The Process of Separating Bovine Serum Albumin Using Hydroxyapatite and Active Babassu Coal ( Orbignya martiana

Bovine serum albumin is one of the major serum proteins; it plays an important role as a result of its functional and nutritional properties which have bioactive peptides. Adsorption method was used to separate protein, which involves hydroxyapatite, synthetic hydroxyapatite, and active babassu coal. Initially, characterization was carried out using the zeta potential of the adsorbents. Kinetic pseudo-first- and pseudo-second-order models were applied. For isotherms, equilibrium data studies were carried out using the Langmuir and Freundlich models, in addition to determining the efficiency of adsorptive process. The results of the zeta potential showed loads ranging from +6.9 to −42.8 mV. The kinetic data were better represented in the pseudo-second-order model with chemisorption characteristics. The adsorption capacity of the adsorbents decreased as pH increased, indicating that the electrostatic bonds and some functional groups of active babassu coal contributed to the reduction of adsorption, especially oxygen linked to carbon atoms. The value of pH 4.0 showed the best results of adsorption, being obtained as the maximum adsorption capacity (qm) and yield (%) (where qm=87.95 mg g−1 and 74.2%; 68.26 mg g−1 and 68.6%; and 36.18 mg g−1, 37.4%) of hydroxyapatite, synthetic hydroxyapatite, and active babassu coal, respectively

The Process of Separating Bovine Serum Albumin Using Hydroxyapatite and Active Babassu Coal (Orbignya martiana)

Bovine serum albumin is one of the major serum proteins; it plays an important role as a result of its functional and nutritional properties which have bioactive peptides. Adsorption method was used to separate protein, which involves hydroxyapatite, synthetic hydroxyapatite, and active babassu coal. Initially, characterization was carried out using the zeta potential of the adsorbents. Kinetic pseudo-first-and pseudo-second-order models were applied. For isotherms, equilibrium data studies were carried out using the Langmuir and Freundlich models, in addition to determining the efficiency of adsorptive process. The results of the zeta potential showed loads ranging from +6.9 to −42.8 mV. The kinetic data were better represented in the pseudo-secondorder model with chemisorption characteristics. The adsorption capacity of the adsorbents decreased as pH increased, indicating that the electrostatic bonds and some functional groups of active babassu coal contributed to the reduction of adsorption, especially oxygen linked to carbon atoms. The value of pH 4.0 showed the best results of adsorption, being obtained as the maximum adsorption capacity ( ) and yield (%) (where = 87.95 mg g −1 and 74.2%; 68.26 mg g −1 and 68.6%; and 36.18 mg g −1 , 37.4%) of hydroxyapatite, synthetic hydroxyapatite, and active babassu coal, respectively

Yacon (Smallanthus sonchifolius) beverage spontaneously fermented

  Abstract: Yacon (Smallanthus sonchifolius) is a tuberous root with a high phenolic compounds and fibers content which has a prebiotic effect, both important for preventing and/or promoting the reduction of non-communicable chronic diseases risks. However, this root’s shelf life is highly reduced and culminates the reduction of the beneficial to health compounds, which can be avoided by some strategies. In this sense, this work aimed to produce yacon beverages added with anti-browning agents (cysteine or citric acid) and evaluated the spontaneous fermentation during storage. Three yacon beverages have been produced with cysteine or citric acid (0.05% w/w) and a control beverage. Beverages were analyzed by microbiological counts, nutritional composition, physical-chemical characteristics, total phenolic compounds and phenolic acids, for 60 day storage. The data were evaluated by ANOVA and compared using the Duncan test (p≤0.05) or regression models were adjusted. Regarding microorganisms, all beverages have reached 109 CFU.ml-1 after 30 day storage. To the anti-browning agents use, the differences were occasional; however, the citric acid beverage had a desirable pH (< 4.5) for a fermented beverage, which allows inhibition of undesirable bacteria and a higher proportional initial FOS amount and less variation with 30 and 60 day storage. However, the citric acid beverage have presented smaller amount of phenolic compounds like chlorogenic and gallic acids (230.37 ± 168.63 and 40.87 ± 1.32, respectively). So, we conclued that spontaneous fermentation was a preparation technique which has added nutritional and functionals values to the yacon beverage, in special to beverage added citric acid, with a higher proportion of FOS

Predictive modeling of growth Listeria monocytogenes and Salmonella enterica in co-culture with Enterococcus faecalis

A microbiologia preditiva é uma ferramenta que pode ser utilizada para garantir a segurança alimentar, cujo principal objetivo é o desenvolvimento de modelos matemáticos que possam predizer a multiplicação ou inibição de micro- organismos em condições específicas. Alterações de pH, atividade de água, temperatura, presença de agente inibidor, dentre outras, devem ser consideradas na construção de modelos de predição. A modelagem do comportamento bacteriano em co-cultura descreve, além das condições intrínsecas e extrínsecas as que os micro-organismos são submetidos, as interações entre populações microbianas. Esta abordagem não é encontrada com frequência na literatura, por isto, o objetivo geral desta pesquisa foi desenvolver modelos de predição do comportamento de Salmonella enterica e Listeria monocytogenes em co-cultura com Enterococcus faecalis. Também foram ajustados modelos de crescimento de S. enterica, L. monocytogenes e E. faecalis em monocultura. A influência de E. faecalis no crescimento de L. monocytogenes também foi estabelecida pela simulação de Monte Carlo. De acordo com os resultados, houve aumento da fase lag, redução da taxa de crescimento e redução da população máxima atingida em ambos os patógenos estudados. Verificou-se que E. faecalis exerce ação antagonista em relação aos patógenos estudados, sendo o efeito bioconservante mais expressivo em L. monocytogenes. A simulação de Monte Carlo indicou probabilidades de ocorrência de taxas de crescimento diferentes, numa mesma condição experimental do crescimento de L. monocytogenes em co-cultura com E. faecalis. Esta informação adicional deve ser mais utilizada na área de microbiologia preditiva. E. faecalis como inibidor de S. enterica e L. monocytogenes pode ser uma alternativa dentre os métodos de conservação já existentes e a modelagem dessa inibição deve ser utilizada para nortear novas pesquisas na área.Predictive microbiology is a tool that can be used to guarantee food safety, whose main objective is the development of mathematical models that can predict the multiplication or inhibition of microorganisms under specific conditions. Alterations of pH, water activity, temperature, presence of inhibitory agent, among others, should be considered in the construction of prediction models. The modeling of bacterial behavior in co-culture describes, in addition to the intrinsic and extrinsic conditions that the microorganisms are subjected to, the interactions between microbial populations. This approach is not often found in the literature, therefore, the general objective of this research was to develop models to predict the behavior of Salmonella enterica and Listeria monocytogenes in co-culture with Enterococcus faecalis. Growth patterns of S. enterica, L. monocytogenes and E. faecalis in monoculture were also adjusted. The influence of E. faecalis on the growth of L. monocytogenes was also established by the Monte Carlo simulation. According to the results, there was an increase in the lag phase, reduction of the growth rate and reduction of the maximum population reached in both pathogens studied. It was verified that E. faecalis exerts an antagonistic action in relation to the studied pathogens, being the most expressive bioconservant effect in L. monocytogenes. The Monte Carlo simulation indicated the probability of occurrence of different growth rates, in the same experimental condition of growth of L. monocytogenes in co-culture with E. faecalis. This additional information should be more used in the area of predictive microbiology. E. faecalis as an inhibitor of S. enterica and L. monocytogenes may be an alternative among existing conservation methods and the modeling of this inhibition should be used to guide new research in the area.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Caracterização físico química, perfil sensorial e aceitação de morangos submetidos à irradiação

A irradiação de alimentos é um método de conservação não térmico utilizado em diferentes alimentos e em diferentes doses. Sabe-se que, dependendo da dose aplicada, esse método pode ocasionar alterações nas características físico-químicas e sensoriais, que afetam a qualidade do produto. Portanto, um dos objetivos deste estudo foi analisar o efeito da irradiação nas características físico-químicas e sensoriais de morangos irradiados. A irradiação das amostras de morango ocorreu um dia após a colheita e foi realizada no Laboratório de Radiação Gama do Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), em Belo Horizonte-MG. As doses utilizadas foram 1 kGy, 2 kGy, 3 kGy e 4 kGy e a amostra controle (0 kGy). Foram avaliados pH, acidez total titulável, sólidos solúveis, ratio (relação entre teor de sólidos solúveis e acidez total titulável), açúcares redutores, totais e não redutores, pectina, ácido ascórbico, firmeza, cor, antocianinas, compostos fenólicos e capacidade antioxidante. Para a caracterização sensorial das amostras, foi utilizado o método Perfil Descritivo Otimizado (PDO), sendo avaliados os atributos sensoriais cor, sabor adocicado, gosto ácido, firmeza e suculência, por 15 julgadores previamente selecionados. Além da caracterização sensorial, foi realizada a análise de aceitação sensorial por 60 consumidores de morango em duas sessões. A irradiação não alterou significativamente a maioria das características físico-químicas analisadas, ao comparar todas as doses empregadas, incluindo o morango controle (não irradiado); apenas a firmeza apresentou valores diferentes estatisticamente: com o aumento da dose, houve diminuição da firmeza do fruto. No PDO, as amostras diferiram quanto à cor, sabor adocicado, firmeza e suculência, sendo que a amostra controle e a amostra irradiada com 1 kGy tiveram maiores valores de firmeza e menores de suculência e sabor adocicado. Em relação à aceitação, a amostra controle e a amostra irradiada com 1 kGy não diferiram estatisticamente pelo teste Tukey a 5%, mas diferiram das amostras irradiadas com doses de 3 kGy e de 4 kGy; no entanto, a amostra irradiada a 2 kGy não diferiu de nenhuma outra dose. Foram realizados estudos de correlações entre os dados físico-químicos de pH, acidez total titulável (ATT), sólidos solúveis (SS), açúcares totais e açúcares não redutores, antocianina (método pH diferencial), pectina, firmeza instrumental, relação entre SS/ATT (ratio) e alguns parâmetros de cor (a*, b*, c* e L), e os dados do teste sensorial descritivo, ou seja, os atributos de firmeza, suculência, sabor adocicado e gosto ácido. Os resultados obtidos foram correlações significativamente positivas entre pH e ratio, sólidos solúveis e pectina, antocianinas e parâmetros de cor (a* e c*), açúcares e parâmetros de cor (b* e c*), firmeza sensorial e firmeza instrumental, suculência e sabor xvi adocicado e firmeza sensorial e gosto ácido. Já as correlações negativas foram entre acidez e ratio, sólidos solúveis e firmeza, antocianina e L*, firmeza sensorial e sabor adocicado e suculência com: firmeza instrumental, firmeza sensorial e gosto ácido. Neste trabalho, também foi realizada a caracterização físico-química e sensorial de morangos irradiados nas doses determinadas por Lima Filho et al. (2014) como sendo correspondentes ao limiar de detecção (LD) sensorial (0,405 kGy) e ao limiar de rejeição (LR) sensorial (3,6 kGy) para morangos irradiados. Além disso, foi verificada a influência da embalagem na aceitação sensorial de morangos irradiados na dose 3,6 kGy. Todas as medidas físico-químicas apresentaram pequena variação entre as amostras controle (0 kGy) e o LD e o LR. Não houve diferença significativa em relação à aceitação da amostra irradiada na ausência e na presença da embalagem, provavelmente devido ao grau de conhecimento do painel de consumidores em relação ao processo de irradiação de alimentos. Conclui-se que a irradiação é um método de conservação que pode ser utilizado em morangos, uma vez que exerce pouca influência, no período de tempo estudado, nas suas características físico-químicas e sensoriais.Irradiation is a non-thermal preservation method used in different foods and at different dosages. Changes in the physico-chemical characteristics and in food quality depend on the applied dosage of radiation. Therefore, the aim of this study was to analyze the effect of radiation in the physico-chemical characteristics of irradiated strawberries. The irradiation of the samples was taken one day after harvest and was performed at the Laboratory of Gama Radiation of the Development Center of Nuclear Technology (CDTN) in Belo Horizonte-MG. The radiation doses used were 1 kGy, 2 kGy, 3 kGy and 4 kGy and the control sample (0 kGy). We evaluated the pH, titratable acidity (ATT), soluble solids (SS), the ratio (SS/ATT), total sugars, reducing and non-reducing sugars, pectin, ascorbic acid, firmness, color, anthocyanins (by three different methods of analysis), phenolics and antioxidant capacity. For the sensory characterization of the samples, it was used the Optimized Descriptive Profile (PDO). Fifteen selected judges participated of the analyses. The attributes evaluated were characteristic color, sweetness, sour taste, firmness and juiciness. Sensory acceptance was performed with 60 consumers of strawberry in two sessions. Irradiation did not significantly change most of the analyzed characteristics; only the firmness showed statistically different values: by increasing the dose, the firmness of the strawberry decreased. In PDO, the samples differed in color, sweetness, firmness and juiciness, and the control sample and the sample irradiated at 1 kGy had higher values of firmness and lower juiciness and sweetness. Regarding acceptance, the control sample and the sample irradiated at 1 kGy did not differ by Tukey test at 5%, but they differed from samples irradiated at doses of 3 kGy and 4 kGy; the sample with a dose of 2 kGy did not differ from any other sample. In this study we tested correlations between pH, titratable acidity (ATT), soluble solids (SS), total sugars and non-reducing sugars, anthocyanins (pH differential), pectin, instrumental firmness, relation SS/ATT (ratio), the color parameters “a”, “b”, “c” and “L”, and the sensory descriptive data, which were firmness, juiciness, sweetness and sour taste. Significantly positive correlation were found between pH and ratio, SS and pectin, anthocyanins and “a”, “c” values, sugars and “b”, “c” values, sensory firmness and instrumental firmness, juiciness and sweetness, sensory firmness and sour taste. Significantly negative correlation were found between ATT and ratio, SS and instrumental firmness, anthocyanins and “L”, juiciness and instrumental firmness, sensory firmness and sour taste, xviii sensory firmness and sweetness. In this study, we also determined the physico-chemical and sensory characteristics of strawberries irradiated at the DT and CRT dosages, and evaluated the influence of packaging in sensory acceptance of irradiated strawberries at the CRT dosage (3.6 kGy). There was little variation in physico-chemical characteristics between control sample and DT and CRT samples; however the instrumental firmness decreased with the increasing of the dose. The values of the global difference of color, ΔE* were above 8.0, therefore, the difference in color between samples are easily noticeable to the human eyes. The values of the attributes sour taste and sweetness were similar between samples, but for firmness, juiciness and color the values varied according to radiation doses. The sensory acceptance of control sample did not statistically differ (p>0.05) from the CRT sample, and the information that the strawberry was irradiated did not affect the sensory acceptance; in other words, the control sample and the CRT sample had good acceptance. It can be concluded that irradiation is a preservation method that can be used in strawberries since it exerts little influence on their physico-chemical and sensory characteristics, in the studied period of time