Effect of storage time on the antinutritional factors, stability and rheological behaviours of flaxseed fortified wheat flours

Abstract

Whole wheat flour (WWF) and straight grade flour (SGF) were fortified with partially defatted flaxseed flour (PDF) and full fat flaxseed flour (FFF). The fortified flours were stored for a period of 60 days. Studies were conducted to evaluate the influence of storage intervals on stability, cyanogenic glycoside (HCN) content and rheological properties at 0, 30 and 60 days of storage. No HCN was detected in WWF samples while, its maximum concentration 0.37 and 0.44 mg/kg was found in 20% PDF and FFF fortified WWF, respectively. The storage intervals showed non-significant effect on the concentration of HCN among different composite flours. The peroxide value ranged from 0.82 to 0.92 mEq/kg in PDF fortified SGF composite flours, while it varied from 0.82 to 1.01 mEq/kg in FFF fortified SGF composite flours. The mixing time decreased significantly as the level of PDF and FFF fortification increased in SGF. Lower mixing times were recorded in both types of composite flours after 60 days of storage interval while fresh samples exhibited the higher mixing times. Significant changes in peak height percentages of both types of flours were observed during storage period of 60 days.