Psychrotrophs, mesophiles, thermophiles.summarize possible mechanisms for inhibiting the factors that promote deterioration of quality in food systemsĥ.1 Food Deterioration: the need for food preservation Terms to remember.describe the factors (chemical, enzymatic, microbiological) that commonly contribute to food deterioration and spoilage.Upon completing this lesson you will have the fundamental knowledge required to fully appreciate the concepts of food preservation to be covered in Lessons 6 through 10.Īfter completing this lesson, you will be able to: Finally, as an introduction to food preservation, you will learn the principles upon which food preservation techniques are based. You will also learn about various types of chemical spoilage, such as enzymatic browning of fruit and vegetable tissues. We will discuss the important environmental factors in food that affect the growth of disease-causing and spoilage-causing microorganisms in food. In this lesson you will learn about the chemical, enzymatic and microbiological factors that are responsible for food deterioration and spoilage. 7 5.5 Factors Affecting Microbial Growth, Enzyme Activity and Chemical Reactions in Foods.4 Oxygen and temperature requirements for microorganisms:.2 5.1 Food Deterioration: the need for food preservation.As a result, the substrate cannot bind and enzyme action is reduced. The molecular structure of the inhibitor closely resembles that of a substrate and it competes with the substrate for the substrate-binding site of the enzyme.
The reason is that at V max, there are no free enzyme molecules available that can bind with extra substrate molecules.īinding certain chemicals to the enzyme, acts as a competitive inhibitor to the substrate. This velocity does not rise any further even if there is an increase in substrate concentration. In the final stage, the reaction reaches a maximum velocity or V max. If the substrate concentration increases, initially the velocity of enzymatic reaction rises. Thereafter, with an increase in pH and temperature, enzyme activity decreases as they get denatured. The enzyme activity increases steadily with an increase in pH and temperature up to the optimum pH and optimum temperature. Low temperature inactivates the enzymes and high temperature denatures the enzymes. Temperature and pH affect the enzyme activity. Some factors such as temperature, pH and change in substrate concentration or the binding of specific chemicals alter the tertiary structure of the protein thereby affecting the activity of the enzymes.
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