Compostos bioativos e capacidade antioxidante de cajá e umbu-cajá obtidos por liofilização.

Abstract

This work was carried out with the purpose of obtaining cajá and umbu-cajá powder, through the drying process by lyophilization and characterizing them for the physicochemical characteristics, bioactive compounds and antioxidant capacity. Initially, the fruits had their physical properties evaluated. For the preparation of the pulps used in the drying processes the concentrations of 0, 5, 10, 15 and 20% of maltodextrin were evaluated. Integral pulps were characterized for physicochemical parameters, bioactive compounds, antioxidant capacity and microbiological analyzes. The formulations were submitted to the physico-chemical analyzes and lyophilized afterwards, in a freezer dryer operating at -56 ± 3 ºC, for a period of 48. The whole pulps were classified as acidic and with relevant values of flavonoids, carotenoids, ascorbic acid, phenolic compounds and antioxidant capacity. The formulations presented reduced water content and titratable total acidity and increase in total solids, total soluble solids and density. The Page model what was it the best fit for the experimental drying data, providing a higher coefficient of determination and lower mean square deviation. The increase in the concentration of maltodextrin exerted influence on the drying time by lyophilization. The obtained powders were characterized how much to the of physicochemical parameters, bioactive compounds and antioxidant capacity. The increase in the concentration of maltodextrin reduced the water content, the water activity and influenced significantly in all the chemical parameters evaluated. For the selection of the best powder of each variety were taken into consideration the water content, water activity, color and vitamin C; The formulation containing 10% maltodextrin, for both varieties, was subjected to the determination of the water adsorption isotherms at three temperatures (20, 30 and 40 ° C) and the accelerated storage for 90 days in Metallic packaging under controlled conditions of temperature (25 and 40 ºC) and relative humidity (75%). The pulps of the two samples that presented water content close to the legislation and without tack were characterized in terms of physical parameters and microbiological analyzes. The powdered samples of cajá and umbu-cajá were classified as hygroscopic, presenting high solubility and rapid wettability besides the capacity of free flow. The particles of the powders of the two samples presented porous and amorphous agglomerated particles, with internal cavities. The powders of the two varieties of Spondias are suitable for consumption since they are microbiologically according to the current legislation. The models that best fit the experimental data of the adsorption isotherms of the powders were the GAB and Peleg, models, and classified as type III. As for storage, it was found that the laminated packaging did not prevent the absorption of water, thus increasing the water content and, consequently, the water activity. The colorimetric analysis revealed that the lyophilized powders presented intense color. The results indicate that the powders of the lyophilized fruits present as relevant source of ascorbic acid, carotenoids, flavonoids, phenolic compounds and good antioxidant activity. The observed variations for the two temperatures (25 and 40 ºC) did not significantly alter the nutritional characteristics of the powders; However, samples stored at 25 ° C showed the highest retention of the bioactive compounds.