Dry Fractionation of Cupuassu (Theobroma grandiflorum) Fat: Physical–Chemical Properties and Polymorphic Behavior

Abstract

Physical chemical properties of cupuassu fat were modified by dry fractionation. Stearin and olein fractions were obtained at 29, 26, and 24 C. Polymorphic behavior of unfractionated cupuassu fat (UCF) and its fractions were studied in situ by small-angle (SAXS) and wideangle (WAXS) X-ray scattering using synchrotron light. Polymorphic transitions were followed in real time tempering samples with a thermal cycle. For UCF, the main polymorphic form crystallized under selected conditions was the β' 2. α and β' 1-forms appeared in trace amounts. β 2-form was obtained after storage at 25 C for 3 months. Stearins obtained at 26 (S-26) and 24 C (S-24) showed a similar polymorphic behavior. However, S-26 with improved physical properties might be more suitable for chocolate production or as a trans-fat alternative than UCF. Stearin fraction obtained at 29 C (S-29) had a complex polymorphic behavior. The α-form was the first polymorphic form detected followed by β' 2-form. There was a polymorphic transition from α to β' 1-form but no transition between β'-forms. They were independent to each other showing fractionation in two different solid solutions. Increased contents of the triacylglycerols (TAG) SOA and SOB together with lower contents of SOO compared to UCF led to co-crystallization because there was no complete compatibility among all TAG present in S-29. β 1-form crystallized after storage forming crystals with a double-layer arrangement and a characteristic morphology. This form could be useful for accelerating crystallization process in melted liquid systems.

Effect of sucrose esters on polymorphic behavior and crystallization kinetics of cupuassu fat and its fractions

“…The capillary melting point (average of three replicates) of the stored sample was 31.6 ± 0.4°C. Triacylglycerols (TAGs) composition of CF was previously reported (Rodríguez‐Negrette et al, 2020). The main TAGs were POO (6.4 ± 0.4 g/100 g), SOO (21.6 ± 1.3 g/100 g), POS (9.9 ± 0.5 g/100 g), AOO (7.2 ± 0.4 g/100 g), SOS (18.9 ± 0.5 g/100 g), and SOA (11.6 ± 1.5 g/100 g), with P: palmitic acid, O: oleic acid, S: stearic acid, and A: arachidic acid.…”

“…The yields of S‐29, S‐26, and S‐24 were 9.2 ± 1.0, 23.3 ± 1.7, and 36.5 ± 1.6 g/100 g, respectively. Stearin fractions obtained at 29, 26 or 24°C had a higher content of the SOS TAG (23.7 ± 1.1, 25.7 ± 0.2, 20.2 ± 0.3 g/100 g, respectively) and a lower content of the TAGs POO (3.9 ± 1.2, 4.4 ± 0.7, 5.2 ± 0.6 g/100 g, respectively) and SOO (18.1 ± 1.1, 19.5 ± 0.2, 20.4 ± 0.5 g/100 g, respectively) than CF (Rodríguez‐Negrette et al, 2020).…”

“…To obtain stearin fractions, dry fractionation was performed as previously described (Rodríguez‐Negrette et al, 2020). Briefly, CF was melted at 60°C and kept at this temperature for 30 min to erase crystal memory.…”

“…It is used industrially to prepare white chocolate, chocolate mass and butter. Although its melting point is lower than that of cocoa butter, its physical properties may be improved by dry fractionation (Norazlina et al, 2020; Rodríguez‐Negrette et al, 2020). It was reported that cupuassu fat (CF) and its stearin fractions showed a complex polymorphic behavior (Rodríguez‐Negrette et al, 2020; Silva et al, 2009).…”

“…Although its melting point is lower than that of cocoa butter, its physical properties may be improved by dry fractionation (Norazlina et al, 2020; Rodríguez‐Negrette et al, 2020). It was reported that cupuassu fat (CF) and its stearin fractions showed a complex polymorphic behavior (Rodríguez‐Negrette et al, 2020; Silva et al, 2009). Controlling crystallization and polymorphic behavior will improve its suitability for industrial applications.…”