Antioxidant properties and digestion behavior of polysaccharides from Chinese yam fermented by Saccharomyces boulardii

Impacts of wheat flour substituted with various levels of Chinese yam (Dioscorea opposita Thunb.) flour (from 0% to 25%) on the dough rheological characteristics, gluten structure, baking performance, and antioxidant properties of bread were investigated. The water absorption increased significantly (p < 0.05), while development time and stability decreased remarkably (p < 0.05) as the proportion of yam flour increased. SEM results indicated that the addition of yam flour destroyed the gluten network structure in the dough. Fourier Transform Infrared Spectroscopy (FTIR) spectra showed that addition of yam flour decreased the content of α-helix and β-sheet in gluten. With the increase in the proportion of yam flour, the specific volume and overall acceptability decreased (p < 0.05) whereas the total phenolics content (TPC), polysaccharides content, total flavonoids content (TFC), allantoin content, The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capability, fractal dimension, and hardness increased (p < 0.05). Overall, breads made of wheat flour replacement with no more than 15% Guihuai number 2 yam flour were of a high quality and had more antioxidant properties. These showed that Guihuai number 2 had broad application prospects in baked products.

Download Full-text

Comparison of different drying methods on Chinese yam: changes in physicochemical properties, bioactive components, antioxidant properties and microstructure

International Journal of Food Engineering ◽

10.1515/ijfe-2020-0009 ◽

2020 ◽

Vol 16 (9) ◽

Author(s):

Qing-ming Li ◽

Lei Xia ◽

Feng Wang ◽

Shi-yin Guo ◽

Jin-hao Zou ◽

...

Keyword(s):

Antioxidant Properties ◽

Principal Component ◽

Far Infrared ◽

Pasting Properties ◽

Microwave Drying ◽

Vacuum Drying ◽

Drying Methods ◽

Bioactive Components ◽

Chinese Yam

AbstractIn the present study, we aimed to assess the effects of hot air drying (HAD), microwave drying (MD), far-infrared radiation drying (FIRD), vacuum drying (VD) and microwave vacuum drying (MVD) on the quality, bioactive components, pasting properties, antioxidant properties, in vitro digestibility and microstructure of Chinese yam. Results showed that these drying processes greatly affected the quality of yam (p<0.05). MVD yam had a good color and its bioactive components were maintained. VD and MVD samples had the lowest setback value and breakdown value, indicating that they had a better cold paste stability and hot paste stability. In addition, MVD samples had a uniform honeycomb microscopic pore structure, and thus the rehydration rate of MVD samples was significantly higher compared with the other drying approaches. When five differently dried samples were compared by principal component analysis (PCA), the MVD samples were found to have the highest comprehensive principal component values. Therefore, based on our results, MVD was an ideal approach to dry high-quality yam.

Download Full-text