Resumo A microencapsulação é um processo indicado para proteger substâncias que são susceptíveis à degradação ou redução da sua funcionalidade por causa de diferentes reações, por exemplo, oxidação, hidrólise, entre outras. O objetivo deste estudo foi avaliar o efeito da microencapsulação, usando como materiais de parede maltodextrina ou amido modificado, sobre a estabilidade de hidrolisados proteicos de okara. A pesquisa analisou a microestrutura, a capacidade antioxidante e a cor das amostras durante a estocagem dos pós por 120 dias a 35 °C. As micrografias obtidas por microscopia eletrônica de varredura indicaram que o processo de microencapsulação favoreceu a integridade física das partículas. A diferença de cor observada entre as amostras encapsuladas e não encapsuladas foi proveniente, provavelmente, da adição de materiais de paredes que contribuíram para a mudança da cor do pó obtido por spray drying. Os resultados indicaram que as microcápsulas obtidas por spray drying usando maltodextrina ou amido modificado mantiveram a cor dos pós e apresentaram boa habilidade em sequestrar o radical livre ABTS e teor de substâncias redutoras do reagente Folin-Ciocalteu durante a estocagem.

Abstract Microencapsulation is a process used for protecting substances that are susceptible to degradation or reduction of their functionality due to different reactions such as oxidation, hydrolysis, among others. This study aimed to evaluate the effect of microencapsulation, using maltodextrin or modified starch as wall materials, on the stability of okara protein hydrolysates. We analyzed the microstructure, antioxidant capacity, and color of the samples during powder storage for 120 days at 35 °C. Micrographs obtained by scanning electron microscopy indicated that the microencapsulation process favored the particles’ physical integrity. The color difference observed between the encapsulated and unencapsulated samples was probably due to the addition of wall materials that contributed to color change of the powder obtained by spray drying. The results indicated that the microcapsules obtained by spray drying using maltodextrin or modified starch maintained the powder color and showed good ability to sequester the free radical ABTS and content of reducing substances from the Folin-Ciocalteau reagent during storage.

Resumo O objetivo deste trabalho foi avaliar diferentes tipos de formulações com maltodextrina e colágeno hidrolisado na secagem por atomização de cocona (Solanum sessiliflorum Dunal), e nas propriedades dos pós resultantes. Foram avaliadas proporções pré-estabelecidas de sólidos de polpa:sólidos de agente carreador (P:AC) e relação entre agentes carreadores maltodextrina 10DE:colágeno hidrolisado (MD:HC). O processo foi realizado na secagem por atomização a 120 °C como temperatura de ar de entrada. Foram preparadas 12 soluções de alimentação com 20% de sólidos, variando-se a proporção de P:AC (1:3, 1:4, 1:5 e 1:6) e a relação MD:CH (0:100, 50:50 e 100:0). A recuperação de sólidos foi determinada para avaliar o processo de secagem. Os pós de cocona foram analisados quanto a umidade, atividade de água, distribuição de tamanho e diâmetro médio de partícula, estrutura química (FTIR) e cor. Na proporção P:CA de 1:6, a recuperação de sólidos foi de 96,2% para a amostra com colágeno hidrolisado, valor bem maior quando comparado com o valor da amostra com maltodextrina, que foi de 39,2%. A estrutura química dos pós de cocona pode ser considerada um sinal de um bom processo de encapsulamento. A cor dos pós foi similar à dos agentes carreadores. A formulação com maior teor de colágeno hidrolisado foi capaz de melhorar a recuperação de sólidos, garantir que a polpa de cocona fosse encapsulada e obter pós de frutas com propriedades bioativas.

Abstract This work aimed to evaluate the effect of carrier agents containing maltodextrin and protein, represented by hydrolyzed collagen on the spray drying process of cocona (Solanum sessiliflorum Dunal), and on the properties of the resulting powders. We used pre-established proportions between the solids of cocona pulp and the carrier agents (P:CA), and among carrier agents themselves, maltodextrin and hydrolyzed collagen, (MD:HC). The process was carried out in a spray dryer at an inlet air temperature of 120 ºC. We prepared twelve feed solutions containing 20% of total solids, with P:CA ratios of 1:3, 1:4, 1:5 and 1:6, and MD:HC ratios of 0:100, 50:50, and 100:0. Solids recovery was obtained for the evaluation of the spray drying process. The cocona pulp powders were analyzed for moisture content, water activity, particle size distribution, mean particle diameter, chemical structure (FTIR) and color. For a P:CA of 1:6, for the sample formulated with hydrolyzed collagen only, solids recovery (96.2%) was much higher than that of the sample with maltodextrin only (39.2%). The chemical structure of cocona powders can be considered a sign of a good encapsulation process. The color of the cocona pulp powder was similar to that of the carrier agents. The formulation with highest content of hydrolyzed collagen improved the recovery of solids, guaranteed the cocona pulp encapsulation, and obtained fruit powders with bioactive properties.

Resumo O objetivo do trabalho foi avaliar as atividades antioxidante e antimicrobiana de hidrolisados proteicos de soro de leite obtidos por diferentes proteases (Alcalase e Flavourzyme) e sua mistura (proporção 50:50). Previamente à hidrólise enzimática, o soro de leite foi concentrado por ultrafiltração com membranas cerâmicas tubulares. A reação enzimática foi realizada de acordo com o método pH-stat, sendo coletadas alíquotas com diferentes graus de hidrólise ( GH), ao longo de cada hidrólise proteica. Os hidrolisados foram analisados quanto a estimativa do teor de peptídeos, atividade antioxidante pelos métodos de captura do radical livre ABTS+ e do radical peroxila (Oxygen radical antioxidant capacity - ORAC), eletroforese e atividade antimicrobiana. Os máximos GH alcançados foram 15%, 52% e 63%, para Flavourzyme, mistura das enzimas e Alcalase, respectivamente. A atividade antioxidante aumentou com o GH. Os hidrolisados proteicos obtidos pela Alcalase apresentaram maiores atividades antioxidantes que os outros hidrolisados. Entretanto, nenhum hidrolisado proteico apresentou atividade antimicrobiana contra as cepas de Salmonella choleraesuis subsp. Enteritidis (ATCC 13076) e Listeria monocytogenes (ATCC 9117).

Abstract The objective of this work was to evaluate the antioxidant and antimicrobial activities of whey protein hydrolysates obtained using different commercial proteases (Alcalase and Flavourzyme) as well as their blend (50:50 ratio). Prior to the enzymatic hydrolysis, the whey was concentrated by ultrafiltration using tubular ceramic membranes. The enzymatic reaction was carried out according to the pH-stat method, in which aliquots were collected with different degrees of hydrolysis (DH) during the protein hydrolysis. The protein hydrolysates were evaluated with respect to the estimated peptides content, antioxidant activity by capture of free radical ABTS+ and the peroxyl radical (Oxygen radical antioxidant capacity - ORAC) methods, electrophoresis and antimicrobial activity. The maximum DH values reached were: 15%, 52% and 63% for Flavourzyme, the blend of enzymes and Alcalase, respectively. The antioxidant activity increased with the DH. The protein hydrolysates obtained using Alcalase presented higher antioxidant activities than the other samples. However, no samples presented antimicrobial activity against Salmonella choleraesuis subsp. Enteritidis (ATCC 13076) or Listeria monocytogenes (ATCC 9117).

Abstract This work aimed to evaluate the enzymatic hydrolysis of okara protein concentrate with respect to degree of hydrolysis (DH) in order to obtain a protein hydrolysate with high antioxidant capacity and aglycones isoflavone content. A central composite rotatable design was carried out to evaluate the influence of temperature (40 to 70°C), enzyme:substrate ratio (0.5 to 5.0%, g/100g protein) and pH (7.0 to 9.0) on DH. The optimal condition was 55°C, pH 9 and enzyme:substrate ratio of 5.0%, resulting a DH value of 35.5%. After protein hydrolysis at optimal condition, the antioxidant capacities of hydrolysate increased from 58.29 to 383.49 μM Trolox equivalent/g solids (ABTS method) and 2.41 to 15.32 μM Trolox equivalent/g solids (FRAP method) when compared with protein concentrate. The higher radical scavenging ability of hydrolysate was due to great amount of hydrophobic amino acids (34.92 g/100g protein). Moreover, the protein hydrolysate obtained under optimal condition had 3 times higher aglycone isoflavone content than non-hydrolyzed sample. These results showed that protein hydrolysis of okara could be an alternative approach to increase antioxidant activity and enrich aglycones isoflavone in this byproduct generated from soymilk industry.

Abstract In the search for alternative wall materials to replace gum Arabic (GA), a good but expensive encapsulating agent, this work aimed to evaluate the effectiveness of maltodextrin 10DE in combination with GA (GA/MD, 50:50 ratio) for the microencapsulation of grape seed oil by spray drying. The addition of maltodextrin to gum Arabic did not influence the mean particle diameter, powder bulk density, encapsulation efficiency or the total oil retained in the microspheres. Although the oil encapsulated with GA showed greater retention of phenolic compounds after spray drying, the sample encapsulated with GA/MD had greater ferric reduction antioxidant power and DPPH radical scavenging activity, and a lower peroxide index.

Abstract The objective of this work was to evaluate the antioxidant activity of protein hydrolysates obtained by the enzymatic hydrolysis of okara using an endopeptidase (Alcalase) and exopeptidase (Flavourzyme). The reaction was monitored by the pH-stat procedure in which five aliquots were collected during the hydrolysis by each enzyme, corresponding to different degrees of hydrolysis (DH). The antioxidant activities of the aliquots were evaluated by the ABTS, DPPH and FRAP methods. For the hydrolysates obtained using Alcalase, the antioxidant activities increased from: 68.6 to 99.5% (ABTS), 14.5 to 17.7% (DPPH) and 222.6 to 684.9 µM Trolox (FRAP), when the DH varied from 0 to 33.6%. With respect to Flavourzyme, the results were: 67.2 to 88.2% (ABTS), 9.5 to 18.5% (DPPH) and 168.0 to 360.3 µM Trolox (FRAP), when the DH increased up to 5.8%. The results showed that the protein hydrolysates had antioxidant capacities, which were influenced by the degree of hydrolysis and the type of enzyme.

The objective of this study was to obtain babassu coconut milk powder microencapsulated by spray drying process using gum Arabic as wall material. Coconut milk was extracted by babassu peeling, grinding (with two parts of water), and vacuum filtration. The milk was pasteurized at 85 ºC for 15 minutes and homogenized to break up the fat globules, rendering the milk a uniform consistency. A central composite rotatable design with a range of independent variables was used: inlet air temperature in the dryer (170-220 ºC) and gum Arabic concentration (10-20%, w/w) on the responses: moisture content (0.52-2.39%), hygroscopicity (6.98-9.86 g adsorbed water/100g solids), water activity (0.14-0.58), lipid oxidation (0.012-0.064 meq peroxide/kg oil), and process yield (20.33-30.19%). All variables influenced significantly the responses evaluated. Microencapsulation was optimized for maximum process yield and minimal lipid oxidation. The coconut milk powder obtained at optimum conditions was characterized in terms of morphology, particle size distribution, bulk and absolute density, porosity, and wettability.

A influência da temperatura, pH e razão enzima:substrato na cinética de hidrólise enzimática de carne de frango utilizando a protease Alcalase® 2,4 L foi avaliada neste trabalho. Os experimentos foram conduzidos à temperatura de 43 a 77 °C, razão enzima:substrato de 0,8 a 4,2% p/p e pH de 7,16 a 8,84, de acordo com um planejamento experimental completo, totalizando 17 ensaios. A reação foi monitorada, utilizando-se o método pH-stat para obtenção dos graus de hidrólise em função do tempo de processo. As curvas de hidrólise obtidas apresentaram uma alta taxa inicial de reação, seguida da sua diminuição até alcançar uma fase estacionária. Os resultados experimentais da cinética de reação foram ajustados a um modelo empírico, que consiste na variação do grau de hidrólise em função do logaritmo neperiano do tempo. Esse modelo apresentou um bom ajuste, com coeficientes de determinação superior a 0,96 e desvio relativo médio inferior a 10%. Os parâmetros do modelo foram avaliados através de um planejamento experimental, de modo a verificar a influência das variáveis de reação sobre eles. O aumento da razão enzima:substrato e da temperatura acarretou maiores valores do parâmetro a. O parâmetro b não sofreu influência da variável razão enzima:substrato e o seu valor aumentou com o aumento da temperatura. A variável pH afetou significativamente os parâmetros estudados.

The hydrolysis of chicken breast meat by commercial protease Alcalase® 2.4 L was studied in order to evaluate the temperature, renzyme:substrate ratio, and pH influence on enzymatic hydrolysis kinetics. The tests were carried out under different conditions with respect to temperature (43-77 °C), enzyme:substrate ratio (0.8-4.2% w/w, g enzyme/100 g protein), and pH (7.16-8.84) according to factorial 2³ experimental design with the total of 17 tests. The reaction was monitored by the pH-stat method to obtain the degree of hydrolysis values at different intervals of time. The hydrolysis curves were characterized by high initial reaction rates followed by decreases in the reaction rate up to the stationary phase. The results were fitted an exponential model that presented a good fit with high determination coefficient and low average relative error. The variables influence on model parameters was observed by experimental design. An increase in the enzyme:substrate ratio and temperature led to higher parameter a values. The parameter b was not affected by the enzyme:substrate ratio and its value increased with higher temperature. The variable pH affected significantly the parameters a and b.