RESUMO
Amino acids (AAs) are an abundant class of nectar solutes, and they are involved in the nectar attractiveness to flower visitors. Among the various AAs, proline is the most abundant proteogenic AA, and γ-amino butyric acid (GABA) and ß-alanine are the two most abundant non-proteogenic AAs. These three AAs are known to affect insect physiology, being involved in flight metabolism and neurotransmission. The aim of this study was to investigate the effects of artificial diets enriched with either ß-alanine, GABA, or proline on consumption, survival, and hemolymph composition in honey bees belonging to two different ages and with different metabolism (i.e., newly emerged and foragers). Differences in feed intake among diets were not observed, while a diet enriched with ß-alanine improved the survival rate of newly emerged honey bees compared to the control group. Variations in the hemolymph AA concentrations occurred only in newly emerged honey bees, according to the diet and the time of hemolymph sampling. A greater susceptibility of young honey bees to enriched diets than older honey bees was observed. The variations in the concentrations of hemolymph AAs reflect either the accumulation of dietary AAs or the existence of metabolic pathways that may lead to the conversion of dietary AAs into different ones. This investigation could be an initial contribution to studying the complex dynamics that regulate hemolymph AA composition and its effect on honey bee physiology.
Assuntos
Aminoácidos , Néctar de Plantas , Abelhas , Animais , Aminoácidos/metabolismo , Néctar de Plantas/análise , Néctar de Plantas/metabolismo , Hemolinfa/metabolismo , Dieta , beta-Alanina/análise , beta-Alanina/metabolismo , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/metabolismo , Prolina/análise , Prolina/metabolismoRESUMO
Euphorbia resinifera O. Berg is a plant endemic to the Northern and Central regions of Morocco known since the ancient Roman and Greek times for secreting a poisonous latex containing resiniferatoxin. However, E. resinifera pseudo-inflorescences called cyathia are devoid of laticifers and, therefore, do not secrete latex. Instead, they exudate nectar that local honey bees collect and craft into honey. Honey and cyathium water extracts find a broad range of applications in the traditional medicine of Northern Africa as ointments and water decoctions. Moreover, E. resinifera monofloral honey has received the Protected Geographic Indication certification for its outstanding qualities. Given the relevance of E. resinifera cyathia for bee nutrition, honey production, and the health benefit of cyathium-derived products, this study aimed to screen metabolites synthesized and accumulated in its pseudo-inflorescences. Our analyses revealed that E. resinifera cyathia accumulate primary metabolites in considerable abundance, including hexoses, amino acids and vitamins that honey bees may collect from nectar and craft into honey. Cyathia also synthesize volatile organic compounds of the class of benzenoids and terpenes, which are emitted by flowers pollinated by honey bees and bumblebees. Many specialized metabolites, including carotenoids, flavonoids, and polyamines, were also detected, which, while protecting the reproductive organs against abiotic stresses, also confer antioxidant properties to water decoctions. In conclusion, our analyses revealed that E. resinifera cyathia are a great source of antioxidant molecules and a good food source for the local foraging honeybees, revealing the central role of the flowers from this species in mediating interactions with local pollinators and the conferral of medicinal properties to plant extracts.
Assuntos
Euphorbia , Néctar de Plantas , Animais , Néctar de Plantas/análise , Néctar de Plantas/metabolismo , Euphorbia/metabolismo , Látex/análise , Látex/metabolismo , Antioxidantes/metabolismo , Flores/metabolismo , Água/metabolismoRESUMO
El Agraz (Vaccinium meridionale Swartz), es una baya que posee alta capacidad antioxidante debido a su contenido de compuestos polifenólicos como antocianinas, ácidos fenólicos y flavonoides. El objetivo de este estudio fue evaluar la composición proximal inicial y el efecto en las características fisicoquímicas (pH, °Brix, acidez titulable (AT)), actividad antioxidante y antiproliferativa de néctares elaborados a partir de agraz liofilizado, almacenados du- rante 42 días. Se prepararon dos néctares: NA (sacarosa) y NB (aspartame), se evaluó cambio en pH, °Brix y AT cada7días durante el almacenamiento. Se determinó contenido de fenoles y antocianinas totales mediante Folin-Ciocalteau y método diferencial de pH, respectivamente, actividad antioxidante mediante FRAP y ORAC. Se analizó la actividad antiproliferativa con sulforodamina B en células SW480 (adenocarcinoma de colon). Los resultados mostraron que ambos néctares presentaron estabilidad en °Brix, pH yAT y el NB presentó menor aporte calórico. El contenido de fenoles totales aumentó durante el almacenamiento. El contenido de antocianinas y capacidad antioxidante se redujo significativamente (p<0,05). NA presentó mejor actividad antiproliferativa a las 72h, con un porcentaje de inhibición del crecimiento celular a una concentración de 1g/mL de 63,50% (IC50=0,6g/mL). Se puede concluir que NA presentó mayor capacidad antiproliferativa y NB mejor actividad antioxidante, que aunque disminuyó significativamente durante el almacenamiento, continuó siendo alta comparada con estudios reportados en la literatura. Para productos realizados a partir de bayas del género Vaccinium. Se requieren estudios adicionales in vivo que permitan comprobar su eficacia quimiopreventiva y dilucidar mecanismos moleculares de acción para beneficio de la salud humana, demostrando su potencial funcional descrito hasta ahora in vitro(AU)
Effect of storage time on the physicochemical characteristics, antioxidant and antiproliferative nectar of unripe (Vaccinium meridionale Swartz). Agraz (Vaccinium meridionale Swartz) is a berry that has high antioxidant capacity due to its content of polyphenolic compounds as anthocyanins, phenolic acids and flavonoids. The aim of this study was to evaluate the initial proximal composition and the effect on the physicochemical characteristics (pH, ° Brix, titratable and acidity (TA), antioxidant and antiproliferative activity of nectars made from unripe lyophilized and stored for 42 days. Two nectars were prepared: NA (sucrose) and NB (aspartame), was evaluated change in pH, °Brix and AT every 7 days during storage. It was determined and total phenols content by Folin-Ciocalteu anthocyanins and pH differential method, respectively, antioxidant activity by FRAP and ORAC. Antiproliferative activity with sulforhodamine B in SW480 cells (colon adenocarcinoma) were analyzed. The results showed that both were stable nectars ° Brix, pH and changes in AT. The NB has lower calories. The content of total phenols increased during storage. The anthocyanin content and antioxidant capacity was significantly reduced (p <0.05). NA presented better antiproliferative activity at 72 h, with a percentage of inhibition of cell growth at a concentration of 1g / ml of 63.50% (IC50 = 0.6 g/mL). It can be concluded that NA had a higher antiproliferative capacity and NB better antioxidant activity than even decreased significantly during storage, remained high com- pared to studies reported in the literature. Further studies "in vivo" to verify their chemopreventive efficacy and elu- cidate molecular mechanisms of action for the benefit of human health, showing their functional potential described so far "in vitro" are required(AU)
Assuntos
Humanos , Masculino , Feminino , Vaccinium , Néctar de Plantas/análise , Polifenóis , Antioxidantes , Armazenamento de Alimentos , Alimentos, Dieta e Nutrição , Valor NutritivoRESUMO
Este estudo avaliou a capacidade antioxidante e os indicadores físico-químicos de néctares caseiros de laranja, manga e maracujá, mantidos sob refrigeração (5 ± 2 o C) por 24 horas. Os néctares foram preparados em laboratório e mantidos sob refrigeração, simulando as condições domésticas. As análises foram realizadas após o preparo (T0) e durante o acondicionamento sob refrigeração (1 h, 4 h e 24 h). Os sólidos solúveis, pH e cor foram determinados respectivamente por refratometria, potenciometria e colorimetria. Carotenoides e ácido ascórbico foram analisados por cromatografia líquida de alta eficiência; a concentração de compostos fenólicos foi determinada utilizando-se o reagente de Folin Ciocalteau e a atividade antioxidante pelo teste do DPPH. Ácido ascórbico, β-caroteno e compostos fenólicos foram identificados em todos os néctares. Foram encontrados α-caroteno e β-criptoxantina no néctar de laranja e licopeno no néctar de manga. Durante 24 horas de refrigeração, os compostos analisados e a atividade antioxidante mantiveram-se estáveis. De forma geral, os parâmetros físico-químicos também se mantiveram estáveis durante o período avaliado. Em conclusão, sob as condições utilizadas no presente estudo, os néctares não apresentaram alteração da capacidade antioxidante, podendo ser considerados fontes de carotenoides e vitamina C, mesmo se consumidos após 24 horas de preparo.
The objective of the study was to evaluate the antioxidant capacity and the physical-chemical indicators of homemade nectars of orange, mango and passion fruit, kept under refrigeration (5 ± 2 °C) for 24 hours. The nectars were prepared in laboratory and kept under refrigeration simulating the domestic conditions. The samples analyses were performed after their preparations (T0) and during the refrigerated storage (1 h, 4 h and 24 h). Soluble solids, pH and color were determined by refractometry, colorimetry and potentiometry, respectively. Carotenoids and ascorbic acid were analyzed by high performance liquid chromatography, the concentration of phenolic compounds were determined by using Folin Ciocalteau reagent, and the antioxidant activity by the DPPH test. Ascorbic acid, β-carotene and phenolic compounds were identified in all of the analyzed nectars samples. The α-carotene and β-cryptoxanthin were found in orange nectar and the lycopene in mango nectar samples. During the refrigeration for 24 hours, the analyzed compounds and the antioxidant activity remained stable. In general, the physical-chemicals parameters also remained stable during the storage for 24 hours. In conclusion, under the conditions used in this study, the nectars might be considered as antioxidant sources, even if consumed after being prepared 24 hours before.
Assuntos
Antioxidantes , Citrus sinensis/química , Mangifera/química , Néctar de Plantas/análise , Néctar de Plantas/química , Passiflora/química , Alimentos Resfriados , Carotenoides , Compostos Fenólicos , Ácido AscórbicoRESUMO
O presente estudo objetivou desenvolver néctares de cagaita (Eugenia dysenterica DC.), caracterizá-los quanto aos parâmetros microbiológicos, sensoriais e químicos e verificar a estabilidade do produto durante o armazenamento. Quatro formulações de néctar contendo 20, 30, 40 e 50% de polpa foram desenvolvidas e avaliadas microbiológica (coliformes totais e termotolerantes, bolores, leveduras e Salmonela spp) e sensorialmente (teste de aceitação). A formulação mais aceita foi avaliada quanto ao conteúdo de sólidos solúveis (SS), pH, acidez titulável (AT), relação SS/AT, umidade, proteínas, lipídios, carboidratos, fibra alimentar total (FAT), cinzas, carotenoides e ácido ascórbico (AA), verificando-se a estabilidade do produto armazenado sob congelamento (-18ºC/90 dias) e refrigeração (5ºC/72 horas). Não foi observada a presença dos micro-organismos pesquisados nas quatro formulações desenvolvidas. As formulações com 40 e 50% de polpa apresentaram maior aceitação para os atributos cor, sabor e impressão global. O néctar contendo 50% de polpa apresentou SS de 11,43 ºBrix, pH de 3,59 e relação SS/AT de 19,37. Verificou-se (em 100 g) AT de 0,59 g de ácido cítrico; 85,75 g de umidade; 0,29 g de proteínas; 0,27 g de lipídios; 12,93 g de carboidratos; 0,68 g de FAT; 0,08 g de cinzas; 55,31 kcal; 0,25 mg de carotenoides e 19,6 mg de AA. Durante o armazenamento não foram observadas alterações estatisticamente significativas nos valores de SS, AT, pH, carotenoides e AA. O néctar de cagaita atendeu as características químicas e os padrões microbiológicos estabelecidos pela legislação brasileira, alcançou boa aceitação dos consumidores e apresentou excelente estabilidade durante o armazenamento.
Assuntos
Técnicas Microbiológicas , Pradaria , Armazenamento de Alimentos , Néctar de Plantas/análise , Análise de Alimentos , Microbiologia de Alimentos , FrutasRESUMO
Helicteres guazumifolia Kunth and Helicteres baruensis Jacq. (Sterculiaceae) are two sympatric species of shrubs common along the North Western tropical dry forest of Costa Rica. i recorded their nectar production within a 24 hour cycle. i also describe the morphology of extrafloral nectaries with scanning electron microscopy. in H. guazumifolia secretion was restricted to the first day of flower life span, shortly after anthesis (0600 hr - 1800 hr). Flowers secreted on average 15.63 ±8.45 µl (N=409). Nectar is composed of three main sugars: sucrose, fructose and glucose (mainly sucrose). A total of 17 free amino acids were identified: mainly proline, arginine, threonine and tyrosine, with a concentration above 70 Ng/µl. values were different for H. baruensis. Nectar secretion was confined to the second day after anthesis, starting at 1600 hr and ending at 0600 hr the following day. Flowers secreted on average 77.03 ±64.99 µl (N=163) of nectar. Nectar is also composed of three main sugars; however, it showed a tendency to be hexose-rich, having more fructose and glucose than sucrose. There were also 17 free amino acids, mainly proline, alanine, tyrosine, arginine and threonine. Patterns of nectar production are different between the two species for timing, and for amount and composition of nectar secretion. Rev. Biol. Trop. 57 (Suppl. 1): 161-177. Epub 2009 November 30.
Helicteres guazumifolia Kunth y Helicteres baruensis Jacq. (Sterculiaceae) son dos especies simpátricas de arbustos comunes en el bosque tropical seco de la zona noroeste de Costa Rica. Registré los patrones de producción de néctar de las dos especies según la hora del día o de la noche cuando hubo secreción de néctar. En H. guazumifolia se limitó al primer día del período de vida floral, desde el inicio de la antesis a las 0600 hr hasta las 1800 hr. Las flores secretaron en promedio 15.63 ±8.45 µl (N=409) de néctar. El néctar está compuesto por tres azúcares principales: sacarosa, fructuosa y glucosa, y es rico en sacarosa. Se identificó un total de 17 aminoácidos diferentes en el néctar floral. Prolina, arginina, treonina y tirosina fueron los aminoácidos más abundantes con una concentración mayor a 70 Ng/µl. En contraste, las flores de su pariente H. baruensis, secretaron néctar en el segundo día de vida de la flor, después de la antesis; se inició a las 1600 hr y cesó a las 0600 hr del día siguiente. Las flores secretaron en promedio 77.03 ±64.99 µl (N=163) de néctar. El néctar también está compuesto por tres azúcares principales; no obstante, tiende a ser rico en hexosas, con más fructuosa y glucosa que sacarosa. También contiene 17 aminoácidos libres, siendo los más concentrados prolina, alanina, tirosina, arginina y treonina. Se observan claramente patrones diferentes de producción de néctar entre las dos especies según la hora, la cantidad y la composición del néctar. También describí la morfología de los nectarios florales usando fotomicrografías tomadas con microscopio electrónico.