Ozone in Food Processing

Colm O'Donnell, Brijesh K. Tiwari, P. J. Cullen, Rip G. Rice, Colm O'Donnell, Brijesh K. Tiwari, P. J. Cullen, Rip G. Rice

• Publisher: Wiley-Blackwell
• Year: 2012
• Print ISBN: 9781444334425
• eBook ISBN: 9781118307434
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

This book is the first to bring together essential information on the application of ozone in food processing, providing an insight into the current state-of-the-art and reviewing established and emerging applications in food processing, preservation and waste management.

The chemical and physical properties of ozone are described, along with its microbial inactivation mechanisms. The various methods of ozone production are compared, including their economic and technical aspects. Several chapters are dedicated to the major food processing applications: fruit and vegetables, grains, meat, seafood and food hydrocolloids, and the effects on nutritional and quality parameters will be reviewed throughout. Further chapters examine the role of ozone in water treatment, in food waste treatment and in deactivating pesticide residues. The international regulatory and legislative picture is addressed, as are the health and safety implications of ozone processing and possible future trends.

1

Status and Trends of Ozone in Food Processing

Colm O’Donnell, B.K. Tiwari, P.J. Cullen and Rip G. Rice

1.1 Why ozone?

Interest in ozone has expanded in recent years in response to consumer demands for ‘greener’ food additives, regulatory approval and the increasing acceptance that ozone is an environmentally friendly technology. The multifunctionality of ozone makes it a promising food processing agent. Excess ozone autodecomposes rapidly to produce oxygen and thus leaves no residues in foods from its decomposition. In particular, the US Food and Drug Administration (FDA)’s rulings on ozone usage in food have resulted in increased interest in potential food applications worldwide. Ozone as an oxidant is used in water treatment, sanitising, washing and disinfection of equipment, odour removal, and fruit, vegetable, meat and seafood processing.

1.2 Drivers of ozone in the food industry

1.2.1 Regulation

While food safety assurance is a global concern, approaches to regulation differ throughout the world. Globally the regulatory status of ozone for food processing applications is still in an evolving state of flux, and in some countries has not been addressed to date. Legislation governing ozonation for treating, handling, processing and storage of foods has typically developed in response to the evolving use of ozone from initial applications for water treatment, through surface and equipment cleaning, food produce washes, and finally to use as a direct food additive. The use of ozone in food processing has become increasingly important as a result of the affirmation of ozone as a GRAS (Generally Recognised as Safe) chemical in 1997 (Graham et al. 1997) and its subsequent approval by the US FDA as an antimicrobial additive for direct contact with foods of all types (FDA 2001). The use of ozone in food processing has been approved to various degrees in many countries, including the USA, Japan, Australia, France and Canada. Given the complexities of food matrices and the range of foods produced, demonstrating process validation is a challenge for industry. However, more expedited validation processes are likely with validation of comparable products.

1.2.2 Surface cleaning and disinfection

The need to develop nonresidual and validated cleaning approaches for the food industry has been clearly indentified. Ozone offers the food industry an alternative or complementary cleaning and sanitising agent. The efficacy of ozone for physical, chemical and biological cleaning within food processing units has been reported. The potential inclusion of ozone-containing water within the clean-in-place (CIP) cycle offers significant opportunities for food processors. Comparisons of treatment efficacy against traditional approaches are discussed in Chapter 10. Applications of ozone for sanitising various food processing equipment items are reviewed. The use of ozone for cleaning within comparable process industries, such as pharmaceuticals, is also outlined.

1.2.3 Food safety and shelf life extension

Food treatment approaches include ozone applications in both the gaseous and aqueous phases. Washes in ozone-containing water, storage in ozone-rich atmospheres and direct addition of ozone in fluid foods are reviewed. The antimicrobial efficacies of ozone for control of pathogenic microorganisms of concern in the food industry are reviewed in Chapter 3. The effectiveness of ozone against microorganisms present in food systems depends on several factors including the amount of ozone applied, the residual ozone in the medium and various environmental factors such as medium pH, temperature, relative humidity, additives and the amount of organic matter surrounding the cells.

Storage grains are susceptible to a number of insects, which cause considerable damage to the stored grains and could potentially develop resistance to the currently employed insecticides. Increasing environmental problems and new legislation have tended to reduce the permitted pesticide amounts or even prohibited their use. Ozone use in fumigation is an alternative to chemicals in controlling insect development. The use of ozone for the control of fungi and mycotoxins in grains is discussed in Chapter 6.

The potential of ozone for the degradation of pesticide residues found in food is discussed in Chapter 13. The proposed mechanisms for degradation of pesticides, including organophosphates and organochlorinated compounds, are outlined. The efficacy of both gaseous and aqueous ozone for degradation and the processing parameters governing the process are reviewed.

1.2.4 Nutrient and sensory aspects

Taste and sensory properties are consistently rated as the most important factors driving consumption and repeat purchase of food products. The principal driver for industrial adoption of new processing technology is to meet consumers’ demands for improved taste and nutrition. Ozone is a strong oxidising agent and its effect on such parameters must be considered prior to any potential food application. Effects will be dependent upon the mode of application, the dose, food composition and so on. Each application chapter discusses the reported effects on such parameters.

1.2.5 Consumer and processor acceptability

Consumers are not only concerned about the ingredients within the foods they consume, but also about the processes that are employed in bringing food ‘from farm to fork’. A growing body of consumer research suggests that consumers are increasingly conscious of the food supply chain, which will continue to influence their perceptions of emerging food processes. Paradoxically, consumers are demanding foods which are minimally processed, meet their nutritional and taste desires yet require minimal preparation. Understanding and addressing consumer issues related to any novel food process are some of the most important challenges facing the developers of innovative food products. Research suggests that acceptance of new technologies is based to a great extent on public perceptions of the associated risks, and that perceptions of risk are influenced by trust in information and the source that provides it (Frewer et al. 2003). Several consumer research studies have consistently shown that consumers have poor knowledge and awareness levels towards most novel food processing techniques, which serves as a major impediment to their acceptance. Thus, effective communication regarding details of the technologies and their benefits becomes essential for successful marketing of these products. If a novel technology allows the introduction of new products with tangible benefits, consumers are most likely to accept it.

For the processor, it is critical that any process adopted is safe for the production staff. Chapter 15 reviews the precautions dealing with the release of gaseous ozone in amounts that might cause discomfort or injury to plant workers. The health and safety issues associated with ozone are reviewed, followed by a discussion of the commonly accepted worker safety regulations for breathing gas-phase ozone.

1.2.6 Technology advances

There have been significant developments in the methodologies of ozone production, including corona discharge/plasma and UV radiation, which make ozonation a more attractive approach for food processing. Economic and technical aspects of ozone production are outlined in Chapter 4, including process controls, production scales, application approaches and the limitations of each procedure. Challenges encountered in the industrial production of ozone are addressed, along with future trends. Novel systems for generation of ozone within sealed packages under air or modified atmospheres are described. Such approaches are suitable for many food applications, from fresh produce to meat products.

1.2.7 Environmental impact

To achieve the full potential of commercial exploitation of novel technologies, issues related to environmental impacts, such as wastewater and gas emissions, the conservation of nonrenewable resources and energy consumption, must be investigated and understood by food processors, since they can represent significant potential reductions in processing costs (Pereira and Vicente 2010). The food industry is a significant consumer of energy, with the principal type of energy used for traditional thermal processing being fossil fuel. Water is a key ingredient in the food industry, playing a fundamental role in many of the common food processing methods and unit operations, such as soaking, washing, rinsing, blanching, heating, pasteurising, chilling, cooling and steam production, acting as an ingredient, and being used for general cleaning, sanitation and disinfection purposes. However, the industry is not so well known for its use of water-saving devices and practices. While ozone has been a globally successful water treatment method, the literature has shown that it has not been largely employed as yet by the food industry, even though it was approved for application in the reconditioning of recycled poultry chilling water by the US Department of Agriculture in 1997 (Güzel-Seydim et al. 2004). Chapter 11 discusses the potentials of ozone as an alternative for potable water treatment, wastewater treatment and water reuse in the food industry. Applications are identified in the fruit and vegetable, meat and dairy sectors. The efficacy of ozone for physically, chemically and microbiologically safe reuse of water in the food industry is discussed.

1.3 The hurdle concept

Combining a number of preservation methods may enhance the overall antimicrobial effect so that lower process intensities can be employed. This approach, known as ‘hurdle technology’, has already been applied successfully using traditional techniques of food preservation (Leistner and Gorris 1995). Combining ozone methods with other food preservation techniques can (1) enhance the lethal effects, (2) reduce the severity of treatment required to obtain a given level of microbial inactivation and (3) prevent the proliferation of survivors following treatment. The choice of hurdles – several combinations of either novel thermal, novel nonthermal or conventional processing technologies – is generally made to maximise the synergistic effect on the microbial inactivation kinetics. Food preservation using combined methods involves successive or simultaneous applications of various individual treatments. Combined treatments are advantageous, principally because many individual treatments alone are not adequate to ensure food safety or stability.

1.4 Challenges

Despite significant scientific advances and the demonstrated industrial potential of ozone in seafood, meat and decontamination of pesticide residues in the food chain, there is a paucity of reported studies in this area in general. Also, the potential for reduced processing costs through the use of ozone technologies has not been widely disseminated. Awareness and understanding of ozone applications for foods is key to improved uptake of ozone technology by industry. Increased clarity of the regulatory status of ozone for food applications would facilitate increased global adoption by the food industry.

1.5 Objective

The objective of this book is to demonstrate the potential technoeconomic benefits of employing ozone in the food industry to facilitate increased industry adoption. This book provides an insight into the current state of the art and reviews emerging applications of ozone processing. The principles of ozonation, process control parameters, microbial inactivation mechanisms and the effects on food nutritional and quality parameters are outlined. Separate chapters are dedicated to covering different food processing applications. Finally, health and safety aspects of ozone as used in food processing plants and future trends in industry adoption of ozonation are discussed.

References

FDA (2001) Hazard analysis and critical control point (HACCP): procedures for the safe and sanitary processing and importing of juice; final rule, Federal Register, 66: 6137–6202.

Frewer, L., Scholderer, J. and Lambert, N. (2003) Consumer acceptance of functional foods: issues for the future, British Food Journal, 105: 714–31.

Graham, D.M., Pariza, M.W., Glaze, W.H., Erdman, J.W., Newell, G.W. and Borzelleca, J.F. (1997) Use of ozone for food processing, Food Technology, 51(6): 72–6.

Güzel-Seydim, Z.B., Greene, A.K. and Seydim, A.C. (2004) Use of ozone in the food industry, Lebensm.-Wiss. Technol.-Food Sci. Technol., 37(4): 453–460.

Leistner, L. and Gorris, G.M. (1995) Food preservation by hurdle technology, Trends in Food Science and Technology, 6: 41–46.

Pereira, R.N. and Vicente, A.A. (2010) Environmental impact of novel thermal and non-thermal technologies in food processing, Food Research International, 43: 1936–43.

2

Regulatory and Legislative Issues

B.K. Tiwari and Rip G. Rice

2.1 Introduction

Ozone has been used commercially for the treatment of drinking water since 1906 Nice, France (Hill and Rice 1982) and is increasingly employed in the food industry for produce preservation and sanitising of food-contact surfaces. Demand for new preservation approaches arises from growing consumer preference for minimally processed foods, frequent outbreaks of food-related illnesses, identification of new food pathogens and the passage of legislation governing food quality and safety. The World Health Organization (WHO) identified foodborne diseases as a considerable threat to human health and the global economy which requires a concerted effort on the part of three principal partners, namely governments, the food industry and consumers. For sanitising applications, ozone may be preferred over traditional sanitisers such as chlorine because of the relatively low inactivation rate of chlorine at concentrations which are limited by regulation, combine...

Table of contents

• Cover
• Title page
• Copyright page
• Contributors
• 1 Status and Trends of Ozone in Food Processing
• 2 Regulatory and Legislative Issues
• 3 Chemical and Physical Properties of Ozone
• 4 Generation and Control of Ozone
• 5 Ozone in Fruit and Vegetable Processing
• 6 Ozone in Grain Processing
• 7 Ozonation of Hydrocolloids
• 8 Ozone in Meat Processing
• 9 Ozone in Seafood Processing
• 10 Ozone Sanitisation in the Food Industry
• 11 Ozone for Water Treatment and its Potential for Process Water Reuse in the Food Industry
• 12 Ozone for Food Waste and Odour Treatment
• 13 Efficacy of Ozone on Pesticide Residues
• 14 Modelling Approaches for Ozone Processing
• 15 Health and Safety Aspects of Ozone Processing
• Index
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• Plates