ABSTRACT
ABSTRACT: Green or "detox" juice is a mixture of fruit juice with vegetables, which has been used intensively by consumers seeking for healthy food. Physicochemical properties of Green juice were accessed in the present research, which brings new insights for the use of this beverage in human diet. A total phenolic content of 2833.60 mg GAE (Gallic acid equivalent)/ g of juice and a Total Antioxidant Capacity by FRAP of 323.62 µM Fe2SO4 / g of juice and by ABTS•+ of 333.11 µM Trolox/ g of juice, indicated good antioxidant properties. Low energy and reducing sugar content indicate its use for low calorie diet, but low carbohydrate and protein content prove that Green juice cannot be used as meal replacement. The addition of a microbial biosurfactant (YlBio) and chia gel as bioemulsifiers was tested in the Green juice formulation to reduce solid decantation and increase consistency. YlBio and chia gel were able to change the Newtonian behavior of the Green juice to a Pseudoplastic behavior due to stabilization properties and also increase consistency, without the need to add synthetic stabilizers.
RESUMO: O suco verde ou "detox" é uma mistura de suco de frutas com vegetais que tem sido intensamente utilizado por consumidores que buscam alimentos saudáveis. As propriedades físico-químicas do suco verde foram avaliadas no presente trabalho, o que traz novas perspectivas para o uso dessa bebida na dieta humana. Um conteúdo fenólico total de 2833,60 mg de EAG (equivalente em ácido gálico) / g de suco) e uma capacidade antioxidante total por FRAP de 323,62 µM de Fe2SO4 / g de suco e por ABTS•+ de 333,11 µM de Trolox / g de suco, indicam boas propriedades antioxidantes. Um baixo teor de energia e açúcar redutor indica seu uso em dietas de baixa caloria, mas o baixo teor de carboidratos e proteínas prova que o suco verde não pode ser usado como substituto de refeição. A adição de um biossurfactante microbiano (YlBio) e do gel de chia no suco foi testada na formulação do suco verde, para reduzir a decantação de sólidos e aumentar a consistência. YlBio e o gel de chia foram capazes de mudar o comportamento do suco de fluido Newtoniano para um fluido pseudoplástico devido às propriedades estabilizantes, e também aumentaram a consistência do suco, sem a necessidade de adição de estabilizantes sintéticos.
ABSTRACT
Objective: To determine the rheological properties of Dange ophthalmic in-situ gel and its common gel by using dynamic rheological experiments. Methods: Dange ophthalmic in-situ gel was prepared by adopting Poloxamer as thermosensitive material, and Dange gel was prepared by carbopol. Anton Paar MCR302 Rheometer was used to determine the rheological parameters of above two kinds of gel at different temperatures which speculated the phase transition time and gelling temperature of in-situ gel. Results: Dange ophthalmic in-situ gel was Newtonian liquid at low temperature, with its viscous modulus dominated. It was shear-thinning pseudoplastic fluid under the conditions of phase transition at room temperature, with its elastic modulus dominated. The phase transition temperature (Tg) was (24.4 ± 0.1)°C, and the gelling time was 9 s. Dange gel existed in network structure among a certain temperature range, it was stable and did not change with temperature. Conclusion: The test has established the rheological evaluation system of Dange ophthalmic in-situ gel or its common gel, accurately evaluated the rheological properties of the two gels by dynamic rheological parameters, and it can be used as the basis for the quality control of products.