Freeze-dried berry powders can serve as effective stabilizers in ice cream and other frozen dairy desserts containing cream and whole or skim milk powder, according to a study by U.S. Department of Agriculture food technologists.
What is freeze-drying? Freeze-drying is a multi-step process. In the simplest terms, it involves removing water from a frozen product through sublimation of ice, i.e. the transition of ice into a state of water vapor bypassing the liquid state. This is possible by freezing the product inside the chamber of the freeze-dryer while lowering the pressure in the chamber.
The experiments conducted by the team of researchers used 3.5% powders made from berries. Their addition resulted in slowing or avoiding the melting of frozen desserts.
Strawberry powder proved to be the best additive, followed by raspberry powder, which completely prevented melting of the ice cream, which maintained its shape even after it reached room temperature.
Freeze-dried berry powder improves stability and texture by absorbing moisture from the premix base. This is likely due to the fibers in the fruit that become fully hydrated causing an increase in dessert viscosity and resistance to melting.
Food stabilizers, in addition to slowing or avoiding the melting of frozen desserts, increase the sense of creaminess, prevent ice crystals from forming, whey from sticking, and ice cream from shrinking during freezing.
In the food industry, the most commonly used stabilizers include: E401 (sodium alginate), E407 (carrageenan), E412 (guar gum), E415 (xanthan gum). The names of these stabilizers are negatively associated with consumers by their “artificial” and chemical sounding names, some of them may cause allergies, increase allergic reactions to other products and contribute to digestive disorders.
Freeze-dried berry powders, in addition to serving as stabilizers, increase their nutritional value as they are an additional source of vitamins and antioxidants. Freeze-dried berries can therefore be used to produce ice cream with increased nutritional value, which has in its composition only ingredients of natural origin.