Effects of low‐temperature microwave treatment of wheat germ

MERILES, SILVINA PATRICIA; STEFFOLANI, MARIA EUGENIA; PENCI, MARIA CECILIA; CURET, SEBASTIEN; BOILLEREAUX, LIONEL; RIBOTTA, PABLO DANIEL

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE

JOHN WILEY & SONS LTD

Año: 2022

0022-5142

The aim of this study was to evaluate the effect of microwaves on enzyme activity, and on functional and physical properties of wheat germ (WG). Microwave treatments were performed at 50, 60 and 70 ºC for 5-20 min. Lipase activity was severely affected at 60 and 70 ºC while lipoxygenase was not. Microwave treatment did not cause changes in germ moisture content or color parameters. No significant changes were observed in equilibrium moisture content when comparing adsorption and desorption processes of raw and microwave-treated wheat germ. According to the dielectric properties of raw wheat germ, it could be considered as transparent to energy (ε´ < 1.87 and ε" < 0.35). Thermal analysis of proteins showed a low denaturation degree (below 35% compared to raw material) as a consequence of microwaves. In addition, some functional properties were enhanced like oil retention capacity. Conformational changes due to microwave treatment were associated to the slight decline observed on the monolayer moisture content.