Application of sous-vide technology in the processing of different apple cultivars and its effect on physico-chemical properties

Apples and their products are among the most common dishes on the menu of European consumers. In human nutrition, apples are classified as sources rich in polyphenolic substances, phytochemicals, fiber and other substances beneficial to human health. Their advantage is affordability across all economic classes in society. Apples are consumed raw or variously heat-processed (various purees, compotes, etc.). However, the common method of heat treatment can cause the degradation of health-promoting substances. Therefore, this study was focused on the evaluation of the effect of heat treatment in vacuum (sous-vide) or in the traditional way without vacuum on selected apple cultivars. In both methods, selected physical and chemical properties were evaluated, for example parameters such as antioxidant capacity, content of total polyphenols and evaluation of changes in the cell structure of selected apple cultivars. For the purposes of the study, five apple cultivars were selected – Champion, Golden Delicious, Rubín, Idared and Goldstar. Apple samples were subjected to heat treatment at temperatures of 60, 70, 80 and 90 °C, always in two variants—without vacuum and in vacuum. Analyzes were carried out to determine the total content of polyphenols, as well as determination of antioxidant capacity (FRAP, CUPRAC and DPPH), changes in the cell structure of apples were monitored using SEM. The results show that the sous-vide cooking method is a suitable alternative to the heat treatment of fruit, in terms of preserving the organoleptic quality and improving the properties of the products supporting human health.