Elucidation of soaking and steaming duration in parboiling: effects on the physical quality and appearance of local rice cultivars

Abstract

Enhancing the quality of rice grains is essential to meet consumer demand and boost farmers’ income. Various factors, such as processing techniques and parboiling methods, play a crucial role in influencing the overall quality of rice grains. In this study, the effects of soaking and steaming durations on the parboiling process were studied on rice grains’ physical quality and appearance. The 10 kg of paddy grains of the two most consuming cultivars (Surkha Zurati and Barah) were soaked in natural water and then steamed for 15, 20, and 25 min under two covering methods: cloth + lid and cloth. The parboiled grains were dried (12–13%) and milled for a physical quality test. The results revealed that cloth + lids increased the amount of head rice and decreased broken and chalky grain production. The maximum head rice rate was recorded for 25 min, followed by 20 and 15 min of steaming for all treatments and cultivars. The lower broken and chalky grains were recorded after 25 min of steaming (cloth + lid), and the highest values were observed after 15 min (cloth) for both cultivars. The cloth + lid method produced darker yellow grains after parboiling compared to the cloth treatments only in both cultivars. Furthermore, the rice grain darkness increased with increasing steaming duration. Hence, head rice, chalkiness, broken grains, and discoloration can be managed through parboiling. This method can be useful for rice processors to improve rice grain quality using adequate parboiling technology.

Keywords:

• Chalkiness
• discoloration
• rice
• physical quality
• processing rice

REVIEWING EDITOR:

• Manuel Tejada, University of Seville, Spain

SUBJECTS:

• Processing, Preservation, Food Packaging, Food Biotechnology, Food Engineering, Food Chemistry, Food Additives & Ingredients, Product Development

Acknowledgments

The authors appreciate the Rice-based Agriculture Development Project in Afghanistan (RIPA/JICA) and the Agricultural Research Institute of Afghanistan (ARIA) for providing funding for this study. The authors extend their appreciation to the Researchers Supporting Project number (RSP2024R182) of King Saud University, Riyadh, Saudi Arabia.

Authors’ contributions

Z.N. and S.F. assumed the idea, conducted the experiment, and wrote the manuscript. All authors Z.N., K.K., S.A., R.M, S.F, H.O.E., and M.A.E. analyzed the data, wrote, and revised the manuscript. All the authors have read and agreed to the latest version of the manuscript.

Disclosure statement

The authors declare no conflicts of interest and have proofread the final version of the manuscript.

Data availability statement

All data are available within this publication.

Additional information

Funding

This research was supported by the Rice-based Agriculture Development Project in Afghanistan (RIPA/JICA). Researchers supporting the project (RSP2024R182) at King Saud University.