired flavor and aroma in the finished products. This chapter aims to provide an overview of cocoa and coffee processing with particular emphasis on drying and roasting aspects and its impact on product quality.

Abstract

Application of ultrasound is one of the most promising uses of novel technologies in food processing. Use of ultrasound at various stages of drying has resulted in significant decrease in drying time and improvement in quality characteristics of dried products. The chapter discusses the principle behind use of ultrasound, general application in food industry with detailed description of various drying processes and equipments assisted by ultrasound.

Abstract

Foam Mat Drying (FMD) is an economical alternative to drum, spray and freeze-drying for the production of food powders. The raw material is converted into stable foam by adding foaming agent through beating or whipping in presence or not of foam stabilizers, and dehydrated by different classical airflow and thermal means. A high-quality food powder attributes can be obtained by the proper selection of foaming method, foaming agents, foam stabilizers, time taken for foaming, suitable drying method and temperature. FMD can be used for large production of food powders because of its suitability for all types of food materials, rapid drying at lower temperature, retention of nutritive value and bioactive compounds, good reconstitution characteristics and flowability and cost-effective for producing powders.

In this chapter, basics of foam and its structure, mechanisms of foaming, types of foaming agents and stabilizers for the production of stable foam have been discussed. The influence of foaming agents, foaming properties, thickness of foam and drying temperature on the drying characteristics of mat are also studied. This chapter analyzes the application of foam drying process for different food materials, the microstructure and whole quality attributes of obtained powder, and the energy consumption and costs of FMD as well.

Abstract

Pulse combustors provide an advantageous superposition of unsteady gas flow and high intensity sound waves. Such a combination does not only accelerate drying rates because of increased heat and mass transfer but also allows processing of liquids, pastes and agglomerated solids in a dispersed state due to aerodynamic impact from the high intensity sound wave. Over last decades, applications of pulse combustion in drying have been exploited continuously and different pulse combustion dryers have been designed and fabricated. In pilot tests and technical reports on these dryers, short drying time, high energy efficiency and product quality are generally reported, which cause that pulse combustion drying is regarded as a technology of the future in convective drying.

This chapter attempt to introduce basic knowledge and state-of the art about this emerging technology and summarizes some recent studies in pulse combustion drying and equipment design. Following a concise description of pulse combustion and pulse combustor, the basic types of pulse-combustion dryers are presented, including spray dryers, fluidized bed dryers, impinging dryers, and dryers of special design. The existing commercial applications and pilot test projects are described and potential applications are identified.

Abstract

Increasing global demand for ‘fresh-like’ processed food products has forced food industries to investigate into various minimal processing techniques. Food processing in general has been associated with thermal processing, alone or in various combination with chemical and mechanical preservation and processing methods. However, thermal processing methods are energy intensive in nature and tend to reduce product quality and freshness at the cost of shelf-life gain. Advance technique such as microwave, radio-frequency and freeze drying do maintain the product quality but their implementation at industrial scale involves high operational and maintenance cost. An ideal processing method therefore would be one that can process food products without losing its quality, is energy efficient and is easily scalable. In this chapter, we discuss about ‘Electrohydrodynamic (EHD) Drying’, which is can be classified as a minimal processing technique. The heat and mass transfer principles involved in EHD drying have been extensively discussed and so has been the key consideration for designing an EHD drying system.

Abstract

This chapter presents the principle of fluidisation and its use in drying of food materials. Being a convective drying process, capacity and kinetics are limited by process conditions and material properties. The influences are discussed as well as presenting the main equations that describe drying in fluidised beds. The main focus lies on hot gas drying, additionally superheated steam drying as well as atmospheric fluidised bed freeze drying and microwave-assisted fluidised bed drying are presented and discussed.

Abstract

Airflow drying persists as the main dehydration operation. Indeed, the high expense of freeze-drying in term of equipment cost and energy consumption considerably restricts its use and confines its applications to high added value products (pharmaceutical products, cosmetics, etc.). However, airflow drying undergoes fundamental problems such as low operation performance, poor product quality and short reliability of the equipment. The time of drying is long; particularly at the end of the operation, which implies crucial energy consumption. The poor quality of the end product is related to thermal degradation and in particular to the compactness of texture as a result of the phenomena of shrinkage and case hardening. Another main problem common to all drying operations, including freeze-drying, is the safety of the end products. Swell-drying is defined as an operation that combines optimized hot air drying with instant controlled pressure controlled texturing. The improvement of texture, the preservation of sensory and nutritional quality, the possibility of manufacturing expanded granule powders and the reduction of drying time and energy consumption allow considering swell-drying as the most relevant drying process.

Abstract

Agriculture is the major sector for the livelihood of the billions of people worldwide. Increasing population and decreasing arable lands are the major concern for the fulfillment of the desired food production. After green revolution more production in the crop is obtained by worldwide. Several insects and pests are responsible for the inhibition of desired production in agriculture. Therefore, pesticides play a major role in the control of destructive insects and pests. After ban of organochlorine pesticides, organophosphorus pesticides has been used vigorously. Beside the effective pest management in agriculture, residual organophosphorus pesticides are more lethal for human and other living creature. Monitoring of these compounds is very much essential in the food and agricultural samples. Chromatographic techniques are well adopted techniques for the hundreds of residual pesticides. Introduction of various analyzers in chromatographic techniques improve the monitoring of the residual pesticides from different samples. Therefore, recent advancement in residual pesticides isolation and chromatographic techniques has been discussed in this book chapter.

Abstract

We are very fortunate to be born in a nation which is blessed with awesome decent variety of natural products, fruits, vegetables, cereals, pulses and so forth. The population of India expanded consistentlythat cause a genuine sustenance and shelter problem. The supply of food is not adequate to fulfill the demand of the consumers. This shortage of food is the root for adulteration of foodstuffs by the traders. Food adulteration is a procedure in which the nature of sustenance is brought down either by the addition of inferior quality material or by extraction of valuable ingredient. An adulterant is a chemical substance which should not be contained within other substances (food, beverages) for legal or other reasons. The addition of adulterants is called adulteration. Food is adulterated to increase the quantity and make more profit. The food is sucked of its nutrients and the place where the food is grown is often contaminated. For instance: milkis mixed with water. Vanaspati is utilized as an adulterant for ghee. Adulteration of food is unsafe as it may be toxic and causes serious health hazards to the consumer. To evade this issue government has passed an act which is known as preservation of Food Adulteration Act. It covers security from risks involved due to contamination of poisonous elements. Instead of government efforts the informed and aware consumers will have the capacity to dispense with this issue. So, here in the chapter adulterants their types, effect on human health, laws and control measurement were reviewed and discussed.

Abstract

Consumers increased response to new products with high sensory, organoleptic and nutritional potentials has impelled a search for new substitutes to processing methods. For several years, thermal processing was the main technology for producing safe products with long shelf lives, although in most cases losses of fresh flavors, vitamins, and some physicochemical characteristics were the price of safety and long-term stability. Pulsed electric field (PEF) processing as a non- thermal technique has been proven to inactivate microorganisms with minimal losses of flavor and food quality, possibly making it the answer to present-day consumer demands. In addition, the low processing temperatures used in this non- thermal technology allow the process to be nutrient preserving, energy efficient, which translates into lower costs and fewer environmental impacts. In this chapter, the the configuration of various PEF equipment, their electric configuration and recent application of this technique in processing of foods have been discussed in detail.