eChapters

Microbial contamination sources: Foods may be contaminated by microorganisms at any time during harvest, storage, processing, distribution, handling, or preparation. The primary sources of microbial contamination are soil, air, animal feed, animal hides and intestines, plant surfaces, sewage, and food processing machinery or utensils. Since most foods either carry or eventually acquire bacteria, molds, or yeasts, microorganisms are the major causes of food spoilage. The increased load of microorganisms leads to rapid spoilage.

Organisms: Bacteria and fungi (yeasts and molds) are the principal types of microorganisms that cause food spoilage and food- borne illnesses. The typical microorganisms that cause food spoilage are bacteria (e.g., Pseudomonas), yeasts (e.g., Candida), and molds (e.g., Rhizopus). The growth of microorganisms in the food will increase the load of microorganisms, and the heavier load will add to the difficulty of preventing spoilage and may influence the kind of spoilage to be anticipated.

Food spoilage may be defined as any change that renders food unfit for human consumption. These changes may be caused by various factors, including contamination by microorganisms, infestation by insects, or degradation by endogenous enzymes (those present naturally in the food). In addition, physical and chemical changes, such as the tearing of plant or animal tissues or the oxidation of certain constituents of food, may promote food spoilage. Foods obtained from plant or animal sources begin to spoil soon after harvest or slaughter. The enzymes contained in the cells of plant and animal tissues may be released as a result of any mechanical damage inflicted during postharvest handling. These enzymes begin to break down the cellular material. The chemical reactions catalyzed by the enzymes result in the degradation of food quality, such as the development of off- flavours, the deterioration of texture, and the loss of nutrients. The enzymatic changes in foods are desirable to some extent as in the case of ripening of fruits, but continued enzymatic activity beyond an optimum point becomes food deterioration due to rotting. The native enzymes may be inactivated by heat, radiation or by the use of specific chemicals.

Tea as a Beverage

Tea is the most popular beverage consumed in the world after water. All types of teas including black. green, oolong, white and pu-erh tea are mainly made from the buds and young leaves of tea plants, Camellia sinensis (L.) O. Kuntze belongs to the family Theaceae [1]. Depending on the different processing techniques of tea leaves, tea types are categorized as “Green Tea” (unfermented), “Black Tea” (fully fermented), “Oolong Tea” (partially fermented), “Pu-ErhTea” (post fermented) and white tea (unfermented) [2]. The manufacturing process for these different types of teas mainly differ in the degree of enzymatic oxidation (fermentation) process [1].

Introduction

Coffee is a beverage made from the roasted and ground seeds of the African tropical evergreen coffee plant. Coffee is one of the world’s three most popular beverages (together with water and tea), as well as one of the most profitable international commodities, and it is the world’s second most marketed product after petroleum (Myhrvold, 2021).Coffee is a popular beverage that is enjoyed around the world for its taste, health benefits, and ability to enhance physical performance (Simkin, 2008).

16.1. CANNED FOODS-PRESERVATION

Canning is a method of preserving food from spoilage by storing it in containers that are hermetically sealed and then sterilized by heat. The process was invented after prolonged research by Nicolas Appert of France in 1809, in response to a call by his government for a means of preserving food for army and navy use. Appert’s method consisted of tightly sealing food inside a bottle or jar, heating it to a certain temperature, and maintaining the heat for a certain period, after which the container was kept sealed until use. It was 50 years before Louis Pasteur was able to explain why the food so treated did not spoil: the heat killed the microorganisms in the food, and the sealing kept other microorganisms from entering the jar. Samuel C. Prescott and William Underwood of the United States set canning on a scientific basis by describing specific time-temperature heating requirements for sterilizing canned foods.

Most vegetables, fruits, meat and dairy products, and processed foods are stored in tin cans, but soft drinks and many other beverages are now commonly stored in aluminum cans, which are lighter and do not rust. Aluminum cans are made by impact extrusion; the body of the can is punched out in one piece from a single aluminum sheet by a stamping die. This seamless piece, which has a rounded bottom, is then capped with a second piece as its lid. The tabs used in pop- top cans are also made of aluminum. Bimetal cans are made of aluminum bodies and steel lids.

Canneries are usually located close to the growing areas of the product to be packed, since it is desirable to can foods as quickly as possible after harvesting. The canning process itself consists of several stages: cleaning and further preparing the raw food material; blanching it; filling the containers, usually under a vacuum; closing and sealing the containers; sterilizing the canned products; and labeling and warehousing the finished goods. Cleaning usually involves passing the raw food through tanks of water or under high- pressure water sprays, after which vegetable or other products are cut, peeled, cored, sliced, graded, soaked, pureed, and so on. Almost all vegetables and some fruits require blanching by immersion in hot water or steam; this process softens the vegetable tissues and makes them pliable enough to be packed tightly, while also serving to inactivate enzymes that can cause undesirable changes in the food before canning. Blanching also serves as an additional or final cleansing operation.

10.1 CEREALS AND CEREAL PRODUCTS

CONTAMINATION: The sources of contamination in cereals and cereal products are soil, insects, air, etc. Most of the microorganisms are removed with the outer portions of the grain during milling. The bleaching agents used during milling also reduce numbers of microorganisms. The bacteria in wheat flour include Bacillus, Micrococcus, Flavobacterium. Mold spores are chiefly of Aspergillus spp and Penicillium spp and in addition Alternaria, Cladosporium and other genera are found. The numbers of microbes in cereals and cereal products vary widely from few hundred per gram to million. Corn meal contains several hundred to several thousand bacteria and mold per gram.

14.1. EGGS

India is the third largest producer of eggs. Fresh eggs are gathered on automatic collection belts at the farm and stored in a cooler at about 7°C. The eggs are then delivered to a central processing plant, where they are washed, sanitized, and graded. Grading involves the sorting of eggs into size and quality categories using automated machines. Flash candling (passing the eggs over a strong light source) detects any abnormalities such as cracked eggs and eggs containing bloodspots or other defects. Higher-grade eggs have a thick, upstanding white, an oval yolk, and a clean, smooth, unbroken shell.

14.1.1. Eggs Contamination

More than 90 percent of all eggs are free of contamination at the time they are laid; contamination with Salmonella bacteria and with certain spoilage organisms occurs essentially afterward. They become contaminated by faecal matter from the hen, by the lining of nest, by handling, by wash water and packing materials. The total number of microorganisms per shell of a hen’s egg was found to range from 100 to 10,000,000 with a mean of about 100,000. Proper washing and sanitizing of eggs eliminates most Salmonella and spoilage organisms deposited on the shell. The organism Salmonella enteritidis, a common cause of gastroenteritis (a form of food poisoning), has been found to be transferred through the hen ovary in fewer than 1 percent of all eggs produced. Ovarian- transferred S. enteritidis can be controlled by thorough cooking of eggs (i.e., until there are no runny whites or yolk).

13.1. CONTAMINATION

MICROFLORA: The flora of living fish depends upon the microbial contents of the waters in which they live. The slime in the outer surface of the fish contain bacteria of the genera: Pseudomonas, Alcaligenes, Micrococcus, Flavobacterium, Corynebacetrium, Bacillus, Sarcina, Serratia and Vibrio. The same species of bacteria are found in shrimps, crabs, lobsters and similar sea foods. Oysters and Shell fish that pass large amount of water through their bodies, pick-up soil and water microorganisms in this way including human pathogens. Common spoilage microorganisms of fish include species of Pseudomonas, Moraxella, and Acinetobacter, found mainly in marine fish, and Bacillus and Micrococcus, found in freshwater fish. Fish may also contain pathogenic (disease-causing) microorganisms such as Salmonella and Escherichia coli. Pathogenic contamination is of special concern with mollusks because they are often eaten raw and as whole animals.

SOURCES: Boats, boxes, bins, fish houses and fishermen are the sources of contamination of these bacteria. The bacterial population ranges from few hundred to few million per square centimeter. Because of their soft tissues and aquatic environment, fish are extremely susceptible to microbial contamination. At the time of harvest, fish carry a high microbial load on the surface of their skin, in their intestinal tract, and in their gills. The type and number of microorganisms that live in fish vary according to the season, the species, and the natural habitat. Additional contamination may occur during the harvesting, handling, or processing of the fish. Harvested fish must be immediately stored in a low-temperature environment such as ice or refrigerated seawater. This chilling process slows the growth of microorganisms that live in fish and inhibits the activity of enzymes. Because fish have a lower body temperature, softer texture, and less connective tissue than land animals, they are much more susceptible to microbial contamination and structural degradation. If immediate chilling is not possible, then the fish must generally be sold and eaten on the day of the harvest.

11.1. FRUITS-Maturation, Ripening and Storage

Fruits are natural foods containing substantial quantities of essential nutrients and the best sources of minerals like sodium, potassium and magnesium, vitamins (antioxidants), such as vitamin A, C and enzymes. They are rich in fructose and water. Fruits are living biological entities that perform a number of metabolic functions. Two functions of particular importance in fruit processing are respiration (the breaking down of carbohydrates, giving off carbon dioxide and heat) and transpiration (the giving off of moisture). Senescence is the period when chemical synthesizing pathways give way to degradative processes, leading to aging and death of tissue. Fruit ripening is thus the result of many complex changes, some interactive but many independent of one another. Once the fruit is harvested, respiration and transpiration continue, but only for as long as the fruit can draw on its own food reserves and moisture. It is this limited ability to continue vital metabolic functions that defines fruit as perishable.

CONTAMINATION

The healthy inner flesh of meat contains few or no microorganisms, although they have been found in lymph nodes, bone marrow and intestine. Staphylococcus, Streptococcus, Clostridium and Salmonella have been isolated from lymph nodes of red meat animals. During slaughtering the lymph nodes are removed from edible parts. The important contamination, however comes from external sources during bleeding, handling and processing. During bleeding, skinning and cutting the main sources of microorganisms are from the exterior of the animal- hide, hoof and hair and the intestinal tract. The exterior of the animal harbours large number and many kinds of microorganisms from soil, water, feed and manure as well as its natural surface flora.

Knives, cloths, air and hands and clothing of workers can serve as intermediate sources of contamination. During handling and processing the contamination can come from containers, air, other contaminated meat, equipments and personnel.

Molds that grow on the surface of the meat include the species of Cladosporium, Sporotrichum, Geotrichum, Mucor, Monilia, Penicillium and Alternaria. The important bacteria found in meat are Staphylococcus, Sarcina, Streptococcus, Clostridium, Leuconostoc, Lactobacillus, Proteus, Flavobacterium, Bacillus, Streptomyces, Escherichia and Salmonella.

15.1 CONTAMINATION

Milk is sterile at secretion in the udder, but contaminated by bacteria when it leaves the udder of a healthy cow. Milk is subject to contamination from the animal and adjacent areas. Bacteria found in manure, soil and water may enter milk from these sources. Certain diseases may be transmitted through milk, from a cow. It is essential that cows producing milk should be free from any contagious or infectious disease. Bovine tuberculosis comes from consumption of milk of tuberculous cows. Tuberculosis, brucellosis, mastitis and actinomycosis are the human disease transmitted through milk. The disease producing bacteria may find their way into milk and cause infectious diseases in children and adults.

COMMON BACTERIA IN MILK: The common bacteria found in milk are: Rickettsia, Coxiella burnetii, lactic acid bacteria, Lactobacillus bulgaricus, Streptococcus thermophilus, aerobic rods, Bacillus subtilis, Bacillus cereus, anaerobic bacteria, Clostridium butyricum .

Sources of Microbial contamination: Milk contains relatively few bacteria when it leaves the udder of a healthy cow. Milk is subject to contamination from the animal udder, skin and adjacent areas barn yard, milk utensils, milkers. Bacteria found in manure, soil and water may enter milk from these sources.

Communication material is the joint product of knowledge, skill and attitude base of the communicator. Further, most of the communication done on behalf of certain organization also reflects the objective, work culture, strategy and contribution of the organization. Hence analysis of communication material is of greater relevance in exploring the trends, vision, behavior and future course of action. In this chapter, we are going to discuss the content analysis; it’s meaning and practical application.

Introduction

Indian forests are being denuded at an appalling rate of 1.5 million ha per year but only a tenth of this is being renewed. This has resulted in the accelerated dwindling of forest resources to a meager level of 23.55 per cent of the total geographical area against the mandated requirement of 33 per cent. This low forest cover coupled with poor productivity (0.5 -0.7 m³ ha-1 yr^-1) in comparative global statistics (2.1 m³ ha-1 yr^-1) of Indian forest has ushered in a total mismatch between supply and demand of both domestic and industrial wood besides creating environmental de- stability and disequilibrium. The National Forest Policy of 1988 has resolved to phase out the supply of raw material to wood based industries and ultimately totally stopped the raw material supply from the forest (Anon., 1988). The policy also indicated that wood based industries have to become self reliance in meeting the raw material demand by establishing direct linkages with the farmers by providing lending facilitates and other input needs. This is going to pave the way for a strong industry-farmer nexus, with many farmers attracted towards tree husbandry due to assured marketability and income. As the activity gets intensified, location specific problems warranting solution are also found to be in the ascendancy.

Abstract

Most dryers operate at low thermal efficiency. The development of models and control systems offers an opportunity to improve dryer operation and efficiency. Dryer control is very important and with deeper understanding of the drying concept, new “smart” dryers can be made more reliable and more cost-effective than classical dryers. This chapter will provide an overview of necessity of control and safety measure in food drying system, and terminology related with drying control system. Different control strategy includes conventional and advanced techniques implemented in drying operation are reviewed  here and simple outline of intelligence control system in drying technology are briefly described in succeeding section. Various hazards in drying process and risk and safety management will also be discussed.

Introduction

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

ABSTRACT

The improper disposal of food waste poses an environmental threat. The management of food waste in a sustainable way is always a challenge. Food waste is generated at various stages starting from food production till consumption. The cooked food waste generated due to various reasons leads not only to a loss of the food produced but also the water and energy used to cook it. This cooked food leftover can be served to the needy people or if not possible, can be processed further. This chapter focuses on various technological options for the management of cooked food waste in a sustainable way.

Keywords: Cooked food waste, Compost, Bokashi, Bio-surfactants, Environment

In the semi-arid tropics, where small farmers depend heavily on rain-fed agricultural systems, variability in precipitation has a dramatic impact on crop production and livelihoods. Because small-scale agriculture depends on rain-fed cultivation, it is vulnerable to factors such as flooding and drought. Unfortunately, the frequency of unexpected heavy rainfall or flood events has increased in many areas of Africa, including Southern Zambia. About 75% of farmers in Zambia engage in small-scale farming, with an average farm size of 2 ha (VAM Steering Committee Zambia, 1998). Most of these farmers cultivate maize, which is a staple food in Zambia, and stable maize production and increased productivity are important both for food security and to provide a livelihood to farmers.

In spite of its importance, little has been done to assess interactions of climatic variability with productivity performance of different livestock species, sustainability of livestock production systems, livestock based livelihoods and application of science of climate change on small holder and subsistence livelihoods. The climate and its change affect all productive traits and physiological functions of farm livestock and related livelihoods. Heat stress is the most detrimental constraint to livestock production, particularly in mountainous regions. Introduction and selection for highly productive animals and breeds has increased their susceptibility to adverse impacts of climate change. It is necessary to incorporate resilience through selection and breeding for thermo-tolerance and development of adaptable breeds. Modifications in shelter designs and management of production facilities will also be helpful in mitigating adverse climate impacts on animal production and health. Modern animal husbandry practices that target increased per animal productivity allow efficient utilization of feed nutrients and increase returns from fewer animals. Livestock need to be looked for their immense contribution to nutritional security and livelihoods. A well designed livestock production system is among the best ways for sustaining and improving livelihoods and this chapter details the possible options.

Seed yield is the foremost important attribute and is the end product of many complex component characters which singly or jointly influence the seed yield. Seed yield does not possess gene per se as such. It is the interaction phenotype of the harmonious understanding, mutual adjustment and manifestation of its component characters. As most of the component characters are polygenic, they are greatly influenced by the environment. So, the selection of genotypes based on yield as such is not likely to be effective. The information on the strength and direction of association of the component characters with seed yield and also among themselves will be very useful in formulating an effective breeding programme for seed yield improvement in a given time. Correlation studies provide about the magnitude and direction of genetic association between the seed yield and its component characters.

Correlation coefficients provide the measure of association between two characters. But, they do not provide the causal basis of such association. Further, correlation between seed yield and its component characters are often misleading due to the inter-relationship that exist among the component characters and the operation of size symmetry and component compensation that thwart the breeding progress. The direct contribution of each component to the seed yield and the indirect effects it has through its association with other components cannot be differentiated from mere correlation studies. This is how, it became necessary for a plant breeder to have information on the direct and indirect effects of these components on the seed yield to identify the key characters for improvement.

Concept of correlation was given by Karl Pearson in 1890.

The study of strength and nature of relationship between two variables is called correlation. Two variables are said to be correlated, if the change in one variable affects the other variable. Correlation is also known as covariation.

Bivariate Distribution: Distribution involving two variables is known as bivariate distribution. For example, Height and weight of persons, yield and production of a crop in.

On basis of type of association between variables, correlation is of two types:

Counselling represents a purposeful, collaborative relationship between a trained professional and an individual seeking assistance with personal, emotional, psychological, or behavioral concerns. This helping relationship is founded on principles of trust, confidentiality, and mutual respect, creating a safe environment where individuals can explore their thoughts, feelings, and experiences without judgment. The American Counseling Association defines counselling as a professional relationship that empowers diverse individuals, families, and groups to accomplish mental health, wellness, education, and career goals. This definition emphasizes the empowerment aspect of counselling, highlighting its role in facilitating personal growth and development rather than simply addressing problems or deficits. The fundamental nature of counselling involves a systematic p