ABSTRACT We aimed to verify the morphophysiological changes in jaboticaba tree (Plinia peruviana (Poir.) Govaerts) saplings under shade gradient to improve knowledge on the appropriate light environmental conditions for the saplings production and field homogeneous or intercropping cultivation of this species. The saplings were grown under full sun and artificial shade levels (30%, 50%, and 80%). Growth, photosynthetic pigments, gas exchanges, chlorophyll fluorescence, and leaf anatomy characters were evaluated. Our results showed that jaboticaba tree saplings growth was improved under full sun and 30% of shade. Under 50% and 80% shade the saplings demonstrate phenotypic plasticity, such as larger and thinner leaves. Chlorophyll fluorescence, chlorophyll content, and quantum yield of photosystem II were higher under higher shade level, but the CO2 assimilation rate was not different between light conditions. These changes are typically found in shade-tolerant plants and is related to perform photosynthesis more efficiently in highly variable light conditions. Despite that, we recommend that cultivation be carried out under full sun or up to 30% shade to maximize jaboticaba tree saplings growth in nurseries and orchards.

RESUMO: O objetivo deste trabalho foi determinar a composição centesimal e a cinética de secagem de pinhões doces em comparação com pinhões típicos de Araucaria angustifolia. Este estudo baseia-se na composição centesimal, cor e duração da secagem dos pinhões de ambos os tipos e na influência da temperatura e da geometria de corte no processo de desidratação. Os pinhões doces apresentaram menor valor calorífico e conteúdo de carboidratos. Por outro lado, apresentaram maior teor de lipídios, fibras alimentares, proteínas e cinzas quando comparados aos pinhões típicos. A cor dos pinhões doces é rosa claro, enquanto o pinhão típico é branco amarelado. Os pinhões doces também são mais macios. A cinética de secagem das sementes se enquadra bem nos modelos logístico e de Thompson. Para acelerar as taxas de secagem, recomendamos fatiar os pinhões em seções finas e secá-los a temperaturas de 60 °C para pinhões típicos e 70 °C para pinhões doces.

ABSTRACT: The objective of this research was to determine the proximate composition and kinetics drying of sweet pine nuts compared to typical pine nuts of Araucaria angustifolia. This study is based on the proximate components, color, and duration of pine nuts drying of both types, and the influence of temperature and cutting geometry on the dehydration process. Sweet pine nuts had lower calorific value and carbohydrate content, but higher lipid, dietary fiber, protein, and ash contents when compared to typical pine nuts. Color of sweet pine nuts is light pink whereas the typical pine nut is yellowish-white. Sweet pine nuts were also softer. Drying kinetics of the seeds fit well into the logistic and Thompson models. To accelerate drying rates, we recommend slicing pine nuts into thin cross-sections and drying them at temperatures of 60 °C for typical pine nuts and 70 °C for sweet pine nuts.