Efeitos da pasteurização térmica sobre as características químicas, físico-químicas, sensoriais e reológicas da polpa de umbu (Spondias tuberosa Arr. Câmara)

Abstract

In the Brazilian Northeast region it s common to verify the umbu loss for the maturation excess and for the lack of other alternatives of exploitation. The racional exploration of the umbuzeiro in the form of processed products it would make possible an increase in the income of the small agricultural producer, who does not have access to a sophisticated technology. In this work it has been evaluated the effect thermal pasteurization, type HTST, on the chemical and sensorial characteristics of umbu pulp. Initially, the fruits were submitted to blanching followed by depulping. To the blanched pulp five different thermal treatments were applied: 88°C/10 seconds; 88°C/30 seconds; 92°C/20 seconds; 96°C/10 seconds e 96°C/30 seconds, in accordance to a complete factorial planning with repetition of the central point (92°C/20 seconds). After that, chemical, rheological and sensorial analyses were carried out in order to verify significant differences between the blanched pulp and processed pulps. The results showed that there was not significant difference regarding chemical and physicochemical characteristics in the established processes. The study of rheological behavior of the pulps indicated a non Newtonian character, of shear thinning nature. The instrumental analysis of color presented significant alterations on the L* parameter for the temperature factor, on the a* parameter for the time factor and for the interaction of the time x temperature factors. The b* parameter did not present alteration in relation to the established processes. In general, results showed that samples tended to discoloration and browning. The samples slightly lost their green and yellow hues under the conditions of longer process. The sensorial evaluation showed that the processed pulp at 88°C for 10 seconds was closer to the reference pulp for majority of the analyzed attributes, and the bitter taste lightly tended to increase with the increase of temperatures.