Two sample preparation methods for the determination of minerals from grape juice were investigated for the purpose of methodological evaluation: using hydrochloric acid by shaking, and digestion in closed system, under pressure, using microwave power. The concentrations of minerals were evaluated by the technique of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The minerals contents of Ca, P, Na, K, Mg, Zn, Fe, Mn, and Cu did not differ significantly at the level of 5% (it Tests F) for both methodologies used. The precision and accuracy of both methodologies were evaluated using grape juice. The extraction methodology with hydrochloric acid was used for the determination of mineral amounts in processed juices from pineapple, acerola, cashew, guava, mango, passion fruit and grape. To enhance the interpretation of the amounts of minerals, from a nutritional point of view, techniques of Principal Components Analysis (PCA) and Hierarchic Cluster Analysis were used (HCA).
juice; mineral; multivariate analysis; ICP-OES
