Why Does Salt Preserve Food

Preserving food with table salt is an ancient human exercise that dates dorsum before written records. Beefiness jerky, pickles, and smoked salmon are all examples of mutual foods that are preserved using table salt. Only are salty foods really prophylactic to eat? How does salt equally a preservative compare with other methods of food condom?

Homemade preserved lemons with salt — Poppy Barach / Getty Images

Salt as a Preservative

Table salt has been used as a preservative for ages, and works to preserve food in two ways:

Salt dries food. Salt draws water out of food and dehydrates it. All living things require water and cannot abound in the absenteeism of information technology, including the bacteria which can cause food poisoning. Salt is used to preserve beef jerky by keeping it dry out, and information technology prevents butter from spoiling past cartoon water out, leaving just the fatty.
Salt kills microbes. High salt is toxic to most (not all) microbes considering of the effect of osmolarity, or water pressure. Water diffuses between cells in the environment so that the concentration of solutes (such as salt) is the same on both sides of the cell. In very loftier table salt solutions, many microbes will rupture due to the difference in pressure between the outside and inside of the organism. High salt can also exist toxic to internal processes of microbes, affecting Deoxyribonucleic acid and enzymes. Solutions high in carbohydrate likewise have the aforementioned effects on microbes, which is why it is used as a preservative of foods, such as jams and jellies.

Misconceptions Virtually Common salt Preservation

Many people believe that saltier foods are more resistant to microbial growth. As a result, they are more willing to eat questionable foods if they accept higher salt contents.

Hither are the facts. Most bacteria, with the exception of halophiles (salt-loving bacteria), cannot abound in weather where the salt concentration is greater than 10%. But molds can withstand even higher salt levels. To get x% salt, you would need to deliquesce 180 g salt in 1800 g water, which is approximately equivalent to ane loving cup of salt dissolved in vii.five cups of h2o.

How salty is 10% salt? Have yous ever accidentally swallowed water when swimming in the ocean? Seawater is 3.5% common salt. Imagine drinking seawater that is 3 times saltier.

What Foods Have Enough Salt (>10%) to Cease Bacteria Growth?

Here is a sample list of foods that many people would consider "salty." The percentage of salt is calculated by dividing the total weight of the food by the weight of table salt. The following nutrition information was obtained past using CalorieKing's food database.

1 serving McDonald's French fries (medium): 260 mg/117 thousand = 0.2% table salt
1 serving Doritos, nacho Cheese flavour: 314 mg/48 yard = 0.seven% salt
1 serving Campbell's chicken noodle soup (condensed): 1,779 mg/252 g = 0.7% salt

Notation that none of these are even close to the 10% salt cutoff for preventing bacterial growth. Traditionally salt-preserved foods are either stale, such as beef jerky, or crave refrigeration after opening, such as pickles or cured ham.

Brines and Condiments

Brines and condiments are known to have high salt content, but do they meet the 10% salt requirement to inhibit bacterial growth?

ane packet ketchup: 100 mg/eight.5 g = one.i% salt
one packet mustard: 65 mg/5.67 g = 1.1% salt
i parcel soy sauce: 333 mg/5.67 g = v.8% common salt

So, fifty-fifty soy sauce is not salty enough to forestall bacterial growth. Why tin can it be kept unrefrigerated? Since soy sauce does not have other essential ingredients necessary for microbial growth, such equally proteins or carbohydrates, there is little take a chance of leaving it out on your countertop.

Traditionally Salt-Preserved Foods

So far, the foods we've listed are known to exist salty simply aren't normally foods in which we consider salt to be the reason the food can be safely eaten. How well-nigh the foods that are traditionally thought of as salt-preserved foods?

1 dill pickle: 306 mg/34 g = 0.9% common salt
1 piece beef jerky: 443 mg/20 one thousand = 2.2% salt
1 slice ham: 365 mg/9.iii thou = 3.9% salt

Even traditionally salt-preserved foods do not run across the 10% table salt requirement to stop microbial growth. But additional features well-nigh these foods, such every bit dehydration (beef hasty) or addition of acid (pickles) or preservatives (ham), assistance foreclose spoilage. In addition, many salt-preserved foods require refrigeration after opening in order to wearisome microbial growth.

Exercise Higher Salt Levels Prevent Spoilage Better Than Lower Common salt Levels?

For most edible foods, the answer is no, a higher salt concentration doesn't assist keep your nutrient fresh unless you want to chance getting sodium poisoning. Almost foods listed above accept salt levels less than 4% (with the exception of soy sauce).

College Salt May Actually Help Bacteria Abound

Did you know that bacteria grow best in atmospheric condition saltier than most foods we consume? Science labs where bacteria is routinely grown for experiments utilize a solution called "LB," or Luria Goop, for optimal growth of bacteria. What is the salt concentration of LB? It is 1% or roughly the saltiness of a dill pickle.

Salt Intake Is a Public Health Trouble

Even if salt was a skilful preservative, would it be a good thought? It'due south thought that the common salt content of the Western diet is contributing to poor wellness, including kidney disease. From heart affliction to autoimmune disease, to osteoporosis, learn why you may desire to throw away the common salt shaker to live longer.

The Common salt of This Commodity

There seems to be plenty of evidence that salty foods aren't microbe proof foods. That said, anyone asking these questions and learning almost food rubber is a very wise consumer. Food poisoning is common. The Centers for Disease Control and Prevention (CDC) estimates that annually 48 1000000 people (1 in 6) become infected past a foodborne affliction, 128,000 are hospitalized, and 3,000 die.

While salt isn't the solution, in that location are many things you can practise to go on your food safe. First of all, practice good kitchen safety. Never utilize the aforementioned cut board for raw meat and vegetables or fruits. Buy foods well before the expiration dates. Even if a food is not expired, if the scent is suspect, throw it out. Stay up to engagement on the news to hear of whatsoever food-poisoning outbreaks. Avoid unpasteurized milk to reduce your risk of milk-borne infections.

Refrigerate foods promptly afterwards eating and apply safety food-storage practices. Rut foods thoroughly when re-heating. It'southward important to annotation that fifty-fifty reheating tin sometimes pb to food poisoning. Some bacteria, such every bit Staph, produce toxins. While the bacteria are killed in reheating, the toxins are rut stable and persist. Finally, learn to recognize the signs and symptoms of food poisoning and talk to your healthcare provider if you are not feeling well.

By Ingrid Koo, PhD
Ingrid Koo, PhD, is a medical and science author who specializes in clinical trial reporting

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