Desenvolvimento de processos de extração de hidrocoloides do ora-pro-nóbis (Pereskia aculeata Miller)

Abstract

The desires of the consumers’ for products with excellent sensorial qualities, longer durability and lower costs cause the industries of the food sector search for new technologies and sources of raw material. The objective of this work was developing a hydrocolloid-extracting process, in a natural manner, by utilizing as raw material the Barbados gooseberry (Pereskia aculeata Miller). A number of operations such as pressing, filtering, freeze concentration, precipitation and drying were involved. The independent variables evaluated were: temperature and the amount of the water utilized in homogenizing to determine the most efficient conditions in extracting, the result being obtained in each step, analyzed by response surface method. The conditions presenting best results were: we of 3.6 liters of water to each kilogram of raw material at the temperature of 75°C.In this case the final yield of the product were of 0.67%. Under those conditions, pseudoplastic behavior (n< 1) in all the steps of the process was found. To determine some characterisitcs of hydrocolloid obtained, gums were prepared at different concentrations and submitted to the viscosity analysis, capacity and stabilization of emulsion at ambient temperature and at 80°C. The gums manufactured with 1% of the hydrocolloid presented satisfactory results, namely, 7,306 mPa.s for viscosity and 83.2%; 85.71% and 80.49% for capacity and stability of emulsion ambient temperature and at 80°C, respectively. The process developed proved both viable and applicable. The hydrocolloid obtained presented desirable characteristics for application in the food industry such as thickening, emulsifying capacity, in addition to being odorless.