Morphological, histological, chemical and functional characterization of Prosopis alba flours of different particle sizes.

Prosopis alba (algarrobo) flours are traditional food resources from Argentina. The aim of this work was to determine the effect of particle sizes of Prosopis flour on its chemical composition and functional properties. Flours were obtained by mechanical methods (F1 to F4, >840, 840 to 500, 500 to 149 and <149 µm, respectively). F1 and F2 contain 40% mesocarp while F3 and F4 show 80 and 90%, respectively. Mesocarp reserve parenchyma is rich in free and bound phenolic compounds, carbohydrates and fibers of the vascular system, CaCO3 crystals, and minerals (Fe, Ca, Mg, K). Apigenin C-glycosides and phenylpropanoids acids were identified in all fractions whereas F4 showed the highest level. All fractions showed functional properties. F3 and F4 showed the highest activity as H2O2 and HO• scavenger. F1 and F2 showed the highest activity as reductor agents and lipoperoxidation inhibitors. Flours with different granulometry may be suitable as functional ingredient or nutraceutical whereas flours with a smaller particle size (F3 and F4) are more interesting as functional ingredients because of their high content of bound phenolic compounds and particle homogeneity and could be used either alone or together.

Morphoanatomical and histochemical characterization of Larrea species from Northwestern of Argentina

Abstract Larrea divaricata Cav., L. cuneifolia Cav. and L. nitida Cav., Zygophyllaceae, are evergreen xerophytic shrubs occurring in Northwestern Argentina used in traditional medicine. The aim of this work was to characterize the morphology, anatomy and histochemistry of the vegetative organs of three Larrea species by light and scanning electron microscopy in order to provide supporting data for their correct identification and to determine the site of synthesis and accumulation of its main active compounds. The shape, number and percentage of coalescence of leaflets, presence or absence of mucrones and rachis and the shape of the stipules represented the main botanical differences between the studied Larrea species. Anatomically three species presented amphystomatic leaves, with thick resinous slightly striated cuticle with resinous deposits, polygonal epidermal cells with straight anticlinal walls, ciclocytic, brachy-paracytic and paracytic stomatal types, non-glandular trichomes and isolateral mesophyll. The position and abundance of the sclerenchyma at the mid vein and petiole transection allows the differentiation of the three species, been more abundant in L. cuneifolia. Secondary phloem and parenchyma cells presented abundant calcium oxalate druses and solitary rhomboidal crystals. Epidermal cells and cuticle layer of leaflets and stipules of the three species presented amber resin deposits and content which stained positively for polysaccharides, phenolic compounds, flavonoids and tannins, while mesophyll palisade cells showed small refracting droplets stained positively for lipophilic substances.