Effects of aleurone layer on rice cooking: A histological investigation

• Published in: Food chemistry 2016-01, Vol.191, p.28-35
• Main Authors: Wu, Jianyong, Chen, Jun, Liu, Wei, Liu, Chengmei, Zhong, Yejun, Luo, Dawen, Li, Zhongqiang, Guo, Xiaojuan
• Format: Article
• Language: English
• Subjects: Adhesiveness; Aleurone layer; Cooking; Hardness; Histological characters; Hot Temperature; Oryza - chemistry; Rice; Viscosity; Water
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.11.058

•Aleurone layer (AL) slightly affected rice cooking quality.•AL remarkably affected texture and peak viscosity of rice.•Histological characters of AL during cooking were clearly showed in situ.•Channels formed in AL during cooking which facilitated the cooking of rice.•AL affected rice texture by forming a reinforced coated film on rice surface. Understanding how aleurone layer (AL) affects rice cooking behaviour is important for rice processing. Individual effects of AL on rice cooking behaviour were evaluated and histological characters of AL before and after cooking were investigated. AL slightly affected rice cooking quality (optimum cooking time, water absorption, volume expansion ratio and total solids loss) while remarkably affected rice texture (hardness and adhesiveness) and peak viscosity. Histological investigation showed that channels were formed in AL during cooking. The channels facilitated the penetration of water, which could explain why AL exhibited slight effects on rice cooking quality. In addition, thick cell walls and thermally stable aleurone grains were widely distributed in AL. Leached components accumulated on them and formed a reinforced coated film on rice surface during cooking, which may be a possible mechanism accounting for the remarkable effect of AL on rice texture. Histological characters of AL are closely related with rice cooking behaviour.