Process Modeling and Optimization of Magnetic Field Pretreatment of Sweet Pepper and Fluted Pumpkin Leaf.

Abstract

Modelling and optimization of magnetic field (MF) pretreatment of sweet pepper (SP) and fluted pumpkin leaf (FPL) were done with response surface methodology. Three pretreatment factors combined were: types of MF (static, pulse, and alternating), MF strength (5 - 30 mT), and pretreatment time (5 - 25 min). All the MF pretreated, control (blanched), and fresh samples were dried at 50˚C and analyzed for fibre, vitamin C, potassium, microbial load, and colour; data obtained were used for modelling and optimization of the process. Results showed that the selected 30 developed model equations reliably described the characteristics of the process with adequate precision values of greater than four (4) and significant probability values (p ≤ 0.05) in all cases. The best-optimized process conditions for the MF pretreatment process are Static MF at 14.31 mT magnetic field strength and 16.40 min pretreatment time for SP and Alternating MF at 10.42 mT magnetic field strength and 9.96 min pretreatment time for FPL. Magnetic field (nonthermal) pretreatment was able to achieve all the optimization goals better than blanching (thermal) pretreatment.