How do moisturizers work?

Foods have different water activity. Water activity (water activity) is the ratio of the amount of water vapor pressure of food to the vapor pressure of distilled water at a certain temperature. Water activity values range from 0.00 for absolutely dry matter to 1.0 for distilled water.

Another meaning of water activity is the amount of free water that is available for various reactions. Microorganisms can use this free water to support their growth. But the lower the water activity, the less moisture is available for the growth of microorganisms . This is why foods like dried fish and powdered milk last for months to years. Generally, perishable foods have a water activity higher than 0.9. This is where bacteria thrive. That is why, for example, fresh vegetables, meat and fish spoil faster. To make a food product more stable during storage, water activity must be reduced or controlled .

And that’s what moisturizers are for. They can bind moisture in food , thereby reducing the activity of water. In addition, they also absorb moisture from the air.

Honey, salt and sugar are some of the oldest humectants used in food. They are still widely used, especially in home processing (jams and marmalades). Try our original recipes for homemade marmalade in 10 ways . Traditionally, medium moisture foods were simply dried until the desired water activity was achieved. Today, however, food processors combine heat treatments such as surface drying and humectants for a stronger effect.

What humectants are used in the food industry?

In the food industry, food manufacturers use polyols as humectants. In chemistry, polyols are compounds that contain multiple hydroxyl groups. They are also called sugar alcohols , because their chemical structure resembles that of sugar and some of them are identical to alcohols.

Polyols are sweeteners. They are colorless and odorless . One of the main differences between sugar and polyols is that polyols are not as easily fermented by microbes in the mouth as sugar. They are therefore non-cariogenic – they do not cause tooth decay. In addition, they are sweet but have fewer calories than sugar. Therefore, some manufacturers add them to diet products, also because of their moisturizing and plasticizing properties. It is worth noting that not all polyols are good humectants, as some are non-hygroscopic.

In which foods can we find moisturizing substances?

  • chewing gums
  • candies
  • lemonade
  • cheeses
  • shredded coconut
  • pastry
  • drinks
  • dairy products
  • fruit and vegetable juices
  • processed fruits and vegetables

Are humectants in food safe for us?

Moisturizers are usually safe when used in recommended doses. However, their excessive consumption can cause digestive problems such as abdominal pain and diarrhea.