Abstract
This study was conducted to improve the method of assessing the thickness distribution of crude brown rice using a quadrat-sampling slot-sieving grader. The official method for assessing the thickness distribution of crude brown rice is to shake about 200 g of crude brown rice for 5 min, then use a sieving grader. Using Koshihikari and Nipponbare varieties in good ripening conditions, we used a 2 × 3 factorial design with three randomized blocks to assess the relationship between the time of shaking (2 min, 5 min, 8 min) and the sample weight of crude brown rice (ca. 200 g, ca. 100 g). No significant relationship was found between the sample weight and the time of shaking. However, each main effect was shown to be significant. The results of multiple comparison using the Holm method revealed that shaking of 100 g crude brown rice for 2 min is the best method. This method reduces the sample weight of crude brown rice, thereby shortening the shaking time. This method is a practical method that can reduce assessment costs when in good ripening conditions.
