Sensory, physical and chemical characteristics, and acceptance of lowland or upland rice

O objetivo deste trabalho foi caracterizar química, física e sensorialmente três genótipos de arroz polido de cultivo irrigado e cinco de terras altas. Determinaram-se: a composição centesimal, o amido, a amilose, a temperatura de gelatinização (Tg), a absorção de água ao cozimento, a cor, a textura instrumental, o perfil sensorial e a aceitação de atributos. A composição centesimal e o teor de amido variaram entre os genótipos. O 'Moti' e a linhagem N2583 foram classificados como cerosos, 'Douradão' apresentou amilose muito baixa, e os demais genótipos, amilose baixa. 'Irga 417', 'Moti' e AB101002 apresentaram Tg baixa; 'Douradão', alta; e os demais, intermediária. O 'Moti' e a linhagem N2583 crus apresentaram os maiores valores de L*; no entanto, após o cozimento, esses valores diminuíram e foram idênticos em todos os genótipos. 'Arroz‑da‑terra' apresentou maior a*, 'BRS Primavera' e N2583 apresentaram maior b*; e após o cozimento, houve redução desses valores. Na análise sensorial, destacaram-se 'AN Cambará', por pontos escuros e formato alongado; AB101002, 'Irga 417' e 'BRS Primavera', pela firmeza, cor branca e grãos soltos, que foram bem aceitos; e o 'Moti', por ser pegajoso, macio e com brilho, foi o menos aceito. Os atributos sensoriais do arroz são mais associados a características químicas, intrínsecas ao genótipo, do que à atribuição de plantio a terras altas ou irrigadas.The objective of this work was to evaluate the chemical, physical, and sensory properties of three polished rice genotypes of irrigated and five of upland cropping systems. The proximate composition, starch, amylose, gelatinization temperature (GT), water absorption during cooking, color, instrumental texture, sensory profile, and acceptance of attributes were determined. The proximate composition and starch content varied among genotypes. 'Mochi' rice and the lineage N2583 were classified as waxy; 'Douradão' showed very low amylose, and the other genotypes showed intermediate amylose. 'Irga 417', 'Mochi' rice, and AB101002 showed a low GT; 'Douradão', a high GT; and the others, an intermediate GT. Raw 'Mochi' rice and the lineage N2583 showed the highest L* values; however, after cooking, these values reduced and were identical for all genotypes. 'Arroz‑da‑terra' had the highest a* value, and 'BRS Primavera' and N2583, the highest b*; after cooking, there was a reduction of these values. In sensory analysis, 'AN Cambará' stood out by dark spots and long format; AB101002, 'Irga 417' and 'BRS Primavera', by firmness, white color, and loose grains, which had good acceptance; and 'Mochi' rice, by its stickness, softness and brightness, was the less appreciated. The rice sensory attributes are most associated with chemical characteristics, intrinsic to the genotype, than with the grain attribution to upland or irrigated cropping system

Metodologias Para O Estudo De Propriedades Morfológicas E Térmicas De Amido

Starch, a carbohydrate used as a reserve of energy in most plants, is widely used in the food industry, either as a main component or as a thickener. Considering the application of this as an ingredient in the food industry, the study of the morphological and thermal properties of this food is of great importance because it can predict its behavior during and after the processing of this. Methodologies such as scanning electron microscopy, light scattering and optical microscopy are the most used tools in the morphological characterization of the starch granule generating accurate results and good quality. Regarding the methodologies for the study of thermal properties, the rapid amylographic analyzer and the differential scanning calorimetry are the most used. The set of results obtained with these methodologies, allows to know the technological properties of the starch, characterizing them, and even to identify the origin of this one.Amido, carboidrato utilizado como reserva de energia na maioria das plantas, é amplamente empregado na industria alimentícia, seja como componente principal ou como um espessante. Tendo em vista a aplicação deste como um ingrediente na indústria de alimentos, o estudo das propriedades morfológicas e térmicas deste é de grande importância, pois pode prever seu comportamento durante e após o processamento deste.  Metodologias como a microscopia eletrônica de varredura, espalhamento de luz e a microscopia ótica são as ferramentas mais utilizadas na caracterização morfológica do grânulo do amido gerando resultados precisos e boa qualidade. Com relação às metodologias para o estudo das propriedades térmicas, o analisador amilografico rápido e a calorimetria diferencial de varredura, são as mais utilizadas. O conjunto de resultados obtidos com essas metodologias, permite a conhecimento das propriedades tecnológicas do amido, caracterizando-os, e até mesmo identificar a origem deste

Nutritional composition of rice bran submitted to different stabilization procedures

In order to inactivate enzymatic deterioration, whole rice bran samples were subjected to two stabilization methods. Changes in nutritional value in terms of, concerning chemical composition, minerals and fatty acid content, were evaluated to supplement existing data and promote the utilization of rice bran in the human diet. The following homemade heat treatments were applied: roasting on a conventional stove or heating in a microwave oven. Based on the results, the different heating methods affected sample composition, since the levels of some nutrients of treated samples showed significant changes (p<0.05) compared to corresponding raw samples. The rice bran treated on a conventional stove produced products with lower moisture (5.14±0.10 g/100 g) and nutrients such as sodium 11.8%; palmitic acid 9.9% and stearic acid 8.1%. The microwave oven procedure resulted in better nutrient preservation, with slightly higher moisture content (6.28±0.10 g/100 g), and appears to be a practical and rapid tool for home heat stabilization of rice bran

CALIDAD DEL ARROZ DE TIERRAS ALTAS EN FUNCIÓN DEL TIEMPO DE COCCIÓN Y DEL CULTIVAR DE ARROZ

Was studied the effects caused by the cultivar and cooking time on grain quality of five cultivars of upland rice (BRS Primavera, BRS Pepita, BRS Sertaneja, BRS Monarca and BRS MG Curinga) that were cooked at different cooking times (0, 10, 20, 30 and 40 min). The identified water content, starch and amylose, high viscosity and tendency to retrogradation and cooking tests were performed (yield, stickiness and texture). The results showed that the longer the cooking time the greater the availability of the contents of starch and amylose for their determinations and their values differ among cultivars of upland rice. Synergism was observed between the factors studied, increasing the water content and decreasing the maximum viscosity and the tendency to retrogradation with increased cooking time has been noted that cultivars BRS Pepita and BRS MG Curinga can absorb more water when they are hot and presented more stickiness when is cold and cultivars BRS Primavera, BRS Sertaneja and BRS Monarca can absorb minor water when they are hot and can be show dry grains and singles and harden after cooling.Se han estudiado los efectos que causan el cultivar y el tiempo de cocción en la calidad de granos de cinco cultivares de arroz de tierras altas (BRS Primavera, BRS Pepita, BRS Sertaneja, BRS MG Curinga y BRS Monarca) que fueron cocidos en diferentes tiempos de cocción (0, 10, 20, 30 e 40 min). Se han determinado los contenidos de agua, almidón y amilosa, viscosidad máxima y tendencia a la retrogradación y se realizaron ensayos de cocción (rendimiento, pegajosidad y textura). Los resultados demostraron que cuanto mayor es el tiempo de cocción mayor es la disponibilidad de los contenidos de almidón y de amilosa para sus determinaciones y sus valores difieren entre los cultivares de arroz de tierras altas. Se ha observado sinergismo entre los factores estudiados, aumentando el contenido de agua y disminuyendo la viscosidad máxima y la tendencia a la retrogradación con el aumento del tiempo de cocción se ha notado que los cultivares BRS Pepita y BRS MG Curinga pueden absorber mayor cantidad de agua cuando calientes y presentarse más pegajosos cuando fríos y los cultivares BRS Primavera, BRS Sertaneja y BRS Monarca pueden absorber menor cantidad de agua cuando calientes y sus granos pueden presentarse secos y sueltos y endurecerse después de enfriados. Se han estudiado los efectos que causan el cultivar y el tiempo de cocción en la calidad de granos de cinco cultivares de arroz de tierras altas (BRS Primavera, BRS Pepita, BRS Sertaneja, BRS MG Curinga y BRS Monarca) que fueron cocidos en diferentes tiempos de cocción (0, 10, 20, 30 e 40 min). Se han determinado los contenidos de agua, almidón y amilosa, viscosidad máxima y tendencia a la retrogradación y se realizaron ensayos de cocción (rendimiento, pegajosidad y textura). Los resultados demostraron que cuanto mayor es el tiempo de cocción mayor es la disponibilidad de los contenidos de almidón y de amilosa para sus determinaciones y sus valores difieren entre los cultivares de arroz de tierras altas. Se ha observado sinergismo entre los factores estudiados, aumentando el contenido de agua y disminuyendo la viscosidad máxima y la tendencia a la retrogradación con el aumento del tiempo de cocción se ha notado que los cultivares BRS Pepita y BRS MG Curinga pueden absorber mayor cantidad de agua cuando calientes y presentarse más pegajosos cuando fríos y los cultivares BRS Primavera, BRS Sertaneja y BRS Monarca pueden absorber menor cantidad de agua cuando calientes y sus granos pueden presentarse secos y sueltos y endurecerse después de enfriados