INTRODUCTION
Human nutrition is undergoing significant changes due to demographic changes in the society and the industrialization of food production that lead to increased imbalance of the major diet components. The newly formed nutrition structure undoubtedly has a negative effect on the body's protective systems, thereby increasing the risk of many diseases.
Unfavorable ecological situation in Russia is another factor contributing to increased probability of diseases, and this motivates the search for procedures increasing the body's resistance to adverse envi-ronmental effects. Oxygen deficiency, more commonly known as hypoxia, is an acute problem of the society nowadays, along with micronutrient deficiency. Unbalanced diet, excessive alcohol consumption, sedentary lifestyle, chronic stress, and pollution of the environment are the main causes of this problem.
Many experts in the field of functional food and dietary products consider oxygen cocktails, which have a positive physiological effect due to the presence of pure oxygen and micronutrients added to the cocktail base, promising basic components of oxygen therapy. Saturation of such drinks with oxygen results in the formation of foam consisting of stable microscopic bubbles filled with the gas, with an oxygen content of about 150 cm3 per serving. The use of syrups containing vitamins and herb extracts enhances the effect of treatment. Convenience of use and better preservation of oxygen in the drink require the foam to be stable during at least 15–20 minutes.
The effect of oxygen therapy is due to the high content of oxygen in the drinks. Intense absorption of oxygen through the mucous membranes of the stomach enables its entry into the blood and intensive oxygenation of tissues, thereby improving cellular metabolism, activating blood circulation, and normalizing metabolic and regenerative processes, as well as reflexes. Absorption of valuable micronutrients increases due to the overall activation of metabolic processes. This contributes to increased micronutrient activity and a stronger physiological effect of both micronutrients and oxygen [1].
Moreover, oxygen cocktails are used to treat insomnia and chronic fatigue. They promote increased stress resistance of the organism and faster recupe-ration of the brain after excessive mental loading.
The actual functional effect of the cocktail is highly dependent on the foaming agent used to form the oxygenated foam. A foaming agent of high quality enables the production of foam with a high stability and expansion ratio.
Eggwhite- or dairy-based foaming agents are used in the food industry. Extracts of tea, soybean, and cotton seeds have foaming properties similar to those of egg white. Stabilizers, such as casein, alginates, gelatin, and others, are usually added to edible foams to improve the stability of the latter [4, 6, 7].
Selection of a foaming agent by the manufacturer is guided by the specific properties of the former, which underlie its qualitative characteristics. Foaming agents most widely used in the production of aerated foods are listed in Table 1 [8, 9, 10].
The commonly used foaming agents have certain disadvantages: for example, the use of licorice root extract requires the addition of certain essential amino acids in order to ensure the presence of the required amount of all the essential amino acids in the final product.
