4,701 research outputs found
Estabilidade e propriedades sensoriais da bebida de farelo de arroz parbolizado orgânico e os efeitos de seu consumo em ratos
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias, Programa de Pós-Graduação em Ciência dos Alimentos, Florianópolis, 2009O farelo de arroz estabilizado é um subproduto do beneficiamento dos grãos de arroz. O uso deste farelo vem crescendo no País devido ao seu valor nutricional e benefícios à saúde. Com o objetivo de oferecer alternativas para o consumo do farelo de arroz, foi elaborada uma bebida de extrato deste farelo em dois diferentes sabores. A bebida foi tratada termicamente e avaliada quanto à composição química, estabilidade e propriedades sensoriais, parâmetros de qualidade pertinentes ao novo produto. Os parâmetros para avaliar a vida de prateleira foram acidez titulável, pH e reologia. Foi realizado um ensaio biológico com ratos, para avaliar os efeitos do seu consumo no colesterol total e glicose e outro ensaio biológico para determinar o comportamento de ratos no nado forçado e no labirinto em cruz elevado com determinação de ACTH plasmático, além do efeito desta bebida na absorção de cálcio em ratos. A análise da composição nutricional mostrou um produto rico em ácidos graxos insaturados e minerais, especialmente, fósforo, potássio, manganês e magnésio. A reologia mostrou que a bebida obtida com este farelo estabilizado conservou-se por 20 dias sob refrigeração. A análise sensorial indicou que a bebida de farelo de arroz foi aceita dentro das formulações estabelecidas. Foi verificado que, em ratos, a bebida de farelo de arroz não apresentou efeito significativo (p>0,05) sobre o colesterol, mas apresentou efeito significativo (p0,05). Não houve efeito negativo na absorção de cálcio.The stabilized rice bran is a byproduct of processing grain of rice. Use of this meal is growing in the country because of its nutritional value and health benefits. Aiming to offer alternatives to the consumption of rice bran, was prepared for a drink of this bran extract in two different flavors. The drink was treated and evaluated as to the chemical composition, stability and sensory properties, the quality parameters relevant to the new product. The parameters to evaluate the shelf-life were acidity, pH and rheology. An assay was conducted with rats to evaluate the effects of its consumption in total cholesterol and glucose and other biological test to determine the behavior of rats in the forced swim and in the plus maze with determination of plasma ACTH, in addition to the effect of this drink in the absorption of calcium in rats. The analysis of the nutritional composition showed a product rich in unsaturated fatty acids and minerals, especially phosphorus, potassium, manganese and magnesium. The rheology showed that the drinks with the meal stabilized lasted 20 days under refrigeration. The sensory analysis indicated that the drink of rice bran was accepted into the formulations established. It was found that in rats, the drink of rice bran showed no significant effect (p> 0.05) on cholesterol, but significant effect (p 0.05). There was no negative effect on the absorption of calcium
How good are rodent models of carcinogenesis in predicting efficacy in humans? A systematic review and meta-analysis of colon chemoprevention in rats, mice and men
No full textTumours in rodent and human colon share many histological and genetic features. To know if rodent models of colon carcinogenesis are good predictors of chemopreventive efficacy in humans, we made a meta-analysis of aspirin, beta-carotene, calcium, and wheat bran studies. Controlled intervention studies of adenoma recurrence in human volunteers were compared with chemoprevention studies of carcinogen-induced tumours in rats, and of polyps in Min (Apc(+/-)) mice: 6714 volunteers, 3911 rats and 458 mice were included in the meta-analyses. Difference between models was small since most global relative risks were between 0.76 and 1.00. A closer look showed that carcinogen-induced rat studies matched human trials for aspirin, calcium, carotene, and were compatible for wheat bran. Min mice results were compatible with human results for aspirin, but discordant for calcium and wheat bran (no carotene study). These few results suggest that rodent models roughly predict effect in humans, but the prediction is not accurate for all agents. Based on three cases only, the carcinogen-induced rat model seems better than the Min mouse model. However, rodent studies are useful to screen potential chemopreventive agents, and to study mechanisms of carcinogenesis and chemoprevention
Abstract Bibliography of the Chemistry, Processing, and Utilization of Rice Bran and Rice Bran Oil
No full textThis compilation of references and abstracts relating to the chemistry, processing, and utilization of rice bran and rice bran oil covers the period 1876 to 1951. The references are arranged alphabetically by author under each subject division listed in the table of contents. Subject and author indexes are provided
Extração de orizanol da borra de neutralização do óleo de farelo de arroz: [dissertação]
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia de AlimentosO y-orizanol é definido como uma mistura de ésteres do ácido ferúlico com esterol ou álcoois triterpênicos. Sendo um composto antioxidante natural, possui grande importância para indústria de alimentos e farmacêutica. O conteúdo de ?-orizanol no óleo de farelo de arroz bruto está na faixa de 1 % - 2 %. Este composto tem sido utilizado no Japão para conservar óleos, alimentos e bebidas e também em fórmulas medicinais e cosméticas. O objetivo deste trabalho foi recuperar o ?-orizanol presente na borra da neutralização do óleo de farelo de arroz (RBOS). A matéria-prima utilizada na realização deste trabalho foi a borra proveniente da neutralização do óleo bruto de farelo de arroz (RBOS), da indústria IRGOVEL S.A., localizada no município de Pelotas, Rio Grande do Sul. A borra de neutralização foi inicialmente tratada com álcali para sua saponificação e posteriormente foi seca durante 2 h ao ar livre e 4 h em estufa. A matéria insaponificável contida na RBOS foi extraída e tratada com solvente orgânico, posteriormente este material foi permeado por coluna cromatográfica e o resíduo foi cristalizado para purificação do orizanol. A RBOS saponificada e o insaponificável extraído da RBOS foram submetidos à extração supercrítica (ESC), sendo testadas diversas condições de temperatura e pressão. Os extratos obtidos foram analisados quanto ao teor de orizanol, por HPLC-UV. O teor de orizanol presente na RBOS foi de 1,45 %, dentro da faixa citada na literatura. O rendimento da ESC utilizando a RBOS saponificada variou desde 0,22 % ± 0,04 % até 12,51 % ± 0,52 %, sendo que tanto pressão como temperatura apresentaram efeitos significativos no rendimento, com o maior valor obtido em 300 bar e 60 °C. Nestas condições se obteve, também, o maior teor de orizanol extraído, 16 %, e a maior recuperação de orizanol, que foi de 75 % do orizanol presente na RBOS. Os valores de rendimento obtidos para o insaponificável extraído da RBOS variaram de 0,90 % ± 0,04 % até 6,31 % ± 0,38 %, sendo que a maior recuperação e teor de orizanol, 6,26 % e 9,9 %, respectivamente, foram obtidos a 300 bar e 45 °C. Os modelos de transferência de massa utilizados para descrever as curvas de ESC foram: Esquível et al., (1999), Gaspar et al., (2003) e Martínez et al., (2003). O modelo Martínez et al., (2003) apresentou o melhor ajuste para as curvas de ESC da RBOS saponificada e da fração insaponificável extraída da RBOS. The gamma-oryzanol is defined as a mixture of ferulic acid esthers with sterol ore triterpenic alcohols. It is considered a natural antioxidant compound with increasing importance in the food and pharmaceutical industry. The ?-orizanol in raw rice bran oil is in the range of 1 % - 2 %, and is been used in Japan to preserve oils, foods and soft drinks and in medicals and cosmetics. The objective of this study is to recuperate ?-orizanol from the rice bran oil soap stock (RBOS). The raw material utilized in this study was provided by IRGOVEL S.A., located in Pelotas, Rio Grande do Sul. The neutralization sludge was initially prepared with alkali for the saponification and in sequence dried during 2 h at air and 4 h in oven-drying. The unsaponificable material from the RBOS was extracted and treated with organic solvent, in sequence it was permeated trough a chromatographic column and the residual crystallized to purificate the oryzanol. The saponificated RBOS and the unsaponificated extract from RBOS were extracted with supercrítical solvent (ESC) under different pressure and temperature conditions. The obtained extracts were analyzed to quantify the ?-orizanol via HPLC-UV. The ?-orizanol content in the RBOS was 1.45%, in between the literature data. The ESC yield utilizing saponificated RBOS varied from 0.22 % ± 0.04 % to 12.51 % ± 0.52 %. The temperature and pressure presented important effects over the yield with the best value been obtained at 300 bar and 60 ºC. At these conditions the highest ?-orizanol amount was extracted, 16%, and the major ?-orizanol recovery of 75% from the ?-orizanol present in the RBOS. The yield values obtained for the unsaponificable extracted from the RBOS varied from 0.90 % ± 0.04 % to 6.31 % ± 0.38 %. The higher ?-orizanol recovery (6,26 % and 9,9 %) was respectively from 300 bar and 45 ºC. The mass transfer models utilized to describe the supercrítical extraction curves were: Esquível et al. (1999), Gaspar et al. and Martínez et al (2003). The Martínez et al. (2003) model presented the best fit to the saponificated RBOS and to the unsaponificated RBOS fraction extraction ESC curves
Detection and isolation of typical gut indigenous bacteria in ICR mice fed wheat bran and wheat straw fibre
No full textWheat bran (WB) and wheat straw fibre (WSF) are by-products of the wheat flour industry.
To prove the existence of indigenous gut bacteria responsible for WB and WSF, the Institute of Cancer Research (ICR) mice were fed a diet containing no fibre (CS), 10% WB, or 5% WSF for 14 d. The caecal microbiome was analysed by 16S rDNA (V4 region) amplicon sequencing. Typical colonies were isolated and estimated by 16S rRNA gene BLASTn analysis.
The predominant amplicon sequence variants in all diet groups belonged to Bifidobacterium pseudolongum- and Faecalibaculum rodentium-like bacteria. Lactobacillus johnsonii- and Limosilactobacillus reuteri-like bacteria were high in the WB group compared with those in the CS group. Lactobacillus johnsonii Wheat-1 and L. reuteri Wheat-12 strains could be isolated. Lactobacillus johnsonii Wheat-1 exhibited good fermentation activity in 10% (w/v) WB suspension.
Superoxide anion radical scavenging capacity of the WB suspension was significantly increased by the fermentation.journal articl
Corn-bran: Alternative cellulosic filler for polypropylene
No full textIn this study, the use-ability of corn bran (CB) as a reinforcing filler in polypropylene (PP) matrix was investigated. The properties of CB/PP composites were compared with wood fiber (WF) filled PP composites. In order to enhance the interfacial adhesion, maleated-PP (PP-g-MAH) (MaPP) was used. The CB/PP and WF/PP composites were compounded in an Xplore laboratory compounder. The CB/PP/MaPP and WF/PP/MaPP composites were characterized by tensile test, differential scanning calorimetry (DSC), thennogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The morphology investigated by scanning electron microscopy (SEM). It was shown that corn bran can be an alternative candidate to be used as a reinforcing natural filler source for thermoplastic composites
Biocatalysis for rice bran valorization
No full textThe use of biocatalysis for the conversion of biomass into value added products is rapidly growing. We report here the application of biocatalytic processes to the valorization of rice bran oil and protein.
Because of the large amount of rice produced annually, by-products of rice milling, such as rice bran (ca. 70 kg/tonn of rice), are plentiful and readily available. Although rice bran is a rich source of highly nutritional proteins (10-16%), lipids (15-22%), carbohydrates (34-52%), and a number of micronutrients (e.g. vitamins, minerals, antioxidants, and phytosterols), it is currently under-utilized. The aim of this work is to exploit the protein and the oil fraction of rice bran by using a biotechnological approach to obtain high-added value products.
Rice bran protein (RBP) are valuable because they contain essential amino acids and are hypoallergenic. However, the heterogeneous and complex nature as well as the poor solubility of RBP due to strong aggregation and/or extensive disulfide bond cross-linking are limiting factors in their utilization as food ingredients. A biocatalyzed process based on the use of proteases, also in combination with carbohydrate-hydrolyzing enzymes, was developed to solubilize RBP and to enhance the extractability of the entrapped protein components.
On the other hand, rice bran oil (RBO) is characterized by a high free fatty acids (FFA) content. This feature makes RBO unsuitable for processing into edible oil; however, it can be a valuable feedstock for the production of chemicals. In fact, a significant number of high-value products require FFA in their manufacturing. RBO was submitted to a preparative lipase-catalyzed hydrolysis affording pure FFA in a moderate yield.
This work is supported by Fondazione Cariplo (RiceRes Project, 2014-0558
Wheat Bran Sourdough as a Functional Ingredient
No full textSeveral studies indicate that high-content whole grains diets work as a protective factor to chronic diseases. This decreased risk is related to the high content of fiber and bioactive compounds found mainly in the bran, which is usually removed during milling because of its fast rancidity. The increasing demand for functional foods and the pressure to ensure the exploitation of agro-industrial by-products have attracted great interest in bran-enriched foods/flours. The Healthgrain European Project recently emphasized the possibility to increase the amount of bioactive compounds in cereals by-products through biotechnological processes. Bran fermentation has been shown an efficient pre-treatment in order to enhance technological and nutritional properties of high fiber products (Katina et al. 2007). From a nutritional point of view, the fermentation effect on water-extractable arabinoxylans (WEAX) deserve particular attention, because of the positive effects on glycaemic and insulinaemic responses (Lu et al. 2000). Moreover, microbial xylan-degrading activity positively affects the bioavailability of functional compounds commonly found in the bran. This study aims to develop a innovative biotechnological process of wheat bran stabilization by microbial acidification. Briefly, bran sourdoughs were produced at 18 °C through continuous propagation by back-slopping of ripe dough (10% inoculum) until a stable microbiota was established. At each refreshment step (every 24h), analysis of the bacterial content and the acidity of the dough, measured as pH and total titratable acidity (TTA), were performed on the ripe sourdough. Furthermore, the amounts of fiber and bioactive compounds, such as WEAX, ferulic and phytic acids, were determined before and after bran fermentation. Lactic acid bacteria (LAB) rapidly increased after the first day of bran fermentation and reached high amounts (109 CFU g-1). Yeasts population fluctuated during propagation, but after 8 refreshments it stabilized at the level of 107 CFU g-1. The TTA and pH developments followed the LAB growth with the pH rapidly decreasing from 6.5 to 4.1. Results suggest that wheat bran sourdough is a “stable” functional ingredient for bakery products that can be used to improve their nutritional and technological properties
Harnessing Filamentous Fungi for Enzyme Cocktail Production Through Rice Bran Bioprocessing
No full textValorization of agri-food residues has garnered significant interest for obtaining value-added compounds such as enzymes or bioactive molecules. Rice milling by-products, such as rice bran, have limited commercial value and may pose environmental challenges. Filamentous fungi are recognized for their ability to grow on residues and for their capacity to produce large amounts of metabolites and enzymes of industrial interest. Here, we used filamentous fungi to produce enzyme cocktails from rice bran, which, due to its polysaccharide composition, serves as an ideal substrate for the growth of fungi producing cellulases and xylanases. To this end, sixteen fungal strains were isolated from rice bran and identified at the species level. The species belonged to the genera Aspergillus, Penicillium, and Mucor. The Aspergillus species displayed the highest efficiency in cellulase and xylanase activities, especially A. niger var. phoenicis and A. amstelodami. A. terreus, A. tritici, and A. montevidensis stood out as xylanolytic isolates, while P. parvofructum exhibited good cellulase activity. A. niger var. phoenicis followed by A. terreus showed the highest specific enzymatic activities of α- and β-D-galactosidase, α-L-arabinofuranosidase, α- and β-D-glucosidase, and β-D-xylosidase. Additionally, proteomic analysis of A. terreus, A. niger var. phoenicis, and P. parvofructum exoproteomes revealed differences in enzyme production for rice bran degradation. A. niger var. phoenicis had the highest levels of xylanases and cellulases, while P. parvofructum excelled in proteases, starch-degrading enzymes, and antifungal proteins. Finally, two Penicillium isolates were notable as producers of up to three different antifungal proteins. Our results demonstrate that filamentous fungi can effectively valorize rice bran by producing enzyme cocktails of industrial interest, along with bioactive peptides, in a cost-efficient manner, aligning with the circular bio-economy framework
Rice bran oil based biodiesel production using calcium oxide catalyst derived from Chicoreus brunneus shell
No full textEnvironmental pollution and the declining global supply of accessible fossil fuels are the key drivers of the search for alternative sources of energy. Biodiesel, a renewable liquid transport fuel, is commercially-produced using heterogeneous catalysts. \ud
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Heterogeneous catalysts obtained from seashells appeared as promising alternatives thanks to their low preparation cost and increased efficiency in transesterification. In this study, shells from Chicoreus brunneus (known as Adusta murex) were calcined, hydrated, and dehydrated to produce CaO heterogeneous nanocatalyst for the transesterification of rice bran oil into biodiesel. \ud
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Field emission scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, surface area measurement (Brunauer-Emmett-Teller method), and X-ray diffraction were used to characterise the seashell-derived catalyst. The properties of the rice bran oil-derived biodiesel (acid value, calorific value, density, oxidation stability, and flash point) conformed to the American Society of Testing and Materials (ASTM) D6751 and European EN 14214 biodiesel standards, except for kinematic viscosity. \ud
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Therefore, the impact of the parameters used for production of the CaO heterogeneous nanocatalyst (calcination temperature and time) and the transesterification reaction (catalyst loading and methanol to rice bran oil ratio) on the kinematic viscosity of RBO-derived biodiesel were determined. \ud
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A model for the transesterification process was developed using a combination of artificial neural networking with ant colony optimisation. The model predicted that C. brunneus-derived CaO catalyst prepared at 1100 °C for 72 min could be used to produce biodiesel from rice bran oil with a minimum kinematic viscosity (4.42 mm2 s-1) confirming to both the ASTM D6751 and EN 14214 biodiesel standards in a transesterification reaction operating with a 35:1 methanol to rice bran oil molar ratio and 0.5 wt% catalyst mass
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