ESR detection of black pepper using standard addition method

ESR techniques for studying the detection of radicals induced in gamma ray irradiated pepper were studied. The representative ESR spectrum of the pepper composed of a sextet centered at g=2.0, a single at the same g-value and a singlet at g=4.0. This reflects the evidence of three independent radicals in the pepper before irradiation. Upon gamma ray irradiation, a new pair of signals appeared. Using standard addition method for solid sample technique we prepared the experimental samples containing 2.0 - 20.0 w/w % irradiated black pepper. The progressive saturation behavior (PSB) at various microwave power levels indicated quite different relaxation behaviors of those signals. For the evaluation of radiation-induced radicals and irradiation effects we proposed a new protocol using the standard addition method. This would be called an advanced protocol for the detection of irradiated black pepper. (author)