The Science of Preservatives in Food

Preservatives slow spoilage by stopping microbes, oxidation, or chemical breakdown.
Salt and sugar are the oldest preservatives, drawing water out of microbes through osmosis.
Vinegar and acids lower pH, creating an environment where bacteria can’t thrive.
Sulfites keep dried fruits bright and prevent unwanted fermentation in wines.
Nitrates and nitrites preserve cured meats and give them their pink color.
Antioxidants like BHA and BHT prevent fats and oils from turning rancid.
Ascorbic acid (vitamin C) doubles as a nutrient and preservative, slowing browning in foods.
Calcium propionate is common in bread, stopping mold from growing.
Freezing and canning are physical preservation methods that complement chemical ones.
Natural alternatives like rosemary extract and tocopherols (vitamin E) are on the rise in “clean label” foods.