The effects of drying methods and harvest season on piperine, essential oil composition, and multi-elemental composition of black pepper.

This study aimed to evaluate the piperine content, essential oil composition, and multi-elemental composition of black pepper samples according to different drying methods and harvest season. Differences in essential oil composition and B, Ca, K, Mg, and S were noted according to sampling campaign, indicating secondary metabolism plant alterations. Mechanical drying resulted in essential oil composition changes due to high temperature exposure during processing. Increases in Fe and Cr contents when employing mechanical dryers with direct heating were also observed, due to direct contact with metallic structures and particulate material from the burning process. The As and Pb contents of several samples were higher than the maximum permissible limits, reaching 0.46 and 0.56 mg kg-1, respectively, thus surpassing legislation safety limitations for human consumption.

Multi-element rice grains analysis by ICP OES and classification by processing types.

As major food staple, rice (Oryza sativa L.) is cultivated in irrigated fields absorbing widely trace elements wich may or may not migrate during processing types. Thus, we aimed to evaluate five national rice brands found in local market, in order to verify concentration of elements As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sb, Se, Sn, Sr, V, Tl and Zn, presenting the differences and migration patterns between brown, parboiled and polished rice for each brand. Data were evaluated using ANOVA, post-hoc Tukey and PCA. The two major components presented 94.33% variance, indicating strong differentiation in samples by their processing types from their mineral composition. K is widely distributed over the grain, Mg, Fe and Ba are more distributed in the outer layers being more susceptible to loss, and Ca, Sr and Zn are more sensitive to the parboiling hydrothermal process.