GINGEROL DECREASES AFTER PROCESSING AND STORAGE OF GINGER

Fresh cooked ginger and processed ginger products were extracted with methanol and analyzed by HPLC to study changes in the levels of [6]-, [8]-, and [10]-gingerols after the products had been cooked and processed, and during storage of the products. Sensory tests evaluated the intensity of pungency in different processed products. Cooking and processing of paste and senbei decreased (p less than or equal to 0.05) gingerol levels, but blanching and freeze-drying had no effect. Gingerols in all products degraded gradually with storage. Ginger powder had a lower degradation rate than the paste stored at 4 degrees C. Likewise, ginger senbei was more stable than ginger powder stored at room temperature (approximate to 23 degrees C).