The last of three articles on food processes and ingredients touches upon simpler, less exotic but no less natural means of controlling food spoilage and pathogenic bacteria in foods.
Fermentation — Foods that undergo fermentation, or the controlled growth of non-pathogenic bacteria in production, have a significantly lower risk of being infected with pathogenic bacteria. This protective effect arises in at least two ways. First, the “good” bacteria usually outnumber the pathogens by millions, if not billions, and out-compete other organisms for nutrients. Second, as the “friendly” bacteria grow, the byproducts of their growth, such as lactic acid, produce conditions that inhibit all bacterial growth.
Drying — Bacteria, like humans, need certain basic conditions to live and grow: warmth, water and food. Thus drying food prevents bacteria from growing in and on these foods. However, the cleanliness of the environment and equipment used to dry foods really dictates the food safety of the finished products. The amount of drying required for a food to inhibit bacterial growth is unique to the food, because the composition of every food can vary greatly. Spices, sugar and honey have been used for centuries to preserve foods mainly by removing water from them.
Salt Curing — Like sugar and spices, salt has been used for centuries to preserve food. Covering foods with salt not only draws moisture out of foods, but salt also dissolves (ionizes) and migrates into the food to produce conditions few bacteria can grow in, let alone survive for lengthy periods of time.
Smoke Curing — Used for ages, smoke curing cooks, dries and chemically preserves foods. Not many food processors today smoke foods in the traditional way, and instead spray smoke concentrates onto foods during the cooking process. Scientists have only recently begun to analyze the components of wood smoke to discover its anti-microbial ingredients. A source tells me that ingredient companies are attempting to patent smoke components or “fractions” that exhibit potent anti-microbial properties. Some of these components, I have been told, have little “smoke” flavour and aroma, and appear to control bacterial growth at very low application levels.
Freezing — When food is frozen free (fluid) water turns into ice, making the water unavailable to bacteria for normal growth, and energy necessary for life processes to occur is removed. Chemical processes, including life, slow down a lot at 0°F or -18°C. But while slow-freezing processes can injure and even kill bacteria, unfortunately they are rarely good at preserving product freshness and eating quality.