Cooked Rice Drying by Microwave Assisted Hot Air

doi: 10.14456/mijet.2020.2

Authors

  • Lamul Wiset
  • Nattapol Poomsa-ad Mahasarakham University

Keywords:

microwave-hot air combination, cooked rice, drying time

Abstract

This research aimed to study the process of instant rice, cooked rice was dried under different microwave power levels. Quality of products was investigated. Milled rice was pretreated by exposing to microwave at power of 800 W for 30 sec and without exposure before cooking with rice cooker.  Cooked rice was dried at drying temperature of 60 °C combined with microwave power at different levels of 0, 400, 600 and 900 W at constant air velocity of 0.23 m/s. Each run used for 500 g. Sample with initial moisture content of 68-72% wet basis was dried down to about 8-11% (aw less than 0.5). Result found that the drying time was affected by pretreatment method and microwave power. The drying time of cooked rice with pretreatment was 386, 170, 140, and 116 min at microwave power of 0, 400, 600 and 900 W, respectively, which was shorter than without pretreatment. Hardness and stickiness of rice with pretreatment were higher than rice without pretreatment. The L*(lightness) and b*(yellow value) of dried cooked rice with and without pretreatment had similar trend that it was decreased when the microwave power increased. However, rehydration ratio of cooked rice with pretreatment was higher than without pretreatment.

Author Biographies

Lamul Wiset

Postharvest Technology and Agricultural Machinery Research Unit,

Drying Technology Research Unit, Faculty of Engineering, Mahasarakham University,

Khamriang, Kantarawichai, Maha Sarakham 44150, Thailand

Corresponding Author: lamulwiset@hotmail.com, Telephone and Fax: +66-43-754316

 

Nattapol Poomsa-ad, Mahasarakham University

Postharvest Technology and Agricultural Machinery Research Unit, Drying Technology Research Unit, Faculty of Engineering, Mahasarakham University,

Khamriang, Kantarawichai, Maha Sarakham 44150, Thailand

*Corresponding Author: lamulwiset@hotmail.com, Telephone and Fax: +66-43-754316

References

[1] Rewthong, O., Soponronnarit, S., Taechapairoj, C., Tungtrakul, P., Prachayawarakorn, S. (2011). Effects of cooking, drying, and pretreatment methods on texture and starch digestibility of instant rice. Journal of Food Engineering. Vol. 103, pp. 258-264.
[2] Hus, R.J., Chen, H., Li, S. and Chaing, W. (2015). Effects of cooking, retrogradation and drying on starch digestibility in instant rice making, Journal of Cereal Science, vol. 65, pp. 154-161.
[3] Mestres, C., Ribeyre, F., Pons, B., Fallet, V., and Matencio, F. (2011). Sensory texture ofcooked rice is rather linked to chemical than to physical characteristics of raw grain. Journal of Cereal Science. Vol. 53, pp 81-89.
[4] Motevali, A., Minaei, S. And Khoshtagaza, M.H. (2011). Evaluation of energy consumption in different drying methods. Energy conversion and Management. Vol. 52, pp. 1192-1199.
[5] Tsubokural, Y., S. Fukuzaki1, S. Noma, N. Igura and M. Shimoda. (2009). Glycation of ovalbumin in solid-state by conductive and microwave heating. Food Science Technology Research. Vol. 15(4). pp. 377-380.
[6] Le, T.Q. and Jittanit, W. (2015). Optimization of operating process parameters for instant brown rice production with microwave-followed by convective hot air drying. Journal of Stored Products Research, vol. 61, pp. 1-8.

Published

2020-01-03

How to Cite

Wiset, L., & Poomsa-ad, N. (2020). Cooked Rice Drying by Microwave Assisted Hot Air: doi: 10.14456/mijet.2020.2. Engineering Access, 6(1), 7–11. Retrieved from https://ph02.tci-thaijo.org/index.php/mijet/article/view/10.14456.mijet.2020.2

Issue

Section

Research Papers