Effect of stabilization and fatty acids chain length on the crystallization behavior of interesterified blends during storage

Agradecimentos: Ana Paula Badan Ribeiro thank CNPq (303429/2018-6) for productivity grant and São Paulo Research Foundation-FAPESP (16/11261-8). Kamila Ramponi Rodrigues de Godoi thank CNPq (140789/2017-0) for PhD scholarship grant. Lisandro Pavie Cardoso thank CNPq (302626/2016-6 and 307896/2019-6) for productivity grant. This study was financed in part by the "Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES)"–Finance Code 001 Abstract: In this work, we studied the influence of fatty acid chain length and crystallization temperature on the crystallization behavior during the storage of binary blends modified by chemical interesterification. The blends were produced with soybean oil and fully hydrogenated oils from palm kernel, palm, soybean, microalgae, and crambe, evaluated separately, at a ratio of 50:50 (% w/w). The blends were crystallized by two crystalline stabilization methods. In method I, the samples were maintained at 25 ? for 24 h before the analyses. In method II, the samples were maintained at 5 ? for 24 h, followed by crystalline stabilization at 25 ? for 24 h before the analyses. The interesterification reaction caused considerable changes in the TAGs profile with increasing asymmetric TAGs. These TAGs changes promoted an increase in the crystallization induction time, a decrease in the maximum solids content, and changes in crystals morphology. The increase in the FAs chain length promoted the increased nucleation rate that influenced morphology crystals. Method II promoted a reduction in the me-dium diameter of crystals and the appearance of the 13 phase with storage time. For crystallization carried out at higher temperatures (method I), we observed that 13' was favored. Unusual polymorphic transitions were observed with storage time in samples with higher tristearin content. We identified clear correlations between the predominance of 13' phase in the interesterified blends and TAGs of S2U and SU2-type. In addition, the blends with a more diverse range of fatty acids concerning chain size also showed the 13' polymorph. 13 polymorph, on the other hand, was associated with symmetric TAGs, S3 and U3, and CN-54 type TAG. In this study, we used the Rietveld method to quantify the polymorphs and amorphous content in the blends before and after the randomization reaction. This approach allowed a deeper understanding of the crystalline behavior in the blends, which would be difficult to achieve by performing only a visual analysis of the X-ray diffractograms CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES Fechado