How to Preserve Food Using Salt
Salt (sodium chloride) has been used as a food preservative for centuries. In effect it was the first natural ‘chemical’ preservative added to foods and has been used extensively in the preservation of fish, meat and vegetables ever since. The value of salt in preserving foods was so highly prized by the Ancient Romans that it was used as a form of currency. Salt remained the most used form of food preservation until much more recent times when modern food preservation methods were developed such as refrigeration, freezing and canning foods. In fact the value of salt in food preservation still continues today where it is often used in combination with other preservation methods, it also remains a primary method of food preservation in countries/ areas where there are limited refrigeration facilities or access to newer technologies.
Action of salt
Salt acts as a preservative by inhibiting microbial growth. Salt acts by drawing water out of the cells of foods and bacteria through a process known as osmosis. Reducing the amount of water available to bacteria inhibits or slows bacterial growth and reproduction. High concentrations of salt can also rupture bacterial cells due to differences in pressure between the outside and inside of the microorganism.
Salt is also effective in protecting foods against moulds and yeast- it prevents the fermentation of yeast and the growth of moulds by reducing water supply.
How salt is used to preserve foods
Vegetables are generally preserved by pickling them in a salt and water solution (brine), while meat may be rubbed with salt and dry cured or may be injected with a salt solution.
Considerations when using salt in home preservation
Salt will not prevent all microbial growth as although most microbes cannot grow in conditions where the concentration of salt is above 10%, preserving foods with a solution that is over 10% salt will have detrimental effects on the flavour, texture and structure of the preserved food. Most often foods must be preserved in much lower salt concentrations to retain the desirable qualities of the food. Different bacteria and fungi also have differing tolerance to salt, this should be considered along with an awareness of what microbes are likely to spoil the food you are aiming to preserve.
Using salt affects the perceived health benefits of a food. Although some salt is vital to health, an excess of sodium in the diet leads to retention of water by the body which can cause hypertension (high blood pressure) which is a risk factor for stroke and heart disease. Remember though to follow tested recipes and recommendations regarding the amount of salt required for home food preservation. This is essential as reducing the amount of salt in preserved foods will make foods more prone to microbial activity effecting food safety.
Choose your salt carefully- use a pickling salt or Kosher salt, this is important as ordinary table salt may contain other additives such as iodine (which was originally added to salt to help increase people's iodine intake in order to avoid incidents of enlarged thyroid glands).
Understanding more about our food
Maintaining good health or yourself or others includes knowing how to prepare or store food as well as understanding the types of food that are good for you. Whether you are embarking on a self-sufficient lifestyle, trying to improve health and diet, or if you provide food or nutritional related services to others.
ACS offer a great selection of courses in all of theses areas. Under the guidance of our expert tutors, students can learn about self-sufficiency, diet, nutrition and health. If you would like to know more please get in touch with our expert tutors today - they will be happy to answer any questions, and discuss the different study choices which we have available to meet your goals.
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