Kinetic Modelling of Color Change During Cooking of Unparboiled and Parboiled rice MR297
Jhauharotul Muchlisyiyah (1,2), Rosnah Shamsudin (1,3,*), Roseliza Kadir Basha (1), and Radhiah Shukri (4)

(1)Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
(2)Department of Food Science and Biotechnology, Faculty of Agricultural Technology, Universitas Brawijaya, Jalan Veteran Malang, 65145, Indonesia
(3)Laboratory of Halal Science Research, Halal Products Research Institute, Universiti Putra Malaysia, Putra Infoport, 43400 Serdang, Selangor, Malaysia
(4)Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

Corresponding author email: rosnahs[at]upm.edu.my

Abstract

MR297 is a rice variety that is extensively grown and consumed in Malaysia. This study aims to examine the kinetics of colour changes (L*, a*, b*, Chroma, and Hue) in unparboiled and parboiled rice MR297 during the cooking process. Furthermore, the study aims to examine the relationship between the moisture change parameters and the colour change of the rice. Eleven established prediction models were used to simulate the kinetic behaviour of colour changes during cooking. The evaluation of all prediction models entailed the utilisation of three statistical indicators: the coefficient of determination (R-squared), standard error of estimates (SEE), and root mean square error (RMSE). The most accurate predictions for the changes in unparboiled rice MR297 while cooking were made using the b* value with the karizaki 8 Model (R-squared=0.999, RMSE = 0.052, SEE=0.064). On the other hand, the best predictions for parboiled rice were made using the Chroma value in the cubic model (R-squared=1.000, RMSE = 0.049, SEE=0.061). A supplementary investigation was performed to investigate the association between the moisture content of cooked rice and the colour changes that occur during cooking. The moisture content of unparboiled rice showed a strong correlation with the b* parameter (R-squared=0.962, p<0.01), but in parboiled rice MR297, the moisture content showed a strong correlation with the L* parameter (R-squared=0.988, p<0.01). This study will be advantageous for researchers and rice processors in formulating the adequacy cooking method.

Keywords: parboiled rice- MR297- cooked rice color changes- kinetic model- correlation

Topic: Food science and biotechnology