Effect of Magnetic Field Pre-treatment on the Fibre Content of Sweet Pepper and Fluted Pumpkin Leaves

Abstract

Sweet pepper (SP) and Fluted pumpkin leaves (FPL) vegetables contain fibre. Thermal pretreatment (heat addition) of vegetables during processing has the tendency of reducing their qualities. Magnetic field (MF) as a non-thermal method of food pretreatment is still grossly underutilized. Therefore, three (3) MF pretreatment parameters (MF types, MF strength and pretreatment time) were imposed on SP and FPL for the investigation of their effect on the fibre content of the two vegetables. A device working on electromagnetism principle was used to conduct the experiment designed. The average capacity and highest value of MF strength of the device are 20 g/min and 30 mT respectively. The fibre content of all pretreated samples and controls (blanched and fresh) were analyzed using standard procedures. Results showed that pretreatment with MF led to fibre content of about 1.7 – 2.6% for SP and 6 – 10% for FPL; but samples of blanched SP and FPL had 1.8% and 1.7% respectively. MF pretreatment in most cases led to better values of fibre than blanching for SP and FPL.