Food Science and Technology (Campinas)
On-line version ISSN 1678-457X
ALVES, Cibele Cristina de Oliveira; RESENDE, Jaime Vilela de; CRUVINEL, Rafael Souza Ribeiro and PRADO, Mônica Elisabeth Torres. Stability of the microstructure and carotenoids contents of the freeze-dried pequi (Caryocar brasiliense Camb.) pulp in the powdered form. Ciênc. Tecnol. Aliment. [online]. 2008, vol.28, n.4, pp. 830-839. ISSN 1678-457X. http://dx.doi.org/10.1590/S0101-20612008000400011.
In this study, food powders obtained from the freeze-dried pequi (Caryocar brasiliense Camb.) pulps (internal mesocarp) were developed by adding alcohols (ethanol and isopropyl alcohol) in concentrations of 0, 5, and 10% and sugars (sucrose and fructose) in concentrations of 0, 5, and 10%. Microstructure analyses by photonic microscopy of the freeze-dried powders were used to evaluate the degree of crystallization. Color analyses using a Minolta colorimeter and the total carotenoid values using a spectrophotometer were also done. The results show that treatments with a sucrose and ethanol combination presented the formation of crystalline structures and the best preservation of the carotenoid contents. The higher the concentration of the alcohol added in the pre-treatments, the better preserved the caretenoids in the freeze- dried powders became. Treatments with fructose and isopropyl alcohol produced freeze- dried powders that were typically amorphous presenting caking phenomena. Pre-treatments with sucrose and ethanol are the solution to these problems since they are able to produce freeze-dried powders of the pequi pulp with physical chemical and microstructural stability.
Keywords : pequi; food powders; microstructure; carotenoids.