BIO 3124 Lecture Notes - Lecture 11: Long Term Ecological Research Network, Hepa, D-Value (Microbiology)
Document Summary
Control of microbial growth: physical methods (sterilization: terminology. Sterilization: killing or removing all forms of microbial life (including endospores), the method most commonly used for sterilization is the use of heat. Endospores and some viruses are not destroyed (hepatitis virus: can survive up to 30 mins, endospores: can survive for periods of 20hours +: pasteurization (65-140 c) Kills pathogenic agents without affecting the taste of food. Does not sterilize (reduce # of potential pathogens, increase food shelf life) Classical pasteurization, htst pasteurization, uht pasteurization: autoclave (121 c) Temperature of 121 c at twice the atmospheric pressure. All organisms and endospores are killed in 15 minutes (everything: dry heat: kills by oxidation, pasteur oven (121-150 c) Not recommended for chemical products (liquids evaporate, destroy chemicals) Can be used for some metals and glass ii) Used for needles, glass, corpses, etc: parameters of death by heat. Thermal death point (tdp): lowest temperature at which all bacteria are killed within 10 mins.
