Vacuum impregnation of apple slices with Yacon (Smallanthus sonchifolius Poepp. & Endl) fructooligosaccharides to enhance the functional properties of the fruit snack

This work aimed to incorporate prebiotic FOS from yacon in apple slices using vacuum impregnation (VI). Three FOS concentrations (10.3, 14.1 and 18.9 g per 100 g of dry matter (DM)), two temperatures (25 and 35 °C), reuse of extracts and stability of the impregnated slices were evaluated. The highest impregnation level (30.5 g per 100 g DM) was obtained at 35 °C with 14.1% FOS extract while levels of common sugars were reduced. Total phenolics and ABTS antioxidant capacity (AC) slightly decreased while ORAC AC was reduced by 55%. Reuse of the impregnation solution in successive cycles after restoring the FOS level maintained the FOS concentration and profile (GF2–GF7), sugars and phenolic antioxidants. FOS in apple slices remained stable during 4 week storage, while a_w, colour and fracture point changed during storage. This work demonstrated the feasibility of yacon FOS to improve the functional properties of dehydrated apple slices.