Salt is perhaps most well known for its roles as a flavoring agent and food preservative. Salt has been used by humans to preserve food for many thousands of years, but salt also plays other, lesser known roles in the food we eat. Salt is an essential nutrient, it provides flavor, texture, and enhances color. If you ever wonder why salt can be found in just about every food item, this is why. Below are a few of the varied ways that salt is used in food production.
Preservative - Salt curing meat and other foods is the oldest method of food preservation and was was heavily used prior to refrigeration. Salt acts as a preservative by drawing out moisture from food, which is essential to microbial growth. Many pathogenic microbes are also simply unable to grow in the presence of salt.
Texture Enhancer - Most people don't realize that salt plays a large roll in creating texture in food. When making yeast breads, the amount of salt greatly affects the rate of yeast fermentation and gluten formation, both of which will significantly affect the bread's final texture. Salt also has a profound effect on the gelatinization of proteins, which occurs in cheese production and many processed meats such as sausage, bologna, and ham. Large salt crystals are also often used to add a crunchy texture, as with pretzels.
Flavor Enhancer - Salt acts in multiple ways to enhance the flavor of food. Not only is the "salty" flavor element one of the most desired by humans, but salt can also affect other flavor elements, such as sweet and bitter. In small amounts, salt will intensify sweetness and is therefore often sprinkled on fresh fruit or added to candies like caramel. Salt can also counteract bitter flavors in food. For this reason salt is often used to "de-bitter" cruciferous vegetables and olives.
Nutrient Source - Although most Americans consume far too much sodium, it is a nutrient essential for survival. Pure table salt is comprised of approximately 40% sodium and 60% chlorine. Most table salts in the United States also have iodine added to them to prevent iodine deficiencies. Iodine deficiencies can cause disorders of the thyroid, including goiters.
Binder - Because salt helps form protein gels, it can be used as a binding agent. When salt is added to foods such as sausage or other processed meats, it causes gelatinization of proteins which then hold the product together.
Color Enhancer - The vibrant color of many processed meats, such as ham or hot dogs, is partially due to salt. The presence of salt helps maintain color, whether artificial or natural, and prevents it from turning grey or muddy.