Qualidade da polpa de lichia em pó, obtida pelo processo de liofilização.

Abstract

The lychee (Litchi chinensis) is a fruit native to Asia, being considered the queen of the fruit. In Brazil, its introduction was given as an ornamental plant and only from the decade of 70, had its consumption expanded. Due to its high commercial value, short harvest period and high perishability, one of the strategies to expand their offer is your dehydration and subsequent use of powder in probiotic dairy drinks. Thus, the objective of the present study verified the production of lychee powder by lyophilization, evaluating the stability of powder during storage and prepares a probiotic milk drink. In this way, were drawn up three formulations, added maltodextrin, at concentrations of 15, 20 and 25%. These formulations were previously characterized, along with the integral pulp, evaluated their rheological behavior and then freeze at a temperature of - 40 °C for 48 h. The powders obtained were subsequently characterized and the best sample, subjected to analyzes of adsorption isotherms of water at temperatures of 30 and 40 °C, analyzed in scanning electron microscopy and stored in laminated packaging by 60 days at temperatures of 20, 30 and 40 °C, when were monitored every 10 days, its characteristics, physical, chemical and physico-chemical properties. In addition, were processed fermented dairy drinks free of powder of lychee and at concentrations of 7, 9 and 11% of powder, which were characterized according to the physical, chemical and physico-chemical properties. The results obtained showed that the dehydrated pulps formulated and suffered changes regarding the parameters evaluated in all samples, depending on the concentration of maltodextrin. The integral pulp and the different formulations exhibited rheological behavior typical of fruit pulps, classifying it as non- Newtonian fluid, pseudoplastic character, whose best fit was with the mathematical model of Mizrahi-Berk. The lyophilization process reflected in changes of the parameters analyzed, taking the powder added to 25%maltodextrin displayed the best characteristics among samples. The analysis of adsorption isotherms of water were determined as type III and the best mathematical model for description of the experimental data was the GAB, to display larger values of R2 and lower rates of errors average. Regarding the analysis of electronic microscopy, it was noticed that the powder of the lychee exhibited amorphous structures and particleboard, with pronounced roughness and high porosity. During the storage period, most of the physical, chemical and physico-chemical parameters were altered, mainly in function of the temperature of exposure and the probiotic dairy drinks have demonstrated significant differences depending on the elevation of the concentration of powder of lychee added as flavor.