Various conditions of a parboiling process affect the qualitative parameters of paddy milling. In this study, the effects of drying temperature (45 and 60 °C), moisture content (8, 10 and 12% w.b.), steaming time (10, 20 and 30 min) and paddy varieties (Hashemi and Alikazemi) were investigated on head rice yield (HRY). The samples were husked using a rubber roller husker and whitened by a laboratory abrasive whitener. Results showed that the main effects of all parameters were significant on HRY (P <0.01). The utilization of higher temperature (60 °C), in comparison with non-parboiled rice, without reducing the milling quality was found as one of the advantages of parboiling. Among all experiments, the highest HRY (68.647%) was achieved in the combination of Alikazemi/45 °C/10 min/8%. In the majority of cases, the combinations including Alikazemi variety had higher HRY than Hashemi. For Hashemi variety, the highest HRY (67.297%) was achieved in combination 45 °C/10 min/8%. In terms of HRY, parboiling causes an increase of 25.8% and 43.3% respectively for Hashemi and Alikazemi. Therefore, it is highly recommended in processing of Alikazemi variety.
CHAKRAVERTY, A. – PAUL SINGH, R. 2001. Postharvest Technology: Cereals, Pulses, Fruits and Vegetables. New York: Science Publishers, 356 pp. ISBN 9781578081684.
DA FONSECA, F. A. – SOARES JUNIOR, M. S. – CALIARI, M. – BASSINELLO, P. Z. – DA COSTA EIFERT, E. – GARCIA, D. M. 2011. Changes occurring during the parboiling of upland rice and in the maceration water at different temperatures and soaking times. In International Journal of Food Science Technology, vol. 46, no. 9, pp. 1912–1920.
IMONIGIE, P. S. – YUSUF, K. A. – ATANDA, E. O. 2017. Development of a temperature-controlled paddy rice parboiler. In American Journal of Mechanical and Materials Engineering, vol. 1, pp. 5–9.
JAGTAP, P. S. – SUBRAMANIAN, R. – SINGH, V. 2008. Influence of soaking on crushing strength of raw and parboiled rice. In International Journal of Food Properties, vol. 11, no. 1, pp. 127–136.
JULIONO, O. 1985. Rice: chemistry and technology. American Associate Cereals Chemists. IMC, pp. 385–411.
KADDUS MIAH, M. A. – ANWARUL HAQUE, M. – DOUGLASS, P. – CLARKE, B. 2011. Parboiling of rice, Part I: Effect of hot soaking time on quality of milled rice. In International Journal of Food Science Technology, vol. 37, pp. 527–537.
KIM, O. W. – KIM, H. – LEE, H. J. 2014. Impact of moisture content on milling characteristics of short-grain rice. In Applied Engineering Agriculture, vol. 30, no. 6, pp. 927–933.
KWOFIE, E. M. – NGADI, M. 2017. A review of rice parboiling systems, energy supply, and consumption. In Renewable Sustainable Energy Reviews, vol. 72, pp. 465–472.
NASIR AHMADI, A. – EMADI, B. – ABBASPOUR FARD, M. H. – AGHAGHOLZADE, H. 2014. Influence of moisture content, variety and parboiling on milling quality of rice grains. In Rice Science, vol. 20, pp. 116–122.
OYEDELE, O. A. – ADEOTI, O. 2013. Investigation into the optimum moisture content and parboiling time for milling Igbemo rice. In Journal of Rice Research, vol. 1, no. 1, pp. 1–3.
PATINDOL, J. – NEWTON, J. – WANG, Y. J. 2008. Functional properties as affected by laboratory scale parboiling of rough rice and brown rice. In Journal of Food Science, pp. 370–377.
PILLAIYAR, P. 1981. Household parboiling of parboiled rice. In Kishan World, vol. 8, no. 20–21.
VITÁZEK, I. – VEREŠ, P. 2013. Drying rate of grain maize. In Acta Technologica Agriculturae, vol. 16, no. 2, pp. 20–21.
ZHANG, X. – LAN, Y. 2007. Effect of drying temperature and moisture content on rice taste quality. In Agricultural Engineering, International CIGR eJournal, Manuscript FP07 023, vol. IX.