Health and Safety Aspects of Food Processing Technologies

Chapter 1 Management of Food Safety and Hygiene: An Overview

Food is a basic human need. Its safety and nutritional quality play a fundamental role in the health of people. The Codex Alimentarius Commission (CAC), the international body which sets standards for foods, defines food hygiene as "all conditions and measures necessary to ensure the safety and suitability of food at all stages of the food chain." The term food hygiene covers two concepts, i) food safety and ii) food suitability. According to the CAC, food safety is "the assurance that food will not cause harm to the consumer, when it is prepared and eaten according to its intended use", whereas food suitability is the "assurance that food is acceptable for human consumption according to its intended use. Food safety constitutes one of the most fundamental and vital aspects of any food operation. However ensuring food safety in the present era has become a difficult task as plethora of chemical, physical and biological agents may contaminate the food supply and threaten public health as well as food business. Today there is adequate scientific and technical knowledge, technological means and managerial experience to ensure the safety of products. Presently concepts like Hazard Analysis and Critical Control Point (HACCP) and risk analysis have been well developed and integrated in the management of food safety and hygiene at national and international level. In this chapter significance of food hygiene, and food safety and various approaches for their management has been reviewed.

 

Chapter 2 Food Contamination and Food Spoilage

The interaction of versatile nutrients present in food leads to several degradative chemical changes that deteriorate the quality and shelf life of food. The deteriorative changes are enhanced during contamination at various stages of processing, handling and storage. These changes include lipid oxidation, enzymatic or non-enzymatic browning, putrefaction and toxicity due to hazardous substances. Contamination occurs from various physical, chemical and biological sources, and is affected by external factors such as time-temperature combinations, poor hygiene and sanitation. Most of the contaminants are from natural sources but some are deliberately added. Recent food contaminants include veterinary drug residues, pesticides, undesirable fermentation products, nanoparticles, packaging materials and radionuclides. Contamination leads to spoilage of foods and may be due to the activity of microorganisms, action of enzymes, chemical reactions (harmful additives, mycotoxins, bacterial toxins and radiations) and physical changes (caused by freezing, burning, drying, pressure). Of all the causes of spoilage, microbiological cause plays a decisive role. Spoilage is enhanced by various extrinsic and intrinsic factors (pH, redox potential, water activity and the presence of antimicrobial substances in a food material). The characteristics of the environment in which the food is maintained, such as temperature, atmosphere and relative humidity also affect food spoilage. Spoilage changes nitrogenous organic compounds of food into alpha keto acid, ammonia, propionic acid, amides, imides, and urea. Complex carbohydrates are hydrolysed to simple sugars by fermentation. Organic acids are oxidized to carbonates causing the medium to become more alkaline. Consumption of such contaminated and spoiled food can lead to various food borne illnesses and intoxication. Therefore, this necessitates the implementation of food hygiene during processing and storage; and also the incorporation of food authentication techniques such as biosensors, aptasensors, spectroscopy techniques in tandem with chemometrics analytical approaches for quantitative assessment of food spoilage. In this chapter, how are food spoilage being regulated, food contamination, the importance of personal hygiene, good work habits and effective measures to increase the shelf-life of food and food products are discussed.

Chapter 3 Microbial escalation in meat and meat products and its consequences

Microorganisms are present everywhere, they play serviceable and detrimental role in various ways; deteriorate the basic need of human life, escalation of their population in foods, hamper the shelf-life of food and illness in human. Among all foods, meat and meat products are staple diet which are used worldwide. Meat and meat products are well known for their high nutritional values as they contain good amount of proteins which comprise of essential amino acids with high biological value. Meat is also rich in vitamin B complex and several important minerals like iron, magnesium and zinc. Being an excellent ecological condition; meat and meat products favour the growth of a variety of microbial flora such as bacteria, yeast and moulds, some of which are pathogens. Under aerobic condition bacterial population grow and spoiled the meat. Meat spoilage frequently caused by the bacterial groups like Pseudomonas spp. Enterobacteriaceae, Brochothrix thermosphacta and Lactic acid bacteria, which alter the component of meat and meat products continuously, thus leading to undesirable modifications in sensory characteristics such as appearance, texture, odor and flavor as well as acceptable qualities. This phenomenon determines not only economic losses, but also the lack of consumable foods. It is therefore, important to understand the causes of spoilage of meat and meat products in order to develop optimum preservation techniques to maintain the freshness of meat and meat products. This chapter summarizes how microbes deteriorate textures and hamper the shelf life of meat and meat products.

 

Chapter 4 Natural Microflora of Different Types of Foods 

The sources of thousands of different microorganisms in food could be either natural or external. The microorganisms in foods divided into three groups as molds, yeast and bacteria. Natural microflora of foods influences the quality, availability and quantity of products. Molds are generally known as spoilage microorganisms in foods. Therefore usage of them in food processing is limited (i.e. mold ripened cheese). Conversely, yeasts and bacteria are widely used as important microorganisms in food industry. Since, yeasts and bacteria have ability to ferment sugars to some industrially important compounds such as ethanol, lactic acid, acetic acid and carbon dioxide. In addition, they can contribute to the texture, aroma-flavor and safety of foods. The microorganisms that intrinsically existing in food play a key role in processing of numerous foods especially fermented fruits-vegetables, milk and meat based fermented products. The aim of the present chapter is to discuss the natural microflora belonging to different foods and also to explain their functions during food processing.

 

Chapter 5 Emerging Technologies in Cereal Processing: Present Status and Future Potential in India 

Grain processing (cereal and pulse) occupies a large and important portion in food production chain in India, and is one of the oldest and most important of all food technologies. Cereal grains and pulses are grown widely throughout the world and their dietary and economic importance is globally appreciated and recognized. In Indian economy, cereals and pulses occupy a prominent place and remain the most consumed staple food in homes. For ten consecutive years from 2006-16 a rising trend in the production of food grains has been registered. Grains like wheat, paddy, maize, barley and pulses touched an increased level of 25, 20, 12, 2, 1 lac tonnes, respectively. The production of millets, however, declined to a recorded level of 66900 tonnes in previous ten years. Cereal grains grown all over the country face potential losses during processing, creating a threat to the countries food reserves. Hence, a valid solution to these problems are to be defined. Moreover, food security has always been the overriding goal of agricultural policy in India. The rapid growth in production followed by losses in cereals demands the utilization of the novel technologies. The introduction of novel technologies has improved the processing and utilization of cereal grains in different countries. Emerging technologies viz radiofrequency, microwave, irradiation and high-pressure processing have found potential application for storage and processing of cereals. The present study envisages the present and future scenario of the novel technologies to be used to reduce the losses in cereals.

 

Chapter 6 Emerging Technologies in Dairy Processing: Present status and Future Potential

Milk and Milk products being nutritious are consumed by wider groups of people. In Indian context, data from FAO reported increase in the production of butter (buffalo milk) from 600000-79700 tons, -ghee (cow milk) from 105050-137550 tons, -buffalo milk 2150000-2863000 tons, -skimmed milk from cow 1890000-2475000 tons; and reported decrease in production of -milk (whole dried) from 14950-6500 tons and -cheese (cow milk) from 12000-2250 tons for the consecutive 10 years (2004-2014). These dairy products are known to be susceptible to microbial and enzymatic spoilage and thus mandate improved processing methods. In recent years, the development of various non-thermal technologies like high pressure processing (HPP), pulsed electric field, ultra-sonication, membrane filtration, ultraviolet light and cold plasma, have demonstrated the potential to produce shelf stable dairy products with retained nutritional parameters. On one hand where growing awareness about the effect of nutrition and bioactive compounds on human health has paved the way for emergence of state-of-art methods of food fortification, on the other, the liability of sustaining increasing and dispersing population resulted in innovations in food processing technologies: together which supported motto of 'healthy food for all'. Specifically, focusing on impacts on safety, quality and nutritional value, the chapter discusses the principle, scope, merits and limitations of emerging technologies with respect to dairy products.

 

Chapter 7 Insect pest infestation during storage of fruits and vegetables 

Fruits and Vegetables are basic to advancing great wellbeing. In fact, Fruits and Vegetables should be the foundation of a healthy diet. Most people need to double the amount of Fruits and Vegetables they eat every day. Fruits and Vegetables are packed with essential vitamins, minerals, fiber, and disease-fighting phytochemicals with a wide range of health benefits. Products of the soil (fruits and vegetables) give medical advantages and are vital for the counteractive action of sicknesses. Fruits and Vegetables are low in fat, salt and sugar. They are a good source of dietary fibre. As part of a well-balanced and healthy diet, a high intake of fruits and vegetables can help to reduce obesity and maintain a healthy weight. Sedentary lifestyle requires food that's nutritious, energizing, and easy to eat on-the-go, like fruits and vegetables. 

However, fruits and vegetables (F&V) are living tissues and highly perishable products which require optimal post-harvest technologies in order to maintain their storage, stability and extend shelf life. Growing consumer demand for convenience in food preparation and consumption, including product form, packaging, quality preservation, and year-round availability has been driving the F&V marketing system to one with an increased focus on value added and cost minimization by streamlining the distribution. Quality and stability of F&V depend upon the cultivar, pre-harvest practices, climacteric conditions, maturity at harvest, harvesting practices and post-harvest handling conditions, making shelf life prediction a difficult task when compared with other food products.

Food commodities of animal and agricultural origin are stored for future consumption and for trade purposes. During storage, the quality of the produce is affected by the pest infestation besides environmental factors. The pests mainly include birds, rodents, insects and microorganisms. Inputs in terms of manpower and finances invested in the production of food commodities will go waste, unless the produce is protected from the degrading agents during storage. Post-harvest deterioration can be controlled by reducing the storage temperature and respiration rate by modification of the atmospheric conditions surrounding the product which would improve stability and extend shelf life of the fresh produce. The aim of the chapter is to focus mainly on the various types of insect infestations causing the contamination and spoilage of perishable as well as dried fruit and vegetable products, hence, by leading to the overall economical loss from the agricultural sector. This chapter also focuses on the various detection and control techniques which can be taken so as to eradicate the loss of various nutrients right from the primary produce on the fields to the target population i.e. human.

 

Chapter 8 Insect pest infestation during storage of cereal grains, pulses and oilseeds

Stored grain insect pests normally cause as much loss of grains in storage after harvest as crop pests cause damage during the growing season. Stored grains are ravaged by a number of insect pests. The stored grain pests infest grains to fulfill their food and shelter requirements resulting in qualitative as well as quantitative losses. The adults and larvae of these insects damage and contaminate grains or their products by burrowing into grain and eat out the starchy portion in the interior. This chapter will summarize integrated pest management (IPM) in stored grains including cereals, oilseeds and pulses, which is complex operation due to diversity of grains and pests requirements. The management of stored grains necessitates the utilization of different methods to guarantee that the attributes of the grains incoming to the storehouse environment do not degenerate during storage time period. These activities involve; regular sampling, sanitation measures, storing sound and dry grains, bringing of proper temperature and aeration, and exploitation of chemical protectants and fumigants. However, the prevention against pests is the only satisfactory means to hold up the good grain quality. A powerful linkage of researchers and food industry can expedite the acceptation of IPM exercises, and improvement and publicity of fresh and reinforced control operations for forthcoming pest situations.

 

Chapter 9 Recent Studies on Healthy Nutrients Changing in Fruit Juices Processed with Non-thermal Technologies 

Fruit juices are the most preferred beverage around the world due to high content healthy nutrients and source of antioxidants, such as vitamins, phenolic and carotenoid compounds. Fruit juice phenolic and carotenoid compounds and some vitamins have important antioxidant function that scavenges free radicals damaging cells with reacting structural molecules and reduce cardiovascular diseases. Therefore, they are unique for growth, maintenance and well-being of human life. Nowadays consumer demands have tendency around both safe to consume and minimal processed foods. Therefore, food processing industry has made an effort in order to improve processing technologies having potential to fulfill those consumer demands in final product.  In the last decades, promising non-thermal food processing technologies, such as pulsed electric fields (PEF), high pressure processing (HPP), ultrasound processing (UP) and ultraviolet light processing (UVLP), have been alternatively developed to the traditional thermal pasteurization for extending shelf life and minimizing loss of healthy nutrients of fruit juices. In the present chapter, effect of non-thermal technologies (PEF, HPP, UP and UVLP) on fruit juices health related compounds (vitamins, phenolic and carotenoid compounds) will be evaluated and discussed from the perspective of recent published research studies in the literature.

 

Chapter 10 Potential industrial use of compounds from by-products of fruits and vegetables

The global consumption of fruits and vegetables is rapidly increasing with increasing world population and health awareness. Waste and by-products are produced in all the phases of food life cycle i.e. during production, industrial processing, and distribution. It has been reported that in the food manufacturing industry 39% of the food is wasted and this is expected to rise to about 126 Mt by 2020 if proper prevention policies are not in place. The by-products of these fruits and vegetables like peels can be wisely used for other industries. It has also been observed that a large portion of fruits and vegetables undergo a post harvest loss in the processing industry. For example, the pulp and the peel after the extraction of juices from fruits and vegetables go unutilised. The fruits and vegetables and their by products are rich in bioactive compounds like phenolic compounds, flavonoids, carotenoids, and anthocyanins. These compounds are known to have anticancer, anti-cardiovascular, antiviral, anti-tumour, antimicrobial and antioxidant activities; and can be used in pharmaceutical, nutraceuticals, cosmetic, chemical industries and for the development of functional foods. Since many of these bioactive compounds posses antimicrobial activity they can also be used in food preservation and to control food-borne pathogens. Compounds from these by-products such as carotenoids, essential oils, and flavours can be incorporated into food products to enhance their sensory properties and to improve their nutritional value and health benefits. The present chapter focuses on various types of bioactive compounds present in the by products of fruits and vegetables, their extraction techniques, and utilization in pharmaceutical, cosmetic and chemical industries. The antioxidant and antimicrobial properties of these bioactive compounds are also discussed.

 

Chapter 11. Phytochemicals of whole grains and effects on health

Grains are one of the most important raw materials for staple food products in the human diet. Since, they are not only a good source of carbohydrate but also provides daily energy necessity, proteins, B-complex vitamins for adequate and balanced nutrition. Moreover, in the recent times, it was elucidated that whole grains involve several bioactive compounds namely phytochemicals. Phytochemicals are non-nutritive dietary bioactive compounds and secondary metabolites that generated by plants for preservation themselves against environmental stress or threats. Whole grain phytochemicals comprise of dietary fiber such as beta-glucan, arabinoxylan, inulin, resistant starch; phenolic compounds as phenolic acids, anthocyanins, carotenoids (lutein, zeaxanthin etc.), tocols (tocotrienols and tocopherols), lignans, alkylresorcinols and other phytochemicals as phytosterols. Phytochemicals improve health and/or hindering some chronic diseases because of whose antioxidant, anticarcinogenic, antimicrobial, antimutagenic, and anti-inflammatory activities. Epidemiological studies support that consumption of whole grains and food products are related to reduced risk of obesity, oxidative stress, type II diabetes, coronary heart disease and some cancer types. The phytochemicals are mainly located in the outer layers of grains as germ and bran parts. For this reason, whole grains phytochemicals content is higher than refined ones by milling process. In many cases, processing effect negatively on bioactive components but also there are contradictory remarks and studies about the stability of phytochemicals during processing.

 

Chapter 12. Chemical Hazards in Foods 

Food safety is a global concern and major issue for both manufacturers and consumers. Many toxic chemicals including food additives, natural biological toxins, adulterants, environmental contaminants, process contaminants, food contact materials, veterinary drugs, pesticides and others can be found in foods and feeds and may pose a risk to human and animal health. Among these chemical hazards, mycotoxins are of greatest concern in terms of chronic toxicity as well as economics. Mycotoxins are secondary metabolites produced by certain fungi belonging predominantly to the Aspergillus, Penicillium and Fusarium and Alternaria genera. Mycotoxins can cause a variety of adverse effects on both humans and animals, ranging from allergic responses to death. Although pesticides play a key role in crop protection, preservation of food and feed materials and prevention of vector-borne diseases caused by pathogens and parasites such as malaria, dengue, leishmaniasis and Japanese encephalitis, their excessive use has a deleterious effect on human health and the environment, ranging from short-term impacts    such as headaches and nausea to chronic diseases like cancer, reproductive harm, and endocrine disruption. Several chemical contaminants including acyrlamide, furan, 3-MCPD, glycidyl fatty acid esters (GE) can also be formed in food by cooking or other food processing methods. Acyrlamide can form as a by-product during the heating of starchy food products like potato and bread to above 120^oC. 3-monochloropropane-1-2 diol (3-MCPD) and GE are other process contaminants that form during the refinement of edible oils and fats. This chapter will focus on an update of current knowledge on most commonly found contaminants in food and feeds.

 

Chapter 13. Risk Management of Chemical Hazards Arising During Food Manufacturing

The three main types of food contaminants are physical, chemical and microbiological. Chemical hazards have been recognized as a potential food safety issue since ancient times. Chemical hazard can be introduced into food at all stages in the supply chain, including production and retail. These hazards can arise in different forms and as a consequence of various events. With the advancement in the technology, detection of such contaminants becomes easier. Risk management of chemical hazard requires a robust food safety management system which includes focus on operational prerequisite programs, such as supplier quality assurance and inventory control as well as Hazard Analysis and Critical Control Point (HACCP). This chapter highlights the various groups of food contaminants, their occurrence in the food chain. Rest of the chapter mainly focuses on food process toxicants, food additives and nutrients and the approaches to be employed to solve the risk they posed to the consumer.

 

Chapter 14. Evaluation of probiotics in terms of food safety and human health 

Probiotics are often referred to as microorganisms (bacteria or yeasts) that generally provide health benefits. There is great interest in probiotics for various medical conditions and millions of people around the world consume probiotics daily with the perception that it is beneficial for health. Members of the Lactococcus and Lactobacillus genus, Streptococcus and Enterococcus strains, and some other LAB strains are generally accepted as safe (GRAS) status, although they contain some opportunistic pathogens. In addition, some of the spore forming bacteria have been researched and used as probiotics. However, nowadays theoretical concerns and side effects are discussed with regard to the safety of probiotics. Systemic infections, the risk of harmful metabolic activities, the risk of adjuvant side effects, and immunomodulation and the risk of gene transfer are among the theoretical concerns discussed. The most common side effects of probiotics include gastrointestinal disorders such as diarrhea, nausea, bloating, dyspepsia and abdominal pain. Other side effects include respiratory tract infections, abscess, allergic reactions and severe medical conditions such as sepsis, fungemia, and endocarditis. The safety of probiotics is related to the potential vulnerability of the consumer or the patient, the dose of use and the duration of consumption and the frequency of consumption. The significance of negative probiotic effects will be better understood by the better understanding of the probiotic interaction mechanisms with the host and colonizing microbes. In this chapter, the evaluation of the safety associated with the consumption of probiotic products is discussed, based on epidemiological data and infectious cases.

Chapter 15. Beneficial bacterial biofilms in food industry

Biofilm is defined as a community in which microorganisms adhere to a living or inanimate surface, embedded in a gelatinous layer in a self-produced matrix of extra polymeric substances, adhered to each other, to a solid surface or to an interface.  Adverse environmental conditions caused biofilm formation by inducing transition of microorganisms from planktonic cell form to sessile cell form and altered metabolism of bacteria in biofilms. Bacteria in biofilm matrix produce the specific secondary metabolites and gain robustness. Although biofilms are often accepted as potentially destructive for clinical and industrial fields, many biofilms are beneficial and there are several reports related to the positive use of these biofilms. Beneficial biofilms could be used for wide applications (antibacterial, food fermentation, biofertilizer, filtration, biofouling, prevention of corrosion, wastewater treatment, bioremediation and microbial fuel cells) in food, medical and environment fields. According to previous reports, certain strains including Bacillus spp. (B. subtilis, B. brevis, B. licheniformis) Lactobacillus spp. (L. casei, L. paracasei, L. acidophilus, L. plantarum, L. reuteri) Enterococcus spp. (E. casseliflavus, E. faecalis) Pseudoalteromonas sp. led to beneficial biofilm formation. Food industry may mostly benefit from biofilms in terms of their biochemical and antibacterial characteristics. Bacteria in biofilm matrix could positively affect quality characteristics of food products such as texture, biochemical composition and sensorial properties via the production of the specific secondary metabolites. Additionally, bacterial biofilms may play an important role as a biocontrol agent and anticorrosive and filtration substance in food industry. Especially, lactic acid bacteria and/or probiotic biofilms is highly important for their ability to act as an antibacterial. For example, the use of lactic acid bacteria biofilms as novel strategy was applied to limit bacterial pathogen growth in the field of food packaging. The objective of this chapter is to highlights the beneficial biofilm formation by various bacteria in food industry.

 

Chapter 16. Next generation probiotics their molecular taxonomy and health benefits 

The concept of probiotics although perceived as new is more than a century old. Since the early studies of the Elie Metchinkoff in 1900 a number of commercial products containing probiotics are in the market. The recent success of converting probiotic products into commercial reality was achieved by the scientists like Minoru Shirota and Kellog. Minoru Shirota is a Japanese scientist who successfully demonstrated the health benefits of probiotics and commercialized the globally known probiotic drink Yakult. This renewed interest in probiotics is due to the recent advances made in understanding the human microbiome and its role in human health. The link between gut microbiome and human health is becoming increasingly clear and is well described. Nevertheless, the gut microbiome is continuously influenced by a number of factors like diet, life style and consumption of antibiotics. A healthy gut microbiome can be retained and maintained by using various probiotics. Moreover, the probiotic microorganisms are no more limited to a few conventionally used bacteria and are being currently represented by more phylogenetically diverse microorganisms than previously thought. These probiotic microorganisms include conventionally used Lactic acid bacteria, like Lactobacillus and recently identified probiotic bacteria like Akkermansia muciniphila, Bifidobacterium infantis, Bacteroides fragilis, Clostridia clusters (IV, XIVa, and XVIII), Faecalibacterium prausnitzii and Streptococcus thermophiles etc. Many of these probiotic strains have a shared mechanism of action, while sub-species-specific, species specific or genus-specific probiotic effects has also been documented. Probiotics are administered as live cultures or as spores, directly or through fermented dairy products, food and drinks. Probiotics based therapies like fecal microbiota transplant are also being used successfully for treating medical conditions and diseases like diarrhea, constipation, vaginitis, necrotizing enterocolitis, inflammatory bowel disease, Clostridium difficile infection, and others. Reports are also emerging showing a clear role of probiotics in immunomodulation, cardiovascular diseases and even in cancer. Yet, a number of microorganisms in the gut remain uncultured and many probiotic microorganisms remain poorly identified, requiring correct identification and a rigorous evaluation as probiotics. Probiotics may be a century old but require fresh attention with the increasing knowledge of gut microbiome and the role of these microorganisms in human health.

 

Chapter 17. Continuing Controversies Regarding Human Health Concerns from Nitrite and Nitrate Consumption in the Diet

Nitrite, salt, seasonings and other ingredients are used for the curing to give unique color, flavor and texture to the meat products. Sodium or potassium nitrite is incorporated into the processed meats to provide desirable meaty flavor, prevent warmed-over flavor, develop a bright reddish pink color and inhibit the microbial growth, particularly for out-growth of Clostridium botulinum spores. Sodium or potassium nitrate can also be used to cure the processed meats. However, nitrate has to be reduced to nitrite by the microorganisms to be effective for curing and mostly used for the slow-cured products including some fermented sausages and country style hams. The safety of nitrite and nitrate used for meat curing was questioned in the 1970s due to their potential to form carcinogenic nitrosamines in the stomach following the ingestion.   Conversely, some potential health benefits were also attributed to both nitrite and nitrate in the recent studies since both compounds contribute to nitric oxide production in human body. Nitric oxide produced directly from nitrite has a significant effect on cardiovascular health by controlling blood flow in the cardiac muscle. Thus, the continuing controversy regarding human health concerns from nitrite and nitrate consumption in the diet were evaluated and discussed in this chapter. 

 

Chapter 18. The Risk of Vancomycin Resistant Enterococci Infections from Food Industry

The contribution of Antibiotic Resistant Enterococci (AREs) and especially Vancomycin Resistant Enterococci (VREs) which may be entered into the food chain has gained importance with the increasing significance of VREs in hospital infections. The relationship of food borne Enterococci with clinical infections has not been fully explained yet. However, it is argued that food borne isolates, with horizontal gene transfer, may play a role in the expansion of virulence genes. Molecular-based studies show that clinical based E. faecalis strains had more virulence factors when compared to food borne strains. Same studies also identified that virulence genes could be transmitted to starter cultures via clinical type conjugation. Various studies in Europe and the USA have investigated the prevalence and epidemiology of VRE, particularly the place of VREs in infection epidemiology and identification of the risk factors. However, there is little information about its incidence in the Middle East and Asia. Vancomycin Resistant Enterococcus epidemiology differs in Europe and the USA. VRE was generally isolated from animals in Europe, which was connected extensive use of ''avoparcin'' as a growth promoter factor for animal feed in food industry. Animals fed with this feed play the reservoir role of transferable vanA type resistance. On the other hand, since ''avoparcin'' was not used in USA, VRE could not be isolated in animals and healthy individuals. However, hospital- acquired VRE infections are more common in the USA than Europe. According to some studies, since Enterococci are used as starter culture and probiotic culture, they should have no relationship genetically with the strains which include vancomycin /resistant to antibiotic/or having resistance and virulence genes.

 

Chapter 19. New Concept in Packaging: Milk Protein Edible Films

Ready to eat (RTE) and perishable foods need specific precautions for packaging. The main function of food packaging is widely used for protection of food quality, to extend the shelf-life by preventing oxygen, moisture, light and provides microbial safety for consumers. The packaging industry are working on renewable, environmentally-friendly and biodegradable alternatives to replace petroleum-based packaging materials. Packaging becomes more important as a vehicle for communication system of product differentiation, content, and branding. Proper and effective packaging prevents any kind of contamination and facilitates storage and transportation by preventing moisture loss, aromas loss, solute transport, water absorption in the food. Edible films and coatings, have a rising interest in recent years, is a form of active packaging and are obtained from proteins (wheat gluten, soy protein, albumin, gelatin, collagen, casein, whey proteins, peanut protein and mung bean protein), polysaccharides, lipids or combinations of these components. Edible films could act as a functional hurdle between the food and the surrounding environment and guarantees the safety of foodstuffs.  Casein based films have great O₂ barrier, while whey protein based films have good water vapour and O₂ permeability. Adding of plasticizers to protein-based film formulations are required to reduce film fragility, to confer certain plastic properties, to improve processability, to increase elongation and water vapor permeability and decrease film stiffness and moisture barrier ability of protein films. We will present in this chapter the principal functions; and properties of milk protein edible films and effects of these films on health

 

Chapter 20. Food Nanotechnology: An Emerging Technology in Food Processing and Preservation 

The advent and rise of nanoscience has led to significant development in modifying various food properties. Food nanotechnologies involve the size manipulation of the particles of a food matrix. The novel physicochemical properties at nanoscale matter enhance textural characteristics, colour, physiochemical stability, sensory attributes, and involve controlled release of active agents, thus enhancing the quality, and shelf life of the food product. In an advanced form, the technology is related to nanoencapsulated food additives. In addition, the application of nanocomposites promises an expansion for the use of edible and biodegradable films in active packaging to preserve fresh foods and to extend their shelf life. Also, the use of nanosensors to detect microorganisms and contaminants is a particularly significant application of food nanotechnology. Apart from the significant benefits, the implications of nanotechnologies indicate that an immediate need for regulation of nanomaterials before their incorporation into food is critical for ensuring acceptance of the technology by the consumers.

 

Chapter 21. Nanoparticles in Food Packaging: Opportunities and Challenges

Packaging is the last stage of food processing; and a successful package is one that protects a product or contents from an environment for a period of time with a reasonable cost. The package affects the quality of foods by controlling the degree to which factors connected with processing, storage and handling can act on components of food. Use of nanotechnology in science brings great opportunities for many industries including food packaging industry. Recently, various engineered nanomaterials such as nanoclay and metallic nanoparticles have been introduced to food packaging as functional additives. Their positive effects on developed packaging materials have been extensively reported.

Nanoclays and metallic nanoparticles are also promising in using active packaging technology, an innovative technology for food preservation based principally on mass transfer interactions between systems "food/packaging". These nanoparticles have been applied to packaging system by using different ways. This chapter aims to give an overview of the use of nanoparticles for food packaging, introduce the nanoclay and metallic nanoparticle types. Recent developments on active packaging by the use of nanoparticles will be summarized. Migration studies and their safety issue will be also discussed according to published research studies in the literature.

 

Chapter 22. Ultrasound: A Food Processing and Preservation Aid

Ultrasound is a form of green technology that has diverse applications in food processing, preservation, and quality control. It is an emerging technology that modifies various properties of food products. The principle phenomenon behind ultrasound is cavitation and mass transfer. High frequency ultrasound is used to monitor the composition of food whereas low frequency ultrasound induces physical and chemical/biochemical changes in food. The technology is a non-invasive technique employed to estimate the composition of food and to induce physical, and chemical or biochemical changes in food. Various frequencies of ultrasound can be significantly utilized to modify physiochemical properties of food during freezing and crystallization, defrosting/thawing, drying, meat tenderization, pickling, emulsification/homogenization. The technique is also useful in extraction of bioactive components, sterilization, defoaming, depolymerization, and inactivating enzymes. Ultrasound minimally affects the quality of food products and is an inexpensive technology, with the only limitation to certain foods which contain small air bubbles.

 

Chapter 23. A Natural Way of Food Preservation: Bacteriocins and applications

Since the consumer demand to foods produced without additives, new friendly preservation strategies become significant in processing of foods. Bacteriocins are ribosomally synthesized peptides produced from many bacterial strains which are approved as natural due to being degraded by digestive enzymes. In Lactic acid bacteria (LAB), many strains have been identified as bacteriocin producers. In fact, nisin was approved by Food and Drug Administration (FDA) to be used as food additive in some foods as well as lacticin and pediocin producers, Lactococcus lactis and Pediococcus acidilactici respectively, have been used as protective cultures in food system. Bacteriocins produced by some LAB have shown wide antimicrobial activity against food related pathogens species such as Bacillus, Listeria, Staphylococcus and Clostridium. However, in recent years bacteriocins having specifically narrow-spectrum antimicrobial activity have been introduced.

Bacteriocins are used either directly in food systems or by the addition of producer strains. In this way, it has been possible to prevent pathogenic microorganisms in various fermented food products. However, the effectiveness of the LAB bacteriocins may reduce due to their adsorption on to the hydrophobic surfaces and degradation with proteases. Therefore, the combinational usage of bacteriocins with other preservation methods, such as high hydrostatic pressure, pulse electrical field or essential oils, were reported successful at inhibiting pathogens including also gram negatives. 

In the first part of the chapter, the general introduction to bacteriocins will be made and new generation bacteriocins will be discussed. In the second part, the applications of bacteriocins at different food systems will be explained and the combinational usage of bacteriocins together with different preservation methods will be exemplified.