Nutritional values of potato slices added with rosemary essential oil cooked in sous vide bags

The sous vide packaging method, in association with rosemary essential oil (REO), was confirmed as a good strategy for the quality preservation of sliced potatoes over refrigerated storage until 11 days. Looking at vegetables as sources of phytochemicals together with the benefits of sous vide cooking method validated by several studies, taking into account the increasing interest in early crop variety and their nutritional value and considering that potatoes must be cooked to be eaten, the potato slices treated with peanut oil and with the addition of REO were monitored on ascorbic acid, total polyphenols content and antioxidant activity. Results demonstrated that the presence of REO have no “a direct” effect on the nutritional content of cooked samples, but it was probably linked with the protection of such compounds. The ascorbic acid (AsAc) was better preserved (24.7 ± 4.06 mg/100 g DM) and values were kept nearest to the raw tubers having moderate loss with a maximum of 20% in Erika. Total polyphenol content (TPC) was well maintained after cooking, ranging from 337 to 257 mg/100 g DM, of course the varieties with the highest content were able to save a high amount of the compound studied, and the antioxidant activity (AA) calculated showed a loss mean value of 48% among cultivars. Hence, we can conclude that potato slices treated with REO, packaged in sous vide bags and cooked at 105 ± 5 °C for 15 min, retain nearly all the nutritive compounds considered in our study. The most suitable cultivar identified to be stored as fresh cut potato slices with the addition of REO in sous vide bags and then cooked, was Elodie: it was able to save the highest nutritive values among cultivars studied holding AsAc and TPC content as well as the smaller reduction in AA from the fresh material.