QUALITY AND ELEMENTAL CHARACTERIZATION OF COMMON SPICES OF BANGLADESH USING NUCLEAR REACTOR-BASED NAA AND GAMMA IRRADIATION TECHNIQUES

Abstract

In this study, elemental characterization and gamma irradiation technique for bacterial decontamination of common spices available in Bangladesh were evaluated. Total concentrations of 17 essential and toxic elements (Al, As, Br, Ca, Cd, Cl, Co, Cr, Fe, K, Mn, Na, Ni, Pb,Sc, V and Zn) in spices were determined by research reactor-based neutron activation analysis (NAA) and atomic absorption spectrometry (AAS) techniques. This study indicates that spices are a good source of a combination of the essential elements-Ca, Fe, K, Mn, Na and Zn. This study revealed that concentrations of some toxic elements As, Cd, Cr and Pb in some spices were higher than the WHO/ FAO permissible levels. However, health risks associated with these elements evaluated by dietary intake, target hazard quotient and target carcinogenic risk indices indicate that people would experience no potential risks due to consumption of the spices. This study also evaluated the effect of gamma radiation on the decontamination of the microbial population, physico-chemical, nutritional and sensory quality of spices during storage. Spices were irradiated with gamma doses of 0 (as control), 2, 4, 6, 8 and 10 kGy, packed in the glass vials and then stored at room temperature (22±20C) and different properties were measured after 6 months. In this investigation, major food borne disease-producing organisms like Bacillus, Salmonella and Listeria species were identified in spice samples by molecular approaches. The results of this study indicated that gamma irradiations with increased doses significantly reduce the population of organisms compared to control and optimum gamma irradiation doses (6 kGy for red chili and turmeric; 4 kGy for cumin, coriander, garlic and black pepper; 2 kGy for ginger powder) were identified for decontamination of the microorganisms in the studied spices.