Regional Center for the Study of Healthy Foods

Valparaíso, Chile

Regional Center for the Study of Healthy Foods

Valparaíso, Chile

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Bejarano A.,Federico Santa María Technical University | De La Fuente J.C.,Federico Santa María Technical University | De La Fuente J.C.,Regional Center for the Study of Healthy Foods
Journal of Chemical Thermodynamics | Year: 2015

Isobaric (vapor + liquid) equilibria of three binary systems (1-methoxy-2-propanol + 2-methoxyethanol), (2-butanone + 2-methoxyethanol) and (water + 2-methoxyethanol), was measured using an apparatus with dynamic recirculation and gas chromatography analysis for both phases. The measurements were carried out at pressures of (74.5, 101.3, and 134.0) kPa and temperature ranged from (343 to 407) K. No partial liquid miscibility was observed for any of the systems studied. Azeotropic behavior was verified for the system (water + 2-methoxyethanol) at the water-rich region. Thermodynamic modeling of the data measured was successfully accomplished for (2-butanone + 2-methoxyethanol) and (water + 2-methoxyethanol). In order to represent the no-ideality of the liquid phase, three alternatives for the activity coefficient model were used, Non Random Two Liquid, van Laar and Wilson. Results showed that the relative root mean square deviations from the experimental molar fractions were, <12% for the vapor phase, and <1% for the liquid phase. © 2015 Elsevier Ltd. All rights reserved.


Nunez G.A.,University of Santiago de Chile | Del Valle J.M.,University of Santiago de Chile | De La Fuente J.C.,Federico Santa María Technical University | De La Fuente J.C.,Regional Center for the Study of Healthy Foods
Journal of Chemical and Engineering Data | Year: 2010

We measured the solubility in supercritical carbon dioxide (CO 2) of farnesol [(2E,6E)-3,7,11-trimethyldodeca-2,6,10-trien-1-ol] and naringenin [(2S)-5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one] using a static-analytic method (a high-pressure static equilibrium cell coupled to an HPLC). The molar fraction of farnesol in the saturated CO 2-rich phase increased between y 2 = 0.13·10 -3 at 333 K and 11.4 MPa to y 2 = 1.91·10 -3 at 333 K and 26.0 MPa for farnesol and from y 2 = 0.49·10 -5 at 313 K and 10.3 MPa to y 2 = 1.65·10 -5 at 333 K and 44.5 MPa for naringenin. The average error of our measurements was about 25 %. Farnesol had an end-temperature crossover point at approximately 17 MPa, whereas naringenin exhibited a monotonous increase in solubility with both temperature and pressure. The differences in solubility between farnesol, naringenin, and other sesquisterpenes or flavonoids reported in the literature were partially explained by differences in molecular weight and polarity between solutes. We correlated experimental data as a function of the system temperature and pressure and the density of the solvent using a literature model that also showed the autoconsistency of the data for CO 2 densities above 412 kg·m -3 for naringenin. © 2010 American Chemical Society.


Vega R.,Pontifical Catholic University of Valparaíso | Zuniga-Hansen M.E.,Pontifical Catholic University of Valparaíso | Zuniga-Hansen M.E.,Regional Center for the Study of Healthy Foods
Bioresource Technology | Year: 2011

Response surface methodology was used as an optimization tool for the production of short chain fructooligosaccharides (sc-FOS) using the commercial cellulolytic enzyme preparation, Rohapect CM. Three independent variables, temperature, concentrations of sucrose and enzyme were tested in the reaction medium. The responses of the design were, yield (g. sc-FOS/100. g initial sucrose), 1-kestose (g/100. g sc-FOS) and volumetric productivity (g. sc-FOS/L. h). Significant effects on the three responses included a quadratic effect (temperature), a linear effect (sucrose and enzyme concentrations) and an interaction between temperature and sucrose concentration. The cost-effective conditions to support the process in a high competitive market were 50 °C, 6.6. TU/mL enzyme, 2.103. M sucrose in 50. mM acetate buffer at pH 5.5, and the synthesis for a 5. h reaction time. Under these conditions, a high Y P/S (63.8%), Q P (91.9. g/L. h) and sGF2 (68.2%) was achieved. © 2011 Elsevier Ltd.


Vega-Paulino R.J.,Pontifical Catholic University of Valparaíso | Zuniga-Hansen M.E.,Pontifical Catholic University of Valparaíso | Zuniga-Hansen M.E.,Regional Center for the Study of Healthy Foods
Journal of Molecular Catalysis B: Enzymatic | Year: 2012

Twenty-five commercial enzyme preparations for use in the food industry were assayed for transfructosylation activity. Three preparations showed high transfructosylation activity from sucrose as well as the ratio of transferase and hydrolase activities. Short-chain fructooligosaccharides (sc-FOS) were not hydrolyzed by the three enzyme preparations after a 12 h reaction time. At a 6 h reaction time, yield and volumetric productivity were in the range from 58.8 to 62.6% (g sc-FOS/100 g initial sucrose) and 52.5 to 55.9 g sc-FOS/L h, respectively. One enzyme preparation was then evaluated for sc-FOS synthesis. Thus, environmental factors influencing the reaction were studied on products. Total sc-FOS concentration was not affected by temperature, pH and enzyme concentration at the studied levels, but high concentrations of sucrose affected the sc-FOS formation. The results suggest that these enzyme preparations can be exploited as a source of food-grade fructosyltransferase, in addition to Pectinex Ultra SP-L. © 2011 Elsevier B.V. All rights reserved.

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