Abstract: To improve the eating quality of non-fried buckwheat instant noodles, different types of potato starch (acetylated and native potato starch) were used to partially replace buckwheat flour. By analyzing the texture properties, sensory characteristics, in vitro digestibility, and physicochemical properties of the product, the effects of the two types of starch on the quality of non-fried buckwheat instant noodles were investigated. The results showed that replacement of buckwheat flour with acetylated potato starch (1%, 25%) or with native potato starch (5%, 10%, 15%) improved the texture properties, sensory quality, and microstructure of the product. According to X-ray diffraction patterns, starch-lipid complexes were formed in the samples. The optimal replacement levels of the two starches were different. Likewise, the resulting noodles differed with respect to estimated glycemic index (eGI) and crystallinity. For acetylated potato starch, the optimal replacement level was 2.5%. As its replacement level increased from 0% to 10%, the eGI decreased from 52.13 to 46.48, while the crystallinity increased from 5.45% to 9.74%. For native potato starch, the optimal replacement level was 15%; the eGI increased from 52.13 to 53.98, and the crystallinity from 5.45% to 6.27%. The findings of this study provide a reference for optimizing the formulation of non-fried buckwheat instant noodles. Replacing buckwheat flour with 2.5% acetylated potato starch improved product quality while reducing eGI, whereas replacing it with 15% native potato starch only improved product quality.

Key words: non-fried buckwheat instant noodles; native potato starch; acetated potato starch; in vitro digestion characteristics; eating quality