CONICET | Buscador de Institutos y Recursos Humanos

Cupuassu fat is a semi-solid vegetable fat obtained from a tree called Theobroma grandiflorum, native to the Amazon. The aim of the present work was to study the polymorphic behavior of cupuassu fat and its fractions (obtained by dry fractionation at 24, 26, and 29°C) crystallized at different temperatures and under a temperature cycle. Samples were analyzed for fatty acid and triacylglycerol compositions, solid fat content (SFC), thermal behavior, crystalline morphology, and polymorphic behavior by small angle X-ray scattering (SAXS) using synchrotron light. Stearin fractions showed a higher content of saturated fatty acids, a higher content of the triacylglicerols POP, POS, SOS, and SOA, and a higher SFC with temperature than original sample and olein fractions. Cupuassu fat crystallized in the α form up to 17°C. Then, the α form suffered a polymorphic transformation to ?2. At 18°C the α form did not crystallized. The first polymorphic form that appeared was the ?1. To crystallize the 2 form it was necessary to applied a temperature cycle. Oleins and stearin obtained at 24°C showed the same behavior as original sample. Stearins obtained at 26 and 29°C did not showed ? crystals when crystallized under a temperature cycle: α form transformed in 2 form or in 1 form, respectively. From these results, stearin crystallized at 26°C that had a 2 tendency, would be the best for chocolate and confections.