Gamma radiation influence in physical and chemical characteristics of Bacaba Oil (Oenocarpus bacaba Mart.)

The bacaba (Oenocarpus bacaba Mart.) is a fruit originating from the Amazon forest, and its oil has similarity to the fatty acid composition of olive oil. The objective of this study was to evaluate the quality of bacaba oil submitted to gamma radiation in the of 5, 10 and 15 kGy. The extracted oil was irradiated at doses of 5, 10 and 15 kGy, and then the physical and chemical analysis were carried out: acid value, peroxide value, iodine value, refractive index, specific gravity, saponification value, coefficient specific extinction at 232 and 270 nm and color. Was possible to evidence that radiation promoted decrease in acidity of the oil 26.67%, 27.27% and 9.09%, respectively, at the doses of 5, 10 and 15 kGy, in relation to oil which has not gone through the process (standard). The values of specific gravity, refractive index and saponification value, have not changed, but the result of peroxides were significantly affected, increasing by 51.99%, 100.44% and 89.40% values relative to the standard. It was also observed a significant increase in K232 and K270 values, suggesting increased oxidation products, conjugated dienes and trienes. The oil color has been affected by the doses, generating a product with a more yellowish color and increased brightness. That way, from the analysis, it concluded that the use of gamma radiation at the doses used were not sufficient to make it, in the short term, unsafe for consumption, but changed substantially oil color. (author)