Thermal Behavior of Albumin Gel in Low Water Content

Abstract

In the differential scanning calorimetry (DSC), it was found that the transition behavior of egg-white gel is complicated in low water contents (w c = w water / w dried gel ) ranging from 0.1 to 1.8. The thermogram shows a glass transition and peaks related to the melting and recrystallization of water. In the present study, the sol-gel transition behavior of albumin of chicken egg in low water contents (w c = 0.19-3.24) was studied by DSC. Moreover, the thermal behaviors of the gels were intensively studied. In a sol-gel transition process, four endothermic peaks were observed. The peak temperatures are increased as the water content w c is reduced (w c < 1). The thermal behavior of albumin gel showed complicated behavior similar to the egg-white gel. Amount of free water (which is frozen at 0 o C) in the gel is estimated from the thermogram.

Thermal Behavior of Bio-related Material Gel in Low Water Content

“…We carried out the dynamic viscoelastic measurements, in order to elucidate the mechanical behavior of NIPA gels in low water content below freezing point [14]. The transition point observed by the dynamic viscoelastic measurements corresponds well to the results of DSC measurements.…”

“…We have already reported the heat of fusion of water in NIPA gels as shown in figure 6(b) [14]. In this case, the free water disappears at w c = 0.9, and the heat of fusion fit on the line parallel to the theoretical line up to w c = 2, which is different from the case of the egg-white.…”

“…The solid line is the theoretical line of the heat of fusion change when it is assumed that all the water in the sample freezes around 0 o C into normal ice. The broken line is parallel to the theoretical line [14].…”