Factors affecting microbial growth in food Implicit factors ⢠Implicit factors: ⢠Specific growth rate / μ ⢠Synergism ⢠Antagonism ⢠commensalism 42. Factors affecting microbial development. Each type of food has its own characteristic constituents which may affect the growth of microbial cells. This allows food to ⦠Disclaimer Copyright, Share Your Knowledge
Food may be plant or animal origin. In the course of growth, harvesting/slaughter, processing and storage, food is subject to contamination from a range of sources. Factors affecting microbial growth in ⢠The relationship between the two, known as Monod equation, is mathematically identical to the Michaelis-Menten equation of enzyme kinetics. 6.1.1. Nutrient content ⢠The concentration of key nutrients can, to some extent, determine the rate of microbial growth. The situation is complicated by the fact that the microflora is unlikely to consist of a single pure culture. These are: ⢠Temperature of storage ⢠Relative humidity of the environment ⢠Presence and concentration of gases ⢠Presence and activities of other microorganisms. These organisms don't produce any smell, discoloration, or any other changes you can detect with your senses. This can be represented mathematically by the expression: where dx/dt is the rate of change of biomass, or numbers x with time t, and µ is a constant known as the specific growth rate. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. You won't even know they're there until you start to feel nauseous or crampy or whatnot. Microbial cells obtain all required nutrients from food nearby. The most important factors that affect microbial growth in foods can be summarized in the following categories: (i) factors related to the food itself, the âintrinsic factors,â which include nutrient content, water activity, pH value, redox potential, and the presence of antimicrobial substances and mechanical barriers to microbial invasion; (ii) factors related to the environment in which the food is ⦠In fact, the microorganisms ⦠The significance of exponential growth for food processing hardly needs emphasizing. TOS4. Extrinsic factors. 13.7.2014 2 Factors affecting microbial growth/behaviour in foods Intrinsic factors Nutrients pH and buffering capacity Redox potential Water activity Antimicrobial structures Extrinsic factors Implicit factors Processing factors Factors affecting microbial growth/behaviour in foods Processing factors. These factors are temperature, irradiation, water activity, pH, acidity, organic acids, curing salts, antibiotics, gases, packaging, and cleaning systems. A continual challenge that we have in the food industry is keeping microbial contamination and growth under control. Extrinsic or environ â mental, external factors are the properties of storage environments which affect both food as well as microorganisms. The most important factors that affect microbial growth in foods can be summarized in the following categories: (i) âIntrinsic factorsâ related to the food itself which include (Nutrient content, water activity, pH value, and the presence of antimicrobial substances); (ii) âExtrinsic factorsâ related to the environment in which the food is stored, including (Temperature of storage, and the composition of gases and relative ⦠1. Each chapter explores the scientific principles of the specific environmental factor; methods of measurement; and effects on growth and ⦠Clipping is a handy way to collect important slides you want to go back to later. As x increases and approaches K, the growth rate falls to zero. If, however, we perform the experiment measuring microbial numbers with time and then plot log x against time, we obtain the curve shown as Figure 3.1 in which exponential growth occurs for only a part of the time. Factors affecting the growth and survival of microorganisms in foods 1.1 Types of factor 1.2 Intrinsic factors 1.3 Extrinsic factors 1.4 Implicit factors 1.5 Concluding remarks Redox Potential (Eh): 4. This last group of factors (subsumed under intrinsic properties by Mossel and Ingram) usually exert their effect in one of two ways: either they change an intrinsic or extrinsic property, for example slicing a product will damage antimicrobial structures and increase nutrient availability and redox potential, or they eliminate a proportion of the product microflora as would occur in washing, pasteurization or irradiation. Our mission is to provide an online platform to help students to share notes in Biology. One way of representing this overall process mathematically is to modify the basic growth Equation (3.1) so that the growth rate decreases as the population density increases. 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