RESUMO
The physicochemical properties of four rice varieties representing high amylose (Jyothi and IR64), intermediate amylose (Taraori Basmati) and waxy (Agonibora) were evaluated to understand their influence on milling. Based on the grain dimensions, Jyothi and Agonibora were classified as long and medium, IR64 as long and slender, and Basmati as extra-long and slender. The head rice yield (HRY) was higher with abrasive milling (61-75%) compared to friction milling (10-60%) although it required longer milling duration. Lower grain thickness, hardness and, amylose and higher bran fat content reduced the friction milling duration while these properties prolonged the duration in abrasive milling. Agonibora variety with low amylose content and high-fat content exhibited the highest HRY in both the types of milling. The study revealed that the selection of milling process should be made with due importance to grain geometry as well as its chemical properties.
RESUMO
The nutritional composition of bran from four rice varieties namely, Jyothi/IR64, Basmati and Agonibora representing high amylose, intermediate amylose and waxy, respectively were evaluated with friction and abrasive mills at different degrees of milling (DOM). Fat and protein content of the bran inversely correlated to amylose content of rice variety. The fat and fibre contents reduced with increased DOM due to increasing starch influx from the endosperm. Abrasive milling produced bran with higher protein content and total dietary fibre, resulting in superior quality bran, while friction milling led to higher fat. Agonibora bran was found to be superior in terms of nutritional quality. Industrial milling resulted in higher protein content in bran, and Jyothi variety had a better amino acid profile.
