Denaturation temperature of dried lens tissue rises with trehalose pretreatment

Trehalose, a non-reducing disaccharide, is known as an exceptional protector against desiccation and heat stress. Differential scanning calorimetry is a simple tool to determine thermodynamic parameters concerning the structural state of proteins. In this study, we measured denaturation temperature (or melting temperature) of dried lenses to know the effect of trehalose pretreatment. Isolated porcine lenses were incubated in wells without any solution or with saline, 100 mM trehalose, or 100 mM cyclic tetrasaccharide in saline at room temperature for 150 min. The solutions were removed, and all lens samples were dried at room temperature and in room humidity until the weight showed no change. The nucleus of each sample was taken out and placed on a measuring platform for differential scanning calorimetry. The denaturation temperature of the dried lenses significantly rose by about 10 °C with 100 mM trehalose pretreatment, compared to no pretreatment, pretreatment with saline or 100 mM cyclic tetrasaccharide (P < 0.05, analysis of variance, P < 0.05, Student–Newman–Keuls tests, n = 7). The denaturation temperature showed no difference among the dried lenses with no pretreatment or pretreatment by saline or cyclic tetrasaccharide. In conclusion, pretreatment with trehalose raises denaturation temperature of the dried porcine lens. Trehalose might stabilize the dried tissue structure to get a higher denaturation temperature.     

A Study on the Preparation,Structure, and Properties of Microcrystalline Cellulose

Abstract

The preparation, structure, and properties of microcrystalline cellulose (MCC) from rice straw were investigated by IR, x-ray, viscometry, polarizing microscope, SEM, etc. The results are as follows:

1. The leveling-off degree of polymerization (LODP) obtained from rice straw is about 80–150. The dimensions of MCC granules are 20–30 μm length, 0.5–0.8 μm thick, and the crystallinity is about 80%.

2. The aqueous suspension of a certain concentration of MCC can form a gel under the effect of shear force. The viscosity of MCC gel increased with an increasing content of MCC in water. A sharper increase of viscosity occurred in the 3–6% range.

3. The addition of one or two valence salts into the MCC gel increased the viscosity.

4. The viscosity of MCC gel has its maximum value at pH 8.

5. The MCC gel as an emulsifying agent can form a stable emulsion in the oil/water system when the ratio of oil/water is below 6/4.