Effect of extrusion cooking on the physicochemical properties, resistant starch, phenolic content and antioxidant capacities of green banana flour.
Green banana flour was extruded through a co-rotating twin-screw extruder with constant barrel temperature. The objectives of this study were to determine the effect of extrusion cooking variables (feed moisture, FM, 20% and 50%; screw speed, SS, 200 and 400rpm) and storing of the extruded flours at 4°C for 24h on the physicochemical properties, resistant starch (RS), pasting properties and antioxidant capacities. Extrusion cooking at higher FM and lower SS increased the amylose content, which was expressed in highest RS content. Water adsorption index (WAI) and pasting properties were increased, while water solubility index (WSI), total phenolic content (TPC) and antioxidant activities (FRAP, ABTS(+), DPPH) in free and bound phenolics were decreased compared to the other extruded samples. Storing the extruded flours at 4°C for 24h prior to oven drying was the main factor leading to a further increase in the content of amylose, RS, TPC and WSI values, as well as pasting properties - in particular peak viscosity. Compared to native banana flour, extrusion cooking caused significant changes in all studied properties of the extruded flours, except for soluble DF and antioxidant capacity (ABTS(+) and DPPH) of bound phenolics.
Institute of Food Technology, Department of Food Science and Technology, University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria; Division of Food Science and Technology, Faculty of Home Economics Technology, Rajamangala University of Technology Krungthep, 149 Chareonkrung Road, Yannawa, Sathon, Bangkok 10120, Thailand.
Chonthira
C
Sarawong
Regine
R
Schoenlechner
Ken
K
Sekiguchi
Emmerich
E
Berghofer
Perry K W
PK
Ng
D000975:Antioxidants / Q000032:analysis*; D003296:Cooking; D005433:Flour / Q000032:analysis*; D028521:Musa / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D012995:Solubility; D013213:Starch / Q000032:analysis*; D013696:Temperature; D014783:Viscosity
D000975:Antioxidants; D010636:Phenols; D013213:Starch
Extrusion cooking; Green banana flour; Phenolics and antioxidant capacity; Physicochemical properties