Effect of chemical oxidizers and enzymatic treatments on the baking quality of doughs formulated with five Canadian spring wheat cultivars.

For many years, the baking industry has been using chemical improvers as a way for compensating for flour quality variation due to growing conditions or wheat cultivar. However, the replacement of chemical dough improvers with natural ingredients or processing aids (i.e. enzymes) allows for the production of 'cleaner label' products. In the present research, dough and bread properties (mixing time, oven rise, loaf volume, crumb firmness and C-cell parameters) were analysed as a function of wheat cultivar (Glenn, Harvest, Lillian, CDC Plentiful and Stettler), additive-type (ascorbic acid, azodicarbonamide, glucose oxidase and fungal xylanase) and concentration. Overall, the cultivar Glenn appeared to have improved baking performance relative to the other cultivars, regardless of the additive and additive concentration. On the other hand, Stettler showed poorer baking quality and performance even with the addition of oxidizers and enzymes in relation to the control. The concentration of additive was found to have little or no effect on improving baking properties within each cultivar. Enzymes had similar or better performance than oxidizers in most cases.

Computer Vision Classification of Barley Flour Based on Spatial Pyramid Partition Ensemble.

Imaging sensors are largely employed in the food processing industry for quality control. Flour from malting barley varieties is a valuable ingredient in the food industry, but its use is restricted due to quality aspects such as color variations and the presence of husk fragments. On the other hand, naked varieties present superior quality with better visual appearance and nutritional composition for human consumption. Computer Vision Systems (CVS) can provide an automatic and precise classification of samples, but identification of grain and flour characteristics require more specialized methods. In this paper, we propose CVS combined with the Spatial Pyramid Partition ensemble (SPPe) technique to distinguish between naked and malting types of twenty-two flour varieties using image features and machine learning. SPPe leverages the analysis of patterns from different spatial regions, providing more reliable classification. Support Vector Machine (SVM), k-Nearest Neighbors (k-NN), J48 decision tree, and Random Forest (RF) were compared for samples' classification. Machine learning algorithms embedded in the CVS were induced based on 55 image features. The results ranged from 75.00% (k-NN) to 100.00% (J48) accuracy, showing that sample assessment by CVS with SPPe was highly accurate, representing a potential technique for automatic barley flour classification.

High molecular weight glutenin subunits and the classification used in Brazilian wheat industry.

Industrial wheat quality flour is related to gluten amount in grain. This study aimed to evaluate the relationship between high molecular weight (HMW) glutenins obtained by SDS-PAGE and gluten strength (W) obtained by the alveograph test and cropping environmental effect on wheat flour quality for Brazilian industry. Fifty-one cultivars/breeding lines were evaluated in three environments. The W value and HMW glutenin score were evaluated by SDS-PAGE. The environment effects on wheat flour were also evaluated. There was a relationship between the W value used in wheat flour industrial classification and score 10 of HMW glutenins, but there was no relation with scores 9 or lower. Cultivars/breeding lines with score 10 of HMW glutenin are less susceptible to environmental effects and produce breeding type wheat flour (W value ≥300) of interest for industry. The cultivars/breeding lines with score 10 for HMW glutenins is the main choice for a wheat breeding program.

Efeitos do ácido fólico não metabolizado na metilação global do DNA, na expressão de RNAm dos genes de DHFR, MTHFR, interferon-γ, TNF-α e interleucina-8, e na citotoxicidade das células NK / Effects of unmetabolized folic acid on global DNA methylation, on mRNA expression of DHFR, MTHFR, interferon-α, TNF-α and interleukin-8 genes, and on NK cells cytotoxicity

Com o início da fortificação de farinhas com ácido fólico (AF) no Brasil, a partir 2004, a população passou a estar exposta de modo compulsório a maiores quantidades desta vitamina. Sabe-se que o AF na sua forma sintética pode não ser completamente convertido para formas metabolicamente ativas, levando ao aparecimento de uma fração não metabolizada no organismo. Este fato é mais preocupante nos indivíduos que além da fortificação, fazem uso terapêutico dessa vitamina, como em pacientes com anemias hemolíticas (esferocitose hereditária (EH), ß-talassemia heterozigótica (ß-TH), entre outras). O objetivo desse estudo foi avaliar se as concentrações séricas de AF não metabolizado (UMFA) afetam a metilação global do DNA; a expressão de RNAm de genes da DHFR, MTHFR, interferon-γ, TNF-α e interleucina (IL)-8; e a citotoxicidade de células NK. Foram incluídos 27 pacientes com EH, 50 indivíduos com ß-talassemia heterozigótica (ß-TH) e 136 indivíduos saudáveis. Outros 30 indivíduos saudáveis foram incluídos num estudo de intervenção com 5mg/dia de AF durante 90 dias. Foram realizadas as análises de: ácido fólico sérico, eritrocitário e UMFA, vitamina B12, homocisteína total; expressões de RNAm dos genes de MTHFR, DHFR, IFN-γ, TNF-α e IL-8; citotoxicidade das células NK; metilação global do DNA e citocinas séricas IL6, IL-8, IL10, IFN-γ e TNF-α. Resultados: Os pacientes EH apresentaram maiores concentrações de AF (sérico, eritrocitário e UMFA) que seus controles, sendo que 55,5% (método microbiológico) e 74,1% (método LC-MS/MS) apresentaram concentrações suprafisiológicas da vitamina, e 74,1% apresentaram concentrações aumentadas de UMFA. No grupo ß-TH foi observado maiores concentrações de folato eritrocitário comparado ao controle e 22% dos indivíduos tinham concentrações suprafisiológicas de AF. No estudo de intervenção, após 45 e 90 dias de uso de AF as concentrações suprafisiológicas estavam presentes em 93,3% dos indivíduos e 100% deles apresentavam concentrações aumentadas de UMFA. Não foram observadas diferenças nas taxas de metilação global do DNA entre os grupos EH e ß-TH quando comparados aos seus controles e não foi verificada correlação entre metilação global e concentrações de UMFA. Tanto EH quanto ß-TH apresentaram maior expressão de RNAm de IL-8, quando comparados aos seus controles. No grupo de intervenção houve maior expressão de IL-8 após 45 dias de uso de AF quando comparado ao período pré-intervenção. Foi mostrada uma correlação inversa entre as concentrações de folato eritrocitário com o número de células NK no grupo EH e com a capacidade citotóxica das células NK no grupo total (EH + controle). No grupo intervenção foi observado menor número e menor capacidade citotóxica das células NK após 90 dias de uso de AF. Conclusões: O uso de AF 5mg/dia foi associado com aumento expressivo das concentrações de folato sérico, eritrocitário, UMFA, na expressão de RNAm de genes da citocina inflamatória IL-8 e redução do número e da citotoxicidade das células NK. Dessa forma, altas doses de AF podem resultar em alterações de componentes do sistema imune podendo prejudicar os mecanismos de vigilância celular das células NK. Os nossos achados sugerem que é importante o acompanhamento terapêutico dos pacientes que fazem uso de AF, especialmente aqueles indivíduos que fazem uso crônico desta vitamina por longo tempo, como os pacientes com anemias hemolíticas, mulheres que desejam engravidar e gestantes

With the beginning of the fortification of flour with folic acid (FA) in Brazil, since 2004, the population has been exposed compulsorily to larger amounts of this vitamin. It is known that FA in its synthetic form can not be completely converted to metabolically active forms, leading to the appearance of an unmetabolized fraction in the body. This fact is more worrying in subjects beyond fortification, make therapeutic use of this vitamin, such as patients with hemolytic anemia (hereditary spherocytosis (HS), ß-thalassemia heterozygotic (ß-TH), among others). The aim of this study was to evaluate if serum concentrations of unmetabolized FA (UMFA) affect the global DNA methylation; mRNA expression of DHFR, MTHFR, interferon-γ, TNF-α and interleukin (IL)-8 genes; and on cytotoxicity of NK cells. It was included 27 patients EH, 50 subjects ß-TH and 136 healthy subjects. Another 30 healthy subjects were included in an intervention study with 5 mg/FA daily during 90 days. Analyzes performed were: serum and erythrocyte folate, and UMFA, vitamin B12, tHcy; mRNA expression of MTHFR, DHFR, IFN-γ, TNF-α and IL-8 genes; cytotoxicity of NK cells; global DNA methylation and serum cytokines IL6, IL-8, IL10, IFN-γ and TNF-α. Results: EH patients presented higher FA concentrations (serum, erythrocytes and UMFA) than controls ones, and 55.5% (microbiologic method) and 74.1% (LC-MS/MS method) showed supraphysiologic concentrations of vitamin, and 74.1% presented increased concentrations of UMFA. In ß-TH group, it was observed higher erythrocyte folate concentrations compared with the control and 22% of subjects had supraphysiological concentrations of FA. In the intervention study, after 45 and 90 days of FA use, supraphysiological concentrations were present in 93.3% of subjects and 100% of them showed increased concentrations of UMFA. It was not observed differences in global methylation of DNA between EH and ß-TH groups when compared to their controls and it was not observed significant correlation between global DNA methylation and UMFA levels. Both EH and ß-TH showed higher mRNA expression of IL-8 gene, when compared to controls. In the intervention group, there was higher mRNA expression of IL-8 gene after 45 days of FA use when compared to pre-intervention period. It was demonstrated an inverse correlation between erythrocyte folate levels and the number of NK cells in EH group; and cytotoxic capacity of NK cells on total group (EH + control). In intervention group, it was observed fewer number and lower cytotoxic capacity of NK cells after 90 days of AF use. Conclusions: The use of AF 5mg daily was associated with a significant increase in serum and erythrocytes folate levels, accompanied by increase in UMFA levels, an increase in mRNA expression of IL-8 gene, and reduction of the number and the cytotoxicity capacity of NK cells. Thus, high doses of AF can result in modifications of the immune system components, which may damage the cell surveillance mechanisms of NK cells. Our findings suggest that is important the therapeutic follow up of patients that are using AF, especially those subjects with chronic use of this vitamin, such as patients with hemolytic anemia, women who wish to become pregnant and pregnant women

Classification of spelt cultivars based on differences in storage protein compositions from wheat.

Wholemeal flours from 62 spelt and 13 wheat cultivars were studied. The quantitative protein compositions of the Osborne fractions determined by reversed-phase high-performance liquid chromatography, showed that the chromatograms of the reduced gliadin fractions were most suitable for the distinction of spelt from wheat and for the classification of spelt. The patterns of the reduced spelt gliadins showed one to three markers that were not present in wheat. Based on these markers, spelt cultivars were classified into three groups ranging from 'typical spelt' to 'similar to common wheat'. Marker 1 was identified as ω1,2-gliadin and markers 2, 3a and 3b were identified as γ-gliadins by means of N-terminal sequence analysis and determination of the relative molecular mass by mass spectrometry. As glutenin-bound ω-gliadins were present in wheat and absent in spelt, this protein type may be used to detect and quantitate small amounts of wheat in spelt products.

(1)H NMR spectroscopy for the in vitro understanding of the glycaemic index.

The glycaemic index (GI) characterises foods by using the incremental area under the glycaemic response curve relative to the same amount of oral glucose. Its ability to differentiate between curves of different shapes, the peak response and other aspects of the glycaemic response is contentious. The present pilot study aimed to explore the possibility of using 1H NMR spectroscopy to better understand in vivo digestion characteristics as reflected in the glycaemic response of carbohydrate-rich foods; such an approach might be an adjunct to the in vivo GI test. The glycaemic response of two types of raw wheat flour (2005 from Griffith NSW, Chara, Row 10, Plot 6:181 and store-bought Colese Plain Flour) and a cooked store-bought flour was tested and compared with results recorded during the in vitro enzymatic digestion of the wheat flour samples by glucoamylase from Aspergillus niger (EC 3.2.1.3) as monitored by 1H NMR spectroscopy. Comparing the digestion time courses of raw and cooked wheat starch recorded in vitro strongly suggests that the initial rate of glucose release in vitro correlates with the glycaemic spike in vivo. During the in vitro time courses, approximately four times as much glucose was released from cooked starch samples than from raw starch samples in 90 min. Monitoring enzymatic digestion of heterogeneous mixtures (food) by 1H NMR spectroscopy showcases the effectiveness of the technique in measuring glucose release and its potential use as the basis of an in vitro method for a better understanding of the GI.

Application of Comet assay to assess the effects of white bean meal on DNA of human lymphocytes

This study was conducted to evaluate the potential induction of genotoxic effects of white bean flour using the Comet assay. The test was conducted with human lymphocytes present in whole blood immediately after collection, by incubation with white bean flour in three concentrations (3.92, 9.52 and 18.18 mg/mL) at 37 ºC for 4 h followed by preparation of slides. Samples were considered positive (above 20% damage) when the damage observed to cellular DNA was higher than the negative control. No genotoxic potential was found at the doses tested. However, it would be premature to suggest absence of risk to human health of DNA damage since the exposure of cells to the extract was restricted to four hours rather than a whole cell cycle. Additionally, further information on toxicology should be obtained in future studies.

Este estudo foi realizado para avaliar o potencial de indução de efeitos genotóxicos da farinha de feijão branco utilizando o teste do Cometa. O ensaio foi realizado com linfócitos humanos presentes no sangue imediatamente após a coleta, por incubação com farinha de feijão branco em três concentrações (3,92, 9,52 e 18,18 mg/mL) a 37 ºC por 4 h, seguida de preparação das lâminas. As amostras foram consideradas positivas (acima de 20% de dano), quando os danos observados no DNA celular foram maiores do que o controle negativo. Verificou-se que as doses testadas não mostraram potencial genotóxico. No entanto, seria prematuro fazer recomendações sobre o padrão de riscos para a saúde humana resultantes de danos ao DNA já que exposição das células ao extrato foi restrito ao período de quatro horas e não durante um ciclo celular completo. Além disso, outras informações sobre a toxicologia devem ser obtidas no futuro.

Efeito hipoglicemiante da farinha do fruto de maracujá-do-mato (Passiflora nitida Kunth) em ratos normais e diabéticos / Hypoglycemic effect of Passiflora nitida Kunth fruit flour on normal and diabetic rats

A região amazônica é detentora de uma vasta biodiversidade de frutos, porém pouco explorada quanto o seu potencial nutricional e econômico. Dentre estes frutos destaca-se o maracujá-do-mato (Passiflora nitida Kunth), espécie silvestre, de fruto comestível, com sabor exótico e de boa aceitabilidade para consumo. No presente estudo objetivou-se analisar as características nutricionais do mesocarpo do fruto da P. nitida e avaliar o potencial hipoglicemiante em ratos normais e diabéticos. A farinha do mesocarpo do fruto foi elaborada e analisada quanto a composição centesimal. A atividade hipoglicemiante foi avaliada por meio de dois modelos experimentais em ratos Wistar. O mesocarpo apresentou baixa concentração de macronutrientes e alto teor de umidade, cinzas e fibras. No experimento agudo, após 15 minutos da administração da sacarose, os níveis glicêmicos foram de 146±12 mg dL-1 no grupo controle e 112±2,5 mg dL-1, no grupo que recebeu 1g kg-1 de peso da farinha. No experimento crônico, após 21 dias, houve redução de 493 mg dL-1 para 302 mg dL-1 (38,7 %) e 195 mg dL-1 (60,4%) na glicemia nos grupos que foram tratados com 20 e 40% de ração enriquecida com a farinha, respectivamente, em relação ao grupo diabético não tratado. Em ambos os modelos experimentais, a farinha do mesocarpo mostrou-se eficaz na redução da glicemia. O fruto de P. nitida mostrou-se um produto natural em potencial para o controle da glicemia no diabetes.

The Amazon region has a vast biodiversity of fruits but is little explored as to its nutritional and economic potential. Among these fruits is "maracuja-do-mato" (Passiflora nitida Kunth), a wild species of edible fruit with exotic flavor and good acceptability for consumption. The aim of the present study was to analyze the nutritional characteristics of P. nitida fruit mesocarp and to evaluate its hypoglycemic potential in normal and diabetic rats. Flour from the fruit mesocarp was prepared and analyzed as to its centesimal composition. Hypoglycemic activity was assessed by means of two experimental models in Wistar rats. The mesocarp showed low concentration of macronutrients and high humidity, ash and fiber content. In the acute experiment, after 15 minutes of sucrose administration, glucose levels were 146 ± 12 mg dL-1 in the control group and 112 ± 2.5 mg dL-1 in the group receiving 1 g kg-1 flour weight. In the chronic experiment, after 21 days, glucose levels reduced from 493 mg dL-1 to 302 mg dL-1 (38.7%) and 195 mg dL-1 (60.4%) in the groups treated with 20 and 40% animal food enriched with the flour, respectively, in relation to the diabetic untreated group. In both experimental models, the mesocarp flour was effective in reducing blood glucose. P. nitida fruit seems to be a potential natural product in the glycemic control of diabetes.

Relationship between population growth of the red flour beetle Tribolium castaneum and protein and carbohydrate content in flour and starch.

The effects of eight diets (atta flour, wheat flour, self-rising flour, rice flour, custard powder, corn flour, tapioca starch, and potato starch) on the development of the red flour beetle, Tribolium castaneum (Herbst), reared at 29-31 degrees C and 66-70% RH were assessed. Five pairs of male and female T. castaneum were reared on the respective diets for 28 d before the experimental setup was dismantled and adult counts were recorded. In another experiment, the insects were allowed to mate and oviposit in each flour or starch type over a period of 7 d before being removed. The counting of pupae and adult emergence began on the day of emergence and was continued on a daily basis until day 140. Proximate analysis was performed for chemical composition of each diet, and the numbers of new adults that developed were found to be positively correlated (r2 = 0.97; P < 0.05) with the protein content and negatively correlated (r2 = 0.93; P < 0.05) with the carbohydrate content. For T. castaneum, the suitable diets were ranked as follows: atta flour > wheat flour > self-rising flour > rice flour > custard powder > corn flour > tapioca starch > potato starch. T. castaneum larval development to the pupal and adult stages developed significantly faster in atta flour (P < 0.05) than in the other diets, and the greatest number of progeny was produced from beetles reared on atta flour. Fewer adults emerged from wheat flour, self-rising flour, and rice flour, and no new emergences were recorded for the remaining diets. Developmental rate was much slower in beetles reared on diets in which a low number in progeny was produced. These data illustrate that different diets can influence the sustainability of these insects and affect their development and growth.

Influence of geographical origin and flour type on diversity of lactic acid bacteria in traditional Belgian sourdoughs.

A culture-based approach was used to investigate the diversity of lactic acid bacteria (LAB) in Belgian traditional sourdoughs and to assess the influence of flour type, bakery environment, geographical origin, and technological characteristics on the taxonomic composition of these LAB communities. For this purpose, a total of 714 LAB from 21 sourdoughs sampled at 11 artisan bakeries throughout Belgium were subjected to a polyphasic identification approach. The microbial composition of the traditional sourdoughs was characterized by bacteriological culture in combination with genotypic identification methods, including repetitive element sequence-based PCR fingerprinting and phenylalanyl-tRNA synthase (pheS) gene sequence analysis. LAB from Belgian sourdoughs belonged to the genera Lactobacillus, Pediococcus, Leuconostoc, Weissella, and Enterococcus, with the heterofermentative species Lactobacillus paralimentarius, Lactobacillus sanfranciscensis, Lactobacillus plantarum, and Lactobacillus pontis as the most frequently isolated taxa. Statistical analysis of the identification data indicated that the microbial composition of the sourdoughs is mainly affected by the bakery environment rather than the flour type (wheat, rye, spelt, or a mixture of these) used. In conclusion, the polyphasic approach, based on rapid genotypic screening and high-resolution, sequence-dependent identification, proved to be a powerful tool for studying the LAB diversity in traditional fermented foods such as sourdough.

Ultrasonic characterisation of flour-water systems: a new approach to investigate dough properties.

The viscoelastic properties of dough are of great interest in the baking industry as they affect the quality of the final product. In this work, the viscoelastic properties of dough were investigated using ultrasonic techniques and then compared with traditional methods. It has been shown that ultrasonics provides a non-destructive, rapid and low cost technique for the measurement of physical food characteristics. A common protocol for dough preparation was used for each type of measurement. Experimental results on more than 30 different flour quality and dough processing were presented. The measurements were correlated and compared with traditional dough quality tests. In addition, the capability of ultrasound measurements for discriminating flours for different purposes was also studied, showing the potential of ultrasound as an alternative measurement method to discriminate types of flours for different purposes.

Classification of cereal flours by chemometric analysis of MIR spectra.

Different kinds of cereal flours submitted to various technological treatments were classified on the basis of their mid-infrared spectra by pattern recognition techniques. Classification in the wavelet domain was achieved by using the wavelet packet transform for efficient pattern recognition (WPTER) algorithm, which allowed singling out the most discriminant spectral regions. Principal component analysis (PCA) on the selected features showed an effective clustering of the analyzed flours. Satisfactory classification models were obtained both on training and test samples. Furthermore, mixtures of varying composition of the studied flours were distributed in the PCA space according to their composition.

Update on wheat hypersensitivity.

PURPOSE OF REVIEW: Wheat is among the six foods responsible for approximately 90% of food allergies in children, and in recent years wheat has been increasingly recognized as a cause of food-dependent, exercise-induced anaphylaxis. Wheat flour is an important cause of baker's asthma, a well-known occupational respiratory allergy to inhaled flour. This review outlines the diverse clinical manifestations of IgE-mediated wheat hypersensitivity and summarizes recent advances in characterization of clinically significant allergens. RECENT FINDINGS: Only a few of the numerous wheat proteins recognized by IgE of sensitized individuals have been characterized at the molecular level. Characterized allergens causing baker's asthma include several water/salt-soluble wheat proteins, however sensitization patterns show a great degree of individual variation. The insoluble gliadins have been implicated in IgE-mediated allergy to ingested wheat, and omega-5 gliadin has been identified as a major allergen in wheat-dependent, exercise-induced anaphylaxis. The presence of IgE to purified omega-5 gliadin in children was highly predictive of immediate clinical symptoms on oral wheat challenge. SUMMARY: Diagnostic skin prick and in-vitro tests measuring sensitization against water/salt-soluble wheat proteins have poor predictive values. Quantification of gliadin-specific IgE in serum or skin prick testing with gliadin could serve as an additional tool in the diagnostic work-up of allergy to ingested wheat.

Propiedades funcionales de la proteína de cují (Prosopis juliflora) / Functionals properties of the mesquite bean protein (prosopis juliflora)

Se preparó un concentrado proteico a partir de la harina de fruto completo del cují (P.juliflora) para evaluar y caracterizar sus propiedades funcionales; índice solubilidad y efecto del calor húmedo sobre la misma, capacidad de absorción de agua y aceite, capacidad espumante, estabilidad de la espuma, capacidad emulsificante, viscosidad de la emulsión y el efecto de la temperatura y el NaCl algunas de estas propiedades, según procedimientos descritos en la literatura a objeto de determinar su potencial aplicación como ingrediente en alimentos y posible competitividad en el mercado como nueva fuente de proteína. El punto isoeléctrico del concentrado osciló en un rango de pH entre 4,00-4,50. La máxima solubilización se obtuvo a pH 10.000 en solución de NaCl 0,75 M y con tratamiento término a 112ºC por un período de 5 min. Bajo las condiciones estudiadas, los gramos de agua absorbidos y los gramos de aceite retenidos sugieren la utilización de la proteína de cují en alimentos donde ambas propiedades sean importantes para garantizar el ®flavor¼ y/o textura del producto. La capacidad espumante, mayor a la albúmina de huevo bajo condiciones similares de pH, mostró una correlación positiva (r=0.004) con el índice de solubilidad, pero disminuyó en presencia de NaCl aún a bajas concentraciones, por lo que el uso de esta proteína por esta propiedad, dependerá del pH y fuerza íonica del producto a procesar

Concentrado proteico de Amaranthus mantegazzianus: caracterización físico-químico-biológica / Protein concentrate of Amananthus mantegazzianus: physicochemical biological characterization

Este estudio tuvo como finalidad obtener un concentrado proteico (CP) de harina de semillas de A.mantegazzianus y someterlo a estudio: composición química porcentual, propiedades funcionales y calidad biológica de la proteína. Para ellos se fijaron las condiciones óptimas de obtención de CP: pH de máxima solubilidad 11,5 pH de mínima solubilidad 5, relación harina/solvente 1:20, tiempo de agitación hora 30 min. a temperatura ambiente. Se obtuvo un producto cuyo contenido proteíco fue 55,3 g/100 g. Las propiedades funcionales fueron evaluadas a través de: índice de solubilidad de nitrógeno (ISN), el que arrojó un dato de 94,9 por ciento a pH 11,5; actividad de emulsificación (AE) con un valor de 47 ñ 4,8; capacidad de absorción de agua (CAA) igual a 2,1 ñ 0,3; capacidad de absorción de aceite (CAAc) con un resultado de 0,8 ñ 0,1. Se calculó el índice de absorción de agua y aceite (IAAAc) como CAA/CAAc resultando un valor de 2,6. Estos resultados califican al producto como útil para panificación por su alta solubilidad, capacidad de absorción de agua y por el valor de IAAAc que revela características hidrolíticas. La calidad biológica del CP fue estudiada mediante la determinación de utilización proteica neta (NPU), con valor de 64 ñ 7,4, digestibilidad verdadera (tD) 88 ñ 7,6, valor biológico (BV) igual a 73, ingesta (I) de 74 ñ 8,9 y una ganancia de peso (delta P) de 23 ñ 4,5. Los valores obtenidos en la evaluación biológica de la proteína nos revelan un buen aprovechamiento nitrogenado, lo que conjuntamente con la caracterización funcional nos permiten inferir que el CP de A.mantegazzianus resulta un buen recurso para enriquecer productos de panificación, elaboración de dietas para regímenes especiales y complemento proteico de alimentos deficientes

Vida de anaquel y evaluación sensorial en tortillas de maíz elaboradas con conservadores y mejoradores / Shelf life and sensory evaluation of corn tortillas, made with preservatives and texture conditioners

Con el propósito de elaborar tortillas empacadas, con una vida de anaquel prolongada y que a su vez tenga la calidad de un producto fresco, se planteó determinar el efecto conservadores y mejoradores sobre las características reológicas, sensoriales y vida de anaquel en tortillas de harina de maíz nistamalizado. Los conservadores evaluados fueron; sorbado de potasio (SK) y propionato de calcio (PCa). Como mejoradores de la textura se usaron: carboximetilcelulosa (CMC) y estearil-2 lactilato de sodio (SS2L). En las tortillas frescas se evaluó pH, rendimiento, textura, elasticidad y evaluación sensorial. Las tortillas empacadas en bolsas de polietileno se almacenaron a 4ºC. Las tortillas que tenían SK (0,1 por ciento), PCa (0,1 por ciento) y SS2L (0,25 por ciento), fueron las más ácidas (pH=5,12), las de mayor vida de anaquel (53 días sin desarrollo de microorganismos), y la menor cuenta total de mesófilos aerobicos (23 unidades formadoras de colonias). Los mayores rendimientos correspondieron a los tratamientos con 0,5 por ciento de CMC, siendo las tortillas más elásticas, pero con menor vida de anaquel (18 y 24 días). Diez días después de empacar las tortillas, fueron recalentadas y evaluadas sensorialmente por 5 panelistas entrenados, quienes juzgaron que el mejoramiento fue el que contenía SK (0,1 por ciento), PCa (0,1 por ciento) y CMC (0,5 por ciento), por ser las tortillas más suaves y elásticas; en el resto de los atributos las mejores tortillas fueron las hechas con el método tradicional (frescas). En la prueba de nivel de agrado, los consumidores señalaron que la tortilla de mejor sabor era la tradicional. no obstante, los tratamientos con mezcla de conservadores (SK y PCa) y mejoradores, obtuvieron calificaciones semejantes a las obtenidas por dos marcas comerciales de tortillas empacadas

Elaboración de una harina integral de yuca (N.esculenta Crantz) para alimentación de pollitos de engorde: I caracterización químico-nutrimental de hojas, raíces y harina integral de yuca / Producción of cassava whole meal (N. esculenta Crantz) to elaborate a feed growing chicks: I chemical and nutritive characterization of leaves, roots and cassava whole meal

Las raíces de yuca son usadas frecuentemente como una fuente de energía en raciones para animales. Las hojas debido a su alto contenido de fibra no son usadas en alimentos para animales no obstante que ellas tienen un buen contenido de proteínas y un nivel balanceado de aminoácidos esenciales. El objetivo de esta investigación fue producir una harina integral de yuca (HIY) con bajo contenido de fibra para usarse en alimentación de pollitos. Hojas y raíces por separado. Fueron deshidratadas a 60ºC por 20 h, molidas en molino de martillos y cernidas en un tamiz de malla 60. Por este procedimiento fueron obtenidas una harina de raíz (HTY) y una harina de hojas (HHY). El contenido de fibra in HHY fue reducido 25.8 por ciento y el contenido de proteína fue incrementado 8.2 por ciento. La HIY fue elaborada con 61.2 por ciento de HRY y 38.8 por ciento de HHY, teniendo un contenido de proteína, y fibra de 9.15 por ciento, y 9.73 por ciento, respectivamente. La Energia Metabolizable Verdadera (EMV) de HIY fue 2,454 kcal/kg con una biodigestabilidad promedio de los aminoácidos de 68.8 por ciento

Elaboración de una harina integral de yuca (N. esculenta Crantz) para alimentación de pollitos de engorde II: evaluación de una harina integral de yuca en pollitos de engorde / Production of cassava whole meal (N. esculenta Crantz) to elaborate a feed growing chicks II: evaluation of cassava whole meal in growing chicks

Aproximadamente, 50 por ciento de las materias primas usadas para alimento de pollos está constituido de sorgo como fuente de energía. El objetivo de esta investigación fue evaluar la calidad nutrimental de una harina integral de yuca (HIY: 61.2 por ciento y 38.8 por ciento de harinas de raíz y hoja, respectivamente) para pollitos en crecimiento. El sorgo fue sustituido parcialmente de una dieta base por 15,30 y 45 por ciento de HIY. Cuatro dietas a base de sorgo, harina de soya y HIY fueron formuladas. Niveles de 0.0, 8.6, 16,4 y 23.7 por ciento de HIY fueron incluidos en las dietas. Pollitos Vantress blancos (96) fueron usados en el experimento durante 28 días. Cada tratamiento fue probado con 24 pollitos. La dieta con 23.7 por ciento de HIY mostró menor ganancia de peso y eficiencia alimentaria (p<0.05) al compararla con las otras dietas, y la relación peso hígado: peso ave aumentó en forma directa con el incremento de HIY en las raciones

Características químicas y nutricionales del grano de cinco (5) genotipos de Canavalia ensiformis / Chemical and nutritional characteristics from grains of five genotypes of Canavalia ensiformis

Se realizó la caracterización del grano de cinco genotipos de Canavalia ensiformis, mediante la determinación de la composición química proximal, presencia de factores antinutricionales (Canavalia y título hemaglutinante) y digestibilidad in vitro. Los genotipos estudiados fueron: Original, Yaracuy, Valle de la Pascua, U-02 y Tovar. Los resultados de la composición química proximal mostraron diferencias significativas entre los genotipos a excepción de la humedad, encontrándose los siguientes promedios: Proteína: 31,37 por ciento, fibra: 8,10 por ciento: cenizas: 2,93 por ciento, grasa: 2,97 por ciento y humedad: 11,68 por ciento. El contenido de canavanina de los genotipos fue variable, oscilando los valores entre 2,02 a 4,86 por ciento presentando el genotipo u-02 el valor mayor, respocto al título hemaglutinante varió entre +2 y +5. La digestibilidad proteica in vitro de las harinas arrojó diferencias signifacativas entre los genotipos, la cual varió entre 47,51 por ciento y 51,84 por ciento, valores muy por debajo al mostrado por la caseína (97,3 por ciento)