2022 Volume 23 Issue 4 Pages 131-137
This study demonstrates correlations between water activity (aw) and albumin denaturation temperature (ADT), and the density of intermolecular hydrogen bonding of free water (Doh(w-s)) in hydrogenated starch hydrolysate (HSH) solutions. We first measured the osmotic concentration (c) of sugar solutions of known molecular weight (MW) and found a significant linear relationship between 1/c and MW (r2=0.998, P<0.0001). Next, Doh(w-s) was calculated using the MW estimated from this relationship and the glass transition temperature, and the relationships between Doh(w-s) and aw, and between Doh(w-s) and ADT were clarified. Linear regression analysis revealed a significant and positive linear relationship between Doh(w-s) and aw (r2>0.900, P<0.0001), and a significant and negative linear relationship between Doh(w-s) and ADT (r2>0.900, P<0.0001). The findings also showed that the ADT of the HSH solutions could be estimated using aw, which is easy to measure, and that the Spearman correlation between the measured and estimated ADT is significant (r2=0.930, P=0.00280). The results suggest that the ADT of HSH solutions can be estimated at any HSH concentration and any sugar composition by measuring the aw values of the solutions.