Effects of in vitro digestion and fecal fermentation on physico-chemical properties and metabolic behavior of polysaccharides from Clitocybe squamulosa

Xueran Geng; Dongdong Guo; Tergun Bau; Jiayu Lei; Lijing Xu; Yanfen Cheng; Cuiping Feng; Junlong Meng; Mingchang Chang

doi:10.1016/j.fochx.2023.100644

Effects of in vitro digestion and fecal fermentation on physico-chemical properties and metabolic behavior of polysaccharides from Clitocybe squamulosa

Food Chem X. 2023 Mar 15:18:100644. doi: 10.1016/j.fochx.2023.100644. eCollection 2023 Jun 30.

Authors

Xueran Geng^{1

2}, Dongdong Guo¹, Tergun Bau³, Jiayu Lei¹, Lijing Xu^{1

2}, Yanfen Cheng^{1

2}, Cuiping Feng^{1

2}, Junlong Meng^{1

4}, Mingchang Chang^{1

4}

Affiliations

¹ College of Food Science and Engineering, Shanxi Agricultural University, Taigu, Shanxi 030801, China.
² Shanxi Key Laboratory of Edible Fungi for Loess Plateau, Taigu, Shanxi 030801, China.
³ Inner Mongolia Agriculture, Animal Husbandry, Fishery and Biology Experiment Research Centre, Inner Mongolia Agricultural University, Hohhot 010019, China.
⁴ Shanxi Engineering Research Center of Edible Fungi, Taigu, Shanxi 030801, China.

Abstract

The aim of this study was to establish a human digestion model in vitro to explore the degradation characteristics of a novel high-purity polysaccharide from Clitocybe squamulosa (CSFP2). The results showed that the content of reducing sugars (C_R ) of CSFP2 increased from 0.13 to 0.23 mg/mL, the molecular weight (Mw) of CSFP2 decreased significantly during the saliva-gastrointestinal digestion. The constituent monosaccharides of CSFP2, including galactose, glucose, and mannose, were stable during in vitro digestion, but their molar ratios were changed from 0.023: 0.737: 0.234 to 0.496: 0.478: 0.027. The surface of CSFP2 changes from a rough flaky structure to a scattered flocculent or rod-shaped structure after the gastrointestinal digestion. However, the apparent viscosity of CSFP2 was overall stable during in vitro digestion. Moreover, CSFP2 still maintains its strong antioxidant capacity after saliva-gastrointestinal digestion. The results showed that CSFP2 can be partially decomposed during digestion. Meanwhile, some physico-chemical properties of the fermentation broth containing CSFP2 changed significantly after gut microbiota fermentation. For example, the pH value (from 8.46 to 4.72) decreased significantly (p < 0.05) after 48 h of fermentation. the OD ₆₀₀ value increased first and then decreased (from 2.00 to 2.68 to 1.32) during 48-h fermentation. In addition, CSFP2 could also increase the amounts of short-chain fatty acids (SCFAs) (from 5.5 to 37.15 mmol/L) during fermentation (in particular, acetic acid, propionic acid, and butyric acid). Furthermore, the relative abundances of Bacteriodes, Bifidobacterium, Catenibacterium, Lachnospiraceae_NK4A136_group, Megasphaera, Prevotella, Megamonas, and Lactobacillus at genus level were markedly increased with the intervention of CSFP2. These results provided a theoretical basis for the further development of functional foods related to CSFP2.

Keywords: 2,2-Diphenyl-1-picrylhydrazyl (PubChem CID 2735032); 4-Methylumbelliferyl alpha-d-glucopyranoside; Acarbose (PubChem CID 444254); Alpha-glucosidase substrate (PubChem CID 87330); Ascorbic Acid (PubChem CID 54670067); Bile acid (PubChem CID 439520); Clitocybe squamulosa polysaccharides; Fecal fermentation; Gut microbiota; Hemin chloride (PubChem CID 53627695); In vitro digestion; Inulin (PubChem CID 24763); Physico-chemical properties.