In the present study, aerial parts of Pterospartum tridentatum plants, collected in three locations in Portugal, at different vegetative stages, were evaluated for their total phenolic content and the antioxidant activity of aqueous extracts. The influence of the seasonal variation in the yield and composition of the extracts was evaluated, in order to select the most appropriate harvest season. Among the populations assayed, the extraction yields have some differences with the harvest period but the highest yield extraction was obtained in the flowering season, using flowers (19.4g/100g plant dry mass) and the lowest extraction yield was also obtained in the same period but using stems. The antioxidant activity of the solid extracts of Pterospartum tridentatum aerial parts, was determined by the radical scavenging activity method using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The greatest DPPH radical scavenging activity was observed in the flowering period (3.6 mMTrolox/Kg dry mater), but no significant differences for the dormancy period. According to these results, we can choose the harvest season more favorable. The total phenolic content (TP) of the extracts was evaluated by measuring the absorbance at 280nm and the values ranged from 270.7 to 402.9mg gallic acid equivalents per g dry matter. The vegetative stage did not influence this total phenolic content. From preliminary experiments, it is also anticipated a significant antimicrobial activity of the solid extracts against bacteria and fungus

Fruit juice does not have the same nutritional value as fresh fruit with regards to the vitamin, mineral and dietary fibre contents and the antioxidant properties. However, it can be part of a healthy diet if it is produced with the minimal addition of sugar. This study aimed to evaluate the performance of the FTIR-ATR technique to discriminate the authenticity (concerning the addition of other pulps) and amount of sugar in peach nectars. This technique is usually used in food analysis because it does not require sample preparation, is quick and allows for the determination of several parameters with a single sample aliquot. The nutritional information provided on the labels of 69 samples of 23 different brands of commercial peach juice, was analysed. The differences in the nutritional composition and in the ingredients were determined according to an analysis of the labels. The largest differences observed between the samples were the sugar contents, the percentages of pulp and the addition of other pulps. All samples were analysed by FTIR-ATR equipped with a controlled temperature flow-through cell. The spectral multivariate analysis suggested it was possible to identify differences in the amount of sugar present and identify the presence of fruit pulps other than peach.