# Effect of Ultrasonic Treatment on Taste and Flavor Quality of Japonic Rice
###### Abstract  
The aim of this study was to investigate the effect of ultrasound treatment on the texture and flavor quality of Japonica rice to provide a basis for the development of a staple food product for the treatment of diabetes mellitus. The texture and flavor qualities of cooked rice were analyzed using a texture analyzer, rapid viscosity analyzer (RVA), and gas chromatography-mass spectrometry (GC-MS). The results showed that with increased ultrasound treatment time, the hardness and chewiness of the cooked rice gradually increased, while adhesion decreased. Additionally, the ultrasound treatment reduced various viscosity parameters of rice during the pasting process, inhibiting paste expansion and regrowth. Key aroma compounds influencing the aroma of cooked rice before and after ultrasound treatment included hexanal, heptanal, 2-pentylfuran, octanal, nonanal, trans-2-octenal, decanal, undecanal, trans-2-nonanal, trans-2-dodecenal, trans-2-decenal, trans-2,4-decadienal, 2-pentadecanone, and indole. The odor activity value (OAV) of these compounds increased significantly and were greater than one after ultrasound treatment. These compounds play a role in composing the unique aroma of cooked rice and contribute to sweet, floral, and nutty aromas. In conclusion, ultrasound treatment can be used to increase the content of resistant starch in cooked rice and has a positive effect on the flavor quality of cooked rice. ultrasound treatment; Japonica rice; resistant starch; rice taste; aroma compounds 202514627  
14 April 2025 30 April 2025  
limiting the starch retrogradation, delaying the aging of straight-chain starch. This modification prevents the recrystallization of branched-chain starch, reduces starch swelling forces, and increases starch resistance to enzymatic hydrolysis [5]. Many chemical, physical, and enzymatic techniques have been employed to accelerate the formation of V-complexes [3; 4; 5; 6]. Recent studies have shown that ultrasound treatment can also facilitate the integration of lipids into starch molecules [4], potentially promoting the formation of V-type complexes. Ultrasound treatment is a cost-effective, efficient, and simple method that can dissolve swollen starch, release linear amylose, enhance lipid dispersibility in gelatinized starch, and facilitate the complexation process between amylose and lipids. These effects can influence the physicochemical and functional aspects of starch [7; 8; 9]. Studies have shown that the generation of single helix complexes through ultrasound treatment significantly enhances the release of additional linear chains from swollen starch granules and improves lipid dispersion in samples [10]. Additionally, ultrasound treatment facilitates the breakage of branched starch branching points by disrupting the C-O-C bond in the \(\alpha\)-1,6 glycosidic bond, leading to an increase in the number of linear chains [3]. However, there has been limited research on the formation of the starch-lipid complex in cooked rice using ultrasound treatment and its effect on cooked rice quality. Given the increasing prevalence of diabetes, there is a growing demand for staple foods with a low glycemic index. Meanwhile, Japonic rice is widely grown and consumed in China compared to other types of rice. Japonic rice has a soft, delicate texture and is somewhat sticky, which is more for cooking rice. Nutritionally, Japonic rice has a higher fat content than other varieties, which is favorable for the production of starch-lipid complexes. Thus, this study investigates the effect of ultrasound treatment on the formation of starch-lipid complexes and their impact on the quality of rice made from five types of Japonica rice in China. These five types of Japonica rice have more cultivation area and consumption level in China, and they are widely popular. They also have different ratios of amylose and amylopectin. Through this study, rice with a low glycemic index, effective maintenance of postprandial blood glucose stability, and good taste quality can be obtained.