Abstract
Dietary fibers and sodium hyaluronate were evaluated for their optical response to a near-infrared beam, P value, which is defined as 1-r, where r is the ratio of the reflection at the measuring wavelength against that at the reference wavelength. The P value rises with increasing water activity (aw) and water content, giving a high correlation coefficient (0.9<) for linear regression with aw or water content when measuring at 1927 nm. The P value per water content in the Guggenheim Anderson and DeBoer (GAB) monolayer water content region appeared to be greater than the value in the multilayer region. This indicates that the water molecule of the monolayer differed from that of multilayers in its response to near-infrared radiation.
Over the whole water content region around and below the multilayer, the logarithm of water content was a potent partner for linear regression with the P value for evaluating the water content of a new dietary fiber or sodium hyaluronate.
