VISCOSITY OF ALKALINE SUSPENSIONS OF GROUND BLACK-AND-WHITE PEPPER SAMPLES - AN INDICATION OR AN IDENTIFICATION OF HIGH-DOSE RADIATION TREATMENT

Forty-nine pepper samples were taken from retail food stores of differ ent cities in Germany. Most of the black and all white pepper samples showed high viscosity values after jellification in alkaline solution. After irradiation with a gamma-ray dose of 6 kGy, viscosity was large ly reduced in each case. Some black pepper samples showed a low viscos ity level already before irradiation. However, thermoluminescence anal ysis did not reveal any sign for irradiation treatment prior to examin ation. Furthermore, the low viscosity level of these samples could not be correlated with a low starch content. It is concluded that the vis cosity levels of irradiated white pepper samples clearly reveal high d ose irradiation treatment. In case of black peppers it is judged that the method can be used to screen for irradiated samples since it is fa st, easy and cheap. However, a positive result should be confirmed by another technique, e.g. thermoluminescence.