Modelling of brown rice and limited-water cooking modes and its potential use for texture prediction

• Published in: Journal of food engineering Vol. 141; pp. 99 - 106
• Main Authors: Briffaz, A., Bohuon, P., Méot, J.M., Pons, B., Matencio, F., Dornier, M., Mestres, C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2014; Elsevier
• Subjects: Brown rice; Chemical and Process Engineering; Computer simulation; Constraining; Cooking; Engineering Sciences; Food and Nutrition; Gelatinization; Heating; Life Sciences; Mathematical models; Rice; Surface layer; Texture; Water transport; Water-to-rice ratio; Water transport; Cooking; Water-to-rice ratio; Gelatinization; Brown rice; Texture
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2014.05.008

•A rice cooking model has been adapted for brown rice and limited-water cooking.•Pericarp effect on mass transfer was identified as a mass-transfer resistance.•The model was validated on 3 excess-water steeping temperatures (50–95°C) and 2 rice cultivars.•Water redistribution was well predicted during holding period.•Water and gelatinization profiles could explain cooked rice texture. This paper describes the adaptation of a one-dimensional rice cooking model including water transfer, starch phase transitions and swelling to simulate both milled and brown Chu-cheong and Chil-bo rice cultivars cooked in excess water or in limited amounts of water. The pericarp was found to play a temperature-dependent role during steeping of brown rice. At 50°C, surface mass-transfer resistance was identified whereas from 75°C the pericarp ruptured. Despite pericarp rupturing, apparent water diffusion coefficients for brown rice (∼1.9×10−10m2s−1) were lower than for milled rice (∼3.3×10−10m2s−1). This was due to the mechanical constraining effect of pericarp with respect to water uptake. In the limited-water cooking mode, predicted water and gelatinization profiles of four selected cooking procedures explained the texture of cooked rice. Indeed, the highly hydrated gelatinized periphery of the cooked grain resulted in high “initial starchy coating” sensory scores whereas the uncooked core increased instrumental firmness.