Academic literature on the topic 'Cryptoxanthin'

Thesis (M.S. in food science)--Washington State University, December 2009.<br>Title from PDF title page (viewed on Jan. 19, 2010). "School of Food Science." Includes bibliographical references (p. 43-57).

Les agrumes très consommés au niveau mondial, représente des sources de caroténoïdes tels que la β-cryptoxanthine, qui contribuent avec les flavonoïdes (hespéridine) aux effets santé de ces fruits et en particulier dans la prévention du diabète de type 2 (DT2). Le DT2 est une pathologie mondiale en croissance exponentielle. L’objectif général de ce travail est par conséquent d’étudier les propriétés nutrition-santé de concentrés de jus de clémentine, obtenus par une technologie membranaire innovante et spécifiquement enrichis en β-cryptoxanthine (βCX) et hespéridine (HES) mais également en pectines. Le devenir digestif de ces phytomicronutriments, garants de la qualité nutritionnelle des concentrés a évalué dans un premier temps en couplant le modèle de digestion in vitro aux cellules intestinales de type Caco-2. Pour une meilleure vision physiologique des mécanismes associés aux premières étapes de la digestion, des modèles de digestion, statique et dynamique, sont comparés. La bioaccessibilité et l’absorption intestinale des caroténoïdes sont fortement influencées par la teneur et structure des pectines. Dans un second temps, les activités biologiques (disglycémie, dislipidémie, inflammation) impliquées dans la prévention du DT2 sont évaluées in vivo chez le rat après administration du concentré d’agrume. L’étude a démontré qu'un aliment à base d'agrume spécifiquement enrichi en βCX et HES est efficace dans la prévention du syndrome métabolique/DT2, soulignant le rôle possible de la βCX et de sa bioconversion en rétinoïdes. Une étude in vitro complémentaire sur macrophages murins révèle des effets anti-inflammatoires synergiques des 2 phytomicronutriments<br>Citrus fruits, which are widely consumed worldwide, represent sources of carotenoids such as βCX, which contribute with flavonoids (HES) to the health effects of these fruits, particularly in the prevention of type 2 diabetes (T2D). T2D is a worldwide pathology that is growing exponentially. The general objective of this work is therefore to study the nutritional and health properties of clementine juice concentrates obtained by innovative membrane technology and specifically enriched in both βCX and HES but also in pectins. The digestive behaviour of these phytomicronutrients, guarantors of the nutritional quality of the concentrates, was first assessed by coupling the in vitro digestion model with the Caco-2 intestinal cells. For a better physiological vision of the mechanisms associated with the first stages of digestion, models of static and dynamic digestion are compared. The bioavailability and intestinal absorption of carotenoids are strongly influenced by the content and structure of pectins. In a second step, the biological activities (disglycemia, dislipidemia, inflammation) involved in the prevention of T2D are evaluated in vivo in rat after administration of the citrus concentrate. The study demonstrated that a citrus food specifically enriched in βCX and HES is effective in preventing metabolic syndrome/T2D, highlighting the possible role of βCX and its retinoid bioconversion. A complementary in vitro study on murine macrophages reveals synergistic anti-inflammatory effects of the two phytomicronutrients

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior<br>Due to the scarce amount of studies on the physicochemical composition and antioxidant capacity of pitanga fruits (Eugenia uniflora L.) this study was performed, with objective of increase data on pitanga fruits from Rio Grande do Sul state (Brazil) by determining the composition and antioxidant capacity of flesh and seeds from pitanga. We analyzed pitanga fruits with different flesh colors (purple, red and orange) from tree selections cultivated at Embrapa Clima Temperado (RS-Brazil). The quality parameters of pitanga fruits (pH, brix, acidity) were within the legal limits established for frozen pulp and only slight differences were observed in these parameters and in the proximate and fatty acid composition among fruits with different flesh color. Orange fleshed pitanga had higher carotenoid content than red samples. The extracts from purple fleshed color pitanga had the highest total phenolic and anthocyanin content along with the highest antioxidant capacity. Antioxidant capacity (DPPH and FRAP assay) of methanolic pitanga extracts was highly correlated to the total phenolic content, but in ethanolic extracts anthocyanin content was correlated only to FRAP antioxidant capacity. These results indicate that pitanga cultivated in the Rio Grande do Sul state, specially the purple fleshed fruits, can be considered sources of bioactive compounds. Pitanga seeds had antioxidant capacity that was partially correlated to their high phenolic content and showed some variation according to the pitanga flesh colors. Accordingly, we suggest that this low value waste of pitanga processing, could be used as a source of natural antioxidants. No relevant differences were found in the proximate composition among seeds from pitanga of different colors. Results revealed that pitanga seeds are a good source of dietary fiber, which could be explored for use in animal and/or human nutrition. However, more studies are necessary to determine if some antinutritional factor like cyanogenic glycosides could be a limit for this application.<br>Devido à escassa quantidade de trabalhos sobre a composição físico-química de frutos de pitanga (Eugenia uniflora L.), este estudo teve como objetivo a caracterização de pitangas do Rio Grande do Sul (Brasil) através da determinação da composição e capacidade antioxidante da polpa e das sementes de pitanga. Foram analisadas pitangas de diferentes colorações de polpa (roxa, vermelha e laranja) de seleções que estão sendo cultivadas na Embrapa Clima Temperado (RS-Brasil). Os parâmetros de qualidade das pitangas (pH, brix e acidez) ficaram dentro dos limites estabelecidos pela legislação brasileira para polpas congeladas. Foram observadas apenas pequenas diferenças nestes parâmetros, na composição centesimal e de ácidos graxos entre as frutas com diferentes colorações de polpa. As pitangas de cor laranja apresentaram maior conteúdo de carotenóides que as de cor vermelha. Os extratos de pitangas roxas apresentaram o maior conteúdo de fenólicos totais e de antocianinas, bem como, a maior capacidade antioxidante. A capacidade antioxidante (valores de DPPH e FRAP) dos extratos metanólicos de pitanga apresentou alta correlação com o conteúdo de fenólicos totais, mas nos extratos etanólicos o conteúdo de antocianinas correlacionou-se apenas com a capacidade antioxidante avaliada pelo método de FRAP. Os resultados indicam que as pitangas cultivadas no Rio Grande do Sul, especialmente as de cor roxa, podem ser consideradas fontes de compostos bioativos. As sementes de pitanga apresentaram também capacidade antioxidante, que foi parcialmente correlacionada com o alto teor de fenólicos, apresentando variação de acordo com a coloração das pitangas. Assim, sugere-se que este resíduo de baixo valor do processamento da pitanga, poderia ser usado como uma fonte natural de antioxidantes. Não foram encontradas diferenças relevantes na composição de sementes de pitanga de diferentes colorações. Os resultados revelaram que a pitanga é uma boa fonte de fibra dietética, que poderia ser explorada para uso na nutrição animal e/ou humana. No entanto, mais estudos são necessários para determinar se a presença de algum fator antinutricional como glicosídios cianogênicos poderia limitar esta aplicação.

The Brown-headed Parrot (Poicephalus cryptoxanthus) is a poorly known species inhabiting open woodland in south-eastern Africa. This study elucidates critical aspects of the species ecology and although each of these categories impinge on one another, it concentrates on two broad biological aspects, diet and breeding biology, and vocalizations. The species has a generalist diet, switching from one suite of food species to another as and when those species become available, with no species critical for its survival. Analysis of dietary items throughout the year and comparison with handling times and availability reveals that at no time is the species under dietary constraint. Evidence from association indices and behavioural observation shows that the popular view that the Brown-headed Parrot forms pairs just before breeding is erroneous. Birds retain pair bonds and the bond is long-term, lasting at least throughout the year. Congregations are therefore of a classical fission/fusion type with the sub-units being the paired males and females. A mathematical model of the growth of captive chicks is presented, as a guideline to alert potential breeders of Brown-headed Parrots of malnutrition or disease. The species is a secondary cavity hole nester and whilst, the breeding biology of the species is summarised, the importance of large and old trees for breeding opportunities of the species is emphasised. This theme is continued by testing various adaptive hatching hypotheses as possible explanations of asynchronous hatching in the species. It is suggested that asynchronous hatching may be an adaptive strategy moderating against the number of suitable nesting cavities. The vocalization repertoire of the Brown-headed Parrot is described and seven separate vocalizations are recognized. None of these are associated with sexual situations, offering further evidence of a long-term pair bond. Evidence is offered that Brown-headed Parrot chicks can recognise their parents from individual vocal signatures supporting previous evidence from a number of species where chicks may mingle with unrelated chicks. Conversely, parents seem to be unable to recognise their chicks in the same way. It is concluded that this inability may be a result of strong one-way selection pressure, where the costs outweigh the benefits for parents with more than one chick or may be related to the experimental design. Individual recognition by voice implies individual voice differences and the adult double chip contact call is analysed using multivariate statistical techniques. The analysis separates individuals on the basis of frequency and temporal patterns and it is concluded that these parameters may allow individual voice differentiation. Finally, high frequency aspects of the double chip contact call are examined. These frequencies lie above the normally accepted upper threshold of avian hearing. From laboratory and field experiments, behavioural evidence is presented suggesting that the Brown-headed Parrot reacts to these frequencies and may use their degradation as a means of ranging distances to conspecifics.<br>Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 2002.