Preparation and characterization of new reference material for inorganic analysis of pumpkin seed flour - An interlaboratory program.

This work describes preparing a certified reference material for pumpkin seed flour for use in inorganic analyses of vegetable foods. The elements studied were potassium, magnesium, phosphorus, zinc, copper, iron, manganese, and calcium. The ISO Guides were employed in the homogeneity and stability tests, interlaboratory program, and assignment of uncertainty value.

Multivariate analysis of the composition of bioactive in tea of the species Camellia sinensis.

This study deals with the development of a separation and quantification method by high performance liquid chromatography with a diode array detector (HPLC- DAD), for the determination of phenolic acids and methylxanthines in tea (Camellia Sinensis) samples. Six phenolic acids (Gallic, trans-cinnamic, caffeic, ferulic and p-coumaric acids) and two methylxanthines (caffeine, theobromine) were studied, according to the principles of green chemistry, with the goal of comparing teas with different processing level. After development and validation of separation and extraction methods was applied to 11 extracts obtained by infusions of green and black tea samples in commercial areas of the city of Salvador-BA, showing feasible and efficient.