Why Use [75% Alcohol] For Disinfection In Food Production?
Jun 03, 2020
Why can't it be disinfected with pure alcohol?
1. This is determined according to the sterilization mechanism and characteristics of alcohol. Since bacteria do not have oxidative organelles such as mitochondria, their oxidative metabolism enzymes are distributed on the surface of the cell membrane; therefore, the dry weight of the cell membrane protein can reach more than 70%, and protein is the target substance of alcohol killing factor.
2. First of all, alcohol disinfectant is a medium-efficiency disinfectant, which can kill Mycobacterium tuberculosis; it cannot kill microorganisms such as bacterial spores, some types of fungi, viruses, etc. The principle of alcohol killing bacteria is that it can penetrate into the bacteria body, absorb the water of bacterial protein, dehydrate and solidify the protein that makes up the bacteria, cause protein denaturation and precipitation, so as to achieve the purpose of killing bacteria.
(1) If the alcohol concentration is too high, reaching a concentration above 80% will greatly enhance and accelerate the speed of protein coagulation, so that when the outer microorganisms of the microbial group come into contact with alcohol, the protein on the cell membrane will undergo rapid denaturation and coagulation. The sturdy coating for the inner layer and the microbial population inside is called the protective layer. This protective layer is a very poorly permeable protein layer, which prevents the alcohol killing factor from continuing to penetrate into the microbial population inside the bacteria, and prevents the alcohol killing factor from entering the bacteria and the inside of the bacteria, and removes all microorganisms. Kill.
(2) Since bacteria do not exist in isolation, but in the form of a group, the microbes in the deep layer of the bacteria group that are not exposed to alcohol-killing factors cannot be killed. These unkilled bacteria in the envelope protection layer wait for an appropriate time, such as: the envelope protection layer ruptures, the ruptured envelope protection layer will be exposed and resurrected to grow and reproduce.
(3) Alcohol that reaches more than 80% and gradually increases in concentration, its permeability gradually decreases. Especially at high concentrations, the alcohol-killing factor cannot penetrate into the bacterial colony through the protective coating formed by the denaturation of the outer bacterial protein, and contact each bacteria in the deep layer, causing the bactericidal ability to gradually weaken , It will not achieve the purpose of disinfection.
(4) Although low-concentration alcohol can enter bacteria, it cannot provide a sufficient number of killing factors, the osmotic pressure will be reduced, and the protein in the body cannot be coagulated, and it cannot kill the bacteria.
