Incorporation of yeast and hot melt extrusion enhance contents of total polyphenol and flavonoids and antioxidant ability in buckwheat flour / Uporaba kvasa in vročega ekstrudiranja poveča vsebnost celotnih polifenolov, flavonoidov in antioksidacijsko ...

A study was conducted to determine the degree of interaction between yeast and hot-melt extrusion on contents of total polyphenol, total flavonoid, and rutin and antioxidant ability in common buckwheat. The highest content of total polyphenol was 95mg/100g in buckwheat flour, which included 2% yeast and was dried for 8 hours after extrusion while that of total flavonoids was 181mg/100g. The highest content of rutin in this study was 4.23mg/100g (156% higher than control, non-extrusion without yeast) in buckwheat flour, included 2% yeast, and dried for 8 hours after extrusion. Antioxidant ability determined by DPPH free radical scavenging ability was higher in yeast-mixed buckwheat flour extruded and dried for 8 hours (23-61%) than non-extruded with or without yeast (19-40%). The highest antioxidant ability (61%) was shown in buckwheat flour mixed with 2% yeast, extruded, and dried for 8 hours after extrusion. These results may be attributed to incorporating extruded buckwheat flour with yeast powder during 8 hours of drying and fermentation followed. Izvleček Namen raziskave je bil ugotoviti interakcijo dodanega kvasa in vročega ekstrudiranja mešanice ajdove moke s kvasom na vsebnosti celotnih polifenolov, flavonoidov in antioksidacijske sposobnosti pri moki navadne ajde. Ajdovi moki je bilo dodanega 2% kvasa, rezanci so bili sušeni 8 ur po ekstruziji. Najvišja vsebnost skupnih polifenolov je bila 95mg/100g z dodatkom 2% kvasa, vsebnost celotnih flavonoidov je bila 181mg/100g. Najvišja vsebnost rutina je bila 4,23mg/100g (156% več kot kontrola, brez ekstrudiranja, s kvasom) pri ajdovi moki z 2% kvasa in sušeno 8 ur po ekstruziji. Antioksidativna sposobnost, določena z DPPH, je bila višja pri uporabi kvasa, ekstruzije in sušenja 8 ur (23-61%), kot brez uporabe kvasa in ekstruzije (19-40%). Najvišja antioksidacijska sposobnost (61%) je bila določena pri ajdovi moki z dodatkom 2% kvasa, ekstrudirano in po ekstruziji sušeno 8 ur. Pričakovati je, da bodo rezultati te raziskave prispevali k uspešni uporabi ekstrudiranja ajdove moke z uporabo kvasa in osem urnega sušenja ter fermentacije.