Co-precipitation of grape residue extract using sub- and supercritical CO2 technology

a micronización y secado de extractos líquidos crudos por procesos verdes no térmicos es muy interesante cuando se desea reducir el espacio de almacenamiento, los costos de transporte y concentrar y encapsular compuestos de interés. En este trabajo, se estudió la co-precipitación de extracto de etanol a partir de residuos de uva con un polímero biodegradable y biocompatible, polivinilpirrolidona (PVP), utilizando tecnología de CO2 subcrítica y supercrítica, es decir, en el presente trabajo mediante un antisolutorio presurizado (PAS). Se utilizó un diseño factorial completo (3 x 3) para evaluar el efecto de la presión (90, 130 y 170 bar) y la temperatura (20, 32 y 45 ºC) sobre el proceso PAS y las características de las partículas formadas por él. Presiones más altas (170 bar) y temperaturas (45 ºC) resultaron significativamente en condiciones operativas con con mejores rendimientos de precipitación global y en la producción de partículas con un diámetro medio más bajo y un contenido residual de etanol. Las partículas tenían una forma casi esférica con tamaños de 1,3 a 4,1 µm. La interacción de baja temperatura (20 ºC) con alta presión (170 bar) llevó a la producción de polvos secos más concentrados en antocianinas y compuestos fenólicos totales, y en procesos con mayores rendimientos de co-precipitación de estos bioactivos. Aunque los factores en estudio no tienen un efecto significativo sobre la capacidad antioxidante (CA) de las partículas, se observó que la CA se correlacionó fuertemente con el contenido de antocianinas y fenoles totales, demostrando así que el poder antioxidante del PAS co-precipitados del residuo de uva que era debido a la presencia de fenólico, principalmente antocianinas. Trece antocianinas fueron identificadas y cuantificadas en el extracto original y micropartículas co-precipitadas por UHPLC, siendo trans-malvidina-3-O-(6"-cumaril)-glucósido, malvidina-3-O-glucósido y malvidina-3-(6"-acetil)-glucósido las principales antocianinas. A partir de los estudios de liberación in vitro, se observó que las micropartículas, producidas en las mejores condiciones experimentales, liberaban compuestos fenólicos más lentamente en fluidos gastrointestinales simulados que el extracto precipitado sin polímero. Las antocianinas totales se detectaron parcialmente en el líquido intestinal, mientras que en el líquido gástrico se liberaron al 100% en un corto período. Al final, se puede concluir que la técnica del PAS, cuando se realiza principalmente en condiciones supercríticas, es un proceso muy prometedor para co-precipitación, concentración y fraccionamiento simultáneo de compuestos polares sensibles, como antocianinas, presentes en extractos de plantas crudas. Además, conduce a la producción de sistemas de administración bioactivos con mejores tasas de disolución en fluidos gastrointestinales simuladosThe micronization and drying of crude liquid extracts by green non-thermal processes is very interesting when it is desired to reduce storage space, transport costs, and to concentrate and encapsulate compounds of interest. In this work, the co-precipitation of ethanol extract from grape residue with a biodegradable and biocompatible polymer, polyvinylpyrrolidone (PVP), was studied using sub- and supercritical CO2 technology, namely in the present work by pressurized anti-solvent (PAS). A full factorial design (3 x 3) was used to evaluate the effect of pressure (90, 130 and 170 bar) and temperature (20, 32 and 45 ºC) on the PAS process and the characteristics of the particles formed by it. Higher pressures (170 bar) and temperatures (45 ºC) significantly resulted in operational conditions with better global precipitation yields and in the production of particles with a lower average diameter and residual ethanol content. The particles had a quasi-spherical shape with sizes from 1.3 to 4.1 µm. The interaction of low temperature (20 ºC) with high pressure (170 bar) led to the production of dry powders more concentrated in anthocyanins and total phenolic compounds, and in processes with higher co-precipitation yields of these bioactives. Although the factors under study do not have a significant effect on the antioxidant capacity (AC) of the particles, it was noted that AC correlated strongly with the content of anthocyanins and total phenolics, thus demonstrating that the antioxidant power of the PAS co-precipitates of the grape residue it was due to the presence of phenolic compounds, mainly anthocyanins. Thirteen anthocyanins were identified and quantified in the original extract and co-precipitated microparticles by UHPLC, being trans-malvidin-3-O-(6"-cumaryl)-glucoside, malvidin-3-O-glucoside and malvidin-3-(6"-acetyl)-glucoside the major anthocyanins. From the in vitro release studies, it was observed that the microparticles, produced from the best experimental conditions, released more slowly phenolic compounds in simulated gastrointestinal fluids than the precipitated extract without polymer. Total anthocyanins were partially detected in the intestinal fluid, while in the gastric fluid were 100% released in a short period. In the end, it can be concluded that the PAS technique, when performed mainly in supercritical conditions, is a very promising process for co-precipitating, concentrating and simultaneously fractionating sensitive polar compounds, such as anthocyanins, present in crude plant extracts. Furthermore, it leads to the production bioactive delivery systems with better dissolution rates in simulated gastrointestinal fluids

EFFECTS OF THE FRUCTOOLIGOSACCHARIDES (FOS) AND INULIN ON BONE METABOLISM OF THE SKELETALLY MATURE FEMALE RATS

The aim of this study was establish if the fructooligosaccharides (FOS) and inulin alone or together attenuate age related bone loss in skeletally mature female rats. Forty 10-month old female rats were randomly assigned to four diet groups for 2 months: control, FOS, inulin and FOS + inulin. Bone mineral density (BMD) using dualenergy X-ray absorptiometry (DXA), femur quality using morphometry and biomechanic properties, biochemical assays by the determination of serum parathyroid hormone (PTH), alkaline phosphatase activity (ALP), degradation products of C-terminal peptides of type I collagen (CTX-I), osteocalcin (OC), osteoprotegerin (OPG) and nuclear factor κappa B ligand (RANk-L). The FOS increased hip axis BMD (0.255 ± 0.005 g/cm2 ) and femur neck width (2.19 ± 0.01 mm) and reduced PTH (4.0 x 10-3 ± 0.0006 µg/L), FOS + inulin increased the femur proportional limit (87.2 ± 1.0 N) and reduced PTH (2.5 x 10-3 ± 0.0006 µg/L) and ALP (23.2 ± 5.1 U/L), all the prebiotics reduced OPG (FOS = 1.1 ± 0.3, inulin = 1.1 ± 0.3, FOS + inulin = 1.4 ± 0.4 µg/L) and RANk-L (FOS = 1.65 x 10-2 ± 0.003, inulin = 1.78 x 10-2 ± 0.003, FOS + inulin = 2.83 x 10-2 ± 0.006 µg/L ), no prebiotics changed OC and CTX-I. The results suggested that the consumption of FOS or FOS + inulin may reduce the bone turnover, however, further studies about prebiotics and their synergistic effect on age related bone loss are required

Antioxidant Potential Of Rat Plasma By Administration Of Freeze-dried Jaboticaba Peel (myrciaria Jaboticaba Vell Berg).

The effect of the intake of freeze-dried jaboticaba peel powder on the antioxidant potential of rats' blood plasma was investigated in two experiments. In the first, 35 male rats, divided into 5 groups, received 7 mg of anthocyanins/100 g of body weight, by gavage. The blood was withdrawn 0, 30, 60, and 120 min after gavage. The antioxidant capacity was evaluated in plasma by ORAC and TEAC. There was no significant difference in the plasmatic antioxidant potential among the groups. In the second experiment, 40 male rats were divided into 4 groups that consumed, respectively, 0, 1, 2, and 4% of freeze-dried jaboticaba peel powder added to their diet. An increase in the plasmatic antioxidant potential was observed for groups that received 1 and 2% of jaboticaba peel powder (1.7 times by TEAC method and 1.3 times by ORAC); however, the group that received 4% of the powder did not show antioxidant effects according to the methods used.592277-8