An exploration of the effects of low-pressure plasma discharge on the physicochemical properties of chia (Salvia hispanica L.) flour

Abstract

This work explores the preliminary feasibility of employing the low-pressure coldplasma technology for the modification of the properties of chia flour. Chia flour wasexposed to low pressure plasma in air for 5 min, 10 min, and 15 min, at two differentpower levels (40 W and 60 W). The oils extracted from untreated and treated chiaflour were exhaustively characterized for fatty acid composition, nutritional value,and rancidity indices using thermal calorimetric methods (DSC/TGA). The resultsindicated a significant change in the colour of flour with an increase in lightness.Infrared and ultraviolet spectroscopy indicated changes in the tocopherol groups ofthe oil extracted from plasma treated chia flour. However, the oil extracted fromplasma treated chia flour revealed a loss of conjugated dienes and formation oftrans-fatty acids as seen in conventional hydrogenation of edible oils. DSC and TGAresults revealed better oxidative stability of low-pressure plasma treated oils thancontrol, which was linked to a relative increase of MUFA in the former.