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The Ingredients for Preserving Foods

The Ingredients for Preserving Foods

Salt is one of the ingredients used in preserving foods.

Culinary Institute of America

From the editor: Food preservation techniques have always been intended to control the growth of microbes, halting the growth of some and encouraging the grown of others. This article summarizes the ingredients used to preserve foods.

1. Salt
2. Nitrates and Nitrites
3 Seasing and Flavoring Ingredients

Salt

The basic ingredient used by the garde manger to preserve foods is salt. This common seasoning, found in virtually every kitchen and on every table, meant the difference between life and death to our ancestors, and it is still important to us from both a physiological and a culinary point of view. Salt changes foods, by drawing out water, blood, and other impurities. In so doing, it preserves them, making them less susceptible to spoilage and rot. The basic processes in which salt plays an important role are:


-Osmosis
-Dehydration
-Fermentation
-Denaturing proteins

Osmosis

Osmosis happens without human intervention all the time, but to make use of osmosis for preserving foods, it is helpful to have a basic idea of how the process occurs. A simple definition states that osmosis is the movement of a solvent (typically water) through a semipermeable membrane (the cell walls) in order to equalize the concentration of a solute (typically salt) on both sides of the membrane. In other words, when you apply salt to a piece of meat, the fluids inside the cell travel across the cell membrane in an effort to dilute the salt on the other side of the membrane. Once there is more fluid outside the cell than in, the fluids return to the cell’s interior, taking with them the dissolved salt. Getting the salt inside the cell, where it can kill off harmful pathogens, is the essence of salt-curing foods.

Dehydration

The presence of “free” water is one of the indicators of a food’s relative susceptibility to spoilage through microbial action. In order to keep foods safe and appealing to eat for long periods of time, it is important to remove as much excess water as possible. Applying salt to foods can dry them effectively, since the salt tends to attract the free water, making it unavailable to microbes. Exposure to air or heat for controlled periods allows the water to evaporate, reducing the overall volume and weight of the food.

Next Page: Fermentation, Denaturing Proteins, Nitrites, and Nitrates>>