Avaliação do perfil metabólico de vacas da raça Holandesa durante o período de transição

O período de transição é um momento de grande desafio para vacas de aptidão leiteira, uma vez que, a maioria dos problemas metabólicos ocorre nesta fase podendo prejudicar toda a expectativa de produção durante a lactação, resultando em impacto econômico significativo para fazendas de produção de leite. Este trabalho teve como objetivo avaliar o perfil metabólico de vacas da raça Holandesa durante o período de transição. Doze vacas Holandesas foram avaliadas, três semanas pré-parto até três semanas pós-parto, em sistema free-stall, localizado em Inhaúma, Minas Gerais, no período de outubro a dezembro de 2012. Avaliou-se o perfil metabólico através da concentração sérica de ácidos graxos não esterificados (AGNE), beta hidroxibutirato (BHBA), colesterol (COLES), proteína total (PT), albumina (ALB), cálcio, fósforo, magnésio bem como a atividade sérica das enzimas aspartato transaminase (AST) e lactato desidrogenase (LDH). As concentrações séricas de AGNE e BHBA foram diferentes entre o pré-parto e pós-parto (p0,05) no período avaliado. A atividade enzimática de AST e LDH foram maiores no período pós-parto (p<0,05). A avaliação do perfil metabólico é uma importante ferramenta de monitoramento e, na situação estudada, demonstrou alterações do perfil energético das vacas entre os períodos pré e pós-parto, relacionadas provavelmente a diminuição da ingestão de alimentos. A luz dos resultados do perfil metabólico, o rebanho avaliado possui pequeno risco para a ocorrência de enfermidades no pós-parto relacionadas ao período de transiçã

Techno-Functional Properties from Hydrolyzed Wheat Gluten Fractions

Many protein sources that are found in the market are obtained as by-products and there is a great interest in using them as protein ingredients with adequate functionality for food formulation. Structure modification permits one to add value and to diversify their uses. The diversification of wheat gluten applications depends on the improvement of its solubility in a wider pH range. One of the alternatives that allow protein modification in these products is the enzymic hydrolysis. The objective of this work was to evaluate foaming properties of protein fractions obtained by extracting, at 3 pH, different hydrolyzed gluten samples. Two commercial enzymes (acid -Ac- and alkaline -Al- proteases) were used to reach 3 different hydrolysis degrees (DH). Extracts pHs (4, 6.5 and 9) were diluted to a protein concentration of 4 g/l. RP-HPLC, free amino groups content, sulphydryl and disulfur content, average peptide chain length were used to characterize each extract. Foam was produced by sparging nitrogen at a known rate through a dilute protein solution. The maximal volume of liquid incorporated into the foam (Vmax) and the rate of liquid incorporation into the foam (Ri) were determined and used as indicators of foaming capacity. The times for half-drainage of the liquid that was incorporated into the foam at the end of the bubbling period (t1/2) and the rate of liquid drainage from the foam were also measured. Regarding Ri, all pH 4 extracts from hydrolyzed samples showed higher Ri than an un-hydrolyzed sample. Extracts from Al hydrolyzed extracts showed higher Ri than those from Ac. In the case of Al extracts, an inverse relation between DH and Ri was observed, but practically no influence of DH on Ri, was observed in the case of Ac extracts. For pH 6.5 extracts, the relation between DH and Ri were in opposite directions, depending on the enzyme, for Ac, Ri decreased with DH, while for Al, Ri increased with DH. At this pH, it was observed that the extracts which foamed more quickly, were those with the highest times for half-drainage of the liquid (t1/2). Some foam parameters correlated between themselves, depending on the extracts. Foaming capacity and stability depend on pH, DH and enzyme and it was possible to correlate parameters with composition evaluated by RP-HPLC.Fil: Drago, Silvina Rosa. Universidad Nacional del Litoral. Facultad de Ingeniería Química; ArgentinaFil: Gonzalez, R. J.. Universidad Nacional del Litoral. Facultad de Ingeniería Química; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Application of surface response methodology to optimize hydrolysis of wheat gluten and characterization of selected hydrolysate fractions

BACKGROUND: The aim of this work was to optimize the hydrolysis experimental conditions to obtain wheat gluten hydrolysates and to characterize fractions from hydrolysates with different hydrolysis degrees in order to develop protein functional ingredients. Surface response methodology was used to analyze the effect of reaction factors on the degree of hydrolysis to assess the conditions for maximum fungal protease enzyme activity. Hydrolysates having three different trichloroacetic acid indices (TCAI) were prepared. Soluble fractions at pH 4, 6.5 and 9 from these hydrolysates were characterized by electrophoresis, reverse-phase high-performance liquid chromatography, free amino group content and peptide chain length. RESULTS: Temperature and pH ranges for highest enzyme activity at 2.5 h were 54–58 ◦C and 4.2–4.4, respectively. Hydrolysate fraction composition differs according to the hydrolysis degree and extracting pH, the difference being more pronounced at low TCAI. Hydrolysate having 32% TCAI is composed of peptides whose size is lower than 18.5 kDa, with an average peptide chain length of 14 amino acid residues. CONCLUSION: The combination of hydrolysis degree and pH of extraction allows fractions of different peptide composition to be obtained, which could be taken into account when trying to find a defined composition related to determined functional characteristics.Fil: Drago, Silvina Rosa. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: González, Rolando J.. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Tecnología de los Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Contribution of the Starch, Protein, and Lipid Fractions to the Physical, Thermal, and Structural Properties of Amaranth (Amaranthus caudatus) Flour Films

Amaranth protein–lipid (PL) and protein (P) films were elaborated and compared with amaranth flour films in order to determine the contribution of the interactions between the biopolymer (starch and protein) and the lipids to the film properties. The films were made by the casting method, using the same glycerol concentration (0.9 g glycerol/100 g solution). A separation of the lipid fraction in the PL films and a polymorphic transformation of the corresponding fatty acids were observed by differential scanning calorimetry (DSC) and verified by an analysis of the microstructure by scanning electron microscopy (SEM). The flour films showed no separation of the lipid fraction, evidence that the lipids were strongly associated with the proteins and homogenously distributed throughout the starch network, contributing to the good mechanical properties when compared to the PL films and to the excellent barrier properties when compared to both the PL and P films. The protein‐protein interactions also contributed to the mechanical properties of the flour films. The presence of proteins and lipids in the flour films had an important effect on film solubility, and also on the color and opacity of the films. This study showed that the flour film properties depended on the interactions formed by their polymers (starches and proteins) and by the lipid, on the distribution of these interactions within the film matrix and on the concentrations of each component in the film.Fil: Tapia Blácido, D.. Universidade Estadual de Campinas; BrasilFil: Mauri, Adriana Noemi. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Menegalli, F.C.. Universidade Estadual de Campinas; BrasilFil: Sobral, Pablo J. A.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentin

Does normalized signal intensity of cervical discs on T2 weighted MRI images change in whiplash patients?

Purpose We tested the hypothesis that whiplash trauma leads to changes of the signal intensity of cervical discs in T2-weighted images. Methods and materials 50 whiplash patients (18–65 years) were examined within 48 h after motor vehicle accident, and again after 3 and 6 months and compared to 50 age- and sex-matched controls. Signal intensity in ROI's of the discs at the levels C2/3 to C7/T1 and the adjacent vertebral bodies were measured on sagittal T2 weighted MR images and normalized using the average of ROI's in fat tissue. The contrast between discs and both adjacent vertebrae was calculated and disc degeneration was graded by the Pfirrmann-grading system. Results Whiplash trauma did not have a significant effect on the normalized signals from discs and vertebrae, on the contrast between discs and adjacent vertebrae, or on the Pfirrmann grading. However, the contrast between discs and adjacent vertebrae and the Pfirrmann grading showed a strong correlation. In healthy volunteers, the contrast between discs and adjacent vertebrae and Pfirrmann grading increased with age and was dependent on the disc level. Conclusion We could not find any trauma related changes of cervical disc signal intensities. Normalized signals of discs and Pfirrmann grading changed with age and varied between disc levels with the used MR sequence

Desarrollo de una estrategia natural para el control de Varroa destructor, integrando el uso de probióticos y productos orgánicos.

Durante los últimos años se han observado pérdidas de colmenas de abejas melíferas alrededor del mundo. Una de las principales causas de pérdidas de colmenas es la presencia de diferentes parásitos y patógenos