|Role of extrusion in reducing anti-nutritional factors in cereal and legume based fortified blended foods|
S. ALAVI (1), Q. Guo (1), B. Lindshield (1), M. Joseph (1) (1) Kansas State University, , U.S.A.; (2) Kansas State University, Manhattan, KS, U.S.A.; (3) Kansas State University, , KS, U.S.A..
The phytate, tannin and trypsin inhibitor content of raw and extruded cereal/legume binary blends, used to make the fortified blended foods by mixing with WPC, oil, sugar and vitamin/ mineral premix, were analyzed in this study. The raw sorghum/ cowpea binary blends (SCB) had phytate content ranging from 804.22 – 1138.50 mg/100g, and the extruded SCB had phytate content ranging from 560 - 830 mg/100g. The raw sorghum/ soy (SSB) and corn/ soy blends (CSB) had mean phytic acid content of 752.80 mg/100g and 567.54 mg/100g, respectively. The extruded sorghum/ soy (SSB) and corn/ soy blends (CSB) had mean phytic acid content of 556.60 mg/100g and 317.64 mg/100g, respectively. Extrusion helped in reducing phytic acid content by 16.92 -29.26%, 26.06%, and 44.03% in SCBs, SSB, and CSB respectively. The control CSB+ had a mean phytic acid content of 1885 mg/100g. Amongst the treatments, the SCBs showed highest phytate followed by SSB and CSB respectively. The CSB+ being just a physical blend of heat treated corn and soy showed highest level of phytic acid concentration. The mean tannin content in raw SCB ranged from 20.05 – 59.50 mg/100g. The mean tannin content in extruded sorghum/ cowpea binary blends ranged from 15.83 – 44.37 mg/100g. The raw SSB and CSB blends had mean tannin content of 65.98 mg/100g and 48.32 mg/100g whereas the extruded SSB and CSB blends had mean tannin content of 53.64 mg/100g and 36.73 mg/100g, respectively causing a reduction of 20.09-26.67%18.69%, and 23.98% in SCB, SSB and CSB. The control CSB+ had a mean tannin content of 150.41 mg/100g. Similarly, there was a reduction of 16.55-23.31%, 19.50%, and 28.26% inn trypsin inhibitors in SCBs, SSB and CSB respectively. Thus, it was found that extrusion was an effective processing method to improve the nutritional quality of fortified blended foods.