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Whey is an industrial by-product with high nutritional value and an extensive use in food products. This study aimed to show some applications of whey and its proteins in food and discuss their effects on child health. The choice of works from the last 10 years was based on the search in databases using relevant descriptors. Few studies were found, a fact that turns this issue into an original one for the development of scientific hypothesis about the functional capability of dairy products. Literature showed that whey proteins enhance various food characteristics sensory. However, the benefits of these proteins in health promotion and prevention of chronic diseases, including the childhood, are controversial. The beneficial actions of these proteins are associated with their high bioavailability of calcium and especially the presence of bioactive peptides, which may modulate allergy and metabolic complications in children. On the other hand, some studies report that infant formulas that have high content of whey proteins are rich in leucine, which would contribute to the early onset of obesity. This review highlighted the need to carry out a greater number of studies in order to elucidate the consequences of the consumption of these proteins on child health.

Food allergy is an adverse immune response to dietary proteins. Hydrolysates are frequently used for children with milk allergy. However, hydrolysates effects afterwards are poorly studied. The aim of this study was to investigate the immunological consequences of hydrolyzed whey protein in allergic mice. For that, we developed a novel model of food allergy in BALB/c mice sensitized with alum-adsorbed β-lactoglobulin. These mice were orally challenged with either whey protein or whey hydrolysate. Whey-challenged mice had elevated levels of specific IgE and lost weight. They also presented gut inflammation, enhanced levels of SIgA and IL-5 as well as decreased production of IL-4 and IL-10 in the intestinal mucosa. Conversely, mice challenged with hydrolyzate maintained normal levels of IgE, IL-4 and IL-5 and showed no sign of gut inflammation probably due to increased IL-12 production in the gut. Thus, consumption of hydrolysate prevented the development of clinical signs of food allergy in mice.

O presente trabalho visou verificar a elaboração, a caracterização e a avaliação da aceitação de duas formulações alimentares achocolatadas (uma contendo albumina e a outra, concentrado proteico de soro de leite - WPC) para crianças de 7 a 10 anos. O desenvolvimento das formulações baseou-se nas recomendações nutricionais para a faixa etária. Foram avaliados os seguintes parâmetros físico-químicos: composição química, estabilidade, pH, viscosidade e fluidez. A análise sensorial englobou as escalas hedônica de atitude, intenção de consumo e doçura e foi realizada por um grupo de 142 julgadores de um centro universitário, com média de 24,5 ± 7,3 anos de idade e 66,2% do sexo feminino. Todos os dados obtidos foram submetidos à análise estatística, adotando-se p < 0,05 como nível de significância. A composição química não diferiu em base seca (p > 0,05). Observaram-se 3,88 (albumina) e 4,79 (WPC) vezes mais proteínas em 100 mL de amostra do que em bebidas comerciais. A primeira formulação mostrou-se mais viscosa (137,33 cP versus 22,33 cP da formulação com WPC) e menos fluida (percorreu 40 mL em 69 segundosversus 29 segundos da formulação com WPC). Quanto ao pH, o produto com albumina apresentou característica alcalina (8,60) e o com WPC ácida (6,28). Ambas as formulações permaneceram estáveis e homogêneas após 24 horas de visualização. A análise sensorial mostrou que as formulações foram similares em todos os testes aplicados (p > 0,05), sendo que as características mais bem avaliadas foram o sabor, a textura e a doçura, para ambas. Houve boa aceitação das formulações, com nota mediana de 7 e valores acima de 80% para a soma das respostas positivas nos testes. Conclui-se que as formulações alimentares analisadas apresentaram boas características físico-químicas e mostraram-se equilibradas nutricionalmente, com potencial para comercialização. This work aimed to develop, characterize and evaluate the acceptance of two chocolate food preparations (one containing albumin and the other whey protein concentrate - WPC) for 7 to 10 year old children. The food preparations were created based on nutritional recommendations established for this age group. The following physicochemical parameters were evaluated: chemical composition, stability, pH, viscosity and fluidity. The sensory analysis included the hedonic and attitude scales, consumption intent and sweetness and was carried out by 142 judges from a university center, averaging 24.5 ± 7.3 years old, of which 66.2% were female. The data were submitted to a statistical analysis, adopting a significance level of p0.05). Values of 3.88 (albumin) and 4.79 (WPC) times more protein were observed per 100 mL of sample than in a commercial beverage. The first preparation was more viscous (137.33 cPversus 22.33 in the WPC one) and less fluid (took 69 seconds for 40mL to flow versus 29 by the WPC one). Concerning the pH, the product with albumin was alkali (8.60) and that with WPC was acid (6.28). Both preparations were stable and homogeneous after 24 h visualization. The sensory analysis showed that the preparations were similar in all the tests (p>0.05) and the best features for both were the flavour, texture and sweetness. Good acceptance of the preparations was observed, with a median score of 7 and values above 80% for the sum of the positive responses in the tests. In conclusion, the food preparations showed good physicochemical characteristics and were nutritionally balanced, with good market potential.

The purpose of this study was to determine the protein quality of lupin (Lupinus albus and Lupinus angustifolius) and to determine their chemical composition, including dietary fiber. The food transformation index, protein efficiency ratio and net protein ratio were significantly higher for the casein group than for the lupin groups. The in vivo digestibility value of casein was 95.81 ± 1.60, and the DV of L. albus and L. angustifolius were 90.89 ± 2.85 and 89.30 ± 2.01, respectively. Amino acid composition scores lower than one were found for almost all essential amino acids in lupin groups. The protein digestibility corrected amino acid scores ranged from 40.00% to 89.07% for L. albus and from 30.36% to 83.05% for L. angustifolius. It was concluded that the two varieties of lupins studied are good protein sources, with no statistical difference between them, and also that this protein has an excellent digestibility, besides being a good source of dietary fiber, especially Lupinus angustifolius. Therefore, the two varieties of lupine were considered as having good quality protein and as being a good alternative for human consumption.

Whey protein concentrate hydrolysates, capable of inhibiting the activity of angiotensin-converting enzyme, were prepared in the present study. Several parameters, such as type of enzyme, enzyme:substrate ratio, and use of ultrafiltration were evaluated. The angiotensin-converting enzyme inhibitory activity was observed only after the enzymatic treatment and high rates of inhibition were obtained, ranging from 17.29 to 91.88%. Most hydrolysates obtained with pancreatin showed higher angiotensin-converting enzyme inhibitory activity than those obtained with papain both in the absence and presence of ultrafiltration. The smallest enzyme:substrate ratio for pancreatin resulted in better angiotensin-converting enzyme inhibitory activity values. The use of ultrafiltration proved to be disadvantageous for inhibitory activity of hydrolysates obtained with papain.

The effects of proteolytic enzyme type (including pancreatin and proteases from Bacillus licheniformis, Aspergillus oryzae and A. sojae) and enzyme : substrate ratio (E :S = 0.5:100, 1:100, 2:100, 3:100, 4:100 and 8:100) were evaluated in this work with the aim of obtaining whey protein concentrate hydrolysates with inhibitory activity toward angiotensin-converting enzyme. Twenty-four hydrolysates were prepared, and their inhibitory activities (IA) were evaluated in vitro, resulting in inhibition rates ranging from 2.02 to 96.66%. Eleven samples had IAs that were very high (>80%). The hydrolysates obtained using the B. licheniformis protease had the highest IA values at all tested E : S ratios. In some cases, lowering the E : S ratio produced a higher IA value. This was observed for the B. licheniformis protease when the ratio was lowered from 2:100 to 1:100, as well as for the A. oryzae protease when lowered from 3:100 to 2:100 and from 2:100 to 1:100.

In this work, the influence of some reactional parameters in the hydrolysis of whey protein concentrate (WPC) was evaluated, in terms of the nutritional quality of peptide profiles of the hydrolysates as well as the reduction of costs for scaling-up the process. Two enzymes (subtilisin and pancreatin) were used for preparing 18 hydrolysates, using different E:S ratios and reaction times, and the distribution of peptides according to chain length was analyzed by size-exclusion chromatography. The studied parameters affected the peptide profiles of WPC hydrolysates and the best result was similar for subtilisin and pancreatin, both using an E:S ratio of 4:100, after 5 h and 10 h, respectively. In these conditions, these enzymes gave rise to the smallest large peptide contents (12.28% and 12.34%, respectively) and one of the highest amount of di- and tripeptides (13.34% and 13.00%, respectively) as well as of free amino acids (45.56% and 47.26%, respectively). However, in terms of number of samples the action of pancreatin was more advantageous than subtilisin, since among the nine hydrolysates, four showed appropriate peptide profiles (P1, P2, P5, and P6), from the nutritional point of view, while the same happened only with one hydrolysate prepared by using subtilisin (S3). Also, the economical advantage of using smaller E:S ratio and reaction time was observed in several cases for both enzymes.

Enzymatic hydrolysis of whey protein concentrate was used to prepare hydrolysates with appropriate peptide profiles for use in the development of dietary supplements. Effects of the type of enzyme (pancreatin and proteases from Bacillus licheniformis, Aspergillus oryzae and Aspergillus sojae) and enzyme:substrate ratio (0.5:100, 1:100, 2:100, 3:100, 4:100 and 8:100) were evaluated. Twenty-four hydrolysates were prepared, and their peptide profiles were characterized by chain length using size exclusion liquid chromatography fractionation, followed by a rapid Correct Fraction Area method for quantifying the peptide and amino acid contents. The use of a protease from Bacillus licheniformis (E:S 8:100) and a pancreatin (E:S 2:100, 3:100, 4:100 and 8:100) yielded preparations of hydrolysates with the highest sums of di- and tripeptide and free amino acid contents (9.99 and 11.28 % for the protease from Bacillus licheniformis and pancreatin, respectively) as well as the lowest amount of large peptides (44.61 and 44.13 %, respectively).

The aim of this study was to prepare enzymatic hydrolysates from whey protein concentrate with a nutritionally adequate peptide profile and the ability to inhibit angiotensin-converting enzyme (ACE) activity. The effects of the type of enzyme used (pancreatin or papain), the enzyme:substrate ratio (E:S ratio=0.5:100, 1:100, 2:100 and 3:100) and the use of ultrafiltration (UF) were investigated. The fractionation of peptides was performed by size-exclusion-HPLC, and the quantification of the components of the chromatographic fractions was carried out by a rapid Corrected Fraction Area method. The ACE inhibitory activity (ACE-IA) was determined by Reverse Phase-HPLC. All parameters tested affected both the peptide profile and the ACE-IA. The best peptide profile was achieved for the hydrolysates obtained with papain, whereas pancreatin was more advantageous in terms of ACE-IA. The beneficial effect of using a lower E:S ratio on the peptide profile and ACE-IA was observed for both enzymes depending on the conditions used to prepare the hydrolysates. The beneficial effect of not using UF on the peptide profile was observed in some cases for pancreatin and papain. However, the absence of UF yielded greater ACE-IA only when using papain.O objetivo deste estudo foi preparar hidrolisados enzimáticos do concentrado proteico do soro de leite com perfil peptídico nutricionalmente adequado e com capacidade para inibir a atividade da enzima conversora da angiotensina (ECA). Os efeitos do tipo de enzima usado (pancreatina ou papaína), da relação enzima:substrato (E:S=0,5:100, 1:100, 2:100 e 3:100) e do uso da ultrafiltração (UF) foram investigados. O fracionamento dos peptídeos foi feito por CLAE de exclusão molecular e a quantificação dos componentes das frações cromatográficas foi realizada pelo método da Área Corrigida da Fração. A atividade inibitória da ECA (AI-ECA) foi determinada por CLAE de fase reversa. Todos os parâmetros testados afetaram tanto o perfil peptídico quanto a AI-ECA. O melhor perfil peptídico foi atingido para os hidrolisados obtidos com papaína, enquanto a pancreatina foi mais vantajosa em termos da AI-ECA. O efeito benéfico do uso de menor relação E:S sobre o perfil peptídico e a AI-ECA foi observado para ambas as enzimas dependendo das condições usadas para o preparo dos hidrolisados. O efeito benéfico da ausência da UF sobre o perfil peptídico foi observado em alguns casos para pancreatina e papaína. No entanto, a ausência da UF produziu maior AI-ECA somente quando a papaína foi usada.

Summary The action of various proteases was tested for preparing whey protein concentrate (WPC) hydrolysates with high degree of hydrolysis (DH), appropriate peptide profiles and reduced phenylalanine (Phe) content. The peptide profile analysis included the fractionation of hydrolysates by size-exclusion HPLC. The rapid correct fraction area method was used to quantify the components of the chromatographic fractions. Activated carbon (AC) was used to remove Phe, and its efficiency was evaluated by measuring the amount of Phe by second-derivative spectrophotometry. The results showed that the DH of WPC hydrolysates increased and that the protease from Aspergillus oryzae yielded the highest DH value. This protease also produced the best peptide profile, that is, the highest di- and tripeptide content (16.14%), the highest amounts of free amino acids (18.43%) and the lowest amount of large peptides (18.76%). The proteases from both A. oryzae and Bacillus subtilis produced the highest Phe removals (79.0 and 77.8%, respectively).

Summary The action of proteases from Bacillus licheniformis and Aspergillus oryzae was studied with the aim of preparing hydrolysates from whey protein concentrate with nutritionally appropriate peptide profile. Various enzyme/substrate ratios were used, and the peptides were fractionated by size-exclusion HPLC followed by their quantification using the rapid method of correct fraction area (CFA). The protease from B. licheniformis (E:S of 8:100) produced the best peptide with a much lower amount of large peptides (44.61%), greater of di- and tripeptides (8.79%) and higher sum of the di- and tripeptides with free amino acids (9.99%) than the other hydrolysates. The advantage of using a lower E:S ratio to obtain a nutritionally adequate peptide profile was observed for the protease of A. oryzae when it passed from 3:100 to 2:100.

This study was carried out to characterize a crude extract from pineapple peel after precipitation by three methods with the aim of obtaining an enzymatic extract from agro-industrial waste. The characterization of these extracts involved the determination of both protein content and specific protease activities. The effects of pH and temperature on specific protease activity and on the stability of the extracts were also evaluated. The optimal values of specific activity for the crude extract (CE) were pH 6.0 (5.76 U mg−1 protein) and 7.0 (5.71 U mg−1 protein) and a temperature of 70 °C (16 U mg−1 protein). The average values for the relative specific activity were 17.4% (pH 3.0 to 9.0) and 42.7% (at 30, 50, and 70 °C). The ethanolic extract had the highest specific activity (10.7 U mg−1 protein) in comparison to the best results obtained for the isoelectric precipitation (7.7 U mg−1 protein) and the ammonium sulfate precipitation (4.7 U mg−1 protein). Moreover, the ethanolic extract was more stable than the CE, retaining 60.9% and 53.7% of the initial specific activity during the evaluation of the stability at different pH and temperature values, respectively. The optimal values of pH and temperature were almost the same for the crude and the ethanolic extracts. In addition, the ethanolic extract was more stable than the CE in the experimental conditions tested in this work.

The common bean (Phaseolus vulgaris L.) is a staple food in the Brazilian diet and represents the major source of dietary protein and other micronutrients and minerals. Despite the considerable protein concentration in beans, the food is considered of low biological value when compared to animal proteins and other plant protein sources. To improve the availability of protein in beans, enzymatic treatments were performed in four cultivars (ON, OPNS, TAL and VC3). The approach was a completely randomized design with four replicates. We used a 4 × 3 factorial arrangement (four cultivars and three treatments: treatment 1-addition of commercial protease (Trypsin 250, Difco), treatment 2-addition of protease from Bacillus sp., and treatment 3:-control without enzyme addition). The enzyme: substrate ratio was 5% w/w (amount of enzyme per total protein in bean flour). The approach was a completely randomized design with four replicates. A 4 × 3 factorial arrangement (four cultivars and three treatments, the same as those mentioned above) was used. The concentration of total protein (g.100 g-1 of dry matter) in the samples ranged from 16.94 to 18.06%, while the concentration of total phenolics was between 0.78 and 1.12% (g Eq. tannic acid.100 g-1 dry matter). The in vitro protein digestibility of enzymatically untreated bean flour (control) ranged from 47.30 to 56.17% based on the digestibility of casein. Concentrations of P, K, Ca, Mg, and Zn observed in the four cultivars tested were within the average values available in the literature. Treatment 2 with protease from Bacillus sp. induced decreases in the levels of Cu and Mn. The average Fe content increased in all bean flour samples when treated with proteases, reaching a maximum increase of 102% in the TAL flour treated with protease from Bacillus sp. The digestibility of all beans tested was significantly increased (p < 0.05) after the enzyme treatment. The greatest change was observed in the OPNS cultivar treated with protease from Bacillus sp., which increased its digestibility from 54.4% (control treatment) to 81.6%.O feijão (Phaseolus vulgaris L.) é um alimento básico na refeição do brasileiro, constituindo uma das principais fontes proteicas da dieta, além de fornecer outros macronutrientes e minerais. Apesar da considerável concentração de proteínas no feijão, este alimento é considerado de baixo valor biológico, quando comparado a proteínas animais e a outras fontes proteicas vegetais. Visando melhorar a disponibilidade proteica do feijão, foram realizados tratamentos enzimáticos em quatro cultivares de feijão (ON; OPNS, TAL e VC3). O delineamento foi inteiramente casualizado, em fatorial 4 × 3 (quatro cultivares e três tratamentos: testemunha, sem protease; hidrolisado 1, adição de protease comercial (Trypsin 250, Difco); hidrolisado 2, adição de protease de Bacillus sp.) com 4 repetições. A relação enzima:substrato foi 5% (m/m, considerando a quantidade de proteínas totais nas amostras de farinha). A concentração de proteínas totais (g.100 g-1 de matéria seca) nas amostras variou de 16,94 a 18,06%, enquanto a concentração de fenólicos totais esteve entre 0,78 e 1,12% (g Eq. ácido tânico.100 g-1 de matéria seca). A digestibilidade protéica in vitro na farinha não tratada enzimaticamente (testemunha) variou entre 47,30 e 56,17%, em relação à digestibilidade da caseína. As concentrações de P, K, Ca, Mg, S e Zn observadas nas quatro cultivares testadas se encontram dentro dos valores médios disponíveis na literatura. No tratamento com protease de Bacillus sp., houve diminuição nos teores de Cu e Mn. O teor médio de Fe aumentou nas farinhas tratadas enzimaticamente, chegando ao incremento máximo de 102% para a farinha da TAL tratada com protease de Bacillus sp. A digestibilidade de todas as farinhas testadas aumentou significativamente (p < 0,05) em função do tratamento enzimático. A maior variação foi observada na cultivar OPNS, cujos valores, respectivamente, para a testemunha e protease de Bacillus sp. , foram 54,4 e 81,6%.

Tendo como objetivo a obtenção de hidrolisados proteicos de farinha de trigo com baixo teor de fenilalanina (Phe), foram preparados, inicialmente, extratos proteicos da farinha de trigo, empregando-se método enzimático pela ação de protease de Bacillus licheniformis. Em seguida, esses extratos foram hidrolisados sob a ação do extrato enzimático bruto (EEB), obtido de casca de abacaxi, e de pancreatina comercial; e alguns parâmetros hidrolíticos foram avaliados, tais como temperatura (30; 35; 40; 50; e 70 °C), tempo (1 hora e 30 minutos; 2 horas e 30 minutos; 3 horas e 30 minutos), e pH de reação (6,0; 7,0; 8,0 e 9,0). Para a remoção de Phe, empregou-se o carvão ativado (CA) e a eficiência deste processo foi avaliada determinando-se o teor de Phe por espectrofotometria derivada segunda, na farinha de trigo, assim como nos hidrolisados após tratamento com CA. Para os três parâmetros estudados, observaram-se efeitos variados sobre a remoção de Phe, sendo que os melhores resultados foram encontrados ao se empregar a associação sucessiva de EEB (E:S 10:100, 1 hora e 30 minutos), com a pancreatina (E:S 4:100, 3 horas e 30 minutos), em pH 7,0 a 50 °C, tendo atingido 66,28% de remoção de Phe, o que corresponde a um teor final de Phe de 522,44 mg.100 g-1 de hidrolisado.With the aim of obtaining wheat flour hydrolysates with low-phenylalanine (Phe) content, protein extracts were prepared using an enzymatic method through the action of a protease from Bacillus licheniformis. Next, these protein extracts were hydrolyzed by a crude enzymatic extract (CEE) obtained from pineapple peel followed by a commercial enzyme (pancreatin). Some parameters, such as temperature (30, 35, 40, 50 and 70 °C), time (1 hour and 30 minutes, 2 hours and 30 minutes, 3 hours and 30 minutes), and pH of the reaction (6.0, 7.0, 8.0 and 9.0) were evaluated. Activated carbon (AC) was used for removing Phe and the efficiency of this process was evaluated by second derivative spectrophotometry, measuring Phe content in wheat flour as well as in its hydrolysates after AC treatment. Varied effects were observed for the three parameters studied, and the best results were found using successive association of CEE (E: S 10:100, 1 hour and 30 minutes) with pancreatin (E:S 4:100, 3 hour and 30 minutes) pH 7.0, at 50°C having reached a final Phe content of 522.44 mg.100 g-1 of hydrolysate.

Visando ao preparo de farinha de trigo com baixo teor de fenilalanina (Phe), extraiu-se, enzimaticamente as proteínas, empregando-se uma protease alcalina de Bacillus licheniformis. Em seguida, os extratos protéicos foram hidrolisados pela ação de enzimas comerciais (pancreatina e bromelina) e de extratos enzimáticos obtidos da casca de abacaxi (bruto e purificado), avaliando-se alguns parâmetros enzimáticos, tais como tipo de enzima, tipo de ação enzimática, tipo de associação enzimática e ordem de ação enzimática. O carvão ativado (CA) foi empregado como meio adsorvente e a eficiência da remoção de Phe foi avaliada por espectrofotometria derivada segunda, determinando-se o teor de Phe na farinha de trigo e em seus hidrolisados, após tratamento com CA. O melhor resultado foi encontrado ao se empregar a associação sucessiva do extrato bruto seguida da pancreatina, tendo atingido 66,28% de remoção e o teor final de Phe de 522,44 mg/100 g de hidrolisado.With the aim of producing wheat flour with low phenylalanine (Phe) content to be introduced in phenylketonuric's diet, the proteins were enzymaticaly extracted, using an alkaline protease from Bacillus licheniformis. Then, the protein extracts were hydrolyzed by the action of commercial enzymes (pancreatin and bromelain) and of enzymatic extracts obtained from pineapple peel (crude and purified). Some enzymatic parameters were evaluated, such as type of enzyme, type of enzyme action, type of enzymatic association and order of enzyme action. The activated carbon (AC) was used as adsorbent and the efficiency of Phe removal was evaluated by second derivative spectrophotometry measuring the Phe content in wheat flour and in their hydrolysates after AC treatment. The best result was found for the successive association of crude extract followed by pancreatin obtaining 66.28% of removal and a final Phe content of 522.44 mg/100 g of hydrolysate.

Visando o aproveitamento de um subproduto industrial e contribuir, assim, para reduzir a poluiçãoambiental, este trabalho teve como objetivo a obtenção de hidrolisados protéicos com elevado teor de ditripeptídeos,a partir do soro de leite. Para tal, empregou-se a pancreatina e diferentes condições hidrolíticasforam testadas. Avaliaram-se o tempo de hidrólise (5, 10 e 15 h), a relação enzima:substrato (E:S) (1:100, 2:100e 4:100) e a concentração da matéria-prima (10 e 15 %). Caracterizou-se o perfil peptídico pelo fracionamentodos hidrolisados por cromatografia líquida de alta eficiência de exclusão molecular e, para a quantificação doscomponentes das frações cromatográficas, empregou-se o método rápido da Área Corrigida da Fração. Para osparâmetros estudados, observaram-se efeitos variados da pancreatina sobre o perfil peptídico dos hidrolisadossendo que, sob o ponto de vista nutricional, nove hidrolisados apresentaram resultados semelhantes, ou seja,altos teores de di-tripeptídeos (12,11%, em média) e de aminoácidos livres (49,06 %, em média), quandocomparados ao hidrolisado protéico de soro comercial.

O presente trabalho teve como objetivo extrair enzimaticamente as proteínas de uma farinha comercial de arroz. Visando aumentar o Rendimento de Extração Protéica (REP), os seguintes parâmetros foram avaliados: tipo de enzima (protease alcalina e neutra); temperatura (40, 50 e 60 °C); pH (9,5, 10,5 e 11,0); tratamento físico da amostra (sem tratamento, ultra-turrax a 16.000 rpm e ultra-som a 120 W, ambos por 5, 10 e 15 minutos); relação Enzima:Substrato (E:S) de 5:100 e 10:100; e concentração inicial de matéria-prima (1:3, 1:5 e 1:10 p/v). Os teores de proteínas da farinha de arroz e dos resíduos foram determinados para o cálculo do REP. Os resultados mostraram que a melhor condição de extração protéica, que levou ao maior REP, foi a que empregou a concentração inicial de matéria-prima a 1:10 (p/v), sem tratamento físico, com pH 10,5, com a protease alcalina na relação E:S de 10:100, a 50 °C, tendo atingido um REP de 63,4%. The enzymatic extraction of proteins from a commercial rice flour was studied in this work. In order to increase the Protein Extraction Yield (PEY), the following parameters were evaluated: enzyme type (alkaline and neutral protease); temperature (40, 50 and 60 °C); pH (9.5, 10.5 and 11.0); physical treatment of the sample (no treatment; Ultra-Turrax at 16.000 rpm and ultrasound at 120 W, both for 5, 10 and 15 minutes); enzyme:substrate ratio (E:S) of 5:100 and 10:100 and initial concentration of raw material (1:3, 1:5 and 1:10 w/v). The PEY was calculated using the protein contents of rice flour and the extraction residues. The results showed that the best condition for protein extraction, which gave the highest PEY (63.4%), was that using an initial concentration of raw material of 1:10 (w/v), no physical treatment, pH 10.5, the alkaline protease, an E:S of 10:100, at 50 °C.

O presente trabalho teve como objetivo extrair enzimaticamente as proteínas de uma farinha comercial de arroz. Visando aumentar o Rendimento de Extração Protéica (REP), os seguintes parâmetros foram avaliados: tipo de enzima (protease alcalina e neutra); temperatura (40, 50 e 60 °C); pH (9,5, 10,5 e 11,0); tratamento físico da amostra (sem tratamento, ultra-turrax a 16.000 rpm e ultra-som a 120 W, ambos por 5, 10 e 15 minutos); relação Enzima:Substrato (E:S) de 5:100 e 10:100; e concentração inicial de matéria-prima (1:3, 1:5 e 1:10 p/v). Os teores de proteínas da farinha de arroz e dos resíduos foram determinados para o cálculo do REP. Os resultados mostraram que a melhor condição de extração protéica, que levou ao maior REP, foi a que empregou a concentração inicial de matéria-prima a 1:10 (p/v), sem tratamento físico, com pH 10,5, com a protease alcalina na relação E:S de 10:100, a 50 °C, tendo atingido um REP de 63,4%.The enzymatic extraction of proteins from a commercial rice flour was studied in this work. In order to increase the Protein Extraction Yield (PEY), the following parameters were evaluated: enzyme type (alkaline and neutral protease); temperature (40, 50 and 60 °C); pH (9.5, 10.5 and 11.0); physical treatment of the sample (no treatment; Ultra-Turrax at 16.000 rpm and ultrasound at 120 W, both for 5, 10 and 15 minutes); enzyme:substrate ratio (E:S) of 5:100 and 10:100 and initial concentration of raw material (1:3, 1:5 and 1:10 w/v). The PEY was calculated using the protein contents of rice flour and the extraction residues. The results showed that the best condition for protein extraction, which gave the highest PEY (63.4%), was that using an initial concentration of raw material of 1:10 (w/v), no physical treatment, pH 10.5, the alkaline protease, an E:S of 10:100, at 50 °C.

Two strains of Bacillus, one from a culture collection (B. subtilis ATCC 6633) and a wild type (Bacillus sp. UFLA 817CF) isolated during coffee fermentation in the south of Minas Gerais, Brazil, were evaluated in relation to secretion of alkaline proteases. The strains were grown on nutrient broth, nutrient broth with sodium caseinate and nutrient broth with three different concentrations of cheese whey powder for 72 h. Samples were collected at 24-h intervals to evaluate the proteolytic activity, protein content and cell population. Maximum protease activity was observed after 24-h growth for both the microorganisms, a period that coincided with the end of the exponential phase. The specific activity values were, respectively, 839.8 U/mg for B. subtilis ATCC 6633 and 975.9 U/mg for Bacillus sp. UFLA 817CF. The 60% saturation presented the best results for specific protease activity in all the growth culture media tested with B. sp. UFLA 817CF. Bacillus sp. UFLA 817CF showed highest enzymatic activity at pH 9.0 and 40°C in the three culture media tested. The protease obtained from culture of the wild Bacillus strain presented stability at pH 7.0 and considerable heat stability at 40°C and 50°C, and could be an alternative for the industry to utilize cheese whey to produce proteolytic enzymes.