Abstract The objective of this research was to evaluate the influence of the enzymatic process on the physicochemical stability of a colloidal system based on cape gooseberry pulp, skin, and seeds (CSCG). The pulp, seed, and skin mixture were homogenized by shearing in a rotor-stator system at 10,000 rpm. A completely randomized factorial design was used, considering the independent variables: Viscozyme® L enzyme concentration [Enzyme] (50, 125, and 200 ppm) and hydrolysis time (HT) (0, 30, 60, 90, and 120 minutes), and the dependent variables: viscosity (µ), zeta potential (ζ), particle size (percentiles D10, D50, and D90), spectral absorption index (R). Both independent variables had a significant impact on the process. [Enzyme] affected mainly μ, D50, D90, and R and HT affected μ and D10. The optimization of the formulation was performed under the criterion of obtaining a CSCG with higher physicochemical stability. The optimization showed desirability of 74.2% with [Enzyme] at 78.5 ppm and HT of 120 minutes. The dependent variables obtained experimentally were: µ = 371.3 ± 242 cP, ζ = -21.8 ± 0.3 mV, D10 = 3.5 ± 0.3 µm, D50 = 135 ± 3.6 µm, D90 = 565.7 ± 25.5 µm, and R = 0.655 ± 0.007. The integration of homogenization processes and enzymatic treatments contributed to obtaining a physicochemical stable colloidal system based on cape gooseberry pulp, skin, and seeds.

Abstract The generation of value from the strawberry agro-chain requires in some cases the disintegration of the structure and formulation of the fruit, resulting in suspensions that behave as thermodynamically unstable colloidal systems and are affected by various forces, such as Van der Waals, electrostatic, steric, hydration, hydrophobic, and phase separation. The aim of this research was to evaluate the influence of the homogenization process and the concentration of gum arabic (GA) on the stability of strawberry-based suspensions. Strawberries with a 9% solid content were used and a centralized-composite central design was proposed (pressure (P) from 4.14-10.34 MPa), time (t) (3-5 min), and GA (0.2-0.4%)) and the dependent variables zeta potential (ζ), spectral absorption index (R), viscosity (μ), and particle size were evaluated. The ζ potential and R-index were not affected by the homogenization process and GA; the suspension was stabilized by the increase of ζ due to t, the GA effect, and the t-GA interaction. Particle size was affected by P but not by t, whereas GA mainly affected D [3,2], D [4,3], and D90. The results indicate that the homogenization and the use of GA as a hydrocolloid confer chemo-physical stability to the strawberry suspension.

Con el propósito de aprovechar la maleza acuática Jacinto de Agua (Eichhornia crassipes) como materia prima lignocelulósica para la obtención de azúcares reductores, se realizó en primera instancia una caracterización bromatológica de las hojas y tallos de la planta. Luego se estudió el efecto de la concentración de ácido sulfúrico (1 -3% v/v), la concentración de sólidos (10 -12.5% p/v) y el tiempo de reacción (15 -25 min.) a 121°C/15 psi, en la producción de azúcares reductores, empleando para ello un diseño central compuesto. Se encontró que la concentración de ácido fue la variable más significativa. Las condiciones óptimas fueron 11.25% p/v de sólidos, 2% v/v H2SO4 y 20 minutos de tiempo de reacción. A estas condiciones se obtuvo una concentración de azúcares reductores de 33.3 g/L.

In order to take advantage of the aquatic weed water hyacinth (Eichhornia crassipes) as lignocellulosic feedstock for the production of reducing sugars, a bromatological characterization of the leaves and stems of the plant was performed. Then, the effects of the sulfuric acid concentration (1 -3% v/v), the concentration of solids (10 to 12.5% w/v) and the reaction time (15 -25 min) at 121°C/15 psi in the production reducing sugars were studied by employing a central composite design. It was found that the acid concentration was the most significant variable. The optimal conditions were solids 11.25% p/v, H2SO4 2% v/v and 20 minute reaction time. These conditions yielded a concentration of reducing sugars of 33.3 g/L.

Com o propósito de aproveitar a erva aquática Aguapé (Eichhornia crassipes) como matéria-prima lignocelulósica para a obtenção de açúcares redutores, foi realizada em primeira instância uma caracterização bromatológica das folhas e talos da planta. Posteriormente, foi estudado o efeito da concentração de ácido sulfúrico (1 -3% v/v), a concentração de sólidos (10 -12.5% p/v) e o tempo de reação (15 -25 min.) a 121°C/15psi, na produção de açúcares redutores, utilizando para tal fim um desenho central composto. Encontrou-se que a concentração de ácido foi a variável mais significativa. As condições ótimas foram 11.25% p/v de sólidos, 2% v/v H2SO4 e 20 minutos de tempo de reação. Nestas condições foi obtida uma concentração de açúcares redutores de 33.3 g/L.