Abstract Biofortification is an important technique where the nutritional quality of food crops is enriched through the increase of nutrient content. Provitamin A deficiency is still a public health concern mainly in developing countries. Since beta-carotene is a vitamin A precursor, the increase of this compound in foods through biofortification is a manner to reach people under hidden hunger condition. This work aimed to evaluate the effect of different cooking styles on carotenoids content and antioxidant activity of two different genotypes of biofortified Cucurbita moschata. In the present study, biofortified pumpkins submitted to different cooking conditions were assessed for antioxidant activity by ABTS, DPPH, β-carotene/linoleic acid systems and have polyphenols and carotenoids content compared. The cooking style affected the antioxidant activity. Pumpkins from genotype 1 showed high levels of carotenoids, α-carotene and all-E-β-carotene compared to samples from genotype 2. There was an increase of all carotenoids in both cooked pumpkins, and steam cooking showed the highest retention percentages. Steam cooking presented a higher percentage of carotenoid retention. Pumpkin consumption in developing countries, especially in the Northeast Brazil may be promoted to combat vitamin A deficiency.

RESUMOA composição da própolis depende do tempo, da vegetação e a localização da área de coleta. Este estudo teve como objetivo determinar as características físicas e químicas, o teor de compostos fenólicos e capacidade antioxidante da própolis de abelhas nativas sem ferrão (Meliponinae) e Apisdo Estado do Tocantins. Para a obtenção dos extratos empregou-se extração com etanol 80% (v/v). Os parâmetros analisados foram: perda de peso por dessecação a 105 °C, cinzas, Teor de cera e pH. Além dessas foi mensurada a atividade antioxidante e o teor de compostos fenólicos totais. Adicionalmente os extratos de própolis foram também analisados por cromatografia líquida de alta eficiência. O teor de compostos fenólicos totais variou entre 121,78 e 631,29 (mg GAE g-1). A atividade antioxidante expressa pelo valor de CE50 variou entre 29,81 e 845,38 µg mL-1. As análises por cromatografia líquida de alta eficiência permitiram inferir a existência de compostos fenólicos. Os resultados indicaram que as amostras de própolis estudadas constituem boas fontes de antioxidantes naturais. A variedade de compostos fenólicos identificada neste estudo, e as diversas funções biológicas relatadas na literatura para estes compostos, indicaram que a própolis de abelhas sem ferrão (Meliponinae) e Apistem um grande potencial farmacológico.

ABSTRACTThe composition of propolis depends on time, vegetation and the location of the collection area. The objective of this study was to determine the physicochemical characteristics, the concentration of phenol compounds and the antioxidant capacity of propolis of native stingless bees (Meliponinae)and Apis from the State of Tocantins. Extraction with 80% ethanol (v/v) was performed in order to obtain the extracts. Parameters examined were: propolis mass loss by desiccation at 105 ºC, ashes, wax concentration and pH. Furthermore, the propolis antioxidant activity was measured, as well as the total concentration of phenol compounds. The extracts were also analyzed by high performance liquid chromatography. The total concentration of phenol compounds varied between 121.78 and 631.29 (mg GAE g-1). The antioxidant activity expressed by the value of CE50 varied between 29.81 and 845.38 µg mL-1. High performance liquid chromatography analysis allowed us to infer the existence of phenol compounds. The results indicated that the studied propolis samples constitute good sources of natural antioxidants. The variety of phenol compounds identified in this study, and the diverse biological functions reported in literature for these compounds indicated that this stingless bee propolis (Meliponinae) and Apis has a high pharmacological potential.