Dynamic changes of proton populations in potato flours during fermentation and their relationship with digestibility and functional properties

The effects of fermentation on the dynamic state of proton populations, digestibility, and functional properties of potato flours prepared from Atlantic and Kexin No. 1 were investigated. Depending on the changes in moisture content and digestibility of potato flours during fermentation, three proton populations were distinguished. Populations P-21 and P-22 of fermented potato flours gradually increased during fermentation, resistant starch content, swelling power, and pasting properties also increased, whereas moisture content, digestible starch content, and water solubility index gradually decreased. Correlation analyses showed that populations P-21 and P-22 had significantly positive correlations with resistant starch content, swelling power, peak viscosity, and breakdown viscosity of fermented potato flours (p < 0.05), while population P-23 had significantly positive correlations with moisture content, digestible starch content, and water solubility index (p < 0.001). The results implied that the proton population was an important factor influencing the digestibility and functional properties of fermented potato flours.