Evaluation of lignin contents in tropical forages using different analytical methods and their correlations with degradation of insoluble fiber

We compared the lignin contents of tropical forages by different analytical methods and evaluated their correlations with parameters related to the degradation of neutral detergent fiber (NDF). The lignin content was evaluated by five methods: cellulose solubilization in sulfuric acid [Lignin (sa)], oxidation with potassium permanganate [Lignin (pm)], the Klason lignin method (KL), solubilization in acetyl bromide from acid detergent fiber (ABLadf) and solubilization in acetyl bromide from the cell wall (ABLcw). Samples from ten grasses and ten legumes were used. The lignin content values obtained by gravimetric methods were also corrected for protein contamination, and the corrected values were referred to as Lignin (sa)p, Lignin (pm)p and KLp. The indigestible fraction of NDF (iNDF), the discrete lag (LAG) and the fractional rate of degradation (kd) of NDF were estimated using an in vitro assay. Correcting for protein resulted in reductions (P < 0.05) in the lignin contents as measured by the Lignin (sa), Lignin (pm) and, especially, the KL methods. There was an interaction (P < 0.05) of analytical method and forage group for lignin content. In general, LKp method provided the higher (P < 0.05) lignin contents. The estimates of lignin content obtained by the Lignin (sa)p, Lignin (pm)p and LKp methods were associated (P > 0.05) with all of the NDF degradation parameters. However, the strongest correlation coefficients for all methods evaluated were obtained with Lignin (pm)p and KLp. The lignin content estimated by the ABLcw method did not correlate (P > 0.05) with any parameters of NDF degradation. There was a correlation (P < 0.05) between the lignin content estimated by the ABLadf method and iNDF content. Nonetheless, this correlation was weaker than those found with gravimetric methods. From these results, we concluded that the gravimetric methods produce residues that are contaminated by nitrogenous compounds. Adjustment for these contaminants is suggested, particularly for the KL method, to express lignin content with greater accuracy. The relationships between lignin content measurements and NDF degradation parameters can be better determined using KLp and Lignin (pm)p methods. (C) 2011 Elsevier B.V. All rights reserved.

Digestive and functional properties of a partially hydrolyzed cassava solid waste with high insoluble fiber concentration

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of type of fiber, site of fermentation, and method of analysis on digestibility of soluble and insoluble fiber in rabbits

The effect of type of fiber, site of fermetation, method for quantifying insoluble and soluble dietary fiber, and their correction for intestinal mucin on fiber digestibility were examined in rabbits. Three diets differing in soluble fiber were formulated (8.5% soluble fiber, on DM basis, in the low soluble fiber [LSF] diet; 10.2% in the medium soluble fiber [MSF] diet; and 14.5% in the high soluble fiber [HSF] diet). They were obtained by replacing half of the dehydrated alfalfa in the MSF diet with a mixture of beet and apple pulp (HSF diet) or with a mix of oat hulls and soybean protein (LSF diet). Thirty rabbits with ileal T-cannulas were used to determine ileal and fecal digestibility. Cecal digestibility was determined by difference between fecal and ileal digestibility. Insoluble fiber was measured as NDF, insoluble dietary fiber (IDF), and in vitro insoluble fiber, whereas soluble fiber was calculated as the difference between total dietary fiber (TDF) and NDF (TDF_NDF), IDF (TDF-IDF), and in vitro insoluble fiber (TDF-in vitro insoluble fiber). The intestinal mucin content was used to correct the TDF and soluble fiber digestibility. Ileal and fecal concentration of mucin increased from the LSF to the HSF diet group (P < 0.01). Once corrected for intestinal mucin, ileal and fecal digestibility of TDF and soluble fiber increased whereas cecal digestibility decreased (P < 0.01). Ileal digestibility of TDF increased from the LSF to the HSF diet group (12.0 vs. 28.1%; P < 0.01), with no difference in the cecum (26.4%), resulting in a higher fecal digestibility from the LSF to the HSF diet group (P < 0.01). Ileal digestibility of insoluble fiber increased from the LSF to the HSF diet group (11.3 vs. 21.0%; P < 0.01), with no difference in the cecum (13.9%) and no effect of fiber method, resulting in a higher fecal digestibility for rabbits fed the HSF diet compared with the MSF and LSF diets groups (P < 0.01).Fecal digestibility of NDF was higher compared with IDF or in vitro insoluble fiber (P < 0.01). Ileal soluble fiber digestibility was higher for the HSF than for the LSF diet group (43.6 vs. 14.5%; P < 0.01) and fiber method did not affect it. Cecal soluble fiber digestibility decreased from the LSF to the HSF diet group (72.1 vs. 49.2%; P < 0.05). The lowest cecal and fecal soluble fiber digestibility was measured using TDF-NDF (P < 0.01). In conclusion, a correction for intestinal mucin is necessary for ileal TDF and soluble fiber digestibility whereas the selection of the fiber method has a minor relevance. The inclusion of sugar beet and apple pulp increased the amount of TDF fermented in the small intestine.

Some functional characteristics of extruded blends of fiber from sugarcane bagasse, whey protein concentrate, and corn starch

Blends of fiber from sugar cane bagasse, corn starch, and whey protein concentrate were extruded. A single screw extruder, equipped with a screw at a constant compression ratio of 1:1 and a die diameter of 3 mm, was used. The best processing conditions were determined according to a central composite rotatable design (α = 1.41) with 5 central points, which gives a total of 13 tests. During the extrusion process the content of insoluble fiber decreased and that of soluble fiber increased. An increase in the contents of fiber and in the barrel temperature resulted in a decrease in the expansion index values and an increase in the water absorption index values; whereas in blends with intermediate fiber contents the effects in these parameters were found to be the opposite. High fiber contents increased penetration force but decreased luminosity, water solubility index values and the adhesive force in gels. The extrusion process improved the functional properties of sugarcane fiber bagasse enabling its addition to diverse alimentary systems.

Composição química do feijão caupi (Vigna unguiculata L. Walp), cultivar BRS-Milênio

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.

Management of canine diabetes

The majority of diabetic dogs appear to have a form of type 1 diabetes analogous to the latent autoimmune diabetes of adults (LADA) in humans. Evidence of acute or chronic pancreatitis occurs in about 40% of diabetic dogs. Blindness caused by cataract formation eventually occurs in the majority of diabetic dogs and is not dependent on glycemic control. Insulin is the mainstay of therapy for diabetic dogs, and a conservative approach to insulin therapy is crucial. Most diabetic dogs require twice-daily dosing with lente or NPH insulin to adequately control their clinical signs. The diet fed should primarily be palatable and nutritionally balanced. Improved glycemic control may be achieved in some dogs if the diet contains increased insoluble fiber.

Caracterização físico-química do amido e da farinha da fruta-pão (Artocarpus altilis) e aplicação em pães de forma

A fruta-pão é um fruto rico em vitaminas e minerais do qual pode ser extraído o amido ou processado à forma de farinha aumentando sua vida de prateleira. Essa farinha pode substituir parcialmente a farinha de trigo em produtos panificáveis. O objetivo do presente estudo foi extrair e analisar algumas características físicas, químicas e tecnológicas do amido nativo de fruta-pão, além de realizar a caracterização físico-química da farinha obtida desse fruto, de suas misturas com a farinha de trigo e verificar a viabilidade destas na elaboração de pão de forma. O amido de fruta-pão foi submetido às análises de umidade, capacidade de ligação de água a frio (CLAF), poder de inchamento (PI), índice de solubilidade (IS), sinérese, microscopia eletrônica de varredura (MEV) e difração de raio X. O amido de milho foi analisado para efeito de comparação. O amido de fruta-pão apresentou maior umidade (18,32%), CLAF (80,33%), PI (198,71 g/g a 90 0C), IS (7,22% a 90 0C) e sinérese (2,69 mL) quando comparado com o amido de milho. Pela análise de MEV, verificou-se que o amido de fruta-pão apresentou grânulos menores que os do amido de milho, mas ambos com formato poliédrico. A difração de raio X permitiu classificar o amido de milho como tipo A e o de fruta-pão como tipo B. As amostras de farinha analisadas continham um percentual de farinha de fruta-pão de 0% (controle), 5%, 10%, 15%, 20% e 100% e foram submetidas às análises de umidade, cinzas, extrato etéreo, carboidratos, proteína, energia, fibra total, solúvel e insolúvel, pH, cor e granulometria. Os mesmos percentuais de substituição foram utilizados para a elaboração dos pães, analisados em relação a umidade, peso, volume, volume específico, altura, perfil de textura, aceitação sensorial e intenção de compra. A substituição da farinha de trigo pela farinha de fruta-pão influenciou na granulometria das misturas, reduziu o teor de proteína de 10,8% para 3,99%, elevou o percentual de carboidratos, cinzas e pH de 73,84%, 0,52% e 5,94 para 83,10%, 2,19% e 6,34 , respectivamente. No entanto, para a umidade, teor de lipídeos e diferença global de cor das amostras não foi verificada influência significativa do percentual de substituição. A farinha de fruta-pão apresentou um maior percentual de fibras totais (21,17%), solúveis (10,39%) e insolúveis (10,77%). Para os pães de forma, o aumento da substituição não influenciou na umidade e no peso dos pães, exceto para a amostra com 100% de farinha de fruta-pão, que apresentou 41,28% de umidade e peso de 588,65 g. Para as demais análises, os maiores percentuais de substituição influenciaram negativamente as características do produto. Em relação a caracterização físico-química das amostras de farinha, o aumento do percentual de substituição influenciou na maioria dos parâmetros avaliados. Para os pães, as formulações com maiores notas hedônicas e com melhor intenção de compra foram as com substituição de 5% e de 10%.

GUAR GUM EFFECTS ON BLOOD SERUM LIPIDS AND GLUCOSE CONCENTRATIONS OF WISTAR DIABETIC RATS1

The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture) on diabetic rats were studied concerning food intake, body weight gain, blood serum cholesterol, triacylglycerols, glucose, LDL-, and HDL-cholesterol concentrations. The effect of gum on indexes of protein absorption and utilization was also investigated. Diets containing 0%, 10% and 20% (w/w) guar gum were fed to diabetic rats for 28 days. In spite of the fact that diabetes elevated blood lipids in all animals, guar gum diet significantly decreased (p <0.05) serum concentrations of cholesterol and triacylglycerols. Furthermore, a concomitant increase in HDL-cholesterol with a substancial elevation of the HDL/LDL cholesterol ratio was found. The most significant result in this assay was the drastic reduction of blood glucose in diabetic rats treated with guar gum diet. The gum promoted a general improvement in the condition of the diabetic rats, in body weight gain and indexes of protein absorption and utilization. The results of this research suggest that guar gum, at concentrations equal to or higher than 10%, should be effective in the treatment of hypercholesterolemia and diabetes, in humans.

Effect of storage and processing of Brazilian flaxseed on lipid and lignan contents

Flaxseed has been widely studied around the world; its incorporation into products habitually consumed by human populations has been stimulated due to its unique nutritional value. The objective of this study was to evaluate the chemical composition of Brazilian flaxseed, to analyze the stability of lipids present in whole flaxseed flour (WFF) or partially defatted flaxseed flour (DFF) stored under several temperatures, and to investigate the effect of bread making on a product containing flaxseed. Whole flaxseed flour presented (g.100 g-1) 25.7 of insoluble fiber, 10.7 of soluble fiber, 38.9 of lipids, and 2.65 of lignan. Defatted flaxseed flour presented 65% less lipids, 36% more fiber and 56% more lignan than whole flaxseed flour. The fatty acid profile was maintained in the defatted flaxseed flour, and it presented a stable composition during storage under ambient temperature, refrigeration, and freezing. The fatty acid profile was similar in the bread containing defatted flaxseed flour after dough development, baking, and storage at room temperature or refrigerated. After baking, 89% of the lignan content was kept in bread. Results show that Brazilian flaxseed has an interesting chemical composition, and that defatted flaxseed, by-product of lipid extraction, presents a good stability to grind and storage under several temperatures. Thus, defatted flaxseed flour can be incorporated in bread, increasing its nutritional and functional value.

Proximate and mineral composition of industrialized biscuits

The aim of this study was to analyze the proximate and mineral composition of 21 types of biscuits. All biscuits showed high fat contents, significantly different (P < 0.05) from those described on the labels, except for three brands. Insoluble fiber fractions were predominant in the analyzed samples. Among the 21 biscuits analyzed, 16 showed food label values 20% higher than those allowed by law, according to RDC 360, for fat, protein, total fiber, calcium, and sodium levels. This difference reached 273% for the sodium content. The calcium content was included only on the label of three samples analyzed, and the values described were significantly lower than those obtained analytically. Considering that biscuits are consumed by people of all age groups and of different socioeconomic levels, the results can contribute to the plans for health policies, such as surveillance of nutritional labeling, ensuring the reliability of the information provided by the food industry and enabling the identification of the relationship between dietary factors and the occurrence of non-transmissible chronic diseases.

Chemical constituents and technological functional properties of acerola (Malpighia emarginata DC.) waste flour

Acerola is a fruit that can be consumed in the form of juice and pulp. However, during its processing, a large amount of waste is generated (seed and bagasse). Adding value to these by-products is of great interest, since their use can enrich foods with nutrients and fiber. In this study, we performed phytochemical screening, determined the proximate and mineral composition, bioactive compounds and the technological functional properties of acerola seed flour and acerola bagasse flour. Seeds were dried in a ventilated oven at ± 45 °C and the bagasse was lyophilized. Samples were ground, stored in flasks protected from light. Phytochemical screening revealed metabolites of nutritional and pharmacological interest and no potentially toxic substances in the flours. Seed flour and bagasse flour showed high levels (g 100 g- 1 of dry matter - DM) of soluble fiber: 4.76 and 8.74; insoluble fiber: 75.76 and 28.58, and phenolic compounds: 4.73 and 10.82, respectively. The flours also showed high absorption of water, oil and emulsion stability, presenting potential for inclusion in meat products and bakery products.

Chemical composition and bioactive compounds of grape pomace (Vitis vinifera L.), Benitaka variety, grown in the semiarid region of Northeast Brazil

Grape pomace (Vitis vinifera L.), Benitaka variety, grown in the semiarid region of Northeast Brazil was evaluated in relation to chemical composition, and content of minerals and functional properties. Its microbiological quality and toxic potential, using Artemia salina sp, were also investigated. The results showed that the flour obtained from these residues had below neutral pH (3.82), moisture (3.33g/100g), acidity of (0.64g of citric acid/100g), and ash (4.65 g/100g). The amount of total dietary fiber (46.17g/100g) stood out quantitatively compared to the content of carbohydrate (29.2g/100 g), protein (8.49g/100g), and lipids (8.16g/100g). The total energy was 224Kcal/100g. With regard to the compounds with functional properties, higher values of insoluble fiber 79% (36.4 g/100 g); vitamin C (26.25 mg of acid ascorbic/100g), and anthocyanins (131mg/100g) were found. The minerals iron, potassium, zinc, manganese, and calcium were present in higher concentrations. There were no significant copper values. The results showed that the grape residues are an important source of nutrients and compounds with functional properties suggesting that they can be incorporated as an ingredient in the diet and/or used as a dietary supplement aiming at health benefits. The residues did not show microbiological contamination and were considered nontoxic.

Qualitative feed restriction for heavy swines: effect on digestibility and weight of organs of digestive tract, and environmental impact of feces

Foram utilizados 50 suínos machos castrados para avaliar o efeito da restrição alimentar qualitativa sobre a digestibilidade dos componentes dietéticos, os órgãos do trato digestório, a composição e a produção fecal. Foram utilizadas cinco dietas experimentais, com níveis de restrição qualitativa de 0, 5, 10, 15 e 20%. Houve redução linear (P<0,001) para todos os coeficientes de digestibilidade, com exceção da fibra em detergente ácido, que apresentou resposta quadrática (P<0,05). Os teores de sólidos totais (P<0,01) e voláteis (P<0,05), e minerais totais (P<0,001) nas fezes aumentaram com os níveis de restrição alimentar, enquanto os níveis de K (P<0,05), Cu (P<0,01) e de N, P, Na, Ca, Mg, Fe e Zn (P<0,001), apresentaram resposta quadrática. A excreção diária de fezes, sólidos totais e voláteis, minerais totais, N, P, K, Mn e Cu (P<0,001), Ca, Na, Mg e Fe (P<0,05) apresentaram aumento em função do nível da restrição alimentar qualitativa. A restrição qualitativa pode ser alternativa para destinação de resíduos da agroindústria, conferindo boas propriedades às fezes suínas, no que diz respeito à utilização para adubação de culturas.

Influência de fontes de nitrogênio no consumo e digestibilidade aparente total e parcial de novilhos alimentados com cana- deaçúcar

The objective of this work was to evaluate the effect of nitrogen sources, using sugarcane supplemented with urea, corn gluten meal-60 or soybean meal. It was evaluated Intake, total and partial apparent digestibility were evaluated using four rumen and duodenal cannulated crossbred steers. The treatments were evaluated in a 4 × 4 Latin square design. The total feces were collected to determine the apparent digestibility on the total intestinal tract. The indigestible acid detergent fiber (iADF) was used as marker of duodenal flux to determine ruminal and intestinal digestibility and dry matter daily flux. The DM, OM, CP, EE, DE, NDF, ADF and TC intakes and digestibility rates were influenced by nitrogen sources, and lower intake was observed in animals fed exclusively with cane sugar compared to animals fed the other experimental diets. Meanwhile the sources of nitrogen did not affect the total digestible nutrients (TDN) values. The RDP sources did not affect the total, ruminal, and intestinal nutrients apparent digestibility. However, the total, ruminal, and intestinal dry matter, and protein apparent digestibility were affected by the RDP sources.

Caracterização de fibras de milho e sua incorporação em barras de cereais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)