Marleny D. A. Saldaña

Induction of pilocarpine formation in jaborandi leaves by salicylic acid and methyljasmonate

Jaborandi seedlings were subjected to different treatments in order to study the induction of pilocarpine in the leaves. In addition four extraction methods were assessed to extract the alkaloid from dried leaves. The highest yielding extraction and recovery was observed when dried leaves were first treated with base and then extracted with chloroform. Salt stress (NaCl), wounding, hypoxia, and N and K omission of the nutrient soln caused reductions in pilocarpine contents. Whereas complete nutrient soln and P omission maintained normal levels of the alkaloid. Salicylic acid and methyljasmonate induced a 4-fold increase of pilocarpine, but this increase was dependent on the concentration and time after exposure.

Extraction of cocoa butter from Brazilian cocoa beans using supercritical CO2 and ethane

This work explores the use of supercritical CO 2 and ethane, both acceptable and non-contaminating solvents for food products, in the recovery of cocoa butter from Theobroma cacao cocoa beans. Continuos extractions were performed using a high pressure apparatus. Extractions were first performed using processed cocoa butter to assess and compare the extraction efficiencies of CO 2 and ethane. These extractions were carried out at 323.2 K, pressures of 15.2 and 24.8 MPa, and CO 2 and ethane flow rates of 1.3 and 0.9 g min -1 , respectively. Extraction yields of cocoa butter using ethane were an order of magnitude higher than obtained with CO 2 . Extractions to explore the capacity of supercritical fluids in the extraction of cocoa butter from cocoa beans were subsequently performed with ethane at 323.2 and 343.2 K, pressures of 15.2, 24.8 and 28.3 MPa and ethane flow rate of 0.9 g min -1 . The results revealed a pronounced effect of pressure on the extraction yield at all temperatures investigated. Extraction curves showed a retrograde behavior for the two temperatures in the whole pressure range. This behavior suggests a range of possibilities for the extraction of cocoa butter from cocoa beans. Cocoa butter fractions with varying fatty acids concentrations were also obtained.

Supercritical carbon dioxide extraction of methylxanthines from maté tea leaves

Methylxanthines are alkaloids found in natural products such as tea, coffee and guarana. These alkaloids are commonly used in cola drinks and pharmaceutical products due principally to their stimulant and diuretic effects on the human organism. In this work, experimental data on the supercritical CO2 extraction of caffeine, theophylline and theobromine from herbal mate tea, a beverage traditionally consumed by the gauchos of southern Brazil, the Argentine, Paraguay and Uruguay, were obtained using high pressure extraction equipment that allows adequate control of temperature and pressure. The continuous extraction/fractionation of mate tea leaves, Ilex paraguariensis in natura using carbon dioxide was carried out at 313.2 and 343.2 K and pressures of 13.8 and 25.5 MPa. Extraction/fractionation curves revealed the large influence of temperature and pressure on extraction yield. CO2 was also found to show a higher selectivity for caffeine than for theophylline and theobromine.

EXTRAÇÃO DOS ALCALÓIDES: CAFEÍNA E TRIGONELINA DOS GRÃOS DE CAFÉ COM C SUPERCRÍTICO

Caffeine, aby-product of coffee decaffeination by-product, acts as a stimulant and diuretic in the human organism. Most of the caffeine is used in the cola soft drink and pharmaceutical industries. Supercritical CO2 has long been used to decaffeinate coffee beans. However, little is known about the extraction of other alkaloids such as trigonelline. This alkaloid and the products generated by its thermal degradation (nicotinic acid - the vitamin niacin) have received a lot of attention because of their nutritional importance. Trigonelline acts mainly on the nervous central system, the secretion bile and the intestine. The main objective of this work was to obtain experimental data on the extraction of the alkaloids caffeine and trigonelline from canephora (Robusta) coffee beans using supercritical CO2. The decaffeination of this coffee can be economically attractive to obtain caffeine and to upgrade the value of this variety of coffee. New data on the continuouos fractionation of Brazilian Robusta coffee beans using supercritical CO2 at 313, 323 and 343 K and pressures ranging from 9,5 to 23,5 MPa for the extraction and separation of caffeine and trigonelline are presented. Caffeine and trigonelline in the extracted mixture were analyzed using HPLC. A thermodynamic model that uses a quartic equation of state was successfully employed to correlate the solubility behavior of pure caffeine in supercritical CO2.

EXTRAÇÃO DO COLESTEROL COM MISTURAS DE DIÓXIDO DE CARBONO E ETANO SUPERCRÍTICO

There are nutritional and dietary factors, such as those linking excess blood cholesterol to heart diseases and cancer, that justify the development of a technology for the reduction of cholesterol levels in consumed meals. Previous studies have demonstrated the viability of using CO2 for the removal of cholesterol from butter oil. Cholesterol has higher solubility in ethane than in CO2. The use of CO2/ethane mixtures, therefore, presents as an attractive alternative, as a compromise between the higher ethane cost better cholesterol removal efficiency obtained and envolved. Using a high pressure experimental extraction apparatus that allows the independent control of temperature and pressure, cholesterol solubilities in supercritical CO2/ethane mixtures with 8%, 16%, 34%, 76%, 88% e 96,5% of ethane were determined at 328,1 K and pressures from 120 to 190 bar. Experimental results show an increase in solubility with pressure and a composition of ethane in the mixture. Experimental data were correlated with a thermodynamics model that uses Peng-Robinson equation with two different mixing rules: the normally used van der Waals and a rule that considers the interaction parameter density dependent resulting in a quartic equation of state. The density dependent mixing rule reveal more successful in the correlation of experimental data.