Extração e purificação de compostos bioativos de cubiu ("Solanum sessiliflorum'), camu-camu ("Myciaria dubia") e araçá-roxo ("Psidium myrtoides") utilizando filtração por membranas com e sem promotores de turbulência

Abstract

Brazil is the third fresh fruit producing country in the world; However, the exotic fruit market, little known by consumers, generates more profitable products and acts on economic growth and diversification, bringing alternatives to meet the need for healthier products. Cubiu (Solanum sessiliflorum), Camu-camu (Myciaria dubia), and Purple guava (Psidium myrtoides), with their species variations, are good examples of exotic fruits. Purple guava and camu-camu, as well as uvaia (Eugenia uvalha) and jaboticaba (Plinia cauliflora), belong to the family “Mirtaceae”, which is known for its significant amount of bioactive compounds. Already cubiu belongs to the family "Solanaceae" which includes species with great economic value, such as potatoes (Solanum tuberosum), tomatoes (Solanum lycopersicum) and tobacco (Nicotiana tabacum). Many techniques have been explored for bioactive extraction, having advantages and disadvantages, being exclusively aqueous extraction a viable alternative for the elimination of organic solvents during processing. After the bioactive extraction stage it is necessary to carry out the extract polishing phase, ensuring the maintenance of the compounds of interest, longer shelf life and ease of transport. Improvement of aqueous extract characteristics can be accomplished by the Membrane Separation Process (MSP). Thus, in this work, an evaluation of the extraction of bioactive compounds present in the fruits of cubiu, camu-camu and purple guava was performed and, afterwards, the MSP was used to improve the characteristics of the aqueous extract of purple guava. Of the fruits evaluated, the one with the highest Phenolic Compound Content (TCF) was camu-camu with a value of 732 mg EAG / 100 g ff (milli grams of Gallic Acid Equivalent in 100 grams of fresh fruit), which is much higher. that found in cubiu 132 mg EAG / 100 g ff and 12% higher than that found in the purple guava 548 mg EAG / 100 g ff. Evaluating the kinetics curves of the aquatic extraction of purple guava, there was an average increase of 25% in the bioactive compounds evaluated using the extraction at 80oC for 40 min, when compared to the initial extract, reaching the maximum values of 291, 7 mg Rutin / 100 g ff, 44.37% and 21.1 mg Ferrous sulphate / g ff in flavonoids, antioxidant capacity (% DPPH) and antioxidant activity (FRAP), respectively. Chromatographic analyzes of aqueous purple guava extract indicate significant content of gallic acid (132.01 µg / g ff), epicatechin (127.03 µg / g ff), EGC Epigallocatechin (60.45 µg / g ff), kaempferol (27.69 µg / g ff) catechin (19.16 µg / g ff) and quercitin (16.13.69 µg / g ff) in fruits. To improve the characteristics of the aqueous extract of purple guava, the clarification step of the extract was used, using commercial microfiltration membranes of 0.22 µm and 0.05 µm. The results were also compared with the clarification using hollow fiber ceramic membrane produced in the laboratory of membranes of FEQ / UFU, where it was found that there is no significant reduction of bioactive in solution. When using a commercial membrane of 0.05 µm, there was a significant reduction in bioactive content in the clarified extract. Filtration of the aqueous extract of the purple guava using a commercial 10 kDa membrane and a pressure of 500 kPa was performed to concentrate the extract and the concentrated extract had values of 315.87 mg Rutin / 100 g f.f. 590.11 mg EAG / 100 g f.f, 36.41% and 28.77 mg Ferrous sulphate / g f.f in flavonoids, phenolic compound content, antioxidant capacity (% DPPH) and antioxidant activity (FRAP), respectively. In order to increase the permeate flux through the membrane, turbulence promoters were coupled to the permeation cell module, which promoted a 78.2% increase in permeate flux in the process of concentration of the purple guava extract with 10 kDa membrane. For a better evaluation of the effect of turbulence promoters on membrane flow, a computational fluid dynamics analysis was performed. The images generated in the computational fluid dynamics were similar to the type of fouling that occurred during the filtration of the purple guava extract. Finally, the membrane filtration process is a promising alternative to improve the characteristics of purple guava extract.