Infrared Spectroscopic Tracing of Hydration/Dehydration Processes of Dry Yeast Cells

Hydration/dehydration processes of dry yeast cells have been monitored by infrared micro-spectroscopy under controlled relative humidity and temperature. Changes in IR absorption bands of water, amides (proteins) and lipids were analyzed during increasing/decreasing RH at 35°C and during heating at 60°C. While water and protein followed RH conditions at 35°C, they show exponential decreases with similar rate constants at 60°C.