What common process in food preservation involves adding salt, sugar, and vinegar?

The process of pickling involves the preservation of food by immersing it in a solution that typically contains salt, sugar, and vinegar. This technique creates a highly acidic environment that inhibits the growth of spoilage-causing microorganisms. The addition of salt not only enhances flavor but also draws moisture out of the food, furthering preservation. Sugar acts as both a flavor enhancer and preservative, helping to balance flavors and contribute to the overall stability of the final product. The vinegar provides acidity, which preserves the food by using low pH to deter bacterial growth.

In contrast, lyophilization refers to freeze-drying, which involves removing moisture from food through sublimation. Leaching is a process where water-soluble substances are removed from food, often through soaking or boiling, but it is not typically a preservation technique. Extrusion is a method of processing food where ingredients are forced through a machine to create varied shapes but is not associated with preservation through the addition of salt, sugar, or vinegar.