Kinetics of water absorption and relation with physical, chemical, and wet‐milling properties of commercial yellow maize ( Zea mays L.) hybrids

Abstract

The kinetics of water absorption of 16 commercial yellow maize hybrids were investigated, and their relationships with the physical, chemical, and wet-milling properties of the grains were examined. The Peleg equation adequately (r > 0.9, p < .001) described the water absorption characteristics. The Peleg constants K1 [0.185–0.278 hr (g/100 g solids)−1] and K2 [0.030–0.038 (g/100 g solids)−1] significantly (p ≤ .05) depended on the hybrids, so also was the equilibrium moisture content, ME, (40.30–49.17 g/100 g solids). Pearson's correlation analysis showed the Peleg constants were highly dependent on the physical and chemical properties of the grains. The Peleg constant K2 significantly (p ≤ .05) related to the starch yield (K2, r = −0.641), which is a very important wet-milling property. Hence, to screen the maize hybrids for their wet-milling properties, their water absorption kinetic parameters or the resulting Peleg constants can be used. Practical applications During wet-milling of maize, steeping or soaking is the first and most important stage that induces several physical and chemical changes that aid separations of kernel components and affect the product quality. Investigating the kinetics of water absorption in several yellow maize hybrids, our results revealed that the hydration parameters depend on the hybrids and correlated with their physicochemical and wet-milling properties. Starch yield and recovery can be predicted from grain hydration parameters, offering a screening option for the wet-milling industry. The information is also useful for breeders, farmers, and marketers in selecting maize hybrids for wet-milling.