Behind The Scenes: Freeze Dried Snacks
Preserving food for future use or to protect it against spoiling has been man’s quest for centuries. Especially for perishable foods like fruits and vegetables, preservation is necessary. Different methods of preservation have been brought forward over the years and with that came the question of safety and healthiness of the foods preserved with regard to the amount of nutrients retained. Freeze drying is being referred to by sellers as “the gentlest” form of preservation. Although most consumers who have tasted the products have given positive reviews, there is still a cloud of misunderstanding out there about freeze drying.
So what really is freeze drying? This is a food preservation method that entails total removal of moisture or water in perishable foods to increase their shelf lives while still retaining the nutrients in the food. Most freeze dried snacks will still have 95 to 99 percent of nutrients as their original form. The process does not distort the size, color, texture or even taste of the food. The food to be preserved goes through a number of steps before being packaged for consumption.
The first is step is freezing. This is the most important step and must therefore be done correctly and with high levels of precision to avoid spoilage of the food. The fruits or vegetables to be preserved are usually placed in a freeze-drying machine where it is cooled to temperatures below its triple point. The triple point is essentially the temperature below which the solid and liquid components of the product cannot coexist. Averagely it is usually -50 or -80 degrees centigrade. This kind of cooling will ensure the liquid sublimes in the next step that follows freezing.
After freezing, the food is placed in a partial vacuum. Controlled amounts of heat are then supplied to the product to aid in sublimation of the water. The vacuum aids in controlling the pressure around the food product and also in quickening the sublimation process. This step is called the drying phase; it is usually done slowly to avoid distorting the structure of the food. A condenser is employed to re-solidify the water vapor to guard it against going into the vacuum pump. 95 percent of water may be removed in the first phase of drying. Secondary drying may be done to remove unfrozen water molecules. On completion of drying, the water content in the product will be very low-1-4%. The product will then be air-tightly sealed to prevent moisture absorption.
In a nutshell, freeze-drying works to remove any water content hence limiting the activity of bacteria or other micro-organisms that might spoil the food. “No additive used” is not a marketing propaganda by sellers, the process conforms to all safety precautions and the product remains healthy nutrition-wise.
Wholesome, nutritious and delicious snacks that are freeze dried are now available for consumers on the market. There is no doubt about them for most consumers exclaims that the freeze dried snacks they bought are “tasty, delicious and you will want to go for more”. According to sellers, their snacks contain no artificial sugars, salts, oils or even trans-fats. Maybe this is the new way of a healthy eating habit!
Posted By Dennis E. Baker