Accelerated aging of rice by controlled microwave treatment

Yejun Zhong; Xiaoyue Xiang; Tingting Chen; Pei Zou; Yunfei Liu; Jiangping Ye; Shunjing Luo; Jianyong Wu; Chengmei Liu

doi:10.1016/j.foodchem.2020.126853

Accelerated aging of rice by controlled microwave treatment

Food Chem. 2020 Apr 18:323:126853. doi: 10.1016/j.foodchem.2020.126853. Online ahead of print.

Authors

Yejun Zhong¹, Xiaoyue Xiang¹, Tingting Chen¹, Pei Zou², Yunfei Liu³, Jiangping Ye¹, Shunjing Luo¹, Jianyong Wu⁴, Chengmei Liu⁵

Affiliations

¹ State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047, China.
² Jiangxi Biotech Vocational College, 608 Nanlian Road, Nanchang 330200, China.
³ Institute of Applied Chemistry, Jiangxi Academy of Sciences, 7777 Changdong Avenue, Nanchang 330096, China.
⁴ State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047, China. Electronic address: jianyongwu@ncu.edu.cn.
⁵ State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047, China. Electronic address: liuchengmei@aliyun.com.

PMID: 32339762
DOI: 10.1016/j.foodchem.2020.126853

Abstract

To obtain the desired technological properties (pasting, texture, and rheology) of naturally aged rice (AR), the aging process of freshly harvested rice was accelerated by controlled microwave treatment at 540 W for 1-3 min. Similar to AR, the rice microwave treated for 2 min showed increased pasting viscosities (peak, trough, breakdown, final, and setback) and pasting temperature, enhanced gel hardness and strength, and reduced gel adhesiveness. The mechanism by which microwaves accelerated rice aging was illustrated. Microwave treatment promoted the formation of protein disulfide bonds and the release of free phenolic acids, which enhanced protein gel network and cell wall strength. This phenomenon inhibited the swelling of starch granules and consequently modified the technological properties of rice. The crystalline structure and fatty acid content of rice flour was uninvolved in the mechanism, but the microwave-induced micromechanical change (intercellular cleavage to intracellular cleavage) of rice endosperm may be involved.

Keywords: Chemical composition; Microwave; Rice aging; Rice noodles; Technological properties.