ESTUDO REOLÓGICO DE EMULSÃO COM POLPA DESIDRATADA E DESENGORDURADA DE ABACATE (Persea americana)

Abstract

This study addresses the rheological, emulsifying, and morphological characterization of freeze-dried (PL) and freeze-dried defatted (PLD) avocado pulp (Persea americana), aiming at its use as a functional ingredient in foods. Considering the growing demand for foods that offer health benefits beyond basic nutrition, this study provides a sustainable alternative for the use of avocado by-products, which are often discarded. Analyses included evaluating the emulsifying capacity of the samples, conducting rheological tests to assess flow behavior and apparent viscosity at different temperatures, and microscopic studies to observe pulp structure and starch granules. The results indicated that PLD has an emulsifying capacity of 53.2%, higher than that of PL, which showed 48.5%, suggesting that lipid removal enhances this property and makes the ingredient more versatile for food applications. Both treatments showed pseudoplastic behavior, where apparent viscosity decreased with increased shear rate, a feature advantageous for stability and applicability in industrial processes. The initial viscosity of PL was lower than that of PLD, particularly at elevated temperatures: PL showed 80 Pa·s at 10 °C and about 30 Pa·s at 50 °C, while PLD reached 160 Pa·s at 10 °C and 60 Pa·s at 50 °C. These differences indicate that PLD has a higher potential to form a resilient structural network. Furthermore, the Herschel-Buckley and Casson models showed the best fit to the experimental data, with determination coefficients above 0.99, validating these models' suitability for representing emulsion behavior. Microscopic analysis confirmed the presence of starch granules and fibers, which contribute to emulsion stability and thickening. This study enhances understanding of the technological properties of avocado pulp, highlighting its potential as a natural emulsifier and thickener in healthy food formulations, with a possible positive impact on the development of products that meet demands for healthier and more sustainable options.