Wheat bran contains a diverse collection of macronutrients, micronutrients and bioactive components, including those thought to have an important role in reducing the risk of many chronic diseases. The complication of wheat bran as a functional food relates to its high insoluble fibre content, which renders bran and its constituent bioactives largely indigestible, and hence with limited bioavailability. The main objective of this thesis research was to evaluate the effects of heat treatments of branon the antioxidant activity and chemical composition of the bran. Presumably, if the solubility of wheat bran can be enhanced by pre-treatment, its biological impact associated with its fibre and resident phytochemicals would also be enhanced. Compared to untreated bran, freeze dried water soluble extracts of thermally treated bran had substantially enhanced levels of antioxidant activity and signficantly increased concentration of a very broad spectrum of bran bioactive constituents including phenolics, minerals, phytate, B vitamins, and non-starch polysaccharide fibre compounds. Results taken together point to the development of novel wheat bran and extracts with considerable commercial potential for whole grain food use and a variety of nutraceutical applications far beyond what may be possible with whole grain wheat or normal bran. Outcomes of the research highlight the conclusion that the nutritional and functional food benefits of normal wheat bran probably represent a fraction of its potential due to the limited digestibility of wheat bran, which in turn, limits the bioavailability of its fiber and constituent bioactive compounds.

Wheat bran contains a diverse collection of macronutrients, micronutrients and bioactive components, including those thought to have an important role in reducing the risk of many chronic diseases. The complication of wheat bran as a functional food relates to its high insoluble fibre content, which renders bran and its constituent bioactives largely indigestible, and hence with limited bioavailability. The main objective of this thesis research was to evaluate the effects of heat treatments of branon the antioxidant activity and chemical composition of the bran. Presumably, if the solubility of wheat bran can be enhanced by pre-treatment, its biological impact associated with its fibre and resident phytochemicals would also be enhanced. Compared to untreated bran, freeze dried water soluble extracts of thermally treated bran had substantially enhanced levels of antioxidant activity and signficantly increased concentration of a very broad spectrum of bran bioactive constituents including phenolics, minerals, phytate, B vitamins, and non-starch polysaccharide fibre compounds. Results taken together point to the development of novel wheat bran and extracts with considerable commercial potential for whole grain food use and a variety of nutraceutical applications far beyond what may be possible with whole grain wheat or normal bran. Outcomes of the research highlight the conclusion that the nutritional and functional food benefits of normal wheat bran probably represent a fraction of its potential due to the limited digestibility of wheat bran, which in turn, limits the bioavailability of its fiber and constituent bioactive compounds.

Doctor of Philosophy / Department of Grain Science and Industry / Yong Cheng Shi / Wheat bran is a by-product of the wheat flour milling industry. The number of food products containing wheat bran is on the rise because it is a well-recognized good source of dietary fiber. Currently, bran is a low-value commodity used mostly in animal feed, but it has the potential for more extensive applications. To understand the functional and nutritional properties of wheat bran and better use wheat bran in food, it is critical to understand the physical structure of wheat bran. For the first time, solid-state ¹³C cross-polarization magic-angle spinning nuclear magnetic resonance (¹³C CP/MAS NMR), X-ray diffraction (XRD), and small angle X-ray scattering (SAXS) were used to study the physical structure of wheat bran and its dissected layers. The XRD and Solid-State ¹³C CP/MAS NMR both confirmed the presence of crystalline cellulose in untreated bran, enzymatically treated bran, and dissected bran layers. Destarched and deproteinized wheat bran (DSDPB) was treated with a mixture of either 7 or 9% sodium hydroxide and 12% urea solvent and structure of the extracted polymers was investigated. Three and 6 cycle dissolution schemes, were examined involving the repeated cooling of the solvent bran mixture to -12.6 °C and then agitating it at 25 °C. When 7% NaOH/12% urea (6 cycle) was applied to DSDPB, 84.1% of the material was solubilized including 89.8% of the arabinoxylans (AX). This procedure recovered more wheat bran AX for characterization than any previous study using alkaline dissolution. Wheat bran was enzymatically and hydrothermally treated to maximize the soluble fraction. Unlike previous research, the starch and protein were kept and not removed before endoxylanase treatment. The retained protein and glucose polymers (starch, β-glucan, cellulose) could provide functional benefits in addition to the arabinoxylan and could make the process more economical. Wheat bran hydrolyzed with thermostable α-amylase, protease, and xylanase was the recommended treatment. The combined solubles had a viscosity of 23 cP (10% w/w solids) and ranged in estimated molecular weight from ~600 to 20,000. The percentage of untreated wheat bran AX that was solubilized was 50% and the percentage of AX in the solubles was 23%.

The marama bean is an underutilised legume growing wild in the arid and semi arid regions of Southern Africa. Sorghum is an important cereal crop in arid regions of the world. The seed coats of marama beans and bran of sorghum contain antioxidant phenolic compounds with potential health benefits. Aqueous extracts for possible use as antioxidant functional food ingredient were prepared from seed coats of marama beans and bran of condensed tannin sorghum by extracting with water (water extract) or with water acidified to pH 2 (acidified water extract). Aqueous extraction was used in order to obtain an extract free from organic solvents, safe for human consumption, and containing compounds representative of those that are available under aqueous conditions of the gastrointestinal tract. The extracts were analysed for total phenolic content, total flavonoid content, condensed tannin content and protein precipitation capacity using spectrophotometric methods and for individual phenolic compounds using HPLC-MS. Proanthocyanidins were characterised using thiolysis degradation in conjunction with HPLC-MS. The antioxidant activities of the extracts were measured using ABTS, DPPH and ORAC assays. Extracts were also evaluated for protective effect against free radical induced human erythrocytes haemolysis, oxidative DNA damage and human LDL oxidation. Extracts from marama bean seed coats had significantly higher total phenolic content, total flavonoid content, condensed tannin content, protein precipitation capacity and phenolic compound concentration than equivalent extracts from condensed tannin sorghum bran. Three phenolic acids and three flavonols esterified to gallic acid were identified in the extracts from marama bean seed coats. Extracts from condensed tannin sorghum bran had six major phenolic acids, two phenolic aldehydes and three flavanones. Proanthocyanidins in extracts from marama bean seed coats were predominantly highly galloylated prodelphinidins while those in extracts from condensed tannin sorghum bran were procyanidins. Extracts from marama bean seed coats had higher antioxidant activity and protective effects against free radical induced erythrocyte haemolysis and LDL oxidation compared to equivalent extracts from condensed sorghum bran. Extracts from condensed tannin sorghum bran showed some protective effect against oxidative DNA damage. However, extracts from marama bean seed coats gave inconclusive results probably due to prodelphinidins binding to DNA. Extraction of marama bean seed coats under acidic condition resulted in reduction in phenolic compound content, antioxidant activity and protective effect against erythrocyte haemolysis, possibly due to co-precipitation of phenolic compounds with interpolymer complex precipitate formed between highly galloylated condensed tannins and cell wall polysaccharides at pH 2. In contrast, extraction of condensed tannin sorghum bran under the acidic condition resulted in an extract with significantly higher phenolic content and protective effect against erythrocyte haemolysis than the water extract possibly due to enhanced extraction of free and esterified phenolics and release of bound phenolic compounds. Water extracts and acidified water extracts (from marama been seed coats or sorghum bran) did not show significant differences in their protective effect against oxidative DNA damage and LDL oxidation. Extraction under acidic condition may be the preferred method for sorghum bran because it increases recovery of phenolic compounds, but not for marama bean seed coats because it causes reduction in phenolic compound content. The findings of this study show that the extracts have a potential to reduce oxidative stress which is implicated in many chronic diseases such as neurodegenerative diseases, cancer and cardiovascular disease. The extracts can be used in the development of functional foods with potential health benefits. / Thesis (PhD)--University of Pretoria, 2012. / Food Science / unrestricted

<p>Sporedni proizvodi dobijeni u procesu mlevenja žitarica, p&scaron;enične i ovsene mekinje, hidrotermički su tretirane u cilju dobijanja gelova, koji se, kao zamenjivači masti, mogu koristiti u formulacijama prehrambenih proizvoda. Optimizacija procesnih parametara (koncentracija mekinja, vreme homogenizacije i temperatura homogenizacije) proizvodnje gelova vr&scaron;ena je primenom postupka odzivne funkcije (RSM). Gelovi od p&scaron;eničnih i ovsenih mekinja, koji su pripremljeni po prethodno utvrđenim optimalnim parametrima (za p&scaron;enične mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 11,7 min i temperatura homogenizacije od 83,2&deg;C; za ovsene mekinje: 22,0% koncentracija mekinja, vreme homogenizacije od 10,0 min i temperatura homogenizacije od 95,0&deg;C), su, dalje, kao zamenjivači masti, bili inkorporirani u formulaciju keksa na različitim nivoima supstitucije masti (30%, 40% i 50%).<br />Fizičke, teksturne i senzorske karakteristike keksa sa zamenjivačima masti ispitane su u poređenju sa kontrolnim (punomasnim) keksom, te je nivo zamene od 30% izabran kao najpogodniji u smislu sniženja sadržaja masti, sa jedne strane, i ostvarenja željenih karakteristika, sa druge strane.<br />S obzirom da su proizvedeni zamenjivači masti na bazi mekinja nutritivno vredni i bogati funkcionalnim komponentama, ustanovljeno je da je dodatak ova dva funkcionalana zamenjivača masti na nivou od 30% doprineo pobolj&scaron;anju nutritivnih i funkcionalnih svojstava keksa u pogledu povećanog sadržaja prehrambenih vlakana i minerala, povoljnijeg odnosa PUFA/SFA, kao i porasta sadržaja antioksidativno delotvornih komponenti.</p> / <p>Wheat and oat brans, by-products of grain processing, were processed by hydrothermal treatments into the form of gels for partial replacement of fat in food products.<br />Response surface methodology (RSM) approach was applied to examine the effects and to optimize process parameters (bran concentration, homogenization time and homogenization temperature).<br />Wheat and oat bran gels prepared according to the previously determined optimal parameters (for wheat bran: 22.0% bran concentration, homogenization time of 11.7 min and homogenization temperature of 83.2 &deg;C; for oat bran: 22.0 % bran concentration, homogenization time of 10.0 min and homogenization temperature of 95.0 &deg;C) were further incorporated as fat substitutes into the cookie formulation at different levels of substitution (30%, 40% and 50%).<br />The physical, texture and sensory properties of cookies with fat replacers were examined in comparison with the control (full fat) cookies, and the fat replacement level of 30% was chosen as the most suitable in terms of reducing the fat, on the one hand, and achieving the desired mentioned characteristics, on the other.<br />Knowing that the produced fat replacers are nutritionally valuable and rich in functional components, it has been found that the addition of these two functional fat replacers at the level of 30% contributed to the improvement of the nutritional properties of cookies in terms of higher content of dietary fibers, minerals and more favourable ratio of PUFA/SFA, as well as higher content of antioxidant components.</p>

Oxidation of lipids influences the color and sensory qualities of meat products. Meat with a high fat content, such as ground meat, is susceptible to lipid oxidation that leads to the development of negative flavor and color changes. Antioxidants, such as butylated hydroxanisole (BHA), butylated hydroxytolune (BHT) and extracts of rosemary, are used in meat products to control the effects of lipid oxidation. Awika (2000, 2003) found that sorghum bran phytochemicals have high antioxidant properties. Our objective is to evaluate the pH, color, sensory and antioxidant effect of 10, 20 and 30% ground beef patties containing rosemary, BHA/BHT, and three levels of sorghum bran during 5 d of aerobic storage at 4°C. Beef trimmings containing either 50% or 90% lean were formulated into three meat blocks containing either 10, 20 or 30% lipid. Within a fat content, ground beef was equally divided into one of six treatments: 1) control-no added ingredients; 2) BHA and BHT at .01% of the meat weight; 3) rosemary at 0.2% of the meat weight; 4) high level of sorghum at 1.0% of the meat weight; 5) medium level of sorghum at 0.5% of the meat weight; and, 6) a low level of sorghum at 0.25% of the meat weight. The ground beef was aerobically packaged and stored for 0, 1, 3, or 5 days at 4°C. pH, thiobarbituric acid reactive substances (TBARS), fatty acid methyl esters (FAME), sensory color, Minolta color space values and descriptive sensory evaluations were determined. Antioxidant addition reduced TBARS values and increased hardness (P<0.020) and springiness (P=0.002) over time compared to controls. The addition of the high sorghum bran level resulted in lower raw color scores (2.0 vs. 2.9) (P<0.0001) and slightly increased bitter basic taste (2.47 vs. 2.65) (P=0.0069) when compared to control patties. The high sorghum level slightly increased pH (6.33 vs. 6.41) (P<0.0001) and resulted in darker (P<0.0001) and less yellow colored (P<0.0001) patties. With storage, patties had higher pH (P<0.0001) and color space values decreased (P<0.0001). Sensory properties of the patties differed across fat levels (P<0.05); however, interactions between fat level and antioxidant treatment were not significant (P>0.05). Moreover, the addition of sorghum bran at low levels can retard oxidative rancidity in ground beef patties without causing detrimental color changes and negatively affecting sensory attributes.

Obesity, glucose intolerance or insulin resistance and elevated blood pressure are now prevalent in the U.S. Increased intake of dietary fiber, omega- 3 fatty acids, and antioxidants may help prevent or manage these diseases. Tortillas are now part of the American diet, and are excellent carriers of higher amounts of fiber and other nutraceutical ingredients. This study was conducted to determine the effects of incorporating nutraceutical ingredients (flaxseed, sorghum bran, oat flour, buckwheat flour) on whole white wheat tortilla quality. Tortillas were prepared using a hot-press, gas-fired oven and were evaluated for physical properties, texture and shelf-stability. Objective and subjective tests demonstrated that whole white wheat and multigrain tortilla doughs were harder, rougher and less extensible than refined flour tortilla dough. Multigrain flour tortillas were thinner, larger and more translucent than the refined flour treatment. Incorporation of whole multigrain flours affected color of the product, giving darker tortillas. Tortilla flexibility decreased over time. After 16 days of storage rollability scores of tortillas decreased drastically. The most pronounced decrease in tortilla flexibility was observed for 5% sorghum bran, 10% buckwheat, and for the treatment prepared with of 5% flax, 5% sorghum, 5% oat, 5% buckwheat. The flexibility loss was higher for whole white wheat and multigrain tortillas than for the refined one which was confirmed with objective and subjective tests. To extend shelf stability of whole multigrain tortillas various amounts of commercial hydrocolloid and ?-amylase were added to the formulation. Tortillas with 75 ppm, 100 ppm of ?-amylase, 1% and 1.5% of gum retained their flexibility during 16 days of storage. Consumer acceptability of the whole multigrain tortillas (5% flaxseed, 5% sorghum bran, 5% oat, 5% buckwheat) was compared with commercial multigrain tortillas and whole white wheat flour tortillas using an untrained sensory panel. The multigrain tortillas were liked by the panel as much as the other samples. Prepared multigrain tortillas had improved nutritional value. Each multigrain treatment contained at least 3 g of dietary fiber, 0.29 g of ?- linolenic fatty acid, lignans and antioxidants. It makes possible to claim them as a ?good source of dietary fiber? and ?an excellent source of ?-linolenic fatty acid?. The formulations tested, together with future refinements, provide more options to consumers seeking healthier alternatives to refined wheat flour tortillas.

The objective of this study was to investigate the potential application of rice bran wax (RBW) organogel to replace solid fat content and create the fat network in ice cream. Ice creams with 10% fat or 15% fat were formulated with RBW organogel as the fat source, and two different emulsifiers were used: polmo, a commercial blend of emulsifiers which contains 80% mono- and diglycerides and 20% polysorbate 80, and Glycerol monooleate (GMO). Candelilla wax (CDW) organogel and carnauba wax (CBW) organogel were also tested for comparison. RBW organogel had the ability to form and sustain structure in 15% fat ice creams when GMO was used as the emulsifier. Transmission electron microscopy revealed that the RBW crystal morphology within the fat droplet, when GMO was used as the emulsifier, was characterized by the growth of crystals at the outer edge of the droplet which increased fat destabilization and network formation. / Nestlé Product Technology Centre, France

Canola meal (Brassica napus L.) and oriental mustard bran (Brassica juncea) were subjected to alkali and acid pretreatment to expose pentosan, for enhancing further enzymatic hydrolysis by endo-1,4-β-xylanase from Trichoderma longibrachiatum for the production of oligosaccharides. Pretreatment especially with alkali, effectively increased the relative content of pentosan to about ~ 41% and ~ 72%. Alkali pretreated canola meal and mustard bran resulted in a pentose content of 2.28 ± 0.15 g and 3.20 ± 0.11 g per 100 g substrates at 18 h and 24 h of reaction respectively, which corresponded to ~ 26% and ~ 28% conversion of original pentosan in substrates. UPLC-MS data showed xyloglucuronic acid (XGlcA) as the major oligosaccharide in the hydrolyzates. Reversed-phase HPLC-DAD indicated the principal phenolic compound in the hydrolyzates was sinapine. DPPH radical scavenging assay showed that endoxylananse hydrolyzates of acid pretreated substrates had strong antioxidant activities in comparison to alkali pretreated samples.

Esta dissertação é composta por 5 artigos. / CNPq / INTRODUÇÃO E OBJETIVOS: O arroz é um dos cereais mais consumidos no mundo e durante o seu beneficiamento, obtém-se o farelo que representa cerca de 8% do peso total do grão. O farelo de arroz desengordurado contém aproximadamente 15% de proteínas de alto valor nutricional. As técnicas de extração permitem além de extrair, selecionar e separar e determinadas substâncias. A extração das proteínas do farelo de arroz em meio alcalino é muito utilizada porque neste pH sua solubilidade é máxima e há a ruptura das paredes celulares. Podem ser usados métodos mecânicos e não mecânicos. A agitação mecânica com a movimentação de líquidos por meio de impulsores giratórios auxilia no rompimento das paredes celulares durante processos de extração. A extração assistida por ultrassom (EAU) utiliza frequências acima de 20 kHz para gerar cavitação em meios líquidos, que nada mais é que o colapso de microbolhas de gás e vapor que ocorre quando as mudanças de pressão no meio são grandes o suficiente, para literalmente dilacerá-lo sob a influência do ultrassom. Com este colapso, há o rompimento celular e a transferência de massa para o meio. Um concentrado de proteína do farelo de arroz (CPFA) deve ter boa solubilidade, propriedades funcionais apropriadas, características organolépticas aceitáveis para serem utilizados como um ingrediente alimentar, e possuir aminoácidos essenciais. Os objetivos deste trabalho foram avaliar os efeitos do pH, temperatura, velocidade da agitação, tempo de agitação, tempo em banho ultrassônico e amplitude da potência na extração das proteínas do farelo de arroz, além de analisar a cor, funcionalidade do CPFA (capacidade de absorção de água e óleo, formação de espuma, estabilidade da espuma, capacidade emulsificante, estabilidade da emulsão e formação de gel), solubilidade, perfil de aminoácidos e sua aceitabilidade quando aplicado em suco de caju. MÉTODOS ─ Verificou-se o rendimento proteico em três tipos de extração alcalina: agitação, banho ultrassônico a 37 kHz e banho ultrassônico a 80 kHz. Numa primeira etapa, aplicou-se o planejamento fatorial fracionário 24-1 (com dois níveis, três repetições no ponto central), totalizando 11 ensaios, tendo como variáveis independentes para a extração com agitação: pH, tempo de agitação (min), velocidade da agitação (rpm) e temperatura (ºC), e para a extração em banho de ultrassom (37 e 80 kHz): pH, tempo de ultrassom (min), temperatura (ºC) e amplitude da potência (%). Na segunda etapa, as variáveis com efeitos significativos (p < 0,05) de cada tipo de extração foram submetidas ao Delineamento Composto Central Rotacional (DCCR) 22 (quatro pontos axiais, três repetições no ponto central), totalizando 11 ensaios. As variáveis dependentes, resposta experimental e predita, foram expressas em g.100 mL-1 de extrato ± desvio padrão médio. Os efeitos foram validados pela Análise de Variância, por meio do software Statistica 8.0, sendo considerada a melhor condição de extração aquela com maior teor proteico e desta, obtido o concentrado. O teor de proteína bruta foi determinado por Kjeldahl e multiplicado por 5,95, e o rendimento, razão do conteúdo total da proteína no farelo de arroz pelo encontrado no CPFA. A cor do concentrado extraído por agitação e por ultrassom foi verificada por colorimetria instrumental e deste último método de extração, determinou-se a composição centesimal (%), minerais (µg.g-1), proteínas solúveis (%), capacidade de absorção de água e óleo (g de água.g-1 de amostra; g de óleo.g-1 de amostra), capacidade de formação de espuma (%), estabilidade da espuma (%), capacidade emulsificante (%), estabilidade da emulsão (%) e capacidade de formar gel, perfil de aminoácidos (g.100 g-1). A aplicabilidade foi verificada por avaliação sensorial de suco de caju (ordenação por preferência e aceitabilidade dos atributos: sabor, cor, aroma e impressão global). PRINCIPAIS RESULTADOS ─ A resposta ótima na extração alcalina com acompanhamento de agitação foi do teor de proteína de 48,53 % (b.s.), em pH 10, velocidade de agitação de 80 rpm, tempo de agitação de 300 min e temperatura de 45 ºC, representando o rendimento de 34,51% na extração. A interação entre as variáveis independentes pH, tempo de agitação e temperatura promoveram efeitos favoráveis para a técnica de extração das proteínas, enquanto que a velocidade de agitação não interfere de modo significativo. O planejamento experimental utilizado foi adequado para estudar os efeitos da associação da agitação mecânica ao processo de extração alcalina das proteínas do farelo de arroz. Nessas condições, o CPFA obtido apresentou forma de pó fino e textura aveludada, com valores de L* de 78,29 ± 0,95, a* -4,97 ± 0,05 e b* 16,51 ± 0,10 para a medida instrumental de cor. Quando se avaliou a extração alcalina associada ao banho ultrassônico, comparou-se o desempenho das frequências de 37 e 80 kHz, comprovou-se que na menor frequência houve maior extração. No ensaio com maior rendimento obteve-se um concentrado proteico com teor de proteína de 83,36% (b.s.), quando utilizado o pH 10, 30 min de ultrassom, 100% de amplitude da potência (30ºC) representando um rendimento de 4,74 % na extração. Portanto, a extração assistida pode ultrassom ser utilizada como um método alternativo para extrair proteínas do farelo de arroz, reduzindo o tempo de extração e consumindo menos energia. A EAU é uma técnica promissora e avançada para a extração de substâncias de interesse alimentar, oferecendo potencial para o desenvolvimento de novos produtos. O CPFA apresentou-se na forma cristalina com valores de L* de 60,42 ± 2,15, a* -1,31 ± 0,53 e b* 20,29 ± 1,39 para a medida instrumental de cor, observou-se menor solubilidade em pH 2, 3, 4 e 5, e maior solubilidade na faixa de pH 6 a 10. A capacidade de absorção de água e de óleo de 1,04 ± 0,07 g.g-1, e 11,75 ± 0,67 g.g-1, respectivamente, superior ao da referência Albumina Bovina Sérica (BSA). A maior quantidade de espuma formada ocorreu em pH 4 e 8 (41,17% ± 2,30; 48,47% ± 1,15) e menor em pH 6 (9,96% ± 0,00), porém a estabilidade das espumas formadas foi baixa em todos os pHs, e em ambos os casos, a BSA apresentou característica espumante superior. CPFA apresentou boa capacidade emulsificante em pH 2, 4, 6 e 8 (56,20% ± 5,39; 66,19% ± 6,57; 67,86% ± 0,19; 72,92% ± 2,95) comparáveis a BSA, mas emulsões menos estáveis em pH 2 (32,50% ± 3,54). Em temperatura de 30 ºC e 8 ºC, o CPFA apresentou baixa capacidade geleificante, com um gel frágil e pouco consistente. O perfil de aminoácidos do CPFA indicou a presença de ácido glutâmico, glicina, histidina, arginina, treonina, valina, metionina, isoleucina, leucina, fenilalanina e lisina, essenciais para a síntese das proteínas. O desempenho sensorial do CPFA foi avaliado em formulações de suco de caju adoçado contendo 0,1%; 0,3% e 0,5% de CPFA e ordenadas de acordo com a preferência de 60 provadores não treinados. Constatou-se que não houve diferença significativa entre as amostras (p > 0,05). Em função deste resultado, um teste de aceitação foi aplicado a 64 provadores não treinados, utilizando uma fórmula de suco de caju adoçado adicionada de 0,5% de CPFA e a Controle (sem CPFA). Verificou-se que houve diferença significativa (p < 0,05) entre as amostras nos atributos cor, sabor, aroma e impressão global. Os provadores gostaram moderadamente do Controle, mas foram indiferentes a fórmula com 0,5% de CPFA, uma vez que acentuou as características sensoriais do arroz ao suco de caju. O CPFA apresentou excelentes propriedades funcionais que o tornam um ingrediente promissor para a indústria alimentícia. / INTRODUCTION AND OBJECTIVES: Rice is the cereal most consumed in the world and during the processing, it is obtained the rice bran which represents 8% of the total weight of the grain. The defatted rice bran contains approximately 15% of protein of high nutritional value. The extraction techniques permit besides to extract, also to select and to separate substances. The extraction of rice bran proteins by alkaline medium is often used because they reach the maximum solubility in the pH and to assist in rupture of cell walls of a food. Mechanical and non-mechanical methods may be used. Mechanical stirring with the movement of liquid through rotating impellers assists in the disruption of the cell walls during extraction processes. The extraction assisted by the ultrasound (EAU) uses frequencies above 20 kHz to generate cavitation in liquids, which is the collapse of microbubbles of gas and vapor that occurs when the pressure changes in the middle are large enough to literally lacerate it under the influence of ultrasound. With this collapse, there is the cell disruption and the mass transfer to the environment. A rice bran protein concentrate (RBPC) should have good solubility, appropriate functional properties, acceptable sensory characteristics to be used as a food ingredient e to have essential amino acids. The objectives of this study were evaluate the effects of pH, temperature, speed of stirring, stirring time, time in ultrasonic bath and amplitude of the power in the extraction of rice bran protein, and analyzing the color, RBPC functionality (water and oil retention capacity, foaming, foam stability, emulsifying capacity, emulsion stability and gel formation), solubility, amino acid profile and its acceptability when applied in cashew juice. METHODS ─ It was verified the protein yield in three types of alkaline extraction: agitation, ultrasonic bath at 37 kHz and ultrasonic bath at 80 kHz. As a first step, it was applied the Fractional Factorial Planning 24-1 (with two levels, three replicates in the central point), totaling 11 trials, with the independent variables for extraction with stirring: pH, agitation time (min), speed stirring (rpm) and temperature (°C) and for the extraction in an ultrasound bath (37 and 80 kHz): pH, ultrasound time (min) temperature (°C) and power range (%). In the second stage, the variables with significant effects (p < 0.05) of each type of extraction were subjected to Design Central Composite Rotational (DCCR) 22 (four axial points, three repetitions at the central point), totaling 11 trials. The dependent variables, the experimental and predicted response were expressed in g.100 mL-1 extract ± average standard deviation. The effects were validated by analysis of variance, using software Statistica 8.0, being considered the best extraction condition one with the highest protein content and thus, obtained the concentrate. The crude protein content was determined by Kjeldahl and multiplied by 5.95. The yield was calculated as the ratio of the total content of protein in rice bran by the one found in the RBPC. The color of the concentrate extracted by stirring and by ultrasound was checked by instrumental colorimetry and from the latter extraction method, it was determined the chemical composition (%), minerals (μg.g-1), soluble protein (%), water and oil retention capacity (g water.g-1 sample; g oil.g-1 sample), foaming capacity (%), foam stability (%), emulsifying capacity (%), stability of emulsion (%), ability to form gel and amino acid profile (g.100 g-1). The applicability was checked by sensory evaluation of cashew juice (preference and acceptability of attributes as taste, color, smell and global impression). MAIN RESULTS ─ The optimal response in the alkaline extraction with monitoring of stirring was of 48.53% protein (DB), at pH 10, stirring speed of 80 rpm, stirring time of 300 min and temperature of 45 °C, representing the yield of 34.51% in extraction. The interaction between the independent variables as pH, stirring time and temperature promoted favorable effects on protein extraction technique while the stirring speed does not interfere significantly. The experimental planning used was adequate to study the effects of the combination of mechanical stirring to alkaline extraction process of rice bran protein. Under these conditions, RBPC obtained presented as a fine powder and velvety texture, with values of L* 78.29 ± 0.95, a* -4.97 ± 0.05 and b* 16.51 ± 0.10 for the instrumental color measurement. When assessing the alkaline extraction associated with the ultrasonic bath, it was compared the performance of the frequencies of 37 and 80 kHz, and it was proved that the lower frequencies have shown higher extraction. In the test with increased yield obtained a protein concentrate with a protein content of 83.36% (DB), when used pH 10, 30 min of ultrasound, 100% power range (30 °C), representing a yield of 4,74% extraction. Therefore, the UAE can be used as an alternative method for extracting rice bran protein, reducing the extraction time and consuming less power. UAE is a promising and advanced technique for extracting substances from food interest, offering potential for the development of new products. The RBPC presented in the crystalline form with values L* 60.42 ± 2.15, a* -1.31 ± 0.53 and b*20.29 ± 1.39 for instrumental measurement of color. It was observed a lower solubility at pH 2, 3, 4 and 5, but greater solubility in the pH range 6 to 10. The water and oil absorption capacity was 1.04 ± 0.07 g.g-1 and 11.75% ± 0.67 g.g-1, respectively, higher to reference Bovine Serum Albumin (BSA). The greater amount of foam was formed in pH 4 and 8 (41.17% ± 2.30, 48.47% ± 1.15) and lower at pH 6 (9.96% ± 0.00), but the stability of the formed foam was low at all pHs and in both cases, and BSA showed higher foaming characteristics. RBPC showed good emulsifying capacity at pH 2, 4, 6 and 8 (56.20% ± 5.39, 66.19% ± 6.57, 67.86% ± 0.19, 72.92% ± 2.95) comparable to BSA, but less stable emulsions at pH 2 (32.50% ± 3.54). In temperature of 30 °C and 8 °C, the RBPC showed low gelling capacity with a fragile gel and little consistent. The amino acid profile of the RBPC presented good amounts of glutamic acid, glycine, histidine, arginine, threonine, valine, methionine, isoleucine, leucine, phenylalanine and lysine, essential for protein synthesis. The sensory performance of the RBPC was evaluated in formulations of sweetened cashew juice containing 0.1%; 0.3% and 0.5% RBPC and ordered according to the preference of 60 untrained panelists. It was observed that there was no significant difference between the samples (p > 0.05). Due to this result, an acceptance test was applied to 64 untrained panelists using a formula of sweetened cashew juice added with 0.5% of RBPC and the control formula (without RBPC). It was found that there was a significant difference (p < 0.05) between samples in attributes as taste, color, smell and overall impression. Tasters liked moderately the control formula, but were indifferent to the formula with 0.5% RBPC because the sensory characteristics of the rice were accentuated. The RBPC presented excellent functional properties that make it a promising ingredient for the food industry. / 5000