Individual or mixing extrusion of Tartary buckwheat and adzuki bean: Effect on quality properties and starch digestibility of instant powder

Zhuo Zhang; Yongqiang Liang; Liang Zou; Yunan Xu; Mengzhuo Li; Bao Xing; Manli Zhu; Yichen Hu; Guixing Ren; Lizhen Zhang; Peiyou Qin

doi:10.3389/fnut.2023.1113327

Individual or mixing extrusion of Tartary buckwheat and adzuki bean: Effect on quality properties and starch digestibility of instant powder

Front Nutr. 2023 Mar 21:10:1113327. doi: 10.3389/fnut.2023.1113327. eCollection 2023.

Authors

Zhuo Zhang^{1

2}, Yongqiang Liang^{1

2}, Liang Zou³, Yunan Xu⁴, Mengzhuo Li², Bao Xing^{1

2}, Manli Zhu^{1

2}, Yichen Hu³, Guixing Ren^{2

3}, Lizhen Zhang¹, Peiyou Qin²

Affiliations

¹ Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, School of Life Science, Shanxi University, Taiyuan, China.
² Key Laboratory of Quality Evaluation and Nutrition Health of Agro-Products, Ministry of Agriculture and Rural Affairs, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China.
³ Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, Sichuan Engineering and Technology Research Center of Coarse Cereal Industrialization, School of Food and Biological Engineering, Chengdu University, Chengdu, China.
⁴ Seed Administration Station of Shijiazhuang, Shijiazhuang, China.

Abstract

Introduction: Tartary buckwheat and adzuki bean, which are classified as coarse grain, has attracted increasing attention as potential functional ingredient or food source because of their high levels of bioactive components and various health benefits.

Methods: This work investigated the effect of two different extrusion modes including individual extrusion and mixing extrusion on the phytochemical compositions, physicochemical properties and in vitro starch digestibility of instant powder which consists mainly of Tartary buckwheat and adzuki bean flour.

Results: Compared to mixing extrusion, instant powder obtained with individual extrusion retained higher levels of protein, resistant starch, polyphenols, flavonoids and lower gelatinization degree and estimated glycemic index. The α-glucosidase inhibitory activity (35.45%) of the instant powder obtained with individual extrusion was stronger than that obtained with mixing extrusion (26.58%). Lower levels of digestibility (39.65%) and slower digestion rate coefficient (0.25 min^-1) were observed in the instant powder obtained with individual extrusion than in mixing extrusion (50.40%, 0.40 min^-1) by logarithm-of-slope analysis. Moreover, two extrusion modes had no significant impact on the sensory quality of instant powder. Correlation analysis showed that the flavonoids were significantly correlated with physicochemical properties and starch digestibility of the instant powder.

Discussion: These findings suggest that the instant powder obtained with individual extrusion could be used as an ideal functional food resource with anti-diabetic potential.

Keywords: Tartary buckwheat; adzuki bean; extrusion; flavonoids; in vitro starch digestibility; instant powder; α-glucosidase inhibitory activity.