Functional properties of pasteurized samples of Aloe barbadensis Miller: Optimization using response surface methodology

Functional properties (FPs) of pasteurized extracts of Aloe barbadensis Miller, rich in bioactive polymer acemannan and cell wall polysaccharides, were optimized using response surface methodology. Box-Behnken design was applied to evaluate the effects of three independent variables: age of plant (X-1 = 3-5 years), pasteurization temperature (X-2 = 65-85 degrees C), and pasteurization time (X-3 = 15-35 min) on swelling (Sw), water retention capacity (WRC), and fat adsorption capacity (FAC). Analysis of variance showed that the contribution of quadratic models was significant for the responses. From response surface plots, age of plant, time and temperature exhibited independent and interactive effects on Sw, WRC and FAC properties. The optimal conditions to obtain alcohol insoluble residues (AIRS) from pasteurized samples with the highest values for the FPs analysed were: (1) X-1 = 3.6 years, X-2 = 65 degrees C, X-3 = 15 min for Sw; (2) X-1 = 4.0 years, X-2 = 75.3 degrees C, X-3 = 20.5 min for WRC; (3) X-1 = 4.0 years, X-2 = 70.1 degrees C, X-3 = 15 min for FAC. These optimum conditions allowed the obtention of AIRs from pasteurized aloe samples exhibiting: (1) Sw of 308.0 mL g(-1) AIR; (2) WRC of 30.0 g H2O g(-1) AIR; and (3) FAC of 33.9 g Oil g(-1) AIR. A close agreement between experimental and predictive values was found. These results may be used for the pasteurization process of A. barbadensis Miller in industry. (C) 2012 Elsevier Ltd. All rights reserved.