DESENVOLVIMENTO DE HIDROGEL DE CARÁ-ROXO (Dioscorea trifida L.) INCORPORADO COM AÇAÍ (Euterpe precatoria Mart) - UMA ROTA REGIONAL PARA MELHORIA DO EXERCÍCIO FÍSICO.

Abstract

In the Amazon forest biome, among the wide variety of native plants, purple yam (Dioscorea trifida L.) and açaí (Euterpe precatoria Mart) are used as high quality functional foods, due to their nutritional and physiological contributions. Few studies with these species have been conducted with the aim of testing the properties in the form of supplements to attenuate oxidative stress markers and circulating glucose concentrations, improve exercise tolerance and increase exhaustion time in response to physical exercise. Thus, this study aimed to develop a supplementary energy hydrogel based on starch from Dioscorea trifida associated with Euterpe precatoria pulp, and to verify the physiological effects on biomarkers of aerobic exercise. Then, the physical-chemical characterization of the vegetable raw material and the hydrogel, the amylose content and the antioxidant capacity (by the DPPH and ABTS methods) were carried out. In addition to these, rheological evaluation techniques, HPLC, X-ray Diffraction (XRD), cytotoxicity by the Alamar Blue method in MRC-5 fibroblasts were used. The lyophilized açaí pulp yield was 17.6%, and the purple yam 9.04%, with 89.50 ± 0.37 of total starch and 11.7% of apparent amylose. The rheological study in steady state showed that the samples analyzed in the form of hydrogel showed a tendency to decrease the apparent viscosity with the increase in the strain rate, behaving as a non-Newtonian fluid with pseudoplastic characteristics, fit properly to the Power Law model. The hydrogel with 5% purple yam starch and 10% freeze dried açaí was more elastic and promising, with greater energy storage and better performance than other formulations. After extraction and characterization, the predominant presence of carbohydrates, proteins, lipids and ash was found. CLAE analysis confirmed the presence of Cyanidin-3-O-rutinoside with 0,974 mg/g and 99% purity. The X-ray diffraction of the freeze dried açaí pulp showed a completely amorphous structure, in contrast, the purple yam starch showed characteristic diffraction peaks and type A crystalline pattern, as well as the hydrogel. The degree of relative crystallinity of the freeze dried açaí pulp was 23,25%, of the purple yam starch was 28,78% and the hydrogel was 20,88%. It was observed that açaí and hydrogel in vitro tests showed rich antioxidant activity, against the radicals DPPH•- and ABTS•+. In the MRC-5 cell viability test, up to a period of 72h, the results showed that the hydrogel, purple yam starch and lyophilized açaí are not cytotoxic at the concentrations tested with CI50 values between 50 to 0,78 µg /mL. Therefore, these results suggest that the hydrogel has compounds that can be used as sports food supplements. Evaluating the results, it is verified the importance of complementary studies to evaluate and elucidate other aspects and physical properties of the hydrogel.