Dry-heat sterilization is generally a less complicated process than steam sterilization; it is, however, relatively slow and requires higher temperatures and/or longer exposure times. This is because of the fact that microbial lethality is lower with dry heat than that for steam at the same temperature.
Sterilization with steam under pressure. mainly at 121 degrees C, 15 pounds of pressure and for 20 mins.
Pressure should be 1.2 Kg/cm
Conductivity. Moisture conducts the heat better than a dry system.
When a liquid is heat labile or can be destroyed by heat then this method is used.
What effect of moist heat sugar
Moist heat, or heat in the form of saturated steam under pressure, is widely used as a sterilization method because it allows for temperatures higher than what can be reached by boiling. It disinfects and sterilizes the life of microorganisms by coagulating its protein.
The canning process is to preserve the food in the can. Sterilization is the process of killing bacteria that is normally heat resistant.
Conductivity. Moisture conducts the heat better than a dry system.
WELL! moist heat is used by heating with steam and the steam can not be formed below 100oC so it is not possible to kill microorganism by moist heat below hundred degree
Dry heat = 1-2hrs @ 160-170 degrees Celsius Moist heat = 15min. @ 121 degrees Celsius
Mechanism of killing by dry heatDry heat kills the organisms by destructive oxidation of essential cell constituentsKilling of the most resistant spores by dry heat requires a temperature of about 160 °C for 60 minutesDry heat is employed for glassware; syringes, metal instruments and paper wrapped goods, which are not spoiled by high temperatures.It is also used for anhydrous fats, oils and powders that are impermeable to moisture.Mechanism of killing by moist heatMoist heat kills the organisms by coagulating and denaturing their enzymes and structural protein.Sterilization by moist heat of the most resistant spores generally requires 121 °C for 15-30 minutes.Moist heat is used for the sterilization of culture media, and all other materials through which steam can penetrateMoist heat is more effective than dry heatSterilization can be done at lower temperatures in a given time at a shorter duration at the same temperature.upon heating wet proteins release free -sh groups and form smaller peptide chains which in turn form new complexes different from the orignal protein molecules
it is steam sterlization in which temp & pressure both works
When a liquid is heat labile or can be destroyed by heat then this method is used.
Sterilization can be accomplished by heat (as in the autoclave), chemicals (as with glutaraldehyde) or radiation. Your average outpatient office uses heat or chemical sterilization.
What effect of moist heat sugar
Advantages: 1. It is faster method of sterilization then dry heat method. 2. Additional parameter "pressure" is involved 3. We can easily sterilize the media solution. 4. It faster method of sterilization. Disadvantages: 1. Glass ware might get broken down. 2. Mishandling may lead to serious accident or explosion.
Moist heat, or heat in the form of saturated steam under pressure, is widely used as a sterilization method because it allows for temperatures higher than what can be reached by boiling. It disinfects and sterilizes the life of microorganisms by coagulating its protein.
sterilization
dry heat sterilization