Processing & Preservation
Combining several mild preservation factors — pH, aw, temperature, preservatives, redox potential — so that their combined effect prevents microbial growth where none alone would suffice.
Why pickles are salty, sour and stored in oil all at once — no single barrier alone would stop spoilage, but combined they do.
The ratio of the vapour pressure of water in a food to the vapour pressure of pure water at the same temperature. It measures how much water is available for microbial growth and chemical reactions — not how much water is present.
A substance that prevents or retards microbial spoilage. Class I preservatives are traditional substances such as salt, sugar and vinegar; Class II are chemical preservatives such as benzoates and sorbates.
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