Effect of electromagnetic field pretreatment on the phytonutrient content of sweet pepper and fluted pumpkin leaf

Abstract

Electromagnetic field (EMF) pretreatment is a novel non-thermal technique of food pretreatment that ensures better food quality than thermal techniques. This study aimed to study the effect of electromagnetic pretreatment on the phytonutrients of two vegetables: sweet pepper (SP) and fluted pumpkin leaf (FPL). Three types of magnetic fields (static, pulse and alternating) in combination with magnetic field strength (5 - 30 mT) and pretreatment time (5 - 25 min) were used to pretreat SP and FPL. All EMF pretreated, blanched (control) and fresh samples were analysed before and after drying for five phytonutrients, and data were processed and presented with bar charts. Carotenoids of SP before and after drying were 33 mg/1 and 48 mg/1respectively. Highest values of phenols for SP were 0.28 mg/l and 0.15 mg/l before and after drying respectively. FPL had carotenoids (40 mg/l - 45 mg/l), alkaloids (1.1 mg/l), phenol (1.6-2.4 mg/l) while flavonoids content after drying increased (6.7% - 21.70%). Saponins content of FPL remained the same before and after drying. EMF pretreatment relatively led to significant improvement in the phytonutrients of SP and FPL than blanching.