Effects of microwave treatment on the microstructure, germination characteristics, morphological characteristics and nutrient composition of maize
Xinyue Lu, Shunmin Wang, Yulu Dong, Yudie Xu, Ningning Wu
Abstract
This study investigated the effects of microwave treatment on the microstructure and germination characteristics of maize seeds, as well as the morphological characteristics and nutritional composition of germinated maize. The results indicated that microwave could alter the microstructure of endosperm cells in maize seeds. Microwave enhanced the germination rate and shortened the average germination time. Besides, the sprout length (20.0 %), fresh weight of edible parts (14.0 %) and reducing sugar content (6.04 %) of germinated maize were significantly increased by microwaving of 200 W/20 s, compared with CK (10 d). In addition, the respiratory rate (41.5 %) and free amino acids content (19.5 %) of germinated maize were also significantly enhanced with microwave of 200 W/20 s, compared with CK (7 d). Microwave could significantly increase amylase activity, accelerate starch hydrolysis, and greatly decrease starch content. For soluble protein and fat content of germinated maize, there were no significant differences among the treatment groups. Correlation analysis showed that the sprout length and fresh weight of germinated maize were highly correlated with their nutritional components. Therefore, microwave can be an effective method to improve the nutritional value of germinated maize.