RESUMO
The aim of this study is to elaborate and evaluate structural characteristics of soybean gelato by varying the content of soybean protein concentrate (2.95 to 17.05%) and vegetable fat (7.95 to 22.05%) using experimental design. The replacement of milk by hydrosoluble extract and soybean protein concentrate presented itself as an alternative to gelato production with unique characteristics, especially in terms of protein, solubility, viscosity, melting point, overrun and acceptability. The addition of up to 5% (m/V) protein concentrate, 14% (by volume) soybean hydrosoluble extract, and 15% (by mass) vegetable fat to gelato formulations resulted in better structural characteristics, with viscosity ranging from 0.45-0.70 Paâs at 10 °C, a non-Newtonian behaviour and protein stability (total protein content 8.44% and solubility 41%). Soybean gelato structural analysis using X-ray diffraction revealed 15° and 35° diffraction angles at 2Θ, characterizing the crystalline part of the product. The thermal analyses showed four bands of mass loss in the temperature range of 40-600 °C, characterizing loss of moisture, decomposition of the soy protein and the fat/emulsifier of the formulations. Thus, the soybean gelato is an innovative product, lactose and milk protein-free with outstanding characteristics for the general public, mainly, for the populations with intolerance to such components.
RESUMO
ABSTRACT: This paper aim to evaluate the ultrafiltration (UF) process for constituents recovery from whey. Sequences of factorial designs were performed by varying temperature (5 to 40°C) and pressure (1 to 3 bar), to maximize the proteins concentration using membrane of 100kDa in dead end system. Based on the best result new experiments were performed with membrane of 50kDa and 10kDa. With the membrane of 50 the protein retention was about 3 times higher than the membrane of 100kDa. The concentrated obtained by UF membrane of 10kDa, 10°C and 2 bar in laboratory scale showed a mean protein retention of 80 %, greater protein solubility, emulsion stability and the identification of β-lactoglobulins (18.3 kDa) and α-lactalbumin fractions (14.2kDa). Therefore, the use of membrane of 100 and 50kDa are became a industrially recommendable alternatives to concentration of whey proteins, and/or as a previous step to the fractionation of whey constituents using membrane ≤10kDa, aiming at future applications in different areas (food, pharmaceutical, chemical, etc.).
RESUMO: O objetivo do estudo foi avaliar o processo de Ultrafiltração (UF) na recuperação dos constituintes do soro de leite. Planejamentos fatoriais sequenciais foram realizados, variando a temperatura (5 a 40°C), a pressão (1 a 3 bar) e visando maximizar a concentração de proteínas usando membrana de 100kDa em sistema dead end. Baseados nos melhores resultados, foram realizados experimentos com de 50kDa e 10kDa. Em relação a membrana de 50kDa, a retenção de proteínas foi cerca de três vezes maior em relação a membrana de 100kDa. O concentrado obtido por membrana UF de 10kDa, 10°C e 2 bar, em escala laboratorial, mostrou uma retenção média de proteína de 80%, maior solubilidade protéica, estabilidade da emulsão e a identificação das frações β-lactoglobulins (18.3kDa) e α-lactalbumin (14.2kDa). Portanto, o uso de membranas de 100 e 50kDa são alternativas recomendáveis industrialmente à concentração de proteínas de soro de leite, e/ou como etapa anterior ao fracionamento de constituintes do soro usando membrana ≤10kDa, visando aplicações futuras em difentes áreas (alimentícia, farmacêutica, química, etc).