Saccharomyces cerevisiae populations and other yeasts associated with indigenous beers (chicha) of Ecuador

ABSTRACT Chicha, a type of beer made mainly with maize or cassava, is a traditional fermented beverage of the Andean region. There have only been a few studies on yeasts associated with chicha fermentation, and the species diversity occurring during the production of this beverage is not known. The objective of this study was to determine the biodiversity of yeasts in chicha, and to characterize the Saccharomyces cerevisiae populations associated with the production of chicha de jora, seven-grain chicha, chicha de yuca, and chicha de morocho in Ecuador. The molecular diversity of S. cerevisiae populations was determined by restriction polymorphism mitochondrial profiles. The beverages were characterized based on their physicochemical parameters. Twenty-six species were identified, and the most prevalent species were S. cerevisiae and Torulaspora delbrueckii. Other yeast species were isolated at low frequencies. Among 121 isolates of S. cerevisiae, 68 different mtDNA molecular profiles were identified. These results showed that chichas are fermented by a high number of different strains of S. cerevisiae. Some other species provided a minor contribution to the fermentation process. The chicha presented generally similar physicochemical parameters to those observed for other traditional fermented beverages, and can be considered as an acid fermented beverage.

Inducible cellulase production from an organic solvent tolerant Bacillus sp. SV1 and evolutionary divergence of endoglucanase in different species of the genus Bacillus

Abstract Bacteria are important sources of cellulases with various industrial and biotechnological applications. In view of this, a non-hemolytic bacterial strain, tolerant to various environmental pollutants (heavy metals and organic solvents), showing high cellulolytic index (7.89) was isolated from cattle shed soil and identified as Bacillus sp. SV1 (99.27% pairwise similarity with Bacillus korlensis). Extracellular cellulases showed the presence of endoglucanase, total cellulase and β-glucosidase activities. Cellulase production was induced in presence of cellulose (3.3 times CMCase, 2.9 times FPase and 2.1 times β-glucosidase), and enhanced (115.1% CMCase) by low-cost corn steep solids. An in silico investigation of endoglucanase (EC 3.2.1.4) protein sequences of three Bacillus spp. as query, revealed their similarities with members of nine bacterial phyla and to Eukaryota (represented by Arthropoda and Nematoda), and also highlighted of a convergent and divergent evolution from other enzymes of different substrate [(1,3)-linked beta-d-glucans, xylan and chitosan] specificities. Characteristic conserved signature indels were observed among members of Actinobacteria (7 aa insert) and Firmicutes (9 aa insert) that served as a potential tool in support of their relatedness in phylogenetic trees.

Desempenho produtivo de frangos de corte e utilização de energia e nutrientes de dietas iniciais com milho classificado ou não e suplementadas com complexo enzimático / Broiler performance and energy and nutrient utilization of starter diets with classified corn or not and supplemented with enzymatic complexes

Dois experimentos foram conduzidos com o objetivo de avaliar o efeito da adição de um complexo enzimático em dietas iniciais elaboradas com milho classificado ou não por mesa densimétrica sobre o desempenho produtivo e a digestibilidade de nutrientes. Foram utilizados 1080 frangos de corte, machos, distribuídos em um delineamento inteiramente ao acaso, em esquema fatorial 2 x 3 (milho classificado ou não vs. dieta controle, dieta controle acrescida de complexo enzimático e dieta controle acrescida de enzimas e com redução de 150kcal de EM), totalizando seis repetições e 36 unidades experimentais. No ensaio de metabolismo, foram utilizadas 96 aves de 21 dias de idade, alojadas em baterias metálicas e distribuídas aos seis tratamentos, com oito repetições e 48 unidades experimentais. Dietas suplementadas com enzima, independentemente da classificação do milho, resultaram em maior (P<0,05) ganho de peso das aves aos 21 dias de idade. A adição de enzimas em dietas com milho classificado melhorou (P<0,05) a conversão alimentar. O CDPB foi maior (P<0,05) para dietas elaboradas com milho classificado, independentemente da suplementação do complexo enzimático, enquanto o CDEE de dietas à base de milho não classificado aumentou (P<0,05) quando as enzimas foram incluídas na deita. Dietas elaboradas à base de milho classificado e acrescidas de complexo enzimático comercial melhoraram (P<0,05) a EMA e a EMAn. As enzimas exógenas podem ser empregadas como ferramenta para melhorar a digestibilidade de nutrientes e de energia dos grãos de milho com variação nutricional.(AU)

Two experiments were performed with the aim of evaluating the effect of inclusion of enzymatic complexes in starter diets containing classified corn or not on the productive performance of poultry and nutrient digestibility. In the performance test 1080 broilers were used, distribuited in a completely randomized design in a factorial 2 x 3 (classified corn or not and corn control diet, control diet plus enzyme complex, and control diet plus enzymes and reduction of 150kcal of ME) and consisting of six replicates and 36 experimental units. In the metabolism trial 96 21-day-old birds were used, housed in metal cages, distributed to six treatments with eight replicates of 48 experimental units. Diets supplemented with enzyme, regardless of the corn classification, resulted in higher (P<0.05) weight gain of birds at 21 days of age. The addition of enzymes in diets with classified corn improved (P<0.05) feed conversion ratio. The CDPB was higher (P<0.05) for diets formulated with classified corn, regardless of the supplementation of the enzyme complex, while the CDEE of not classified corn-based diets increased (P<0.05) when the enzymes were included. Diets formulated with classified corn plus commercial enzymatic complex, improved (P 0.05) the AME and AMEn. Exogenous enzymes may be employed as a tool to improve the digestibility of nutrients and energy of corn with nutritional variation.(AU)

Determinação da energia metabolizável do farelo residual do milho com e sem enzima em dietas para frangos de corte / Determination of the metabolizable energy of residual corn bran with and without enzyme in diets for broilers

O objetivo deste trabalho foi avaliar o valor nutricional e determinar a energia metabolizável do farelo residual de milho (FRM) sem e com o uso da enzima alfa- amilase. Foi realizado um experimento de metabolismo com 180 pintos machos Cobb com 14 dias, distribuídos em um delineamento inteiramente ao acaso, com seis tratamentos, cinco repetições e seis aves por parcela. As dietas experimentais foram: T1: ração referência (RR), T2: 60% T1 + 40% de FRM, T3: RR + enzima, T4: 60% T1 + 40% de FRM com adição de enzima, T5: RR com substituição de 100% do milho pelo FRM e T6: RR com substituição de 100% do milho pelo FRM com adição de enzima. A composição química do FRM foi: 88,33% de matéria seca (MS), 10,23% de proteína bruta (PB), 15,44% de extrato etéreo (EE), 4,33% de cinzas (CZ) e 4555kcal/kg de energia bruta (EB). Os valores dos coeficientes de metabolizabilidade aparente para o FRM sem e com adição de enzima foram, respectivamente, de 73,37% e 76,33% para MS (p=0,0136), 70,44% e 70,39% para PB (p=0,9595) e de 74,79% e 76,77% para EB (p=0,0128). Os valores da energia metabolizável aparente (EMA) e da EMA corrigida para retenção de nitrogênio (EMAn) para o FRM (na base natural) foram de 3322±19 e 3241±18kcal/kg e de 3334±16 e 3261±17kcal/kg, respectivamente, sem e com adição de enzima. A adição da enzima não teve efeito estatístico significativo sobre os valores de EMA e EMAn, entretanto houve efeito positivo no coeficiente de metabolização da energia.(AU)

The aim of this study was to evaluate the nutritional value and the metabolizable energy of residual corn bran (FRM) with and without the use of alpha amylase enzyme. One metabolism assay was done using 180 Ross male broilers at 14 days of age distributed in an entirely randomized design with six treatments, five replications and six broilers per plot. The assay treatments established were: T1: reference diet (RR), T2: 60% T1 + 40% of FRM, T3: T1 (RR) + enzyme addition, T4: 60% T1 + 40% of FRM with enzyme addition, T5: T1 (RR) with 100% replacement of corn by FRM and T6: T1 (RR) with 100% replacement of corn by FRM with enzyme addition. FRM chemical composition was: 88.33% of dry matter (MS), 10.23% of crude protein (PB), 15.44% of crude fat (EE), 4.33% of ashes (CZ) and 4555Kcal/kg of Gross Energy (EB). The FRM apparent metabolizability coefficients with and without the enzyme addition were, respectively, 73.37% and 76.33% for MS (p=0.0136), 70.44% and 70.39% for PB (p=0.9595) and 74.79% and 76.77% for EB (p=0.0128). The apparent metabolizable energy (EMA) and EMA corrected for nitrogen retention values (as is basis) were 3322±19 and 3241±18Kcal/kg and 3334±16 and 3261±17Kcal/kg, respectively, for with and without the enzyme addition to FRM. The enzyme addition had no statistical significance on the EMA and EMAn values, however, a significant effect on energy metabolizability coefficient was observed.(AU)

A new alkalophilic isolate of Bacillus as a producer of cyclodextrin glycosyltransferase using cassava flour

Abstract Cyclodextrin glycosyltransferase (CGTase) catalyzes the conversion of starch into non-reducing cyclic sugars, cyclodextrins, which have several industrial applications. This study aimed to establish optimal culture conditions for β-CGTase production by Bacillus sp. SM-02, isolated from soil of cassava industries waste water lake. The optimization was performed by Central Composite Design (CCD) 2, using cassava flour and corn steep liquor as substrates. The maximum production of 1087.9 U mL−1 was obtained with 25.0 g L−1 of cassava flour and 3.5 g L−1 of corn steep after 72 h by submerged fermentation. The enzyme showed optimum activity at pH 5.0 and temperature 55 °C, and maintained thermal stability at 55 °C for 3 h. The enzymatic activity was stimulated in the presence of Mg+2, Ca+2, EDTA, K+, Ba+2 and Na+ and inhibited in the presence of Hg+2, Cu+2, Fe+2 and Zn+2. The results showed that Bacillus sp. SM-02 have good potential for β-CGTase production.

Caracterização in silico dos genes envolvidos no metabolismo do nitrogênio em milho (Zea mays) / In silico characterization of genes involved in nitrogen metabolism in maize (Zea mays) / Caracterización in silico de genes implicados en el metabolismo de nitrógeno en maíz (Zea mays)

O N é o nutriente mineral requerido pelas plantas em maior quantidade e frequentemente limita o crescimento e produtividade. A partir de uma análise in silico foram identificados 26 genes envolvidos na assimilação do nitrogênio: quatro genes que codificam a enzima nitrato redutase (ZmNR), oito nitrato redutase de transporte (ZmNRT), uma nitrito redutase (ZmNRi), uma nitrito de transporte (ZmNRiT), seis glutamina sintetase (ZmGS), quatro glutamato sintase (ZmGOGAT) e duas glutamato desidrogenase (ZmGDH). A árvore filogenética foi construída onde foi possível observar a formação de cinco grupos distintos de acordo com as funções. A análise da estrutura dos genes mostrou que o número de íntrons variou de 0 a 32. A análise dos domínios conservados mostrou que a maioria dos genes identificados possuem o domínios específicos a função que desempenham na rota de assimilação do N em milho. Além disso, esses genes apresentaram padrões de expressão diferenciais em tecidos e órgãos. Os dados gerados neste trabalho forneceram subsídios para selecionar genes-candidatos para futuras análises funcionais a serem utilizados nos programas de melhoramento de milho.

Nitrogen is a mineral highly requested by plants and often limits both growth and productivity. From an in-silico analysis, a total of 26 genes were identified as being involved in nitrogen assimilation: four genes encoding nitrate reductase enzyme (ZmNR), eight encoding nitrate reductase transporters (ZmNRT), one encoding nitrite reductase (ZmNRi), one encoding nitrite transporter (ZmNRiT), six encoding glutamine synthesis (ZmGOGAT) and two encoding glutamate dehydrogenase (ZmGDH). A phylogenetic tree was generated where the formation of five distinct clusters could be observed according to gene function. Structural genes analysis showed that introns varied from 0 to 32. The analysis of conserved domains showed that most of the identified genes play a domain-specific function in the N assimilation pathway in maize. Moreover, these genes present a differential expression pattern in tissues and organs. Data from this study will provide subsidies to select candidate genes for further functional analyses in maize breeding programs.

N es el nutriente mineral requerido por las plantas en mayor cantidad y a menudo limita el crecimiento y la productividad. Desde un análisis in silico se ha identificado 26 genes implicados en la asimilación de nitrógeno: cuatro genes que codifican la enzima nitrato reductasa (ZmNR), ocho nitrato reductasa de transporte (ZmNRT), un nitrito reductasa (ZmNRi), un nitrito de transporte (ZmNRiT), seis glutamina sintetasa (ZmGS), cuatro sintasa de glutamato (ZmGOGAT) y dos glutamato deshidrogenasa (ZmGDH). El árbol filogenético se ha construido donde ha sido posible observar la formación de cinco grupos distintos de acuerdo con sus funciones. El análisis de la estructura de los genes ha mostrado que el número de intrones ha variado de 0 a 32. El análisis de los dominios conservados mostró que la mayoría de los genes identificados poseen dominios específicos a la función que desempeñan en la ruta de asimilación de N en maíz. Además, esos genes mostraron patrones de expresión diferenciales en tejidos y órganos. Los datos generados en este estudio proporcionan subvenciones para la selección de genes candidatos para posterior análisis funcional, para ser utilizados en programas de mejoramiento de maíz.

Consumo, desempenho e análise econômica da alimentação de cordeiros terminados em confinamento com o uso de dietas de alto grão / Consumption, performance and economic analysis of the feeding of lambs finished in feedlot as the use of high-grain diets

O presente experimento, conduzido no Laboratório de Ovinocultura da Universidade Federal de Santa Maria, teve como objetivo avaliar o efeito do uso de diferentes dietas de alto grão sobre o consumo de nutrientes e o desempenho de cordeiros terminados em confinamento, bem como realizar uma análise econômica da alimentação utilizada para terminação dos animais. Foram utilizados 32 cordeiros machos, castrados, da raça Texel, nascidos de parto simples e desmamados com aproximadamente 50 dias de idade. Os tratamentos foram constituídos por diferentes tipos de grãos, não processados, sendo: grão de milho, grão de aveia branca, grão de aveia preta ou grão de arroz com casca. Os animais foram abatidos quando atingiram o peso vivo de abate pré-estabelecido de 32kg, que corresponde a 60% do peso adulto de suas mães. Cordeiros alimentados com dietas de alto grão de milho apresentam maiores consumos de matéria seca, matéria orgânica, proteína bruta, carboidratos totais e de nutrientes digestíveis totais, menor consumo de fibra em detergente neutro, melhor escore de condição corporal, ganho de peso e conversão alimentar, o que leva à redução do número de dias no confinamento necessários para atingir o peso de abate. Além disso, cordeiros terminados com o uso de dieta de alto grão à base de grão de milho proporcionam melhor resultado econômico quando comparados com cordeiros terminados com as demais dietas de alto grão utilizadas neste experimento. O uso de dietas de alto grão de milho, aveia branca, aveia preta ou arroz com casca para terminação de cordeiros em sistema de confinamento é uma alternativa viável do ponto de vista produtivo. Porém, o uso de grão de milho proporciona melhores resultados produtivos e econômicos.

This experiment was conducted at the Laboratory of Sheep, Federal University of Santa Maria, and aimed to evaluate the effect of using different high-grain diets on nutrient intake and performance of lambs in a feedlot, as well as conduct an economic analysis of feeding used for termination of the animals. A total of 32 Texel breed castrated male lambs, born from a simple birth and weaned at approximately 50 days of age were used. The treatments consisted of different types of grains, unprocessed, as follows: corn grain, white oat grain, black oat grain or grain of rice in the husk. The animals were slaughtered when they reached a pre-established body weight of 32kg for slaughter, which corresponds to 60% of the mature weight of their mothers. Lambs fed diets with high corn grain have higher intakes of dry matter, organic matter, crude protein, total digestible nutrients and total carbohydrate, lower consumption of neutral detergent fiber and better body condition score, weight gain and feed conversion, which leads to reduction in the number of days in confinement needed to reach slaughter weight. In addition, lambs using high-grain diet based grain corn provide better economic results when compared with lambs with other high-grain diets used in this experiment. The use of diets high in grain corn, white oat grain, black oat grain or grain of rice in the husk for finishing lambs in feedlot is a viable alternative from a productive point of view. However, the use of corn grain provides better performance and economic results.

Enhanced alkaline cellulases production by the thermohalophilic Aspergillus terreus AUMC 10138 mutated by physical and chemical mutagens using corn stover as substrate

Abstract A thermohalophilic fungus, Aspergillus terreus AUMC 10138, isolated from the Wadi El-Natrun soda lakes in northern Egypt was exposed successively to gamma and UV-radiation (physical mutagens) and ethyl methan-sulfonate (EMS; chemical mutagen) to enhance alkaline cellulase production under solid state fermentation (SSF) conditions. The effects of different carbon sources, initial moisture, incubation temperature, initial pH, incubation period, inoculum levels and different concentrations of NaCl on production of alkaline filter paper activity (FPase), carboxymethyl cellulase (CMCase) and β-glucosidase by the wild-type and mutant strains of A. terreus were evaluated under SSF. The optimum conditions for maximum production of FPase, CMCase and β-glucosidase were found to be the corn stover: moisture ratio of 1:3(w/v), temperature 45 °C, pH range, 9.0–11.0, and fermentation for 4, 4 and 7 day, respectively. Inoculum levels of 30% for β-glucosidase and 40% for FPase, CMCase gave the higher cellulase production by the wild-type and mutant strains, respectively. Higher production of all three enzymes was obtained at a 5% NaCl. Under the optimized conditions, the mutant strain A. terreus M-17 produced FPase (729 U/g), CMCase (1,783 U/g), and β-glucosidase (342 U/g), which is, 1.85, 1.97 and 2.31-fold higher than the wild-type strain. Our results confirmed that mutant strain M-17 could be a promising alkaline cellulase enzyme producer employing lignocellulosics especially corn stover.

Composição nutricional de milho Bt ensilado com inoculante enzimobacteriano e avaliado em ovinos / Nutritional composition of GMO corn ensiled with bacterial inoculants and sheep digestibility

O objetivo foi avaliar as características agronômicas e químico-bromatológicas de dois híbridos de milho Bt (30F35H e CD397YH) ensilados com inoculante enzimobacteriano. Os teores de FDN foram semelhantes para todas as frações de planta, já o teor de FDA diferiu quanto à planta inteira e colmo, enquanto a lignina diferiu em relação à planta inteira, colmo e sabugo. A DIVMS não apresentou diferença entre os híbridos em nenhuma das frações. As silagens foram produzidas em silos experimentais (aproximadamente 200kg). As concentrações de MS, EE, FDN, NDT e DIVMS não mostraram diferença entre as silagens dos híbridos avaliados. Já os teores de MM, PB, FDA e lignina diferiram. Não houve diferença entre as silagens dos híbridos para os valores de NDT estimado e para a DIVMS. Também não foi observado efeito do inoculante sobre os valores de CHT, CNF, FDN e DIVMS. Conclui-se que o híbrido Pioneer foi superior ao Coodetec em produtividade de MV ha-1, porém a composição nutricional das silagens não diferiu na concentração de NDT e digestibilidade avaliadas em ovinos. Não houve efeito do uso de inoculante na digestibilidade da matéria seca e da fração fibra em detergente neutro das silagens.

The aim was to evaluate the agronomic characteristics and chemical composition of the two corn hybrids (30F35H and CD397YH) ensiled with enzymatic bacterial inoculants. NDF were similar for all plant fractions, since the ADF content differed as to the whole plant and stem, lignin differed in relation to the whole plant, stem and cob. IVDMD did not differ among treatments in any of the fractions. The silages were produced in experimental silos (approximately 200kg). The concentrations of MS, EE, NDF, IVDMD and TDN showed no difference between the silages of hybrids. Since the levels of MM, CP, ADF and lignin differed; there was no difference between hybrids for silage TDN and IVDMD. There was also no effect of the use of inoculants on the values of CHT, NFC, NDF and IVDMD. It is concluded that Pioneer was superior to Coodetec productivity of MV-1 ha. The nutritional composition of silages did not differ in the concentration of TDN and digestibility in sheep assessed. There was no effect of using inoculants on the digestibility of dry matter and neutral detergent fiber content of the silage.

Determinación de humedad en harina precocida de maíz blanco utilizando un horno de microondas doméstico / Determination of moisture in flour precooked white corn using a domestic microwave oven

El contenido de humedad es un parámetro de principal interés entre los índices que regulan la calidad de granos, cereales y sus derivados. Los métodos oficiales para determinar la humedad (AOAC 32.1.03, ISO 6540:1980, NTC 2227:86 y COVENIN 2135:96) tienen la desventaja de consumir mucho tiempo en la determinación porque  requieren la desecación de la muestra en estufa. En este trabajo se compara el método propuesto de secado de la muestra de maíz blanco en un horno doméstico de microondas contra el método rápido convencional de termobalanza infrarrojo y los métodos de referencia oficiales AOAC (32.1.03) y COVENIN (2135:96). Se determinaron las condiciones de análisis: tamaño de muestra, tipo de recipiente, distribución de la muestra, condiciones de operación usando un microondas doméstico de 700 W de potencia, así como el secado en uno o varios pasos. Entre el método propuesto y el método de referencia no se encontraron diferencias estadísticamente significativas a p<0,05; el tiempo de secado se redujo de varias horas a pocos minutos: 4 min con 90% de potencia. Como se puede  concluir que es factible la determinación de humedad por volatilización en una matriz de harina precocida de maíz blanco usando un horno de microondas doméstico.

The moisture content is a primary parameter between indices governing the quality of grains, cereals and cereal products. The official methods for determining moisture (AOAC 32.1.03, ISO 6540: 1980, NTC 2227: 86 COVENIN 2135: 96) have the disadvantage of to be time consuming that require drying oven method. The aim in this paper was compare the proposed method of drying sample of white corn with domestic microwave oven against conventional rapid method of infrared thermobalance and official reference methods AOAC 32.1.03 method and COVENIN 2135:96. Sample size, vessel kind, sample container distribution,   operations conditions using domestic 700 W microwave and also analysis employed to one or more drying steps were determined. Between the proposed and the reference method not statistically significant differences were found at P <0.05; drying time was reduced from several hours to a few minutes: 4 min at 90% power. It can be concluded that the determination of moisture by volatilization in a matrix of precooked white corn flour using a domestic microwave oven is feasible.

Chromium accumulation potential of Zea mays grown under four different fertilizers.

Chromium (Cr) contamination in soil is a growing concern in sustainable agriculture production and food safety. We performed pot experiment with chromium (30 mg/ soil) to assess the accumulation potential of Zea mays and study the influence of four fertilizers, viz. Farm Yard Manure (FYM), NPK, Panchakavya (PK) and Vermicompost (VC) with respect to Cr accumulation. The oxidative stress and pigment (chlorophyll) levels were also examined. The results showed increased accumulation of chromium in both shoots and roots of Zea mays under FYM and NPK supply, and reduced with PK and VC. While the protein and pigment contents decreased in Cr treated plants, the fertilizers substantiated the loss to overcome the stress. Similarly, accumulation of Cr increased the levels of antioxidant enzymes such as catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) indicating the enhanced damage control activity. However, these levels were relatively low in plants supplemented with fertilizers. Our results confirm that the maize can play an effective role in bioremediation of soils polluted with chromium, particularly in supplementation with fertilizers such as farm yard manure and NPK.

Respuesta glicémica al consumo de una barra de cereales-leguminosa (Phaseolus vulgaris) en individuos sanos / Glycemic response to consumption of a cereals and legume (Phaseolus vulgaris) bar on healthy individuals

El objetivo de la presente investigación fue formular una barra de cereales y leguminosa (Phaseolus vulgaris) y evaluar su impacto sobre la respuesta glicémica de individuos sanos, a fin de contribuir con la oferta de alimentos beneficiosos para la salud del consumidor. Para esto se formuló una barra con una mezcla de cereales (maíz y avena) y dos porcentajes (20% y 30%) de Phaseolus vulgaris. Adicionalmente, se preparó una barra de cereales sin leguminosa (barra control). Mediante evaluación sensorial, se seleccionó la barra con 30% de Phaseolus vulgaris, por ser evaluada con mejor sabor y textura, además esa combinación de cereales y leguminosas favorece la complementación aminoacídica y los criterios de formulación previamente establecidos. La caracterización química indicó un contenido de proteínas mayor en la barra con 30% de Phaseolus vulgaris (13,55%), en relación a la barra control (8,5%). Los contenidos de grasa, cenizas y fibra dietética no presentaron diferencias (p>0,05) entre ambas barras evaluadas. Sin embargo, el contenido de fibra soluble y de almidón resistente de la barra seleccionada resultó un 32,05% y 18,67% mayor, respectivamente, que en la barra control, con lo cual se podría contribuir con la disminución de la velocidad de absorción de la glucosa. La barra seleccionada presentó un índice glicémico bajo (49) y carga glicémica intermedia (12,0) en voluntarios sanos, lo que podría traducirse en una posible reducción de la tasa de absorción de glucosa al torrente sanguíneo, asociada a un contenido de carbohidratos de absorción lenta. La barra formulada representa una propuesta de merienda saludable para el consumidor.

The objective of this work was to formulate a cereals and legume (Phaseolus vulgaris) bar and assess its impact on the glycemic response of healthy individuals, in order to contribute to the healthy food supply beneficial to consumers. A mixture of cereals (corn and oats) and different percentages (20 and 30%) of Phaseolus vulgaris was used to formulate the bar. Additionally, a legume cereal bar without legumes (bar control) was prepared. The bar with 30% of Phaseolus vulgaris was selected through sensory evaluation, being scored with better flavor and texture. This combination of cereals and legumes aminoacid improves complementation and reaches the formulation criteria previously established. Chemical characterization indicated a higher protein content in the bar with 30% of Phaseolus vulgaris (13,55%) relative to the bar control (8,5%). The contents of fat, ash and dietary fiber did not differ between the two bars evaluated. However, the soluble fiber and resistant starch of the selected bar was a 32,05% and 18,67%, respectively, than in the control bar; this may contribute to decreasing the rate of glucose uptake. The selected bar presented a low glycemic index (49) and intermediate glycemic load (12,0) in healthy volunteers, which could lead to a possible reduction in the rate of absorption of glucose into the bloodstream, associated with a carbohydrate content of slow absorption. This bar represents a proposal of a healthy snack for the consumer.

Avaliação de modelos de predição da energia metabolizável do milho para suínos / Evaluating models to predict the metabolizable energy of maize for swine

Os objetivos propostos no presente trabalho foram a validação da predição de modelos de regressão linear de 1º grau, dos valores estimados de energia metabolizável (EM) em função dos valores observados de EM do milho, obtidos em ensaios biológicos com suínos. Setenta e quatro registros de composição química e energética do milho foram obtidos na literatura e utilizados para estimar a EM de 41 modelos de predição em função da composição química. A significância dos parâmetros (β0 e β1) da regressão foi avaliada pelo teste t parcial, e a validação da predição dos modelos de 1º grau foi obtida pela aceitação da hipótese de nulidade conjunta β0=0 e β1=1. Os modelos EM7 = 1,099 + 0,740EB - 5,5MM - 3,7FDN; EM9 = 16,13 - 9,5FDN + 16EE + 23PB*FDN - 138MM*FDN e EM13 = 5,42 - 17,2FDN - 19,4MM + 0,709EB são os mais adequados para estimar os valores de EM do milho e podem ser utilizados como ferramenta para formulação de rações para suínos.

The proposed objective of this study was to validate the prediction of linear regression models of the first degree, the estimated values of metabolizable energy (ME) regarding the observed ME values of maize obtained in biological assays with swine. Seventy four records of chemical and energetic composition of maize were obtained from literature and used to estimate the ME of 41 prediction models depending on the chemical composition. The significance of the regression parameters (β0and β1)was evaluated by partial t test and the prediction validation of first degree models was obtained by accepting the null hypothesis β0=0 and β1=1. The ME7= 1.099 + 0.740GE - 5.5MM - 3.7NDF; ME9= 16.13 - 9.5NDF + 16EE + 23CP*NDF - 138MM* NDF and ME13= 5.42 - 17.2 NDF - 19.4MM + 0.709GE models are the most adequate to estimate the metabolizable energy of maize and can be used as a tool to formulate diets for swine.

Characterization of water distribution and activities of enzymes during germination in magnetically-exposed maize (Zea mays L) seeds.

Magnetic seed treatment is one of the physical pre-sowing seed treatments to enhance the performance of crop plants. In our earlier experiment, we found significant increase in germination and vigour characteristics of maize (Zea mays L.) seeds subjected to magnetic fields. Among various combinations of magnetic field (MF) strength and duration, best results were obtained with MF of 100 mT for 2 h and 200 mT for 1 h exposure. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions. Thus, in the present study, changes in water uptake during imbibition and its distribution and activities of germinating enzymes during germination were investigated in maize seeds exposed to static magnetic fields of 100 and 200 mT for 2 and 1 h respectively by nuclear magnetic resonance (NMR) spectroscopy. The magnetically-exposed seed showed higher water uptake in phase II and III than unexposed seed. The longitudinal relaxation time T1 of seed water showed significantly higher values and hence greater molecular mobility of cellular water in magnetically-exposed seeds as compared to unexposed. Component analysis of T2 relaxation times revealed the early appearance of hydration water with least mobility and higher values of relaxation times of cytoplasmic bulk water and hydration water in magnetically-exposed over unexposed seeds. Activities of -amylase, dehydorgenase and protease during germination were higher in magnetically-exposed seeds as compared to unexposed. The quicker germination in magnetically-exposed seeds might be due to greater activities of germination related enzymes, early hydration of membranes as well as greater molecular mobility of bulk and hydration water fractions.

Digestibilidade da silagem de grãos úmidos de milho com diferentes granulometrias para suínos / Digestibility of high moisture corn grain silage with different particle size for swines

Avaliou-se a composição química e determinaram-se os valores de energia digestível (ED) e metabolizável (EM), os coeficientes de digestibilidade da matéria seca (CDMS), da proteína bruta (CDPB), da matéria mineral (CDMM); do extrato etéreo (CDEE); da fibra bruta (CDFB), da energia bruta (CDEB) e do extrativo não nitrogenado (CDENN) e os coeficientes de digestibilidade (CDEB) e metabolizabilidade da energia bruta (CMEB) da silagem de grãos úmidos de milho (SGUM). Foram utilizados 20 suínos, com peso vivo inicial de 28,89±4,9kg, distribuídos em gaiolas de metabolismo. Foi utilizada uma única SGUM, com quatro diferentes granulometrias 513, 587, 717 e 1363µm, que substituiu em 30 por cento a dieta-referência. Os CDMS, CDPB, CDEE, CDMM e CDENN diminuíram com o aumento da granulometria da SGUM. Os CDEB e CMEB também diminuíram de 89,0 para 94,3 por cento, e de 82,9 para 88,5 por cento, respectivamente. Os valores energéticos variaram de 4439 a 4493kcal EB/kg, de 3999 a 4194kcal ED/kg e de 3729 a 3939kcal EM/kg, na matéria seca. Os CDEB e CMEB se reduziram até os diâmetros geométricos médios de 754 e 831µm, respectivamente. A digestibilidade dos nutrientes da SGUM foi influenciada negativamente ao se aumentar o diâmetro geométrico médio das partículas.

The chemical composition; the values of digestible (DE) and metabolizable (ME) energy; the coefficients of digestibility of dry matter (CDDM), crude protein (CDCP), mineral matter (CDMM), ether extract (CDEE), crude fiber (CDFB), crude energy (CDCE), and non nitrogen extractive (CDENN); as well as the coefficient of metabolizability of gross energy (CMGE) of high moisture corn grain silage (HMCGS) were evaluated. Twenty swines, averaging 28.89±4.9kg of live weight, randomly allotted in metabolism cages were used. HMCGS with different particle sizes 513, 587, 717, and 1363µm, replacing 30 percent of basal diet was used. CDDM, CDCP, CDEE, CDMM, and CDENN decreased as the particle size of the HMCGS increased. CDGE and CMGE also decreased from 89.0 to 94.3 percent and from 82.9 to 88.5 percent, respectively. The energy values varied from 4,439 to 4,493kcal of GE/kg, 3,999 to 4,194kcal DE/kg, and 3,729 to 3,939kcal ME/kg, in dry matter basis. CDGE and CMGE decreased until the medium geometric diameters of 754 and 831µm, respectively, and the digestibility of the nutrients of the HMCGS was negatively influenced as the medium geometric diameter of the particles increased.

Characterization of water binding and germination traits of magnetically exposed maize (Zea mays L.) seeds equilibrated at different relative humidities at two temperatures.

A study was undertaken to characterize the water sorption properties and enhancement in germination and seedling vigour of maize (Zea mays L.) seeds exposed to static magnetic fields of 100 mT and 200 mT for 2 and 1h, respectively. Water sorption isotherms were constructed for magnetically- exposed and unexposed seeds by equilibrating over different saturated salt solutions at 25 and 35°C. The germination and vigour parameters were evaluated for magnetically-exposed and unexposed seeds, equilibrated over the wide range of relative humidities (RHs) at 25 and 35°C. Moisture content increased with increase in RH and decreased with increase in equilibrium temperature. The germination and vigour reduced at high and very low humidities. Magnetically-exposed seeds maintained higher germination and vigour at both temperatures and all RHs, indicating the better quality of magnetically- exposed seeds. The leachate conductivity of magnetically-exposed seeds was lower than unexposed seeds at all RHs, suggesting better membrane integrity in magnetically-exposed seeds. Analysis of the isotherms using D’Arcy-Watt equation revealed that irrespective of the temperature, in magnetically-treated seeds weak binding sites were more and strong and multi-molecular binding sites were less compared to the unexposed seeds. Total binding sites were more in unexposed control seeds. The modification of binding properties of seed water and increased seed membrane integrity in magnetically-exposed seeds might have enhanced the germination traits and early seedling growth of maize.

Substituição do milho por polpa cítrica em rações com alta proporção de concentrado para cordeiros confinados / Replacement of corn by citrus pulp in high grain diets fed to feedlot lambs

A polpa cítrica desidratada (PC) é um subproduto altamente energético e com potencial para substituir o milho em rações de cordeiros desmamados precocemente. Dois experimentos foram realizados para avaliarem-se os efeitos da substituição do milho por PC no desempenho de cordeiros e na digestibilidade das rações. No Experimento 1, 64 cordeiros Santa Inês, com peso vivo inicial de 18 (±0,6) kg e 73 (±1) dias de idade, foram utilizados para avaliar o ganho de peso médio diário (GMD), o consumo de matéria seca (CMS) e a conversão alimentar (CA). No experimento 2, 12 cordeiros foram mantidos em gaiolas para ensaio de metabolismo para determinar a digestibilidade aparente das rações no trato digestório total e o metabolismo de nitrogênio. Nos dois experimentos, os cordeiros foram alimentados com uma ração contendo 90 por cento de concentrado (milho moído e/ou PC, farelo de soja e minerais) e 10 por cento de feno de "coastcross" (Cynodon spp). A PC foi adicionada em 23,7; 46,1 e 68,4 por cento da MS, substituindo o milho em 33, 67 e 100 por cento, respectivamente. No Experimento 1, foi observado a maximização do GMD (267g dia-1) e do CMS (1,01kg dia-1), até o teor de substituição de 33 por cento do milho pela PC. No Experimento 2, houve efeito linear (P<0,05) decrescente na digestibilidade da MS (P<0,03) e do PB (P<0,10). Por outro lado, a digestibilidade da FDN aumentou linearmente com a adição da PC. Não houve diferença (P>0,05) entre os tratamentos na digestiblidade aparente da matéria orgânica e no balanço de nitrogênio.

Dried citrus pulp (DCP) is a high energy byproduct and may be used to replace corn in early weaned lamb diets. Two trials were performed to evaluate the effects of replacing corn by dried citrus pulp on lamb performance and diet digestibility. In trial 1, 64 Santa Ines ram lambs (initial BW 18 ± 0.6kg and 73 ± 1 days old) were used to evaluate average daily gain (ADG), dry matter intake (DMI) and feed conversion (FC). In trial 2, 12 ram lambs were placed in metabolism crates to evaluate N metabolism and apparent digestibility of diets. In both trials, lambs were fed a 90 percent concentrate (ground corn and/or DCP, soybean meal and minerals) and 10 percent coastcross hay (Cynodon spp) diet. DCP was added at 23.7, 46.1 and 68 percent (diet DM) replacing corn by 33, 67 and 100 percent, respectively. In Trial 1, the higher ADG (267g day-1) and DMI (1.01kg day-1) were observed when DCP replaced corn by 33 percent in the diet. In Trial 2, apparent digestibility of DM (P<0.03) and CP (P<0.10) showed a linear decrease. However, NDF digestibility increased linearly (P<0.04) with the addition of DCP. OM digestibility and N metabolism were similar among treatments.

Relationship between structural and biochemical characteristics and texture of corn grains

The texture of corn grains is a fundamental characteristic for the industry as well as for grain producers and processors. To further understand the mechanisms involved in grain hardness, contrasting corn cultivars for grain hardness and protein quality were evaluated. The cultivars were Cateto L237/67 (hard endosperm and low protein value), QPM BR 451 (semi-hard endosperm and high protein value); Bolivia-2 (floury endosperm and low protein value), and Opaque-2 (floury endosperm and high protein value). Evaluations were carried out at 10, 20, 30, 40, 50, and 60 days after pollination in developing corn grains and in the mature grain. In developing grains, evaluation consisted in the determination of the area, percentage of starch granules, distribution of starch granules, and protein bodies in the endosperm. In mature corn grains, the parameters evaluated were: density, percentage of total proteins, levels of lysine and tryptophan, and banding pattern of zeins. The results indicate that the higher physical resistance of corn grains from the cultivars analyzed is influenced by the high percentage of total proteins, high synthesis of 27-kDa zeins, presence of protein bodies, and perfect organization of starch granules in the endosperm, independent of their sizes.

Substituição de milho por sorgo baixo tanino em dietas para suínos: digestibilidade e metabolismo / Replacement of corn by low tannin sorghum in pig diets: digestibility and metabolism

Um experimento foi realizado para avaliar os efeitos digestivos e metabólicos da substituição de milho por sorgo em dietas para suínos. Foram utilizados 12 suínos machos castrados, meio-irmãos paternos, com peso vivo médio inicial de 40,8kg, mantidos em gaiolas metabólicas. O delineamento experimental foi inteiramente casualizado com três tratamentos (T1 = dieta controle; T2 = substituição de 50 por cento do milho por sorgo e T3 = substituição de 100 por cento) e quatro repetições. As digestibilidades da proteína e da energia brutas foram 5 e 4 por cento superiores (P<0,05), respectivamente, nos suínos alimentados com a dieta que tinha 50 por cento de substituição, comparadas àquela com substituição total do milho por sorgo. A substituição total do milho por sorgo reduziu (P<0,05) as digestibilidades, em relação à dieta-controle, em 3 por cento para MS, 8 por cento para PB e 5 por cento para EB. O N fecal foi 25 por cento maior (P<0,05), o N absorvido 10 por cento menor (P<0,05) e a excreção fecal de energia 15 por cento maior (P<0,05) para a dieta com substituição total, em relação à dieta-controle. A excreção fecal de N e energia e a absorção de N são influenciadas negativamente pela substituição total de milho por sorgo nas dietas. A substituição em até 50 por cento do milho por sorgo em dietas para suínos não influi na digestibilidade das dietas e no metabolismo dos animais.

An experiment was carried out to evaluate metabolic and digestive effects replacement of corn by sorghum in pig diets. Twelve half brothers barrows weighing 40.8kg and housed in metabolic cages in a completely randomized design with three treatments (T1 = control diet; T2 = replacement of 50 percent corn by sorghum and T3 = replacement of 100 percent) with four replicates. Crude protein and gross energy the digestibilities were 5 percent and 4 percent higher (P<0.05), respectively, for pigs fed 50 percent of corn replacement diet, in comparison with the diet where corn was totally replaced by sorghum. Total replacement of corn by sorghum diets decreased (P<0.05) the digestibilities, in comparison to control diet, in 3 percent for DM, 8 percent for CP and 5 percent for GE. Fecal N was 25 percent higher (P<0.05), absorbed N was 10 percent lower (P<0.05), and the fecal excretion energy was 15 percent higher (P<0.05) for total substitution diet in comparison to control diet. Fecal excretion and absorption of nitrogen are negatively influenced by total replacement of corn by sorghum in the diets. Replacements of up to 50 percent of corn by sorghum in pig diets do not affect the digestibility diet and metabolism of animals.