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

Correlation between grain nutritional content and pasting properties of pre-gelatinized red rice flour

As with any variety of rice, red rice characteristics are subject to varietal differences, growing conditions, types of processing, and nutritional and rheological properties. This study determined the nutritional characteristics (centesimal composition and minerals) and paste viscosity properties of raw grains of four red rice genotypes (Tradicional MNAPB0405, MNACE0501 and MNACH0501) and the paste viscosity properties of pre-gelatinized flours obtained at different cooking times (20, 30 and 40 min). The main nutritional properties were correlated with the pasting properties of the pre-gelatinized flours. The samples showed differences in nutritional properties and paste viscosity. MNAPB0405 and MNACE0501 showed higher levels of fiber and fat and provided higher caloric energy than Tradicional and MNACH0501, which, in turn, showed higher levels of amylose. MNACH0501 showed higher peak viscosity (2402 cP), higher breakdown viscosity (696 cP) and a greater tendency to retrogradation (1510 cP), while Tradicional, MNAPB0405 and MNACE0501 had pasting profiles with peak viscosities varying between 855 and 1093 cP, breaking viscosity below 85 cP and retrogradation tendency between 376 and 1206 cP. The factors genotype and cooking time influenced the rheological behavior of pre-gelatinized flours, decreasing their pasting properties. The protein and amylose levels are correlated with the pasting properties and can be used as indicators of these properties in different genotypes of red rice, whether raw or processed into pre-gelatinized flours

PROPRIEDADES DOS FILMES BIODEGRADÁVEIS DE AMIDO DE CAROÇO DE JACA (Artocarpus heterophyllus): EFEITO DO GLICEROL - DOI: 10.12971/2179-5959.v02n01a06

Com o grande consumo de embalagens plásticas não degradáveis que são lançadas no meio ambiente tem crescido o uso alternativo de materiais de rápida biodegradação.  O amido tem sido considerado um material promissor no desenvolvimento de embalagens plásticas. Filmes de amido de jaca obtidos por espalhamento em placa (casting) foram elaborados com variado conteúdo de glicerol (10, 15, 20 e 25%) e acondicionados em várias umidades relativas do ar obtendo-se isotermas de absorção de água e a permeabilidade ao vapor de água. A estabilidade da vitamina C foi determinada em várias temperaturas de armazenamento (25, 30 e 40°C) por meio da embalagem de cápsulas de vitamina C com os filmes de amido. Os filmes apresentaram comportamento tipicamente hidrofílico, sendo que a hidrofilicidade aumentou com o aumento do teor de glicerol, bem como a permeabilidade ao vapor de água. Observou-se pequena perda de massa das cápsulas de vitamina C (1%) após cinco dias de armazenamento, enquanto a 30 e 40°, as perdas foram bem maiores de 3,5 e 4,2 %, respectivamente

Characterization of starch extracted from the roots of Cissus simsiana Roem. & Schult

The aim of this study was to investigate the characterization of starch from Cissus simsiana Roem. & Schult. roots. The starch was extracted by steeping, wet grinding and sedimentation processes and its yield was calculated. Isolated starch was then characterized for chemical composition, morphology and granules size distribution, X-ray diffraction, mid-infrared spectra, swelling powder and solubility, pasting and thermal properties and clarity and syneresis behavior. The starch yield, based on starch presence in the root that can be isolated, were between 13.68% with 3.12 10-3 mg/g of carotenoids. C. simsiana granules were predominantly ellipsoids with 50-60 mm length and 20-30 mm wide. They exhibited B-type X-ray diffraction pattern with 41.2% of crystallinity, apparent amylose content of 26.2% and presented similar mid-infrared spectra to other starches. Onset and peak gelatinization temperatures were 64.2 and 68.56°C, respectively, and gelatinization enthalpy was 19.2 J/g. The apparent viscosity profile was comparable to cassava starch, but with higher peak viscosity (6500 cP), lower set back viscosity (600 cP) and less clear gel showing syneresis