Effect of polishing duration on physical, milling, cooking, and sensory properties of a novel mix‐colored Nigerian parboiled rice

Abstract

Background and objectives Polishing is a step of milling process to produce white rice. It influences rice quality. This study evaluates the effect of increased polishing duration (0, 1, 2, and 3 min) on the physical, milling, cooking, and sensory properties of novel mix‐colored Nigerian rice. These quality parameters influence the consumers’ choice. Findings Polishing duration had a significant effect on the physical, milling, cooking, and sensory properties of the milled rice. As the polishing duration increased, the length, width, length/width ratio, 1,000‐grain weight, bulk density, true density, porosity, optimum cooking time, cooking loss, aroma, and flavor of the milled rice reduced, while increased polishing duration increased the head rice yield, percentage broken rice, milled rice yield, percentage dockage, kernel elongation ratio, width expansion ratio, water uptake ratio, texture, appearance, and overall acceptability of the milled rice. The correlations between physical, milling, cooking, and sensory properties were strongly significant (p ˂ .01 and p ˂ 0.05). Conclusions This study revealed that increasing the polishing duration improves the cooking, head rice yield, milled rice yield, and some sensory quality attributes of the mix‐colored parboiled rice, but reduced its physical attributes. Significance and novelty The mix‐colored rice showed an improved milling, cooking, and sensory attributes but poor physical characteristics during polishing which is very vital to rice milling industry.

Interactive effects and modeling of some processing parameters on milling, cooking, and sensory properties for Nigerian rice using a one-step rice milling machine

“…This was calculated using Eq. (3) ( Ahmad et al., 2017 ; Okunola et al., 2019 ; Ojediran et al., 2020 ). …”

“…Also, previous research work has only utilized the two-step milling system for their study, using a one-step milling machine will increase the knowledge-base for rice processing industries. However, this present work is an extension of our previous work undertaken to study the effect of polishing time on milling, physical, cooking, and sensory properties of Nigerian rice by Ojediran et al. (2020) .…”

“…Polished rice is more appealing to the consumer, and it is characterized by longer shelf life, better cooking attributes, and faster digestibility although brown rice is more nutritious ( Rathna Priya et al., 2019 ). There are three different rice milling machines; one-step (husking and polishing in a single run), two-step (husking and polishing or whitening are carried out with two different machines), and multi-stage (comprises of the pre-cleaning unit, husking, paddy separation, polishing, grading, a combination of whole and broken rice in percentage, mist polishing, and weighing) rice milling machines ( Dhankhar and Hissar 2014 ; Ojediran et al. , 2020 ).…”

Influence of Husking Machine Type, and its Clearance on the Factory Rice, Mashkhab (M-33) Cultivar

“…The machine led to more organizing whenever was the high productivity because of the low percentage of break-up and this was reflected positively on the increase machine productivity due to increased efficiency and operator's skill among other factors [13], effect of moisture content and shaft speed on the rice breakage experienced during husking operation using a rubber roll husker. It was reported that the interactive effect of shaft speed and moisture content significantly affected the hulling index but did not affect the amount of rice breakage [14]. The prime object of this study is to examine the impact of husking machines (S-KB40 and Y-ST50) on rice, Mashkhab (M-33) cultivar at various clearances among cylinders.…”