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Caracterização histological e detecção de células endócrinas no estomago de peixes de água doce, com diferentes hábitos alimentares Texto completo
2003
Eduardo França Castro | Cláudio César Fonseca | Eliane Menin Eliane Menin | Marco Túlio David das Neves
Células endócrinas do neuroendócrino gastroenteropancreático desempenham diversas funções na fisiologia da digestão. No entanto, estudos de tais células que propiciem subsídios morfológicos para pesquisa a respeito de aspectos nutricionais que visem o aumento na produção da piscicultura no Brasil , são muito escassos. Foram utilizadas três espécies de Teleostei de água doce, com diferentes estrutural microscópica da parede das diferentes regiões do estomago, além da detenção, quantificação média e distribuição de células endócrinas nesta região. Os espécimes foram coletados,identificados aos procedimentos rotineiros para obtenção dos constituintes do aparelho digestório, cujos fragmentos foram submetidos a processamento histológico, desde a fixação, inclusão em parafina, até a colocação. Os resultados obtidos evidenciaram que a estrutura da parede do estomago não apresentou diferenças significativas entre as espécies estruturadas e que o número médio de células argirófilas no estomago (0,0021 células/mm²) é cerca de 38.000 a 57.000 vezes menor, se comparado ao observado em ,mamíferos, como gambá, camundongos e porco. Embora a detecção de células endócrinas no estomago possa indicar um possível controle endócrino local, estudo em peixes, são ainda necessários.
Mostrar más [+] Menos [-]Deep frying: the role of water from food being fried and acrylamide formation | Friture en bain: rôle de l'eau provenant des aliments à frire dans la formation d'acrylamide
2003
Gertz, C. ((Chemisches Untersuchungsamt, Hagen (Allemagne))) | Klostermann, S. | Kochhar, S.P.
The formation of acrylamide during food frying is generally influenced by food type, thermal treatment and equipment. The acrylamide concentration is increased when frying oils containing a higher level of polar materials or silicone or larger amounts of diglycerides. This effect may be caused by moisture escaping from food that has an enhancing effect on the heat transfer. It was noticed that if the moisture in the frying operation was bound by special adsorbents, the acrylamide content could be reduced by more than 50 per cent. The effects of several additives like citric acid on the formation of acrylamide during frying of chips were also investigated. The mechanism of acrylamide formation in fried foods is discussed to explain these findings
Mostrar más [+] Menos [-]The fishing distribution and food of the Japanese stingray (Dasyatis akajei) in the Ariake Sea of the water temperature descending term [Japan]
2003
Kanazawa, T. (Fukuoka-ken. Fisheries Experiment Station (Japan))
Determination of water self-diffusion coefficient in complex food products by low field 1H PFG-NMR: Comparison between the standard spin-echo sequence and the T1-weighted spin-echo sequence Texto completo
2003
Metais, A. | Mariette, François | Technologie des équipements agroalimentaires (UR TERE) ; Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF)
[Departement_IRSTEA]GEAPA [TR1_IRSTEA]42 - ALITECH / IRMA | International audience | In 1990, Van Den Enden et al. proposed a method for the determination of water droplet size distributions in emulsions using a pulsed field gradient nuclear magnetic resonance (PFG-NMR) T1-weighted stimulated-echo technique. This paper describes both the T1-weighted spin-echo sequence, an improved method based on this earlier work, and, the standard PFG spin-echo sequence. These two methods were compared for water self-diffusion coefficient measurement in the fatty protein concentrate sample used as a 'cheese model`. The transversal and longitudinal relaxation parameters T1 and T2 were determined according to the temperature and investigated for each sample; fat-free protein concentrate sample, pure anhydrous milk fat and fatty protein concentrate sample. The water self-diffusion in fat-free protein concentrate samples followed a linear behavior. Consequently, the water self-diffusion coefficient could be easily characterized for fat-free protein concentrate samples. However, it seemed more complicated to obtain accurate water self-diffusion in fatty protein concentrate samples since the diffusion-attenuation data were fitted by a bi-exponential function. This paper demonstrates that the implementation of the T1-weighted spin-echo sequence, using the different T1 properties of water and fat phases, allows the accurate determination of water self-diffusion coefficient in a food product. To minimize the contribution of the 1H nuclei in the fat phase on the NMR echo signal, the fat protons were selectively eliminated by an additional 180° pulse. This new method reduces the standard errors of diffusion data obtained with a basic spin echo technique, by a factor of ten. The effectiveness of the use of the T1-weigted spin-echo sequence to perform accurate water self-diffusion coefficients measurement in fatty products is thus demonstrated.
Mostrar más [+] Menos [-]Efecto de la frecuencia alimenticia en el crecimiento y sobrevivencia de juveniles de langosta de agua dulce Cherax quadricarinatus (von Martens, 1868) (Decapoda: Parastacidae) | Effect of feeding frequency on growth and survival of juvenile crayfish Cherax quadricarinatus (von Martens, 1868) (Decapoda: Parastacidae) Texto completo
2003
Edilmar Cortés Jacinto | Humberto Villarreal Colmenares
"El efecto de la frecuencia alimenticia en el crecimiento y sobrevivencia de juveniles de langosta de agua dulce Cherax quadricarinatus, fue evaluado en 60 días de cultivo. Grupos de juveniles de acociles (crayfish) con peso inicial de 0.89 ± 0.06 g fueron alimentados con cuatro diferentes frecuencias de alimentación por día: cada 24 h (C1), 12 h (C2), 6 h (C3) y cuatro veces al día (C4) con una dieta con 35% de proteína cruda. Las tasas de crecimiento específico (TCE) de 3.02 y 2.79%/día, muestran que las frecuencias alimenticias C3 y C4 maximizan el desarrollo de juveniles de C. quadricarinatus, obteniendo pesos finales de 4.7 y 5.4 g, biomasas de 253.2 y 311.8 g/m2 , con Factores de Conversión Alimenticia (FCA) de 1.8 y 1.2, respectivamente. Los tratamientos C1 y C2 mostraron un FCA significativamente más alto. El intervalo de sobrevivencia fue de 86.7 a 98.3%, siendo estadísticamente menor para los tratamientos experimentales C1 y C2. Los resultados de incremento en peso de los juveniles de C. quadricarinatus, indican que la frecuencia de alimentación óptima es de al menos tres veces al día. Sin embargo, en términos de biomasa final el tratamiento C4 fue significativamente diferente con respecto a los demás tratamientos. La información obtenida contribuirá a mejorar la comprensión de la dinámica de distribución del alimento y correlacionarla con la condición nutricional y rendimiento en la producción de juveniles de C. quadricarinatus." | "The effect of feeding frequency on the growth and survival of juvenile freshwater crayfish Cherax quadricarinatus with initial mean weight of 0.89 ± 0.06 g was evaluated in a 60-day study. Juveniles were fed with four different feeding frequencies: every 24 h (C1), 12 h (C2), 6 h (C3) and 4 h (C4), with a 35% crude protein diet. Specific Growth Rates (SGR) of 3.02 and 2.79%/day showed that feeding frequency treatments C3 and C4 maximize growth of juvenile C. quadricarinatus, reaching final mean weights of 4.7 and 5.4 g, biomasses of 253.2 and 311.8/m2 , and Feed Conversion Ratios (FCR's) of 1.8 and 1.2, respectively. Treatments, C1 and C2 showed significantly higher FCR’s. Survival ranged from 86.7 to 98.3%, and was statistically different among the experimental treatments, except for organisms fed with C1 and C2. Final weights of juvenile C. quadricarinatus showed that a feeding frequency of at least three times a day (C3) was significantly better. However, in terms of biomass, treatment C4 was better. The information obtained will contribute to improve the understanding of the dynamics of distribution of feeds and to correlate it with the nutritional condition of juvenile C. quadricarinatus."
Mostrar más [+] Menos [-]The addition of external water to fresh grass does not affect dry matter intake, feeding behaviour and rumen characteristics in dairy cows | L'addition d'eau externe à l'herbe verte n'affecte pas la quantité de matière sèche ingérée, le comportement alimentaire ou les caractéristiques du rumen chez la vache laitière
2003
Cabrera Estrada, J.I. ((Institut National de la Recherche Agronomique, Saint Gilles (France). Centre de Rennes, UMR Production du Lait)) | Delagarde, R. | Faverdin, P. | Peyraud, J.L.
L'herbe fraîche est un aliment de bonne valeur alimentaire pour les ruminants mais son ingestion par les vaches laitières reste limitée au regard de sa digestibilité. La forte teneur en eau de l'herbe fraîche pourrait limiter la quantité ingérée de MS d'herbe. L'effet de l'eau externe à la plante sur l'ingestion, le comportement alimentaire et l'encombrement ruminal a été étudié sur des vaches laitières nourries à l'auge avec du ray-grass anglais distribué ad libitum. Trois traitements ont été comparés : herbe verte témoin, fauchée une fois par jour (C)C plus de l'eau ajoutée sur l'herbe (SW) et C plus perfusion d'eau dans le rumen après chaque distribution (PW). La distribution d'herbe a été faite à 14:00 h, 19:00 h et 07:00 h le lendemain matin. L'eau de boisson était en accès libre. Dans le traitement SW, la teneur en MS de l'herbe offerte a été réduite de 161 à 117 g / kg brut ( P 0,02) sans changer la composition chimique de l'herbe. Par rapport à C et PW, la quantité brute ingérée d'herbe et la vitesse d'ingestion en brut ont fortement augmenté (respectivement + 36 et 39 pour cent), mais la quantité de MS d'herbe ingérée (16,4 kg MS/ j), la vitesse d'ingestion de MS (35,3 g MS/min) et les durées journalières d'ingestion (468 min) et de rumination (515 min) n'ont pas été modifiées. Perfuser l'eau dans le rumen n'a affecté ni l'ingestion ni le comportement alimentaire. Le poids total du contenu du rumen (150 kg), la teneur en MS du contenu (115 g/kg ), l'osmolarité du liquide ruminal, la proportion d'eau libre et d'eau liée ainsi que le taux de renouvellement des liquides n'ont pas été modifiés par les traitements. En conclusion, pour des vaches en production nourries à l'herbe, un apport même important d'eau externe ne constitue pas de limite à la prise alimentaire, ni à l'encombrement dans le rumen, et n'affecte pas la quantité de MS d'herbe ingérée
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