**4. Conclusions**

In this study, we utilized three types of PPC with different DPs (6.39 ± 0.13, 8.21 ± 0.76, and 9.92 ± 0.21, respectively) to research the influence of PPC on physicochemical and in vitro digestion properties for better application of PPC in starchy food. PPC enhanced the thermal stability and delayed starch gelatinization of PoS. It pronouncedly affected the elastic properties, instead of the viscous properties, of PoS pasting. The reduced thixotropy indicated that the relative stability and uniformity of the starch gel structure was enhanced, showing better gelling properties. Starch digestion and retrogradation could be restrained by PPCs with different DPs in varying degrees. Among the three, PPCs with a lower DP more evidently influenced starch gelling performance, whereas larger PPC molecules exhibited a greater impact on starch long-term retrogradation and digestive properties. This might be attributed to the different type of starch chains combined with PPCs of different DP. The findings of the present study may render a beneficial recommendation for the application of PPC to modify gelatinization, thermodynamic, rheological, and digestive characteristics of PoS-based foods.

**Author Contributions:** Conceptualization, J.X., T.D., J.C., C.L., and T.L.; methodology, J.X. and T.D.; data curation, J.X., and T.D.; writing–original draft preparation, J.X., T.D., and J.C.; writing–review and editing, J.X., T.D., and J.C.; visualization, X.H., and X.S.; supervision, J.X., C.L., and T.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the China National Natural Science Foundation (Grant No. 31760441 and 32060524), the China Postdoctoral Science Foundation (Grant No. 2020M6832211), and the Postdoctoral Foundation of Guangxi Academy of Agricultural Sciences (Grant No. 2020037).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Data are contained within the article.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


**Zixin Yang 1,†, Ting Huang 1,†, Ping Li 2, Jian Ai 1,3, Jiaxin Liu 1, Weibin Bai <sup>2</sup> and Lingmin Tian 1,\***


**Abstract:** The interactions between cell-wall polysaccharides and polyphenols in the gastrointestinal tract have attracted extensive attention. We hypothesized that dietary fiber modulates the fermentation patterns of cyanidin-3-*O*-glucoside (C3G) in a fiber-type-dependent manner. In the present study, the effects of four dietary fibers (fructose-oligosaccharides, pectin, β-glucan and arabinoxylan) on the modulation of C3G fermentation patterns were investigated through in vitro fermentation inoculated with human feces. The changes in gas volume, pH, total carbohydrate content, metabolites of C3G, antioxidant activity, and microbial community distribution during in vitro fermentation were analyzed. After 24 h of fermentation, the gas volume and total carbohydrate contents of the four dietary-fiber-supplemented groups respectively increased and decreased to varying degrees. The results showed that the C3G metabolites after in vitro fermentation mainly included cyanidin, protocatechuic acid, 2,4,6-trihydroxybenzoic acid, and 2,4,6-trihydroxybenzaldehyde. Supplementation of dietary fibers changed the proportions of C3G metabolites depending on the structures. Dietary fibers increased the production of short-chain fatty acids and the relative abundance of gut microbiota *Bifidobacterium* and *Lactobacillus*, thus potentially maintaining colonic health to a certain extent. In conclusion, the used dietary fibers modulate the fermentation patterns of C3G in a fiber-type-dependent manner.

**Keywords:** dietary fiber; fermentation patterns; cyanidin-3-*O*-glucoside; gut microbiota
