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-Introduction. Apples have been part of the human diet since ancient times and are one of the most commonly consumed fruit worldwide, rich in phenolic compounds. Phenolics are naturally occurring non-nutritive plant compounds, possessing several health benefits. The effect of storage conditions on phenolics concentrations and on the antioxidant activity of apple juice and pomace was studied. Materials and Methods. Experiments were carried out with two apple varieties, an ancient Tuscan variety, Panaia-red, and a commercial variety, Golden Delicious. The antioxidant activity was assessed by means of two different in vitro tests: scavenging of DPPH• radical, and inhibition of tyrosine nitration mediated by peroxynitrite (ONOO − ). Analyses of juices were carried out immediately after production and after 2 weeks storage in 3 different temperature conditions: 4 • C, -20 • C and room temperature after pasteurisation. Results and discussion. Highly significant differences were recorded between the two varieties, the Panaia-red juice having a higher concentration of phenolic compounds and a higher antioxidant activity. During apple juice storage, phenolic compound concentrations and antioxidant capacity remained quite stable. A correlation between antioxidant activity and phenolic concentration was observed (0.69 r 0.97). Conclusion. The effects of a short storage time and different conditions of storage on the phenolic concentration and antioxidant activity seem to be less relevant than variety effects. The apple pomace revealed an amount of phenolic compounds, ranging from 6.8 to 15.5 mg GAE 100 g −1 DM of total polyphenols, which paves the way for their use as ingredients in foods lacking in polyphenols.Keywords: Italy / apple / Malus domestica / DPPH• radical / phenolics / shelf-life / tyrosine nitration Résumé -Profil phénolique et activité anti-oxydante du jus et du marc de pomme : effets des conditions de stockage. Introduction. Depuis la plus haute Antiquité, les pommes ont fait partie de l'alimentation humaine et constituent l'un des fruits les plus consommés au monde, et riches en composés phénoliques. Les composés phénoliques sont des composés végétaux naturels non nutritifs mais possédant de nombreuses propriétés nutritionnelles bénéfiques pour la santé. L'étude porte sur l'effet des conditions de stockage sur la concentration de ces composés phénoliques et sur l'activité anti-oxydante du jus de pomme et du marc. Matériel et méthodes. Les expériences ont été réalisées avec deux variétés de pomme, une variété ancienne toscane, Panaia-rouge, et une variété commerciale, Golden Delicious. L'activité anti-oxydante a été évaluée au moyen de deux tests in vitro : la réactivité avec le radical libre DPPH•, et l'inhibition de la nitration de la tyrosine induite par le peroxynitrite (ONOO − ). Les analyses de jus ont été effectuées immédiatement après production et après 2 semaines de stockage à températures différentes : +4 • C, -20 • C, ou à température ambiante après pasteurisation. Résultats et discussi...

Seedlings of the obligate halophytes Sesuvium portulacastrum L. and Tecticornia indica (Willd.) subsp. indica were grown with 0, 200, or 400 mM NaCl for 13 weeks to investigate whether salt tolerance was related to maintenance of adequate photosynthetic activity and pigment equipment. Both species showed growth optimum at 200 mM NaCl and better tissue hydration under salinity but different photosynthetic response to salinity. CO2 assimilation rate and stomatal conductance of S. portulacastrum were highest at 200 mM NaCl, while in T. indica they decreased with salinity. Pigment content increased under salinity in both species. The de-epoxidation state in S. portulacastrum suggests the need for energy dissipation at 400 mM NaCl, while its salt-induced decline in T. indica, despite the reduced photochemistry, suggests the involvement of adaptive mechanisms other than the xanthophyll cycle

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Antioxidant phytochemicals in fruits and vegetables of a vegetarian diet may account for the reduced risk of aging and stress oxidative associated diseases. In this study, a simple, rapid and accurate new bioassay for the determination of the antioxidant activity of purified or crude plant extracts and thier interactions is described, based on the fluorimetric determination of thiobarbituric acid reactive substances (TBARS) released by UV-B radiated red blood cell (RBC) ghosts. Pure resveratrol, white and red wine and pomegranate juice (PJ) were used as antioxidant source to test the biological method. TBARS production is a function of radiation time, the number of RBC ghosts in the radiated sample and the loaded antioxidant. The antioxidant activity of resveratrol was detected at a submicromolar concentration range [0.02 μg/mL-0.1 μmol/L]. The activity of red wine was almost 10 times higher than that of white wine, and PJ juice had the highest activity. Submaximal protective effects of PJ and red wine were additive.

Based on these results, post-harvest UV-B treatment may be considered a promising tool to improve shelf-life and quality of peach fruit.