Puffing characteristics of berry slice under continuous microwave puffing conditions

Abstract

To elucidate the puffing characteristics of the berry slice under continuous microwave conditions, heat and mass transfer and deformation of slices were investigated based on the models of coupled multi‐physics fields involving electromagnetic heating, heat and mass transfer and solid mechanics. The results indicated that transmission mode of microwaves in a microwave cavity determined the electric field distribution inside slices with interior focusing phenomenon described by higher temperature and lower moisture content at the central region of slices than that of edge. The berry slice volume showed a “invisible‐rapid‐maintained” deformation under the synergistic effects of temperature, moisture and internal pressure with sample movement. This study may provide guidance for the elucidation of microwave puffing process of the moving slice and the underlying applications such as technology optimization and quality control of slices like berry. Novelty impact statement This work investigates the puffing characteristics of the moving berry slices under a continuous microwave dryer, and elucidates the heat and mass transfer and deformation process of berry slices by means of experiment and simulation. The distribution of alternating electric field profiles with high and low levels determine the absorption of microwave energy, heat and mass transfer in berry slices to induce the volume deformation and uneven distribution. The volume of berry slices laid on moving conveyor belt under continuous microwave puffing undergoes three deformation trends as invisible change followed by rapid expansion till desired shape.

Effects of mode of heat transfer on puffing quality of rice grain: A modeling and simulation analysis

“…Considering the advantages of microwave heating and the availability of domestic microwave oven, researchers have developed microwaveable popcorn that is available in convenient pouches in the market as a successful food product (Sman & Bows, 2017). However, other cereal based snacks like microwaveable puffed rice and starchy pellets are under research for further improvement in their puffing quality (Guo et al, 2022; Kantrong et al, 2022; Zhang et al, 2022). The major problems associated with the microwave puffing of rice and starchy pallets are less percentage of puffing (PP), incomplete puffing of some grain, uneven puffing of starchy pellets, burning of grain and burning spot in starchy pellets (Maisont & Narkrugsa, 2010; Mishra et al, 2015; Mohapatra & Das, 2011; Sman & Bows, 2017; Swarnakar et al, 2014; Swarnakar et al, 2022).…”

“…Considering the advantages of microwave heating and the availability of domestic microwave oven, researchers have developed microwaveable popcorn that is available in convenient pouches in the market as a successful food product (Sman & Bows, 2017). However, other cereal based snacks like microwaveable puffed rice and starchy pellets are under research for further improvement in their puffing quality (Guo et al, 2022;Kantrong et al, 2022;Zhang et al, 2022).…”