Priscila Zaczuk Bassinello

Important Sensory Properties Differentiating Premium Rice Varieties

In rice-consuming countries, specific varieties are recognized as premium, “gold standard” varieties, while others are recognized as being superior but second best, despite being identical using the current suite of tools to evaluate quality. The objectives of this study were to determine if there are distinguishable differences in sensory properties of premium and second best varieties and whether these differences are common to premium varieties. Color, an important sensory property, was determined on the raw and cooked rice using a colorimeter. As raw rice, some of the premium varieties were whiter than their second best counterparts while others were not. However, when cooked, with two exceptions, the premium varieties were of the same or greater whiteness than their counterparts. A trained sensory panel employed descriptive sensory analysis, an objective tool, to characterize and analytically measure the flavor (aromatics, taste, mouthfeel) and texture of premium and second best varieties collected from nine rice-consuming countries. Sweet taste, popcorn aroma/flavor, and water-like metallic mouthfeel showed significant differences in intensity between the premium–second best variety pairs. Slickness, roughness, and springiness were the major traits that distinguished the texture of varieties. Quality evaluation programs do not routinely measure these texture and flavor traits, but the fact that they distinguished the varieties in most pairs indicates that their measurement should be added to the suite of grain quality tests in the development of new higher-yielding, stress-tolerant varieties. The incorporation of premium quality will ensure that quality is no impediment to widespread adoption leading to enhanced productivity and food security.

Nutritional composition of rice bran submitted to different stabilization procedures

A fim de inativar a deterioracao enzimatica, as amostras de farelo de arroz foram submetidas a dois metodos de estabilizacao. As mudancas do valor nutricional, no que se refere a composicao quimica, os minerais e o conteudo de acidos graxos, foram avaliadas para adicionar mais informacoes aos dados existentes e promover a utilizacao de farelo de arroz na dieta humana. Os seguintes tratamentos caseiros por calor foram aplicados: torra em forno convencional ou de aquecimento em forno de micro-ondas. Com base nos resultados, os diferentes metodos de aquecimento afetaram a composicao das amostras, ja que os niveis de alguns nutrientes mostraram alteracoes significativas (p <0,05), comparado com as amostras cruas correspondentes. O farelo de arroz tratado em fogao convencional forneceu produtos com menos umidade (5,14 ± 0,10 g/100 g) e nutrientes, tais como: de sodio 11,8%; acido palmitico 9,9% e acido estearico 8,1%. O procedimento de forno de micro-ondas resultou em melhor preservacao dos nutrientes, com teor de umidade um pouco maior (6,28 ± 0,10 g/100 g), o que parece ser uma ferramenta pratica e rapida no tratamento termico caseiro para o farelo de arroz.

Microwave and micronization treatments affect dehulling characteristics and bioactive contents of dry beans (Phaseolus vulgaris L.)

BACKGROUND Heat pretreatment is considered the first step in grain milling. This study therefore evaluated microwave and micronization heat treatments in improving the dehulling characteristics, phenolic composition and antioxidant and α-amylase activities of bean cultivars from three market classes. RESULTS Heat treatments improved dehulling characteristics (hull yield, rate coefficient and reduced abrasive hardness index) depending on bean cultivar, whereas treatment effects increased with dehulling time. Micronization increased minor phenolic components (tartaric esters, flavonols and anthocyanins) of all beans but had variable effects on total phenolic content depending on market class. Microwave treatment increased α-amylase inhibitor concentration, activity and potency, which were strongly correlated (r²  = 0.71, P < 0.0001) with the flavonol content of beans. Heat treatment had variable effects on the phenolic composition of bean hulls obtained by abrasive dehulling without significantly altering the antioxidant activity of black and pinto bean hulls. Principal component analysis on 22 constituents analyzed in this study demonstrated the differences in dehulling characteristics and phenolic components of beans and hulls as major factors in segregating the beneficial heat treatment effects. CONCLUSION Heat treatment may be useful in developing novel dietary fibers from beans with variable composition and bioactivity with a considerable range of applications as functional food ingredients.

Qualidade de farelos de arroz cru, extrusado e parboilizado

Rice is the second most consumed cereal in the world, having reached a global production of 661.3 millions of tons, in 2008. Rice bran, resulted from grain milling to obtain white rice or polished parboiled rice, has significant amounts of carbohydrates, proteins, lipids, soluble fiber, vitamins, and minerals. This study had the objective of evaluating some physicochemical and microbiological characteristics of raw rice bran (RRB), extruded rice bran (ERB), and parboiled rice bran (PRB). All the analyses were done according to standardized methods recommended by the Brazilian National Health Vigilance and International Association of Official Analytical Chemists. The PRB presented the highest contents of protein (17.17 g 100 g -1 ), lipids (36.03 g 100 g -1 ), dietary fiber (34.06 g 100 g -1 ), calcium (99.45 mg 100 g -1 ), zinc (15.58 mg 100 g -1 ), cupper (1.45 g 100 g -1 ), and manganese (17.81 g 100 g -1 ), and the lowest levels of carbohydrate (5.73 g 100 g -1 ), ash (7.01 g 100 g -1 ), potassium (507.55 mg 100 g -1 ), and iron (6.83 mg 100 g -1 ). All the rice bran samples showed Aspergillus sp. contamination, but ERB had the lowest colonies counting. All samples showed acceptable microbiological patterns for coliforms at 45oC and Bacillus cereus , and Salmonella sp. absence, according to the Brazilian legislation. The RRB, ERB, and PRB have high nutritive value, being considered good sources of proteins, lipids, dietary fiber, and minerals. KEY-WORDS: Oryza sativa L.; macronutrients; minerals; fungi.

Qualidade de pães com farelo de arroz torrado

The aim of this work was to evaluate the quality of breads formulated with different levels of toasted rice bran (FAT) in a mixture with wheat flour (FT). A completely randomized design was applied including one control and four treatments (7.5, 15.0, 22.5, and 30.0% substitution of FT by FAT) and three repetitions. The acceptability (appearance, texture, and flavor), specific volume, centesimal composition, and caloric value of each treatment were evaluated. Among the breads formulated with FAT, the treatment using 7.5% FAT presented the highest specific volume (3.37 cm3.g-1), which did not differ from the control treatment in terms of appearance (7.23), flavor (7.08) and texture (7.52) sensory scores. Regarding the centesimal composition, the treatment with 7.5% substitution, when compared to the control, presented an increase of 26.02% in the total dietary fiber, 34.85% in insoluble fibers, 11.26% in soluble fibers, 52.70% in lipids, 53.33% in ash, 8.21% in moisture and a reduction of 8.36% in carbohydrates, 8.85% in proteins, and 3.57% in the caloric value. Pan bread elaborated with 7.5% toasted rice bran in replacement of wheat flour could be a viable alternative to include a fiber-rich and low-calorie product in the market.

Cooking quality of upland and lowland rice characterized by different methods

Rice cooking quality is usually evaluated by texture and stickiness characteristics using many different methods. Gelatinization temperature, amylose content, viscosity (Brookfield viscometer and Rapid Visco Analyzer), and sensory analysis were performed to characterize culinary quality of rice grains produced under two cropping systems and submitted to different technologies. All samples from the upland cropping system and two from the irrigated cropping system presented intermediate amylose content. Regarding stickiness, BRS Primavera, BRS Sertaneja, and BRS Tropical showed loose cooked grains. Irrigated cultivars presented less viscosity and were softer than upland cultivars. Upland grain samples had similar profile on the viscoamylografic curve, but the highest viscosity peaks were observed for BRS Alvorada, IRGA 417, and SCS BRS Piracema among the irrigated cropping system samples. In general, distinct grain characteristics were observed between upland and irrigated samples by cluster analysis. The majority of the upland cultivars showed soft and loose grains with adequate cooking quality confirmed by sensory tests. Most of the irrigated cultivars, however, presented soft and sticky grains. Different methodologies allowed to improve the construction of the culinary profile of the varieties studied.

Bebidas saborizadas obtidas de extratos de quirera de arroz, de arroz integral e de soja

Conduziu-se este trabalho, com o objetivo de desenvolver bebidas elaboradas com extratos de quirera de arroz e de arroz integral e comparar as caracteristicas quimicas e sensoriais destas com bebida elaborada com extrato de soja. Utilizou-se um delineamento inteiramente casualisado, com tres tratamentos (bebidas de extrato de quirera de arroz, extrato de arroz integral e extrato soja). As seguintes analises foram realizadas: umidade, cinzas, proteinas, lipidios, carboidratos totais, valor energetico, calcio, magnesio, cobre, manganes, ferro e zinco. Tambem determinou-se a aceitabilidade e a intencao de compra. A bebida elaborada com o extrato de soja contem maiores teores de cinzas, proteinas, lipideos e minerais em relacao ao extrato de quirera de arroz, que possui o maior teor de carboidratos e valor energetico. Todas as bebidas obtiveram boa aceitacao, com intencao de compra pela populacao entrevistada acima de 95%, sendo que mais de 99% dos provadores comprariam a bebida elaborada com o extrato de arroz integral (tratamento de maior aceitacao). As bebidas elaboradas com extrato de arroz integral ou de quirera de arroz sao uma alternativa viavel para as pessoas que possuam intolerância a lactose do leite de origem animal e/ou alergia as proteinas da soja.

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.

Stability and microbiological quality of rice bran subjected to different heat treatments

Rice bran is a byproduct commonly used for animal feeding; however its nutritional value and potential application in human diet have attracted market interest. Its preservation for safe use is still a challenge, so the objective of this study was to determine the quality of commercially available rice bran samples subjected to different heat treatments (extruding, parboiling, toasting, and microwave oven heating) in order to promote stabilization during storage under room temperature. Rice bran samples were collected from two industries, and each treatment was divided in three parts, each corresponding to three repetitions. All samples were evaluated for moisture content, total microorganisms, mold and yeast counting, hydrolytic rancidity, and lipase activity during 90 days of storage. Most of the heat treatments, including domestic and thermoplastic extrusion, generated products which may be used for human consumption under the tested conditions in terms of physicochemical and microbiological quality. The domestic treatments were more efficient in eliminating microorganisms or keeping them within acceptable limits. The toasted rice bran showed satisfactory results in terms of moisture, hydrolytic rancidity control, and lipase activity.

Application of extruded broken bean flour for formulation of gluten-free cake blends

The aim of this study was to determine the physical and microbiological characteristics of extruded broken beans flour, in addition to developing mixtures for gluten-free cake with these flours, evaluating their technological and sensory quality. Gluten-free formulations were prepared with 45%, 60% and 75% of extruded broken beans. All analyzes of the flours and mixtures for cakes were performed according to standard techniques found in the literature. Sensory analyzes of cakes applied the 9-point structured hedonic scale. Results were submitted to variance analysis and comparison of means test (Tukey, p<0.05). The use of extruded broken beans improved the water absorbed and water solubility index of the mixtures for gluten-free cake, and for the lower viscosity and retrogradation when compared to the standard formulation. All cakes were accepted (rate ≥ 7) for all the analyzed attributes. From the technological and sensory standpoints, the development of gluten-free cake mixtures is feasible with up to 75% of extruded broken beans.