Taylor Handbook of Natural Antimicrobials for Food Safety and Quality

1. Auflage 2014
ISBN: 978-1-78242-042-2
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band 269, 442 Seiten

Reihe: Woodhead Publishing Series in Food Science, Technology and Nutrition

Natural additives are increasingly favoured over synthetic ones as methods of ensuring food safety and long shelf-life. The antimicrobial properties of both plant-based antimicrobials such as essential oils and proteins such as bacteriocins are used in, for example, edible preservative films, in food packaging and in combination with synthetic preservatives for maximum efficacy. New developments in delivery technology such as nanoencapsulation also increase the potential of natural antimicrobials for widespread use in industry. Part one introduces the different types of natural antimicrobials for food applications. Part two covers methods of application, and part three looks at determining the effectiveness of natural antimicrobials in food. Part four focuses on enhancing quality and safety, and includes chapters on specific food products. - Reviews different types of antimicrobials used in food safety and quality - Covers how antimicrobials are created to be used in different foods - Examines how the antimicrobials are used in foods to enhance the safety and quality

Autoren/Hrsg.

Taylor, M.

Inhaltsverzeichnis

1;Front
Cover;1
2;Related titles;3
3;Handbook of Natural Antimicrobials for Food Safety and Quality;4
4;Copyright;5
5;Contents;6
6;List of contributors;12
7;Woodhead Publishing Series in Food Science, Technology and Nutrition;14
8;Preface;28
9;1 - The use of natural antimicrobials in food: an overview;32
9.1;1.1 Introduction;32
9.2;1.2 Types of natural antimicrobials: animal sources;34
9.3;1.3 Types of natural antimicrobials: plant sources;37
9.4;1.4 Types of natural antimicrobials: microbial sources;40
9.5;1.5 Challenges to application of natural antimicrobials to foods;43
9.6;1.6 Application of natural antimicrobials;47
9.7;1.7 Conclusions;49
9.8;References;50
10;Part One -
Types;60
10.1;2 - Plant extracts as antimicrobials in food products: types;62
10.1.1;2.1 Introduction;62
10.1.2;2.2 Herbs, spices, and plant extracts as antimicrobials;63
10.1.3;2.3 Essential oils;68
10.1.4;2.4 Plant extracts in combination with minerals;69
10.1.5;2.5 Conclusion;71
10.1.6;Acknowledgment;71
10.1.7;References;72
10.2;3 - Plant extracts as antimicrobials in food products: mechanisms of action, extraction methods, and applications;80
10.2.1;3.1 Introduction;80
10.2.2;3.2 Mechanisms of action of plant extracts;81
10.2.3;3.3 Plant extracts and antibiotic resistance;84
10.2.4;3.4 Extraction methods to maximize antimicrobial properties;85
10.2.5;3.5 Response of Gram-positive and Gram-negative bacteria to plant extracts;88
10.2.6;3.6 Applications of plant extracts in food products;89
10.2.7;3.7 Conclusion;93
10.2.8;Acknowledgment;93
10.2.9;References;93
10.3;4 - Bacteriophages as antimicrobials in food products: history, biology and application;100
10.3.1;4.1 Introduction;100
10.3.2;4.2 Research into bacteriophages;101
10.3.3;4.3 Biology of bacteriophages;102
10.3.4;4.4 Bacteriophages as biocontrol agents in food;105
10.3.5;4.5 The use of phage endolysins as biocontrol agents in food;111
10.3.6;4.6 Combining bacteriophages with other preservation techniques to enhance food safety;113
10.3.7;References;114
10.4;5 - Bacteriophages as antimicrobials in food products: applications against particular pathogens;120
10.4.1;5.1 Introduction;120
10.4.2;5.2 Bacteriophages to control Gram-negative food-borne pathogens;121
10.4.3;5.3 Bacteriophages to control Gram-positive food-borne pathogens;130
10.4.4;5.4 Conclusion and future trends;136
10.4.5;References;137
10.5;6 - Lactic acid bacteria (LAB) as antimicrobials in food products: types and mechanisms of action;148
10.5.1;6.1 Introduction;148
10.5.2;6.2 Characteristics of lactic acid bacteria (LAB);148
10.5.3;6.3 Carbohydrate metabolism in LAB;149
10.5.4;6.4 Effects of culture preparation and storage techniques on LAB;150
10.5.5;6.5 Antimicrobial compounds produced by LAB: organic acids, diacetyl, and hydrogen peroxide;155
10.5.6;6.6 Antimicrobial compounds produced by LAB: bacteriocins;157
10.5.7;6.7 Conclusions;160
10.5.8;Acknowledgments;160
10.5.9;References;160
10.6;7 - Lactic acid bacteria (LAB) as antimicrobials in food products: analytical methods and applications;168
10.6.1;7.1 Introduction;168
10.6.2;7.2 Screening lactic acid bacteria (LAB) for antimicrobial activity;168
10.6.3;7.3 Regulatory framework governing the use of LAB in food;172
10.6.4;7.4 Methods for using LAB as biopreservatives in food;173
10.6.5;7.5 Use of LAB in the biopreservation of particular food products and as a biosanitizer;175
10.6.6;7.6 Conclusions;178
10.6.7;Acknowledgments;178
10.6.8;References;179
10.7;8 - Chitosan as an antimicrobial in food products;184
10.7.1;8.1 Introduction;184
10.7.2;8.2 Overview of antimicrobial activity of chitosan;185
10.7.3;8.3 Mechanism of action;185
10.7.4;8.4 Effects of molecular structure;195
10.7.5;8.5 Effects of environmental conditions;200
10.7.6;8.6 Current applications and future trends;203
10.7.7;References;204
11;Part Two -
Processing;214
11.1;9 - Evaluating natural antimicrobials for use in food products;216
11.1.1;9.1 Introduction;216
11.1.2;9.2 The advantages of using antimicrobials in food preservation;216
11.1.3;9.3 The use of natural antimicrobials in food preservation;217
11.1.4;9.4 Combining antimicrobials with other preservation techniques;219
11.1.5;9.5 Factors affecting the biocidal activity of natural antimicrobials;222
11.1.6;9.6 The regulation of natural antimicrobials;229
11.1.7;9.7 Conclusion;232
11.1.8;References;233
11.2;10 - Physical and chemical methods for food preservation using natural antimicrobials;242
11.2.1;10.1 Introduction;242
11.2.2;10.2 Physical application of natural antimicrobials;242
11.2.3;10.3 Chemical application of natural antimicrobials;249
11.2.4;10.4 Biological application of natural antimicrobials;252
11.2.5;10.5 Commercial natural antimicrobials;254
11.2.6;10.6 Conclusion and future trends;254
11.2.7;References;255
11.3;11 - Nanostructured and nanoencapsulated natural antimicrobials for use in food products;260
11.3.1;11.1 Introduction;260
11.3.2;11.2 Natural food antimicrobials;261
11.3.3;11.3 Nanostructures for antimicrobial delivery;264
11.3.4;11.4 Methods for characterization of nanostructures;273
11.3.5;11.5 Food applications of nanostructured antimicrobial systems;280
11.3.6;11.6 Conclusions and future trends;282
11.3.7;References;283
11.4;12 - Modelling the effects of natural antimicrobials as food preservatives;290
11.4.1;12.1 Introduction;290
11.4.2;12.2 Antimicrobial susceptibility assessment;291
11.4.3;12.3 Mathematical modelling in food preservation;292
11.4.4;12.4 Types of models;292
11.4.5;12.5 Model development;299
11.4.6;12.6 Modelling the effects of natural antimicrobial agents;302
11.4.7;12.7 Conclusion and future trends;309
11.4.8;References;310
12;Part Three -
Using natural antimicrobials in particular foods;316
12.1;13 - Using natural antimicrobials to enhance the safety and quality of fresh and processed fruits and vegetables: types of ...;318
12.1.1;13.1 Introduction;318
12.1.2;13.2 Fresh and processed fruits and vegetables: advances and challenges;319
12.1.3;13.3 Natural antimicrobials used in assuring the safety and quality of fresh and processed fruits and vegetables: antimicrobials ...;322
12.1.4;13.4 Antimicrobials from plants: aldehydes and methyl jasmonate;330
12.1.5;13.5 Antimicrobials from plants: phenolic compounds and isothiocyanates;331
12.1.6;13.6 Chitosan is not from plant origin;334
12.1.7;13.7 Natural antimicrobials of microbial origin: lactic acid bacteria (LAB) and bacteriocins;335
12.1.8;13.8 Conclusion and future trends;336
12.1.9;References;337
12.2;14 - Using natural antimicrobials to enhance the safety and quality of fresh and processed fruits and vegetables: applicati ...;346
12.2.1;14.1 Introduction;346
12.2.2;14.2 Techniques for applying natural antimicrobials to fruits and vegetables: key issues;346
12.2.3;14.3 Encapsulation of natural antimicrobials;347
12.2.4;14.4 Edible films and coatings enriched with natural antimicrobials;349
12.2.5;14.5 Antioxidant properties of natural antimicrobials;350
12.2.6;14.6 Plant antimicrobials as flavoring compounds;353
12.2.7;14.7 Conclusion and future trends;354
12.2.8;References;354
12.3;15 - Using natural antimicrobials to enhance the safety and quality of milk;358
12.3.1;15.1 Introduction;358
12.3.2;15.2 Enhancing the safety and quality of milk-based beverages using natural antimicrobials: milk;359
12.3.3;15.3 Enhancing the safety and quality of infant milk formulas using natural antimicrobials;365
12.3.4;15.4 Enhancing the safety and quality of egg–milk beverages using natural antimicrobials;368
12.3.5;15.5 Conclusion and future trends;371
12.3.6;References;371
12.4;16 - Using natural antimicrobials to enhance the safety and quality of fruit- and vegetable-based beverages;378
12.4.1;16.1 Introduction;378
12.4.2;16.2 Enhancing the safety and quality of fruit- and vegetable-based beverages using natural antimicrobials;379
12.4.3;16.3 Melon and watermelon juices;379
12.4.4;16.4 Orange and orange-based juices;381
12.4.5;16.5 Grape juices;384
12.4.6;16.6 Apple and pear juices;385
12.4.7;16.7 Dark fruit juices;386
12.4.8;16.8 Tomato juices;388
12.4.9;16.9 Other vegetable beverages;389
12.4.10;16.10 Conclusion and future trends;389
12.4.11;References;390
12.5;17 - Using natural antimicrobials to enhance the safety and quality of alcoholic and other beverages;396
12.5.1;17.1 Introduction;396
12.5.2;17.2 Alcoholic beverages;396
12.5.3;17.3 Wine;397
12.5.4;17.4 Beer;397
12.5.5;17.5 Apple cider;398
12.5.6;17.6 Hot drinks;399
12.5.7;17.7 Conclusion and future trends;402
12.5.8;References;402
12.6;18 - Using natural antimicrobials to enhance the safety and quality of poultry;406
12.6.1;18.1 Introduction;406
12.6.2;18.2 Food safety and its role in food quality;406
12.6.3;18.3 Pre-harvest use of natural antimicrobials;408
12.6.4;18.4 Antimicrobials for use on poultry products;411
12.6.5;18.5 Conclusion and future trends;423
12.6.6;References;424
13;Index;434

Leseproben

1

The use of natural antimicrobials in food

An overview

P.M. Davidson, H. Bozkurt Cekmer, E.A. Monu,  and C. Techathuvanan     University of Tennessee, Knoxville, TN, USA

Abstract

Antimicrobials are compounds present in or added to foods, food packaging, food contact surfaces, or food processing environments to inhibit microbial growth or kill microorganisms. This chapter defines and discusses natural antimicrobials (derived from microbial, plant, or animal sources), as well as why there is a need for these compounds. An overview of the efficacy and applications of several types of natural antimicrobials that are currently being investigated and/or are currently available for use in the food industry is presented.

Keywords

Food applications; Foodborne pathogens; Food preservation; Food safety; Naturally occurring antimicrobial

1.1. Introduction

Microorganisms are present throughout the food supply and can contaminate food in various ways, including at the farm level through irrigation water, field workers, insects, and fecal contamination by wild animals, as well as postharvest sources, such as handling by workers, transport vehicles, and processing equipment; wash water; and cross-contamination from other foods. These microorganisms pose two major problems to the food supply: the risk to human health from foodborne illness and the economic losses associated with food loss because of spoilage. Scallan, Griffin, Angulo, Tauxe, and Hoekstra (2011) and Scallan, Hoekstra, et al. (2011) estimated that approximately 48million cases of foodborne illness occur in the United States annually, 128,000 of which result in hospitalizations and 3000 deaths. It also has been estimated that 31% of the available food supply at the retail and consumer levels in 2010 was not consumed, which is equivalent to an economic loss of approximately $161.6billion (Buzby, Wells, & Hyman, 2014). Part of this loss is due to food being discarded because of spoilage either in the retail market before it can be purchased by consumers or in the homes of consumers (Kantor, Lipton, Manchester, & Oliveira, 1997). Economic loss can also be incurred from foodborne illness, not only because of hospital costs and lost work, but also as a result of recalls. In 2008, an outbreak of Listeria monocytogenes from deli meat in Canada that caused 20 deaths cost a company more than $50million in recalls, restructuring costs, and market losses as well as $27million in settlements (Greenberg & Elliott, 2009).

Antimicrobials are chemical compounds that are naturally present in or added to foods, food packaging, food contact surfaces, or food processing environments to inhibit microbial growth or kill microorganisms. The primary functions of antimicrobial food preservatives are to inhibit or inactivate pathogenic and spoilage microorganisms (Davidson & Zivanovic, 2003). The use of antimicrobials is useful to reduce food losses caused by microbiological spoilage and to assist in ensuring microbiological safety. According to Davidson, Critzer, and Taylor (2013), an ideal naturally occurring antimicrobial should (1) be effective at low concentrations in its natural form, (2) be economical, (3) cause no sensory changes to the product, (4) inhibit a wide range of pathogenic and spoilage microorganisms, and (5) be nontoxic.

Although antimicrobial preservatives are already available for use in the food industry, many producers are searching for natural antimicrobial alternatives. There are several reasons for this trend. The most important is that the traditional regulatory-approved antimicrobials have very limited capabilities when it comes to controlling spoilage or pathogenic microorganisms. Many are organic acids and function well only at a low pH, whereas often the major problems with food safety are in foods with a near neutral pH. Because of the generally unfounded fears that synthetic antimicrobials pose possible toxicological problems, there is also a growing demand by consumers for foods with ingredients that contain fewer synthetic additives (David, Steenson, & Davidson, 2013; Davidson & Zivanovic, 2003; Sofos, Beuchat, Davidson, & Johnson, 1998). This has led food companies to seek “green” or “clean” labels. Recommendations for health may also contribute. For example, agencies such as the World Health Organization are advising consumers to reduce their intake of salt to decrease the risk of cardiovascular disease, but salt is commonly used in the preservation of a wide variety of foods (World Health Organization, 2002). The reduction of salt in processed foods could lead to the need for additional preservatives to ensure the safety and maintain the shelf life of products.

There likely will be few, if any, new synthetic antimicrobials coming onto the market. This is, in part, because of the strict requirements of international regulatory agencies to gain approval for novel direct food additives (Davidson & Zivanovic, 2003). For example, the European Food Safety Authority requires rigorous toxicological testing of these antimicrobials, including metabolism and toxicokinetics, subchronic toxicity, reproductive and developmental toxicity, and genotoxicity (EFSA Panel on Food Additives and Nutrient Sources Added to Food, 2012). These batteries of tests, including in vitro and in vivo tests in animals and humans, can take years and a large amount of money before they can be completed to obtain approval, making the pursuit of these antimicrobials unprofitable (Davidson & Zivanovic, 2003).

Another appeal of natural antimicrobials is that several of them, particularly plant-based extracts, have potential health benefits for humans. Mustard, for example, contains isothiocyanates, which have wide-spectrum antimicrobial activity and have been shown to have potential chemopreventive activity, along with several other compounds found in mustard (Vig, Rampal, Thind, & Arora, 2009). Garlic has been used medicinally for thousands of years, and we now know that the organosulfur compounds (most notably allicin) have antimicrobial activity against a variety of bacteria and fungi, as well as chemopreventive and antioxidant activity, reducing the risk of cardiovascular disease and improving immune function (Benkeblia, 2004; Lau, 2006; Rahman, 2007). Other plant essential oils, such as antioxidants, also have health benefits to help combat the degenerative diseases of aging by protecting low-density lipoprotein cholesterol from oxidation, inhibiting cyclooxygenase and lipoxygenase enzymes, and inhibiting lipid peroxidation. Several also have antiviral or antitumor activity (Craig, 1999). These added health benefits may be indirect rather than through the consumption of the plant extract itself, such as in the case of grape seed and rosemary extracts. Gibis and Weiss (2012) found that the addition of grape seed and rosemary extracts to marinades for ground beef patties reduced the formation of possibly carcinogenic heterocyclic amines. The same study also indicated that the extracts exhibited antioxidant activity in the beef patties, showing that, in addition to health benefits, there may also be positive effects on food quality other than the inhibition of spoilage microorganisms. Green tea and grape seed extracts can also reduce lipid oxidation in beef, chicken, and turkey (Perumalla & Hettiarachchy, 2011).

Ironically, while consumers are very clear about their desire for more natural food additives, there seems to be a lack of knowledge that several of the antimicrobial preservatives currently used by the food industry are found in nature. For example, sorbic acid is a food antimicrobial used primarily to inhibit yeasts and mold, and although the commercial form used today is created through chemical synthesis, it was originally discovered by A.W. von Hoffman in 1859 from the oil of unripened rowanberries (Stopforth, Sofos, & Busta, 2005). Although this compound is found in nature and was originally isolated from plants, the fact that it is now chemically synthesized means that it is subject to regulatory approval requirements for use in food and use of scientific nomenclatures required by laws and can no longer contribute to a “green label.” The situation is similar for several other organic acids used as food antimicrobials, including acetic acid (found in vinegar), benzoic acid (found in cranberries), lactic acid (produced in a variety of fermented foods by lactic acid bacteria), and propionic acid, which is produced by Propionibacterium freudenreichii ssp. shermani in Swiss cheese, giving the characteristic holes (“eyes”) and nutty flavor (Fröhlich-Wyder & Bachmann, 2004).

1.2. Types of natural antimicrobials: animal sources

Natural antimicrobials have been identified and isolated from animal, plant, and microbial sources. Following are brief descriptions of some of the more studied natural antimicrobials. The subsequent chapters discuss most of these compounds in depth.

1.2.1. Lysozyme

Lysozyme is a widely occurring enzyme that hydrolyzes the ß-1,4-glycosidic bond between C1 of N-acetylmuramic acid and C4 of N-acetylglucosamine in peptidoglycans. The enzyme is affirmed as generally regarded as safe (GRAS) and approved for direct addition to foods in the United States (Davidson, Taylor, & Schmidt, 2012). Although...