MSG, or monosodium glutamate, is a common and widespread additive in food used mainly for flavor enhancement, but also for preservation. MSG has been used for well over a century as a food additive, but in the last couple of decades anecdotal claims of illness have been linked to MSG consumption.SG is the salt form of glutamic acid, which is a naturally occurring amino acid. Seaweeds and many other plants and vegetables contain glutamic acid.
From Wikipedia, the free encyclopedia. Auto-defrost, automatic defrost or self-defrosting is a technique which regularly defrosts the evaporator in a refrigerator or freezer. Appliances using this technique are often called frost free, frostless or no-frost.
Lab freezers with manual defrost. In a manual defrost freezer, refrigerant circulates inside the walls of the unit. This creates a stable temperature gradient with the coldest temperature close to the walls and less cold temperatures in the middle. A manual defrost freezer must be turned off for defrosting on a regular schedule.