ABSTRACT Propolis produced by selected bees Apis mellifera were collected from March to June of 2013 and in March of 2015 and analyzed in order to evaluate the influence of climate, colony of origin, and food supplementation of colonies on the content of total phenolic and flavonoid by chromatographic analysis and antioxidant activity by radical scavenging of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods. The Principal Component Analysis (PCA) was carried out with propolis collected in 2013 and two clusters were formed. Propolis produced in the months of March and April showed a higher content of total phenolic compounds (TPC) and antioxidant capacity than those produced in May and June. The results of PCA obtained from samples collected in March of 2013 and 2015 showed two clusters, and propolis collected in 2015 were more bioactive and presented a higher content of TPC. The chromatographic analysis of extracts allowed the identification of phenolic acids p-coumaric, ferulic and caffeic with similar chemical profiles that could be closely related to the botanical origin of propolis. It can be concluded that the season and food supplementation of colonies influenced the chemical composition and the biological activity of samples analysed.

The extraction process of bioactive compounds from propolis produced by selected bees was optimized using a 2³ factorial design planning to evaluate the effect of ethanol concentration, time and temperature on the extraction of total phenolic compounds and antioxidant activity. Analysis of total flavonoids, antioxidant activity and chemical characterization performed by high-performance liquid chromatography with photodiode array (HPLC-PDA) detection were carried out in optimal conditions of extraction. Optimizing results suggest that the best condition for extraction of bioactive compounds was obtained in higher levels: time (45 min), temperature (70 °C) and concentration of ethanol (80%). The extract evaluated in optimal conditions presented good antioxidant activity by the radical scavenging 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP) methods and chromatographic analysis identified phenolic acids: para-coumaric, ferulic and caffeic, indicating that this material is a potential source of bioactive compounds.

A intensificação dos sistemas de produção em aquicultura expõe os peixes a inúmeros estressores, os quais afetam negativamente seu crescimento e limitam a rentabilidade dos sistemas de aquicultura. Este estudo determinou o efeito de níveis crescentes de mananoligossacarídeos dietéticos sobre o crescimento e morfologia intestinal do pacu. Os peixes (44,04 g) foram aleatoriamente distribuídos em 32 tanques (500 L; 10 peixes por tanque) e alimentados por 63 dias com uma dieta comercial suplementada com 0,0; 0,2; 0,4; 0,6; 0,8; 1,0; 1,5 e 2,0% de mananoligossacarídeo dietético. Os parâmetros de crescimento não diferiram (P>0,05) entre os peixes alimentados com a dieta controle e as dietas suplementadas com mananoligossacarídeo. O perímetro das vilosidades intestinais foi realizado nos peixes alimentados com a dieta controle, 0,4 e 1,5% de mananoligossacarídeos dietéticos e também não apresentaram diferenças (P>0,05) entre os tratamentos. A suplementação dietética de mananoligassarídeos não teve efeito no pacu. Estudos relacionados à caracterização da microbiota intestinal e experimento que reproduz sistemas comerciais de produção de peixes são necessários para determinar o uso efetivo deste suplemento dietético para a espécie.

Intensification of aquaculture production systems exposes fish to numerous stressors, which may negatively affect their growth and limit profitability of aquaculture systems. This study determined effects of increasing levels of dietary mannanoligosaccharides on growth and intestine morphology of pacu. Fish (44.04 g) were randomly distributed into 32 tanks (500 L; 10 fishes per tank) and fed during 63 days with a commercial diet supplemented with 0.0; 0.2; 0.4; 0.6; 0.8; 1.0; 1.5 and 2.0% dietary mannanoligosaccharides. Growth parameters did not differ (P>0.05) between fish fed control diet and mannanoligosaccharide supplemented diets. Intestinal villi perimeter was performed in fish fed control diet, 0.4 and 1.5% dietary mannanoligosaccharides and also showed no differences (P>0.05) between treatments. Dietary supplementation of mannanoligosaccharides unclear did not have effects on pacu. Studies on the characterization of intestinal microbiota together with experiment that reproduce commercial fish production systems rearing conditions are necessary to determine the effective use of this dietary supplement for the species.

Sistemas intensivos de produção utilizam 100% de dietas artificiais sendo que, qualquer imbalanço ou deficiência de algum nutriente pode ocasionar surtos de doenças e perdas econômicas. O presente estudo determinou o efeito de níveis crescentes de vitamina E na dieta sobre o desempenho e hematologia de juvenis de pacu. Os peixes foram alimentados por 90 dias até aparente saciedade com dietas semi purificadas contendo 0,0; 25; 50; 150; 300 ou 600 mg.kg−1 de DL-α-tocoferil-acetato, rações em um delineamento experimental inteiramente casualizado (n=4). Parâmetros de desempenho e hematológicos foram coletados e analisados. Peixes alimentados com ração de 150 mg.kg−1 de vit E apresentaram maior ganho de peso (p<0,05) e taxa de crescimento específico. Hematócrito, número de eritroblastos e proteina total plasmática foram maiores (p<0,05) nos peixes alimentados com a dieta insenta de vitamina E. O suplemento de vitamina E em dietas artificiais é essencial para o crescimento e a manutenção da eritropoiese nos valores normais para a espécie.

Intensive fish production systems are characterized by 100% artificial feeding, so any dietary imbalances or deficiencies may lead to diseases outbreaks and economic losses. This study was set out to determine the effects of increasing levels of dietary vitamin E on growth and hematology of juvenile pacu. Fishes were fed for 90 days, twice a day until apparent satiation with semi-purified diets containing 0.0; 25; 50; 150; 300 or 600 mg.kg−1 diet DL-α-tocopheryl acetate in a completely randomized design trial (n=4); biometrical and hematological data were collected and analyzed. Fishes fed with vit E diet (150 mg.kg−1) showed higher (p<0.05) weight gain and specific growth. Hematocrit, erythroblast number and total plasma protein were increased (p<0.05) in fishes fed diet with no vit E diet. Vitamin E supplementation in artificial diets for pacu is essential for growth and maintenance of normal erythropoiesis.