Factors that Influence Microbial Growth December 31, 2001 Evaluation and Definition of Potentially Hazardous Foods 1. They include: Hydrogen ion concentration (pH), moisture content, nutrient content of the food, antimicrobial substances ad biological structures. As our foods are of plant and animal origin, it is worthwhile to consider those characteristics of plant and animal tissues that affect the growth of microorganisms. Growth Curve. When plotted on a graph, a distinct curve is obtained referred to as the bacterial growth curve. Preserving agents that increase the acidity of food, such as citric acid, are commonly added to help prevent bacterial growth and allow for longer storage. Factors affecting Microbial growth Physical factors •pH •Temperature •Osmotic pressure •Hydrostatic pressure Factors affecting microbial growth in food (a)Intrinsic factors: These are inherent in the food. Introduction The factors discussed in this section constitute an inclusive, rather than exclusive, list of intrinsic, extrinsic, and other factors that may be considered when determining whether a food or Vinegar and lemon juice have a similar effect. Aims: To study the effect of different fermentation conditions and to model the effect of temperature and pH on different biokinetic parameters of bacterial growth and exopolysaccharides (EPS) production of Streptococcus thermophilus ST 111 in milk‐based medium. Methods and Results: The influence of temperature and pH was studied through fermentation and modelling. Factors that determine whether a particular treatment is -cidal or -static include the types of microorganisms targeted, the concentration of the chemical used, and the nature of the treatment applied. Temperature is the most efficient means to control microbial growth. Bacteria have a minimum, optimum, and maximum temperature for growth and can be divided into 3 groups based on their optimum growth temperature: psychrophils, mesophils, thermophils, or … 17.2: Factors that Influence Bacterial Growth - Biology LibreTexts J.N. For example, bacteriostatic treatments inhibit the growth of bacteria, whereas fungistatic treatments inhibit the growth of fungi. When a broth culture is inoculated with a small bacterial inoculum, the population size of the bacteria increases showing a classical pattern. They include: pH, water activity, oxidation reduction potential, nutrient content, antimicrobial contents, biological structure (b) Extrinsic factors: Are factors external to the food that affect microbial growth… Since bacteria are easy to grow in the lab, their growth has been studied extensively. Microbial growth •The microbial growth is the increase in number of cells rather than in size of individual cells. 2 (Supplement), 2003 —COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY 21 Chapter III Factors that Influence Microbial Growth ability to participate in chemical/biochemical reactions, and its availability to facilitate growth of microorganisms. The acidity of food is also an important factor affecting bacterial growth 1. Method of Obtaining Bacterial Growth Curve Factors affecting microbial growth in food (a) Intrinsic factors: These are inherent in the food. Vol. 1. When more than one condition is somewhat adverse to microbial growth, their inhibitory effects are cumulative. Temperature. Sofos, in Encyclopedia of Food Safety, 2014. 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