PPT-Factors affecting microbial growth in food

a Intrinsic factors These are inherent in the food They include pH water activity oxidation reduction potential nutrient content antimicrobial contents biological structure. Dr. . Kamal. E. M. . Elkahlout. Food Microbiology 2 . Microbial Nutrition and Factors Affecting Growth. Intrinsic and Extrinsic Factors . Factors affecting the growth and survival of micro-organisms in foods. 1. 41. Copyright © McGraw-Hill Global Education Holdings, LLC. Permission required for reproduction or display.. Microbial Growth and . Food . Spoilage. Results . from growth of microbes in food. alters food visibly and in other ways, rendering it unsuitable for . Chapter . 2. Copyright © 2010 by John Wiley & Sons, Inc. All Rights Reserved. FORCES AFFECTING. GROWTH AND CHANGE. The changes that are occurring now in the business environment are tremendous. Managers must understand the various forces that are driving these changes and affecting their businesses in order to be effective. Importance. . The total microbial population in a food varies greatly and depends on:. . *The . level of sanitation . used at all phases.. . *The . degree of abuse . that leads to microbial growth. . A. Microbial Reproduction. 1. binary (transverse) fission. A) parent cell enlarges and duplicates all its genetic material. B) DNA copies move to opposite ends of parent and attach to a section of the cell membrane as it begins to pinch together at the center. Chapter . 2. Copyright © 2010 by John Wiley & Sons, Inc. All Rights Reserved. FORCES AFFECTING. GROWTH AND CHANGE. The changes that are occurring now in the business environment are tremendous. Managers must understand the various forces that are driving these changes and affecting their businesses in order to be effective. Chapter . 2. Copyright © 2010 by John Wiley & Sons, Inc. All Rights Reserved. FORCES AFFECTING. GROWTH AND CHANGE. The changes that are occurring now in the business environment are tremendous. Managers must understand the various forces that are driving these changes and affecting their businesses in order to be effective. Microbiology. Microbial Growth. Microbial requirements for growth:. 1. . Physical. A. . Temperature. Optimal growth temperature. Permissible range. human pathogens optimal = . 37°C. Microbial Growth. and . Hb. synthesis. Dr. Sunita Mittal. Learning Objectives. ▪. Factors affecting erythropoiesis. ▪. Hemoglobin synthesis. Factors regulating Erythropoiesis. Φ. . Growth or Developmental Factors. Musafer. PhD. Microbial growth defined as an increase in cellular constituents resulting an increase in a microorganism size, population number or both.. 1-Lag phase. When M.O are inoculated into fresh culture medium, will not reproduce immediately, therefore this period is called the lag phase. . Growth: . A. n . increase in cell number, not in cell size. .. Bacteria . grow and divide by binary fission, a rapid and relatively simple process. .. Phases . of Growth Bacterial Growth Curve : . When . 1. Temperature. 2. . PH. 3. . Water activity. 4. . Oxygen and redox. Temperature. Minimum Temperature. . The temperature below which no growth occurs.. At temperature below the minimum the properties of cell membranes change so that they can no longer transport materials into the cell. Microbiology. Outline. Microbial growth . in . natural environments. . Measurement . of . microbial population size. Principles of . microbial control. . Physical, chemical and biological control. . Kinetics. Growth Curve. Log CFU/ml. Optical Density. Lag. First Order Kinetics. Food microbiology is concerned with all phases. Of microbial growth (. lag,log. , stationary, death phase).Growth curves are normally plotted as the number of cells on a log scale or log10 cell number versus time..