Evaluation of postprandial glycemic response in rats (Wistar) fed with different starch sources.

The consumption of readily digestible starch sources, such as corn, can negatively impact endocrine disorders related to hyperglycaemia in predisposing animals. In this sense, starch sources containing slowly digestible and resistant fractions can assist glycemic control. The present study analyzed the postprandial glycemic response and blood variables of rats fed with four extruded diets containing corn, brown rice, sweet potato and pea as the main starch source. Thirty-two male Wistar rats (90 days old) were divided into groups of eight animals each. The rats received one of the experimental diets for 30 days according to a completely randomised design. The glycemia was measured on the 29th and 30th days. The glycemia measured on the 29th day was analyzed at 0, 30, 60, 120 and 240 min after oral administration of 50% glucose solution. On the 30th day, the same protocol was repeated after providing 3 g of the experimental diet for each animal to obtain the glycemic curve. After the euthanasia on the 30th day, 7 ml of blood was collected via cardiac puncture for glycated haemoglobin (HBA1c), triglycerides, cholesterol, and aspartate and alanine aminotransferases analysis. Diets with pea and sweet potato provided lower glycemic index, average and maximum glycemia, and glycemic increment in relation to the other starch sources (p < 0.05). Animals fed with the corn diet had higher serum concentrations of triglycerides and HBA1c than the other treatments (p < 0.05). Results demonstrated that pea and sweet potato are interesting starch sources for the control of metabolic disorders related to glycemia.

Effects of cultivars and fertilization levels on the quality of rice milling: A diagnosis using near-infrared spectroscopy, X-ray diffraction, and scanning electron microscopy.

Cultivars and fertilization levels influence rice productivity and can be associated with grain quality. Thus, it is possible to make decisions regarding the choice of cultivars and application of fertilizer levels based on the type of milling, a necessary post-harvest process that may minimize the nutrient load in the grains and result in loss in quality. This study relates the physicochemical composition and morphological quality of brown and polished milled rice grains, cultivar types, and different levels of soil fertilization using near-infrared spectroscopy analysis, X-ray diffraction and scanning electron microscopy. Statistical tools were used to test the various treatments and identify the relationship between factors and variables. A high fertilization level is related to increasing crude protein composition and starch for cultivar IRGA 431 CL associated with polished rice. However, the combination of cultivar IRGA 424 RI and brown rice demonstrated a higher grain resistance, and different percentages of whole, chalky, and damaged rice. The correlation between ash × crude protein and starch × crude fiber was found to be positive for brown rice and negative for the polished rice. Further, an increase in starch content was inversely proportional to the ash content, whereas an increase in crude protein was inversely proportional to the low-fat content in milled rice. The crystalline characteristics of rice starch were preserved at high fertilization levels associated with polished grains that demonstrated high starch content. Polished grains, however, showed more pores and cavities, and consequently greater permeabilities in the surface. It is recommended that batches of grains produced from cultivar IRGA 431 CL with high levels of fertilization be subjected to polished rice milling to achieve high protein and starch quality. However, grains from cultivar IRGA 424 RI with high levels of fertilization are recommended for brown rice milling owing to the high percentage of physical defects observed.

Consumers' Sensory Perception of Food Attributes: Identifying the Ideal Formulation of Gluten- and Lactose-Free Brownie Using Sensory Methodologies.

Products for consumers with special needs (celiac) and those who prefer a differentiated diet are necessary due to growing demand and a niche market to be exploited. The incorporation of other substances in the formulation of cakes requires a detailed analysis of their characteristics and sensorial attributes. However, the use of these flours may change the sensory characteristics of a product that is normally made from wheat flour. This study aimed to identify the ideal formulation of gluten- and lactose-free brownies made with rice flour and beans/lentils in consumer perception, through the combination of sensory tests. Using these data, the aim was to define recommendations for the reformulation of a product of high consumer acceptance, using easily accessible ingredients. The sensory methods used were descriptive analysis with a group of 20 trained evaluators and a group of 100 consumers evaluated through the check-all-that-apply and just-about-right questionnaire; all groups performed the acceptance test by hedonic scale. Data were analyzed using multivariate techniques and correlation matrices. The results showed that the attributes selected by the trained evaluators and consumers were sufficient to indicate that color and texture were the most striking characteristics that should be improved in brownie formulations without gluten and lactose. PRACTICAL APPLICATION: The study assumes that from the combination of sensory methods it is possible to verify the attributes that are most attractive to consumers in gluten-free and lactose-free cake formulations, using easily accessible ingredients that have technological, nutritional, and sensory quality, such as those formulated with wheat.

Brown rice authenticity evaluation by spark discharge-laser-induced breakdown spectroscopy.

Rice is the most consumed food worldwide, therefore its designation of origin (PDO) is very useful. Laser-induced breakdown spectroscopy (LIBS) is an interesting analytical technique for PDO certification, since it provides fast multielemental analysis requiring minimal sample treatment. In this work LIBS spectral data from rice analysis were evaluated for PDO certification of Argentine brown rice. Samples from two PDOs were analyzed by LIBS coupled to spark discharge. The selection of spectral data was accomplished by extreme gradient boosting (XGBoost), an algorithm currently used in machine learning, but rarely applied in chemical issues. Emission lines of C, Ca, Fe, Mg and Na were selected, and the best performance of classification were obtained using k-nearest neighbor (k-NN) algorithm. The developed method provided 84% of accuracy, 100% of sensitivity and 78% of specificity in classification of test samples. Furthermore, it is simple, clean and can be easily applied for rice certification.

Comparative Study of the Phytoprostane and Phytofuran Content of indica and japonica Rice (Oryza sativa L.) Flours.

Phytoprostanes and phytofurans (PhytoPs and PhytoFs, respectively) are nonenzymatic lipid peroxidation products derived from α-linolenic acid (C18:3 n-3), considered biomarkers of oxidative degradation in plant foods. The present work profiled these compounds in white and brown grain flours and rice bran from 14 rice cultivars of the subspecies indica and japonica by ultrahigh performance liquid chromatography coupled to electrospray ionization and triple quadrupole mass spectrometry. For PhytoPs, the average concentrations were higher in rice bran (0.01-9.35 ng g-1) than in white and brown grain flours (0.01-1.17 ng g-1). In addition, the evaluation of rice flours for the occurrence PhytoFs evidenced average values 1.77, 4.22, and 10.30 ng g-1 dw in rice bran, brown grain flour, and white grain flour, respectively. A significant correlation was observed between total and individual compounds. The concentrations retrieved suggest rice bran as a valuable source of PhytoPs and PhytoFs that should be considered in further studies on bioavailability and bioactivity of such compounds.

Evaluación del contenido de amilosa en arroz mediante espectroscopia de infrarrojo cercano-NIRS / Evaluation of rice amylose content by near infrared Spectroscopy

La espectroscopia de infrarrojo cercano NIRS (por sus siglas en inglés) se emplea para el control de calidad de los alimentos. La determinación de amilosa en el arroz es un carácter heredable que correlaciona con la calidad del grano, importante en los programas de fitomejormaiento de arroz. El presente trabajo, establece la viabilidad de evaluar el contenido de amilosa en el arroz con la técnica NIRS. Inicialmente, se determinó entre arroz paddy o integral, cuál es el más apropiado para evaluar amilosa empleando NIRS. Se tomaron espectros a las 540 materiales de arroz procedentes del germoplasma del Fondo Latinoamericano para Arroz de Riego FLAR, y posteriormente se hizo análisis de componentes principales y análisis de regresión múltiple en cada tipo de arroz. El arroz integral fue el que obtuvo mejores resultados estadísticos. En el desarrollo de la calibración se empleó como referencia otra calibración en NIRS basada en harina de arroz con un R2=0.9 de calibración y R2= 0.78 de validación, y se empleó Winisi para desarrollar la quimiometría. Se utilizó mínimos cuadrados parciales MPLS y una matemática de 2,1,1,2; longitud de onda de1100-2492,2, lo que arrojó un R2≥0.68 de validación externa,aceptable para caracterizar las generaciones tempranas, con aproximadamente el 83% de aciertos. Los programas de fitomejoramiento del FLAR evalúan 15.000 materiales en el año en las generaciones tempranas, lo que significa US$ 3.600 dólares y 45 días menos que evaluar con la calibración de harina de arroz, siendo la que actualmente se emplea en el FLAR(AU)

The determination of amilosa in the rice is an inheritable character that it correlates with the quality of the grain, importantly breeder rice. The present work, it establishes the viability of evaluating the content of amilosa in the rice with the technology NIRS. Initially, paddy or integral decided between rice, which is most adapted to evaluate amilosa using NIRS. Spectra took to 540 materials of rice of the germplasms banks of the Latin American Found for Irrigated Rice. FLAR, and later there was done analysis of principal components and analysis of multiple regression in every type of rice. The brown rice was the one that most better statistical results. In the development of the calibration another calibration used as reference in NIRS based on flour of rice with a R2 = 0.9 of calibration and R2 = 0.78 of validation, and Winisi was used to develop the chemometrie. There was in use square minimums partial MPLS and a mathematics of 2,1,1,2; wavelength de1100-2492,2, which a R2 = 0.68 of external, acceptable validation to characterize the early generations, with approximately 83 % of successes. The programs breeding of the FLAR evaluate 15.000 materials in the year in the early generations, which means US$ 3.600 dollars and 45 days less that to evaluate with the calibration of flour of rice, being the one that nowadays is used in the FLAR(AU)

Influence of germination time of brown rice in relation to flour and gluten free bread quality.

The effect of germination time on physicochemical characteristics of brown rice flour and its effect on gluten free bread qualities have been investigated. Germination was carried out at 28 °C and 100 % RH for 12, 24 and 48 h; brown rice and soaked brown rice was also analyzed. Significant changes on hydration and pasting properties of brown rice flour were found during germination. The starch degradation by enzyme activity could be evidenced with the decrease in viscosity and water binding capacity (WBC). No significant effect in specific volume, humidity and water activity of the gluten free bread was found as germination time increase, but a significant softness of the crumb was obtained. However, at 48 h of germination, the intense action of α amylase could result in excessive liquefaction and dextrinisation, causing inferior bread quality. Overall, germinated rice flour showed appropriate functionality for being used as raw ingredient in gluten free breadmaking.

Improvement in metabolic parameters in obese subjects after 16 weeks on a Brazilian-staple calorie-restricted diet.

BACKGROUND/OBJECTIVES: The standard pattern of Brazilian food consumption is based on the combination of rice and beans served together in the main meals. This study assessed the effects of Brazilian-staple calorie-restricted (BS-diet) dietary advice, with brown rice and beans, on metabolic parameters, body composition, and food intake in overweight/obese subjects. SUBJECTS/METHODS: Twentyseven subjects were randomly assigned to a conventional-type calorie-restricted diet (CT-diet) (n = 13) or a BS-diet (n = 14). Glucose metabolism, lipid profile, anthropometric and body composition parameters, and food intake were measured before and after 16 weeks. Paired t-tests/Wilcoxon tests were used for comparison of differences from baseline and unpaired t-tests/Mann-Whitney tests were used for comparison of differences between the groups. RESULTS: After 16 weeks, both groups showed reductions in weight and waist circumference (P < 0.02), and the BS-diet group showed a decrease in body fat (P = 0.0001), and significant improvement in glucose metabolism (fasting plasma glucose, glucose and insulin areas under the curve, Cederholm index, and HOMA2-%ß) (P ≤ 0.04) and lipid profile (cholesterol, triacylglycerol, LDL-c, VLDL-c, and cholesterol/HDL-c ratio) (P ≤ 0.05). In addition, the BS-diet group showed significant improvement in HOMA2-%ß, compared to the CT-diet group (P = 0.03). The BS-diet group also showed a significant reduction in energy, lipids, carbohydrate, and cholesterol intake (P ≤ 0.04) and an increase in fiber intake (P ≤ 0.001), while the CT-diet group showed a significant reduction in intake of energy, macronutrients, PUFA, and cholesterol (P ≤ 0.002). CONCLUSIONS: These results demonstrate the benefits of the BS-diet on metabolic parameters in obese subjects.

Maximising the phytochemical content and antioxidant activity of Ecuadorian brown rice sprouts through optimal germination conditions.

Germinated brown rice (GBR) is considered a healthy alternative to white rice in the fight against chronic diseases. As the functional quality of GBR depends on genotype and germination conditions, the objectives were to identify suitable Ecuadorian brown rice cultivars and optimal germination time and temperature to maximise γ-aminobutyric acid (GABA), total phenolics compounds (TPC) and antioxidant activity of GBR. Regression models for the prediction of phytochemical composition and antioxidant activity in GBR were also obtained. Germination improved GABA, TPC and antioxidant activity in all cultivars. Maximum GABA and antioxidant activity were attained at 34 °C for 96 h, while the highest TPC was found at 28 °C for 96 h in all cultivars. GBR cv. GO displayed the highest antioxidant activity and cv. 15 was the most effective at accumulating GABA and TPC in the optimal germination conditions. Therefore, Ecuadorian GBR could be used for the preparation of functional foods serving as preventative strategies in combating chronic diseases.

Efeitos da parboilização do arroz (Oryza sativa L. ) integral sobre os compostos bioativos e a disponibilidade do amido / Effects of the parboiling process in brown rice (Oryza sativa L. ) on its both bioactive components and starch availability

O arroz (Oryza sativa L.) é consumido principalmente na forma polida, porém uma alternativa nutricionalmente melhor seria o arroz integral, que contém ao redor de 10% de farelo, rico em micronutrientes e compostos bioativos. Dentre esses destacam-se a vitamina E e γ-orizanol, aos quais se atribuem diversos efeitos benéficos à saúde. A literatura descreve vários estudos relacionados à presença desses compostos no arroz integral, porém pouco se sabe a respeito da sua estabilidade com o armazenamento, a parboilização e a cocção caseira. Pelo fato do arroz integral apresentar curta vida de prateleira, uma alternativa para aumentar o prazo para o consumo é o emprego da parboilização. A parboilização, que consiste em um processo hidrotérmico, provoca alterações estruturais no amido do grão e a literatura é controversa no que diz respeito à diminuição da digestibilidade do amido e consequentemente à redução do índice glicêmico (IG). Este trabalho teve como objetivos: avaliar os efeitos da parboilização sobre a disponibilidade do amido por meio da cinética de hidrólise do amido estimando o índice glicêmico (IG) em cultivares de arroz integral com diferentes teores de amilose; analisar o efeito da parboilização, do armazenamento por seis meses e da cocção caseira do arroz integral sobre a estabilidade dos compostos bioativos, e correlacionar os compostos bioativos com a atividade antioxidante do arroz, antes e após o processamento. Foram analisadas 36 amostras pertencentes a diferentes cultivares selecionadas de arroz integral e parboilizado integral das safras de 2007 e 2008 e outras três amostras de arroz integral e parboilizado integral, adquiridas no comércio local da cidade de São Paulo. A partir do índice de hidrólise (IH) in vitro, foi estimado o IG. A vitamina E e o γ-orizanol foram extraídos com metanol, separados por CLAE-fase reversa e quantificados por curvas padrão correspondentes. A atividade antioxidante foi avaliada pelos métodos de DPPH• e ORAC...

Rice (Oryza sativa L.) is consumed mostly in the milled form. However, due to its content of bran, vitamin E and γ-oryzanol, the intake of brown rice has been recommended. Although previous studies ascribed some important health benefits related to these brown rice's compounds, information regarding the effect of cooking, storage and parboiling on these substances remains to be elucidated. Rice parboiling is a hydrothermal process consisting of soaking, heating and drying that provide technological and nutritional benefits to the consumer. Until now, if parboiling process decreases the starch digestibility and consequently reduces the glycemic index (GI) is unclear. The objectives of the present study were: to evaluate the effect of the parboiling process on starch digestibility through a GI estimation by the kinetics of starch hydrolysis in rice cultivars with different levels of amylose; to analyze the effect of traditional parboiling, cooking and storage for six months on the stability of bioactive components as well as to correlate the content of bioactive components of rice with its antioxidant activity before and after parboiling. Thirty-six samples of brown rice and parboiled brown rice harvested in 2007 and 2008 were analyzed. In addition, three commercial cultivars of both brown and parboiled brown samples from local market that were obtained in São Paulo were also studied. The glycemic index (IG) was estimated from the hydrolysis index (IH). Vitamin E homologues and γ-oryzanol were extracted simultaneously with methanol and analyzed by HPLC-RP/UV and fluorescence detection in a single run. Peak areas were converted to the corresponding by the standards of α- and γ-tocopherol, α- and γ-tocotrienol and γ-oryzanol. The antioxidant capacity was evaluated by both, DPPH• and ORAC methods. The results indicated that starch digestibility from all rice samples was little affected by parboiling under the conditions employed in the present study. Samples with...