Pulsed Electric Field Pretreatment Reduces Cyanogen Content and Modifies the Structural and Pasting Properties of Fermented Cassava Flour

Reducing cyanogenic compounds while maintaining the functional properties of cassava flour is an important challenge in modified cassava flour (MOCAF) processing. This study evaluated pulsed electric field (PEF) pretreatment for hydrogen cyanide (HCN) reduction and its effects on flour color, morphology, and pasting properties during subsequent fermentation. Cassava slices of the Adira 2 variety were treated at electrode gaps of 0.5, 1.0, and 1.5 cm for 30, 60, and 90 seconds at 15 kV, corresponding to nominal electric field strengths of 30, 15, and 10 kV cm-1, respectively. The selected PEF condition was followed by fermentation for 24, 48, or 72 hours. Treatment effects were assessed using analysis of variance (ANOVA) followed by Duncan’s multiple range test. The 1.0-cm electrode gap and 90-second treatments reduced HCN content from 7.22 to 3.27 mg kg-1 (54.7%), with a further reduction to 2.21 mg kg-1 after 72 hours of fermentation. PEF increased flour lightness, while a significant interaction between pretreatment and fermentation time affected the b* color coordinate. Peak viscosity increased from 4,676 to 5,352 cP in unfermented flour and from 6,045 to 6,513 cP after 72 hours of fermentation, accompanied by reduced setback. Scanning electron microscopy revealed morphological differences among treatments, with additional alterations following fermentation. These findings demonstrate the potential of sequential PEF pretreatment and fermentation to enhance HCN reduction while modifying the color, morphology, and pasting properties of Adira 2 cassava flour, supporting further evaluation for MOCAF processing.