Effects of milling on texture and in vitro starch digestibility of oat rice

Meng Shen; Kai Huang; Xiao Guan; Jian Xia; Zhu Sun; Zhiquan Yu; Yong Fang

doi:10.1016/j.fochx.2023.100783

Effects of milling on texture and in vitro starch digestibility of oat rice

Food Chem X. 2023 Jul 6:19:100783. doi: 10.1016/j.fochx.2023.100783. eCollection 2023 Oct 30.

Authors

Meng Shen^{1

2}, Kai Huang^{1

2}, Xiao Guan^{1

2}, Jian Xia^{1

2}, Zhu Sun³, Zhiquan Yu³, Yong Fang⁴

Affiliations

¹ School of Health Science and Engineering, The University of Shanghai for Science and Technology, Shanghai 200093, PR China.
² National Grain Industry (Urban Grain and Oil Security) Technology Innovation Center, Shanghai 200093, PR China.
³ Inner Mongolia Yangufang Ecological Agricultural Science and Technology (Group) Co., Ltd, Inner Mongolia, PR China.
⁴ College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210003, PR China.

Abstract

Compared with other oat products, consumers in China prefer oat rice and porridge made from naked oat. However, this oat product usually has poor sensory acceptance, which is directly related to the texture properties. This study aimed to use the milling method to improve the oat rice texture. The nutrient component, microstructure, pasting, and thermal properties of oat treated with different degrees of milling (0 s, 20 s, 40 s, 60 s, and 80 s) were researched. The results showed that milling would damage the bran layer of oat rice, increasing starch, β-glucan, total leached solids content, and the gelatinization enthalpy (ΔH). Meanwhile, oil, protein content, the pasting viscosity, and the pasting temperature were decreased. Milling made oat rice sticky and soft, and the bound water and non-flowing water migrated like flowing water. The cross-section of oat rice showed that milling damaged the surface of oat rice, which was beneficial to water entry and starch dissolution, and increased the viscosity of oat rice. When the milling time was 40 s and 60 s, the appearance, aroma, taste, texture, and overall acceptability of oat porridge were better. Moreover, rapid digestion fraction (k₁) and slow digestion fraction (k₂) are the lowest and have the effect of low blood glucose rise rate.

Keywords: In vitro starch digestibility; Milling; Oat rice; Sensory; Texture.