Drying and intermittence processes on the polished and brown rice physicochemical and morphological quality by near-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy.

In this study was correlate the effects of drying time and intermittence of paddy rice on the physical, physicochemical, and morphological quality of polished and brown rice using near-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Rice grain batches from mechanized harvesting with moisture contents between 24 and 20% (w.b.) were immediately subjected to drying and intermittence (average temperature of the grain mass of 40 °C) for a time of 14 h (number of times that the product underwent the drying and intermittence processes). For each drying time, grain sampling was performed to evaluate the physical quality of paddy rice and the physicochemical and morphological quality of polished and brown rice. The accumulated drying time provided an increase in the temperature of the grain mass, altering the physicochemical and morphological quality of polished and brown rice. The intermittence process did not contribute for the quality of the polished rice.

Effects of drying temperature of corn from the center and extremities of the corncob on drying parameters, protein and starch properties, and carotenoid profile.

The corn grains from the extremities of corncob are known to have a spherical shape and the grains from the center of corncob have higher length and lower thickness. It is understood that these differences in grain dimensions can affect post-harvest processes and the properties of the grains. Therefore, the objective of this study was to evaluate the effects of drying temperature (60, 80, and 100 °C) of corn from the center and extremities of corncob on drying parameters, protein and starch properties, and carotenoid profile. At 60 °C, the drying rate and effective moisture diffusivity of corn from the center and extremities of the corncob did not differ. However, at 80 and 100 °C these parameters were higher in the corn from the center. Corncob part and separation did not significantly affect corn pasting properties. However, they caused significant changes in the properties of the grain proteins, mainly the reduction of the solubility and inactivation of the lipase enzyme, and the reduction of the lutein and ß-carotene contents in the grains from the center and separated after drying. The results of this research show the need to evaluate the effects of these drying conditions during grain storage. In addition, the implementation of an industrial separation step and/or the development of new corn cultivars with more homogeneous grains should be studied.