130 resultados para ACIDS CONTENT


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The purpose of this study was to assess the concentration of vitamins and minerals in meat protein hydrolysates. Calcium, phosphorus and iron were analyzed by inductively coupled-plasma atomic emission spectrophotometry; vitamin C was analyzed by the reduction of cupric ions and vitamins B1 and B2 by fluorescence. Regarding minerals, the beef hydrolysate (BH) had more iron than the turkey hydrolysate (TH) and the chicken hydrolysate (CH); TH had a little more phosphorus. BH had the largest amount of vitamin C, and similar amounts of vitamins B1 and B2. The amount of these nutrients found in the hydrolysates suggests that it is possible to use them to enrich special dietary formulations.

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O feijão caupi é uma das principais culturas alimentares do Nordeste brasileiro. Para melhorar sua resistência contra pragas e produtividade, a nova cultivar (BRS-Milênio) foi obtida por melhoramento genético. Este trabalho objetivou caracterizar o potencial nutricional desta variedade, determinando-se a composição centesimal, o perfil de aminoácidos e ácidos graxos, o conteúdo de minerais e a atividade inibitória de tripsina. A semente contém (g.100 g-1): 24,5 de proteínas; 51,4 de carboidratos; 16,6 de fibra insolúvel e 2,7 de fibra solúvel; 2,6 de cinzas, tendo como principais minerais (mg.100 g-1): ferro - 6,8; zinco - 4,1; manganês - 1,5; fósforo - 510,0 e potássio - 1430,0. O teor de lipídios foi de 2,2%, e seu perfil de ácidos graxos apresenta 29,4% de saturados e 70,7% de insaturados. Foi estimado valor calórico de 323,4 kcal.100 g-1 de semente. Encontrou-se baixa atividade inibitória de tripsina (8,0 UIT.mg-1 de amostra). O perfil de aminoácidos foi favorável ao padrão de referência, exceto pela deficiência de sulfurados, sugerindo a necessidade da combinação desta leguminosa com outras fontes alimentares. Os resultados indicam que o feijão caupi possui atributos desejáveis como altos teores de energia, proteínas, fibras e minerais, baixa atividade inibitória de tripsina e, apesar de reduzido conteúdo lipídico, contém alta proporção de ácidos graxos insaturados.

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It was evaluated the effects of metabolizable energy (ME) and digestible lysine (dLYS) densities on performance and body composition of weaned piglets. The study used 114 piglets weaned at 7.4 ± 0.80 kg, out of which 108 were allotted in the nursery and 6 were slaughtered on the weaning day to determine comparative data of body chemical composition. Six nutrients densities were stipulated from a previous study based on the highest nitrogen retention, maintaining the following ME:LYS relationship in the experimental diets: 3,390:1.291; 3,450:1.409; 3,650:1.411; 3,780:1.461; 3,940:1.507; and 4,109 kcal/kg ME:1.564% dLYS. The experimental diets were offered for 13 days when the piglets reached 12.986 ± 1.449 kg of body weight. The probable residual effects of nutritional density on the subsequent performance of the piglets were evaluated. At the end of initial phase 1, six piglets from each density were slaughtered to determine their chemical composition in body fractions and empty body. There was no significant influence of nutritional levels on the performance of the piglets at the end of the evaluation. The results of food conversion and body composition confirm the level indicated in the previous study, 4 g dLYS/Mcal of ME. The increase of energy and lysine densities confirms the need for a correct relationship among both of them to assure better performance of the piglets at the beginning of the growing phase.

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Objetivou-se quantificar na cana-de-açúcar o teor de carboidratos solúveis (CHOs) que anula a produção de etanol e avaliar os efeitos desses carboidratos sobre o valor nutritivo e outras características fermentativas da silagem de cana-de-açúcar. Utilizou-se o delineamento inteiramente casualizado com três tratamentos, cada um com quatro repetições. Os tratamentos consistiram da retirada total do caldo da cana-de-açúcar, por meio de prensagem, e de sua reconstituição (0, 50 ou 100%) à cana. No nível de 50% de reconstituição, o caldo foi adicionado à cana juntamente com 50% de água e, no nível 0%, adicionou-se 100% de água à cana. A restituição resultou em concentrações de 41,6; 34,0 e 23,0% de carboidratos solúveis na matéria seca (MS). O material foi ensilado em 12 silos experimentais confeccionados a partir de baldes plásticos. A abertura dos silos foi realizada 85 dias após a ensilagem, quando foram determinados os teores dos ácidos orgânicos e a composição química das silagens. A retirada de carboidratos solúveis da cana-de-açúcar teve efeito linear decrescente sobre os teores de matéria seca, o teor de carboidratos solúveis e a digestibilidade in vitro da matéria seca (DIVMS) das silagens, no entanto, ocasionou aumento dos teores de fibra detergente ácido (FDA), fibra detergente neutro (FDN) e lignina. Observou-se efeito linear decrescente da retirada dos carboidratos solúveis sobre os teores de etanol e ácidos lático e butírico e as perdas de matéria seca das silagens. Não se observaram efeitos de tratamentos sobre os dados de estabilidade aeróbia. A produção de etanol seria nula se a cana-de-açúcar contivesse apenas 12,4% de CHOs com base na matéria seca (MS).

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CONTEXT: Hepatic fibrosis occurs in response to several aggressive agents and is a predisposing factor in cirrhosis. Hepatotrophic factors were shown to stimulate liver growth and to restore the histological architecture of the liver. They also cause an improvement in liver function and accelerate the reversion of fibrosis before it progresses to cirrhosis. OBJECTIVE: To test the effects of hepatic fibrosis solution composed by amino acids, vitamins, glucose, insulin, glucagon and triiodothyronine on hepatic fibrosis in rats. METHODS: Fibrosis was induced in rats by gastric administration of dimethylnitrosamine (10 mg/kg) for 5 weeks. After liver biopsy, the rats received either hepatotrophic factors solution (40 mg/kg/day) or saline solution for 10 days by intraperitoneal injection. Blood samples and liver fragments were collected for hepatic function analysis, standard histopathology evaluation, and morphometric collagen quantification. RESULTS: Rats in the hepatotrophic factors group showed a decrease of the histopathological components of fibrosis and an increase of their hepatic mass (12.2%). There was no development of neoplasic lesions in both groups. Compared with the saline group, the hepatotrophic factors group also had a decrease of blood levels of hepatic-lesion markers (AST, ALT) and a decrease of collagen content in the portal spaces (31.6%) and perisinusoidal spaces (42.3%), as well as around the hepatic terminal vein (57.7%). Thus, hepatotrophic factors administration in the portal blood promoted a regenerative hepatic response, with an overall reduction of the volumetric density of collagen, improved hepatic function, and a general improvement in the histopathological aspects of fibrosis. CONCLUSION: Taken together, these results suggest the potential therapeutic use of this hepatotrophic factors solution to treat chronic liver diseases.

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Objective To study the role of energy derived from sugar (both table sugar and sugar added to processed foods) in the total energy content of food purchases in Brazil.Design Food purchase data were collected during a national household budget survey carried out between June 2002 and July 2003 on a probabilistic sample representative of all households in the country. The amount of food purchased in this 12-month period was transformed into energy and energy from sugar using food composition tables. Multiple linear regression models were used to study the association between amount of energy from sugar and total energy content of food purchases, controlling for sociodemographic variables and potential interactions between these variables and sugar purchases.Results There was a positive and significant association between energy from sugar and total household energy purchases. A 1 kJ increase in sugar purchase corresponded to a 3·637 kJ increase in total energy. In the absence of expenditure on meals outside the home, i.e. when household food purchases tend to approximate actual food consumption by household members, sugar purchase of 1926·35 kJ/d (the 90th percentile of the distribution of sugar purchases in Brazil) was associated, depending on income strata, with total energy purchase over 40\201360 per cent of the recommended daily value for energy intake in Brazil.Conclusions The present results corroborate the recommendations of the WHO and the Brazilian Ministry of Health regarding limiting the consumption of sugar

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Bovine rumen protein with two levels of residual lipids (1.9 per cent or 3.8 per cent) was subjected to thermoplastic extrusion under different temperatures and moisture contents. Protein solubility in different buffers, disulphide cross-linking and molecular weight distribution were determined on the extrudates. After extrusion, samples with 1.9 per cent residual lipids content had a higher concentration of protein insoluble by undetermined forces, irrespective of feed moisture and processing temperature used. Lipid content of 3.8 per cent in the feed material resulted in more protein participating in the extrudate network through non-covalent interactions (hydrophobic and electrostatic) and disulphide bonds. A small dependency of the extrusion process on moisture and temperature and a marked dependency on lipid content, especially phospholipid, was observed, Electrophoresis under non-reducing conditions showed that protein extrusion with low feed moisture promoted high molecular breakdown inside the barrel, probably due to intense shear force, and further protein aggregation at the die end

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A gordura vegetal parcialmente hidrogenada tem sido utilizada na aromatização de snacks. Entretanto, o risco à saúde ocasionado pelo elevado consumo de ácidos graxos saturados e trans (AGT) vem estimulando o desenvolvimento de abordagens alternativas a essa gordura. Substituímos a gordura vegetal parcialmente hidrogenada (F) por óleo de canola (O) na aromatização de snacks. Snacks com diferentes níveis de O foram produzidos, embalados e armazenados em temperatura ambiente durante vinte semanas. Monitoramos o perfil de ácidos graxos, o teor de substâncias reativas ao TBA (TBARS), a força de cisalhamento e a aceitabilidade sensorial. A substituição total reduziu o teor de ácidos graxos saturados em 72,5 por cento, em comparação aos snacks comerciais. Os snacks eram inicialmente isentos de AGT, porém, após 8 semanas, esses compostos surgiram, havendo aumento gradual durante o período de armazenamento. Entretanto, estes níveis mantiveram-se inferiores aos observados em snacks comercializados. Também foram observados baixos teores de TBARS e estabilidade da força de cisalhamento. Snacks aromatizados com F ou O foram igualmente bem aceitos durante as vinte semanas de armazenamento. É possível desenvolver snacks com teores reduzidos de ácidos graxos saturados e trans, estáveis durante o armazenamento, mantendo a elevada aceitabilidade sensorial típica deste tipo de produto

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Background: Lignin and hemicelluloses are the major components limiting enzyme infiltration into cell walls. Determination of the topochemical distribution of lignin and aromatics in sugar cane might provide important data on the recalcitrance of specific cells. We used cellular ultraviolet (UV) microspectrophotometry (UMSP) to topochemically detect lignin and hydroxycinnamic acids in individual fiber, vessel and parenchyma cell walls of untreated and chlorite-treated sugar cane. Internodes, presenting typical vascular bundles and sucrose-storing parenchyma cells, were divided into rind and pith fractions. Results: Vascular bundles were more abundant in the rind, whereas parenchyma cells predominated in the pith region. UV measurements of untreated fiber cell walls gave absorbance spectra typical of grass lignin, with a band at 278 nm and a pronounced shoulder at 315 nm, assigned to the presence of hydroxycinnamic acids linked to lignin and/or to arabino-methylglucurono-xylans. The cell walls of vessels had the highest level of lignification, followed by those of fibers and parenchyma. Pith parenchyma cell walls were characterized by very low absorbance values at 278 nm; however, a distinct peak at 315 nm indicated that pith parenchyma cells are not extensively lignified, but contain significant amounts of hydroxycinnamic acids. Cellular UV image profiles scanned with an absorbance intensity maximum of 278 nm identified the pattern of lignin distribution in the individual cell walls, with the highest concentration occurring in the middle lamella and cell corners. Chlorite treatment caused a rapid removal of hydroxycinnamic acids from parenchyma cell walls, whereas the thicker fiber cell walls were delignified only after a long treatment duration (4 hours). Untreated pith samples were promptly hydrolyzed by cellulases, reaching 63% of cellulose conversion after 72 hours of hydrolysis, whereas untreated rind samples achieved only 20% hydrolyzation. Conclusion: The low recalcitrance of pith cells correlated with the low UV-absorbance values seen in parenchyma cells. Chlorite treatment of pith cells did not enhance cellulose conversion. By contrast, application of the same treatment to rind cells led to significant removal of hydroxycinnamic acids and lignin, resulting in marked enhancement of cellulose conversion by cellulases.

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Medium density fiberboard (MDF) is an engineered wood product formed by breaking down selected lignin-cellulosic material residuals into fibers, combining it with wax and a resin binder, and then forming panels by applying high temperature and pressure. Because the raw material in the industrial process is ever-changing, the panel industry requires methods for monitoring the composition of their products. The aim of this study was to estimate the ratio of sugarcane (SC) bagasse to Eucalyptus wood in MDF panels using near infrared (NIR) spectroscopy. Principal component analysis (PCA) and partial least square (PLS) regressions were performed. MDF panels having different bagasse contents were easily distinguished from each other by the PCA of their NIR spectra with clearly different patterns of response. The PLS-R models for SC content of these MDF samples presented a strong coefficient of determination (0.96) between the NIR-predicted and Lab-determined values and a low standard error of prediction (similar to 1.5%) in the cross-validations. A key role of resins (adhesives), cellulose, and lignin for such PLS-R calibrations was shown. PLS-DA model correctly classified ninety-four percent of MDF samples by cross-validations and ninety-eight percent of the panels by independent test set. These NIR-based models can be useful to quickly estimate sugarcane bagasse vs. Eucalyptus wood content ratio in unknown MDF samples and to verify the quality of these engineered wood products in an online process.

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The heartwood of candeia tree is a source of essential oil rich in alpha-bisabolol, a substance widely used in the cosmetic and pharmaceutical industry. Bearing in mind the economic importance of alpha-bisabolol, this work aimed to evaluate the influence of tree age on the yield and content of alpha-bisabolol present in essential oil from candeia, considering two distinct reliefs and three diameter classes, in Aiuruoca region, south Minas Gerais state. The two distinct reliefs correspond respectively to one section of the stand growing at 1,000m of altitude (Area 1) and another section growing at 1,100m of altitude (Area 2). In each section, 15 trees were felled from among 3 different diameter classes. Discs were removed from the base of each tree to estimate their age by doing growth ring count. Soil samples were taken and Subjected to physical and chemical analysis. The logs were reduced into chips and random samples were taken for distillation to extract essential oil. The method used was steam distillation at a pressure of 2 kgf/cm(2)/2.5 h. The chemical analysis was performed in a gas chromatograph (GC) based on the alpha-bisabolol standard reference. The yield of essential oil from trees in Area I was higher than that from trees in Area 2, with the same pattern of influence for older trees. In Area 2, the alpha-bisabolol content was higher in younger trees. No differences were found between the relevant parameters in relation to diameter classes.

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Local food diversity and traditional crops are essential for cost-effective management of the global epidemic of type 2 diabetes and associated complications of hypertension. Water and 12% ethanol extracts of native Peruvian fruits such as Lucuma (Pouteria lucuma), Pacae (Inga feuille), Papayita arequipena (Carica pubescens), Capuli (Prunus capuli), Aguaymanto (Physalis peruviana), and Algarrobo (Prosopis pallida) were evaluated for total phenolics, antioxidant activity based on 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assay, and functionality such as in vitro inhibition of alpha-amylase, alpha-glucosidase, and angiotensin I-converting enzyme (ACE) relevant for potential management of hyperglycemia and hypertension linked to type 2 diabetes. The total phenolic content ranged from 3.2 (Aguaymanto) to 11.4 (Lucuma fruit) mg/g of sample dry weight. A significant positive correlation was found between total phenolic content and antioxidant activity for the ethanolic extracts. No phenolic compound was detected in Lucuma (fruit and powder) and Pacae. Aqueous extracts from Lucuma and Algarrobo had the highest alpha-glucosidase inhibitory activities. Papayita arequipena and Algarrobo had significant ACE inhibitory activities reflecting antihypertensive potential. These in vitro results point to the excellent potential of Peruvian fruits for food-based strategies for complementing effective antidiabetes and antihypertension solutions based on further animal and clinical studies.

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Introduction. We present some protocols aiming at partially characterizing banana fruit quality through measurement of some key biochemical parameters. The principle, key advantages, starting plant material, time required and expected results are presented. Materials and methods. This part describes the required laboratory materials and the steps necessary for achieving four protocols making it possible to measure sugar, organic acids and free ACC contents, and in vitro ACC oxidase activity. Results. Standard results obtained by using the protocols described are presented in the figures.

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We described herein the use of imidazolium ionic liquids [bmim]PF(6) and [bmim]BF(4) in the selective, metal and catalyst-free synthesis of unsymmetrical diaryl selenides by electrophilic substitution in arylboron reagents with arylselenium halides (Cl and Br) at room temperature. This is a general substitution reaction and it was performed with arylboronic acids or potassium aryltrifluoroborates bearing electron-withdrawing or electron-donating groups, affording the corresponding diaryl selenides in good to excellent yields. The ionic liquid [bmim][PF(6)] was easily recovered and utilized for further substitution reactions.

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This study investigates the kinetics of acidification, fatty acid (FA) profile and conjugated linoleic acid (CLA, C18:2 c9, t11) content in fermented milks prepared from organic and conventional milk. Fermented milks were manufactured with five mixed cultures: four different strains of Bifidobacterium animalis subsp. lactis (BL04, B94, BB12 and HN019) and Lactobacillus delbrueckii subsp. bulgaricus LB340, in co-culture with Streptococcus thermophilus TA040. The composition of milk was evaluated, and the kinetics of acidification was followed by continuous pH measurement using the Cinac system. The profile of FA, including CLA, was analyzed by gas chromatography. The chemical composition of conventional and organic milk was similar, with the exception of protein and Fe, the concentrations of which were higher in the organic milk. The rate of acidification was significantly influenced by the type of milk and the bacterial strain used. Co-cultures St-HN019 and St-BB12 showed higher maximal acidification rates in both milks. Final counts of S. thermophilus (9.0-10.1 log(10) colony forming units (CFU) . mL(-1), L)actobacillus bulgaricus (8.2-8.5 log(10) CFU . mL(-1)) and B. animalis subsp. lactis strains (8.3-9.3 log(10) CFU . mL(-1)) did not differ significantly in either milk. Unexpectedly, all fermented organic milks contained significantly higher amounts of CLA than the same milk before fermentation, whereas CLA amounts did not change during fermentation of conventional milk. Regardless of the type of milk, CLA was found to be significantly positively correlated with trans-vaccenic acid and negatively correlated with linoleic acid. Moreover, the CLA contents were significantly higher in fermented milks showing shorter fermentation times.