Study of the autonomous process of inversion of sugarose through thermal influence at ultrasonic processing of vegetable and fruit pures

Relevance. The article presents the results of a study of the increase in the amount of reducing sugars in the inversion of sucrose due only to thermal effects during ultrasonic processing of vegetable and fruit monocomponent purees (with or without added sucrose).The relevance of the study is to identify the quantitative thermal component of a separate process in the total inversion of sucrose at the specified parameters of ultrasonic action on the product. Material and methods. to perform this task, experimental samples of carrot, pumpkin and Apple puree with the addition of sucrose in an amount of 5% (by weight) and without it were previously made, which were then subjected to heat treatment at the same temperature and time exposure (at a temperature of 50 °C for 30 minutes). To study the dependence of the degree of sucrose inversion on the component composition of the processed product, the mass fraction of reducing sugars - fructose and glucose-was determined in the manufactured experimental samples of natural fruit and vegetable purees (without added sucrose) and in mixtures of purees with sucrose (according to a given recipe) before and after heat treatment at the specified parameters, depending on the recipe composition and pH of the medium. Results. The obtained results of the study of the carbohydrate composition before and after thermal exposure show that the amount of reducing sugars in products subjected to heat treatment has significantly increased, compared to the initial content. Thus, in Apple puree with added sucrose, the mass fraction of fructose after heat treatment of the mixture increased by 197 mg per 100 g, i.e. by 3.8%, and glucose -by 192 mg per 100 g, i.e. by 6.7%. The total invert sugar content of the Apple mixture increased by 4.8 %. In the carrot mixture of puree with sugar, the content of total reducing sugars after thermal exposure increased by 5.4%. At the same time, in carrot natural puree, the increase in reducing sugars was only 3.6%, which is 1.5 times lower. In the pumpkin puree mixture with sugar, the total content of reducing sugars increased by 3.9%, and in the natural puree, the amount of invert sugars increased by only 2.7%, which is 1.4 times lower than puree with added sugar.