-The objective of this work was to evaluate the visual and chemical quality of tangerines after mechanical damage by impacts. The tangerine cultivars Montenegrina and Rainha were submitted to different degrees of impact and evaluated for decay and oleocellosis, loss of fresh weight, total soluble solids, total titratable acidity and ascorbic acid degradation, as well as for epicarp color changes. Experiments with three replicates and experimental units of six fruit for each cultivar were done in a completely randomized design. Impact produced qualitative internal and minor external changes on tangerines. The main modifi cations produced by impact on the fruit were losses of citric acid and soluble solids, which increased the solid:acid ratio, and losses of ascorbic acid. 'Montenegrina' tangerines are more susceptible to internal quality damage than 'Rainha'.Index terms: Citrus deliciosa, fl avor loss, nutritional loss, physical damage. Danos mecânicos na pós-colheita afetam qualidade de frutos de tangerinas 'Montenegrina' e 'Rainha'Resumo -O objetivo deste trabalho foi avaliar a qualidade visual e química de tangerinas, após danos mecânicos por impacto. As cultivares de tangerina 'Montenegrina' e 'Rainha' foram submetidas a diferentes graus de impacto e avaliadas quanto à oleocelose e podridão, perda de massa de matéria fresca, sólidos solúveis totais, acidez total titulável e degradação do ácido ascórbico, bem como mudanças na cor do epicarpo. Os experimentos consistiram de três repetições de seis frutos, para cada cultivar, e o delineamento foi inteiramente casualizado. Os impactos produziram mudanças qualitativas internas nas tangerinas, mas as mudanças externas foram mínimas. As modifi cações mais importantes, produzidas por impacto nas frutas, foram as perdas de ácido cítrico e sólidos solúveis, o que aumentou a relação sólidos:acidez, e as perdas de ácido ascórbico. A tangerina da cultivar Montenegrina é mais susceptível a danos qualitativos internos do que a 'Rainha'.Termos para indexação: Citrus deliciosa, perda de sabor, perda nutricional, dano físico.

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In Senegal, post-harvest losses caused by groundnut bruchid, Caryedon serratus, are detrimental to farmers and affect national economy. The objectivie of this study was to investigate the effectiveness of silica nanoparticles against C. serratus. Silica nanoparticles were synthesized by reverse microemulsion and different concentrations (0.17, 0.33, 0.67 and 1.7 mg kg-1) were tested on mortality and fecundity of C. serratus. Result showed that silica nanoparticles had high toxicity on C. serratus adults. Adults' mortality increased with concentrations and time of exposure to each concentration. Up to 100% mortality was observed with high concentrations (0.67 and 1.7 mg kg-1) after 6 and 7 days post exposure, respectively. Additionally, fecundity potential of C. serratus was significantly (P<0.05) reduced by silica nanoparticles. Results of this study clearly demonstrated that silica nanoparticles can be used as a valuable tool for the control of C. serratus in stored groundnut (Arachis hypogaea L.) .

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