Food Microbiology

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  Food Microbiology

  An Introduction

  • Karl R. Matthews, Kalmia E. Kniel, Thomas J. Montville(Authors)
  • 2019(Publication Date)
  • ASM Press

    (Publisher)

  I BASICS OF Food Microbiology

  1    The Trajectory of Food Microbiology

  2    Microbial Growth, Survival, and Death in Foods

  3    Spores and Their Significance

  4    Detection and Enumeration of Microbes in Food

  5    Rapid and Automated Microbial Methods

  6    Indicator Microorganisms and Microbiological Criteria

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  1

  The Trajectory of Food Microbiology

  Learning Objectives The information in this chapter will help the student:

  • increase awareness of the antiquity of microbial life and the newness of Food Microbiology as a scientific field
  • appreciate how fundamental discoveries in microbiology still influence the practice of Food Microbiology
  • understand the origins of Food Microbiology and thus anticipate its forward path

  Introduction Who’s on First? Food Microbiology, Past and Present To the Future and Beyond Summary Suggested reading Questions for critical thought

  INTRODUCTION

  A former president of the American Society for Microbiology (Box 1.1 ) defined microbiology as an artificial subdiscipline of biology based on size. This suggests that basic biological principles hold true, and are often discovered, in the field of microbiology. Food Microbiology

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  Fundamental Food Microbiology

  • Bibek Ray, Arun Bhunia(Authors)
  • 2013(Publication Date)
  • CRC Press

    (Publisher)

  From the above discussion, it is apparent what, as a discipline, Food Microbiology has to offer. Before the 1970s, Food Microbiology was regarded as an applied science mainly involved in the microbio-logical quality control of food. Since then, the technology used in food production and processing, distribution and retailing, and food consumption patterns have changed dramatically. These changes have introduced new problems that can no longer be solved by merely using applied knowledge. Thus, modern-day Food Microbiology needs to include a great deal of basic science to understand and effectively solve the microbiological problems associated with food. The discipline includes not only the microbiological aspects of food spoilage and foodborne diseases and their effective control and bioprocessing of foods, but also basic information of microbial ecology, physiology, metabolism, and genetics. This information is helping to develop methods for rapid and effective detection of spoilage and pathogenic bacteria, to develop desirable microbial strains by recombinant DNA technology, to produce fermented foods of better quality, to develop thermostable enzymes in enzyme processing of food and food additives, to develop methods to remove bacteria from food and equipment surfaces, and to combine several control methods for effective control of spoilage and pathogenic microorganisms in food.

  An individual who has completed courses in Food Microbiology (both lecture and laboratory) should gain knowledge in the following areas:

  • Determining the microbiological quality of foods and food ingredients by using appropriate techniques
  • Determining the microbial types involved in spoilage and health hazards and identify the sources
  • Understanding factors contributing to the emergence of new pathogens or the reemergence of old pathogens
  • Understanding the basic mechanism of pathogenesis of foodborne microbes
  • Designing corrective procedures to control the spoilage and pathogenic microorganisms in food
  • Learning rapid methods of isolating and identifying pathogens and spoilage bacteria from food and the environment
  • Identifying how new and novel technologies adapted for food processing can have specific microbiological problems and designing methods to overcome the problem
  • Designing effective sanitation procedures to control spoilage and pathogen problems in food-processing facilities
  • Effectively using desirable microorganisms to produce fermented foods

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  Microbial Biotechnology in Food and Health

  • Ramesh C. Ray(Author)
  • 2020(Publication Date)
  • Academic Press

    (Publisher)

  1: Microbial biotechnology in food and health: present and future food safety regulation

  Md Latiful Bari, and Sharmin Zaman      Center for Advanced Research in Sciences, University of Dhaka, Dhaka, Bangladesh

  Abstract

  Morbidity and mortality resulting from the consumption of microbial contaminated foods remain significant problems in modern society, and the ability to conduct epidemiological investigations and intervene in foodborne illnesses is a critical part of the existing public health infrastructure. Ensuring safe food supply is a major challenge to the food industry, and there are several factors that can impact the likelihood of contamination and subsequent diseases. These factors include increased consumers' demand for minimally processed, ready-to-eat convenience foods and imported and ethnic foods, the globalization of the food industry, significant changes in the methods used to control microbial spoilage, and changing population demographics. Despite significant efforts by all parties involved, there is still a considerable burden of foodborne illness, in which microorganisms play a prominent role. Microbes can enter the food chain at different steps, are highly versatile, and can adapt to the environment allowing survival, growth, and production of toxic compounds that necessitates the study of food toxicology. Management of food safety till today is based on generally accepted principles of hazard analysis critical control points (HACCP) and good manufacturing practices (GMP). However, a more proactive, science-based approach is required, starting with the ability to predict where problems might arise by applying the risk analysis framework. In this chapter, several advanced technologies and their critical understanding of the epidemiology, pathogenic mechanisms, virulence factors, and other salient characteristics of the major foodborne pathogens were discussed. In addition, the convergence of expanded scientific knowledge and technological advances that create new opportunities for the detection, identification, and monitoring of microbial contamination in food were also described. Finally, the impacts of new genomics research in ensuring food safety were highlighted.

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  Food Plant Sanitation

  Design, Maintenance, and Good Manufacturing Practices

  • Michael M. Cramer(Author)
  • 2022(Publication Date)
  • CRC Press

    (Publisher)

  Chapter 3 Microorganisms of Food Manufacturing Concern DOI: 10.1201/9780429294341-3 If it don’t stink, stuff it! —Anonymous food plant employee They go by many names: germs, bacteria, microorganisms, microbes, even “bugs.” They have been the main focus of several Hollywood movies, including The Andromeda Strain and Outbreak. In The War of the Worlds by H. G. Wells, they were responsible for saving the human race because Martian invaders had no resistance to bacteria that man had been accustomed to for millennia. Microorganisms have been on Earth for millions of years, longer than man. Microorganisms Microorganisms are biological entities, and they can be a benefit or a potential hazard to humans and to the food manufacturing industry. Bacteria represent the largest group of microorganisms [ 1 ]. Most bacteria are harmless; in fact, some provide benefits to humans by protecting the skin and nasal passages and also aid in the digestion process. Some also benefit the food industry when they are used for the production of cultured items such as cheese, yogurt, and fermented sausage. However, they can pose a threat to humans and to the industry when they result in foodborne illness and food spoilage. Microbiological contamination of food may result in product spoilage, reduction in shelf life, or foodborne illness. It is important to understand food-related microorganisms, with regard to growth needs and environmental requirements to better understand their control mechanisms. Fortunately, the food industry has evolved from the dinosaurs who truly believed that if something does not stink, it is OK to stuff to a more science-based understanding of microorganisms that impact the food industry. The common microorganisms that will be reviewed in this chapter, as they relate to foods, are indicator organisms, spoilage organisms, and pathogens

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  Food Science and Technology

  Fundamentals and Innovation

  • Oluwatosin Ademola Ijabadeniyi(Author)
  • 2023(Publication Date)
  • De Gruyter

    (Publisher)

  Part 2:  Food Microbiology and use of microorganisms

  7  Microbial food spoilage of selected food and food products

  Titilayo Adenike Ajayeoba

  Department of Microbiology, Faculty of Science , Nigeria

  Oluwatosin Mary Kaka

  Department of Microbiology, Faculty of Science , Nigeria

  Oluwatosin Akinola Ajibade

  Department of Microbiology, Faculty of Science , Nigeria

  7.1  Introduction

  Foods undergo different levels of deterioration after processing and production. The nature of the raw materials and processing conditions possibly determines physical appearance, temperature, atmosphere, water, activity, pH, and microflora that develops during production and storage (Gram et al. 2002 ). Deterioration may include losses in organoleptic desirability, nutritional value, safety, and aesthetic appeal. Deteriorated foods may be safe to eat, if there are no pathogens or toxins present. They may not cause disease, but differences in texture, smell, taste, or appearance make them to be rejected by consumers. However, spoilage sets in when these products have microbial interactions, and metabolites could lead to food poisoning and intoxication. This is characterized by production of visible microbial growth and production of off-flavor/odor (Siegmund and Pöllinger-Zierler 2006 ). The implications of consuming contaminated food resulted in various illnesses and diseases. Depending on the type of microorganism, quantity consumed, and immune status, the symptoms could be evident within a few hours to several days. Typical symptoms include diarrhea, vomiting, abdominal cramps, headaches, nausea, dry mouth, and difficulty swallowing and fluke-like symptoms (such as fever, chills, and backache) (Addis and Sisay 2015 ).

  Depending on their shelf life and ease of spoilage, foods can be classified into three main groups: stable foods, semiperishable food, and perishable foods. Throughout production and storage, each and every food product harbors its own unique and distinctive microflora at every stage (Gram et al. 2002 ). Microbial growth is the main cause of food quality reduction and shelf life deterioration. Microbial contamination may occur naturally via attachment if the food material can be a growing substrate or through improper handling procedures. The existence of a microorganism is an indicator of contamination at any stage of production (Caldera 2014 ), especially if the presence of such microorganism(s) is not desired. The predominant spoilage of microflora in a food is determined by microbial types, food types, and food environment. Due to chemical, biological, or physical agents, food spoilage may occur (Principles of Food Spoilage). The most important factors influencing microbial growth in food can be either intrinsic [nutrient content, water activity (aw ), pH value, redox capacity, the availability of antimicrobial substances and mechanical barriers to microbial invasion, and environment-related factors in which the foothold occurs] or extrinsic (interactions between food contaminating microorganisms, food composition, packaging and storage conditions of food products, e.g., their ability to use various nutritional sources, withstand stress, and produce growth promoters or inhibitors of other microorganisms; processing factors include treatments such as heating, cooling, and drying, which affect the composition of the food and also the types and numbers of microorganisms that remain in the food after treatment) (Hamad 2012

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  The Microbiological Quality of Food

  Foodborne Spoilers

  • Antonio Bevilacqua, Maria Rosaria Corbo, Milena Sinigaglia(Authors)
  • 2016(Publication Date)
  • Woodhead Publishing

    (Publisher)

  Chapter 1

  Microbial Spoilage of Foods

  Fundamentals

  Leonardo Petruzzi, Maria Rosaria Corbo, Milena Sinigaglia and Antonio Bevilacqua,    University of Foggia, Foggia, FG, Italy

  Abstract

  Despite modern technological advances, spoilage of foods continues to occur. Excessive economic losses are due to microbial spoilage, resulting in final products with an inadequate shape or appearance. Understanding how different properties of a food, its environment and “history,” can influence the microbiota that develops in products, is a pivotal step to control quality and safety. The present chapter discusses the characteristics of microbial spoilage of foods with a focus on the major spoilage microorganisms and how they can be detected and controlled.

  Keywords

  Food spoilage; microbial contamination; enzymes; quality; safety; perishable foods

  1.1 Introduction

  Food spoilage results when microbiological, chemical, or physical changes occur, rendering the food product unacceptable to the consumer. Microbiological food spoilage is caused by the growth of microorganisms which produce enzymes that lead to objectionable by-products in the food. Chemical food spoilage occurs when different components in the food react with each other or with some added component which alter the food’s sensory characteristics. Examples of this include: oxidation; enzymatic browning; and nonenzymatic browning. Physical food spoilage results when moist foods are excessively dehydrated or dried foods absorb excessive moisture (Benner, 2014 ).

  For years, safety (i.e., the exclusion or elimination of pathogens from food) has been studied separately from the prevention of spoilage. In most countries the legislation has tended to reinforce this concept. However, from a microbiological-ecological point of view the two areas cannot be distinguished. In spite of considerable efforts, microbiological safety assurance seems as remote as ever, even in advanced countries. Death, suffering, economic losses, and civil claims on behalf of victims of foodborne diseases are matched by the economic losses caused by food spoilage (Di Renzo et al., 2015

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  The Science of Animal Growth and Meat Technology

  • Steven M. Lonergan, David G. Topel, Dennis N. Marple(Authors)
  • 2018(Publication Date)
  • Academic Press

    (Publisher)

  There are three types of cleanliness and hygiene (physical, chemical, and microbiological) that must be diligently implemented to help ensure safe, wholesome meat and meat products. Physical methods may be the easiest form of cleanliness to perceive and carry out as this refers to, as examples, good dressing practices during slaughter and keeping meat cutting and processing tables clean. Chemically clean is defined, for example, as the removal of detergents and sanitizers from cleaned surfaces and equipment. Inadequate removal of chemicals from equipment or tables could result in costly product quality defects. Microbiologically clean denotes controlling, reducing, and/or eliminating bacteria, yeast, and molds under all conditions of meat production, processing, distribution, and consumption. Bacteria represent the largest group of the three microorganisms and are by far the one that causes the most food spoilage and illness.

  The benefits of proper cleanliness are immense. With proper cleanliness, meat will be safer and have a longer shelf life and have improved sensory and organoleptic quality, decreased product loss, and enhanced public image. In the final analysis, the cumulative benefits of cleanliness mean a more profitable business. It pays to be “clean” when operating a meat business!

  Microbiology

  Microorganisms are often thought of as germs. Some people even call them “bugs,” but they are not insects. What are they? Microbes are single-cell plants that cannot be seen by the naked eye, with the exception of molds. It then usually takes a microscope to observe and identify single-cell organisms, therefore the term microorganisms. Microorganisms are found everywhere—air, soil, water, farms, animals, feces, processing plants, retail stores, restaurants, homes, and people. Indeed, people are one of the main sources responsible for transmission and control of microbial growth and contamination. Interestingly, most microorganisms are harmless. But some cause spoilage, illness, disease, and death, while others are beneficial and are actually used in meat processing formulations, such as using a lactic acid starter culture in summer-sausage production.

  There are three classes of microorganisms; bacteria, molds, and yeasts. Because bacteria are by far the most important in meat spoilage and food-borne illness, they will be emphasized in more detail in this chapter.

  Molds and Yeasts

  A few brief points will be made about the nature and properties of molds and yeast. Molds are multicellular microorganisms that can be visible as a colony (Fig. 12.1 ). They are made up of multiple types of cells that require oxygen for growth. Their optimum pH range is 4.5–6.8, although they can grow over a wide range of pH values, and their minimum water activity (a w

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  Food Protection Technology

  • Charles W. Felix(Author)
  • 2018(Publication Date)
  • CRC Press

    (Publisher)

  1 prepared by the Subcommittee on Microbiological Criteria, National Academy of Sciences, National Research Council, provides definitions of various types of microbiological criteria such as standards, guidelines, and specifications.

  Key to this discussion are the definitions of the purpose of microbiological criteria, a criterion, and the components of a microbiological criterion:

  • Purposes of microbiological criteria — To assess:
    1. The safety of a food
    2. Adherence to good manufacturing practices
    3. The utility (suitability) of a food or ingredient for a particular purpose
    4. The keeping quality (shelf-life) of certain perishable foods
  • Criterion — A yardstick (standard) on which a judgment or decision can be made.
  • Components of a Microbiological Criterion
    1. A statement describing the identity of the food or food ingredient
    2. A statement of the contaminant(s) of concern, i.e., the microorganism, or group of microorganisms, and/or its toxin or other agent microorganisms or group of microorganisms and/or its toxin or other agent
    3. The analytical method to be used for the detection, enumeration, or quantification of the contaminant of concern
    4. The sampling plan
    5. The microbiological limits considered appropriate to the food and commensurate with the sampling plan used

  These three definitions provide the framework for development of microbiological criteria based on food process control factors and risk assessment of the food system.

  Causes And Control Factors For Hazardous Microorganisms In Foods

  Factors which cause foodborne disease outbreaks have been documented by Bryan2 in the United States (Table 1 ) and Roberts3 in England (Table 2

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  Control of Foodborne Microorganisms

  • Vijay K. Juneja, John N. Sofos(Authors)
  • 2001(Publication Date)
  • CRC Press

    (Publisher)

  1

  Microbial Control in Foods: Needs and Concerns

  John N. Sofos

  Colorado State University

  Fort Collins, Colorado

  I.

  INTRODUCTION

  Food safety has been at the forefront of societal concerns in recent years, and the major emphasis it has received is very likely to continue in many parts of the world and into the future. The complexity of food safety issues has increased, as has the number of emerging pathogenic microorganisms, some of which are resistant to antibiotics or to traditional preservation methods, and which sometimes cause illness with low infectious doses (1 ,2 ). In addition to microorganism-associated concerns, societal changes including changing consumer food preferences, lack of adequate food handling education, increases in human populations at-risk for foodborne illness, complex food distribution patterns, increased international trade, and better methods of testing for microbial detection also emphasize the complexity of the safety concerns and the need for development of strategies to address these challenges. In general, food safety is at the forefront of our societal concerns, and it should continue to be there for a number of years to come, because food safety problems and challenges that need to be addressed may actually increase. It is estimated that foodborne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths in the United States each year (3 ). Known pathogens cause 14 million illnesses, 60,000 hospitalizations, and 1,800 deaths, while unknown agents are involved in 62 million cases, 265,000 hospitalizations, and 3,200 deaths. Only a small portion of foodborne illness episodes are reported and investigated annually, and only a small portion of the reported foodborne illnesses are resolved (3 ,4

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