Effect of SatSatSat and SatOSat on crystallization of model fat blends

Abstract

In this study, the crystallization and melting properties of six different fat blends with the same saturated fat content (30%) but with a varying content of trisaturated and disaturated triacylglycerols were investigated using pulsed NMR, DSC and polarized light microscopy. Blends were either palmitic (P) or stearic (S) based, and were combinations of SatSatSat-rich (Sat = saturated) and SatOSat-rich (O = oleic) vegetable oils with high-oleic sunflower oil. The DSC results suggested that PPP forms mixed crystals with POP, leading to a better seeding of the crystallization process than did SSS with SOS. Some blends showed a two-step crystallization, which can be explained by polymorphism. Stop-and-return DSC results suggested an initial crystallization into an unstable polymorph followed by polymorphic transformation during the crystallization for those blends with significant amounts of SatSatSat. Polymorphic transformation was not seen for the blends with low SatSatSat. However, the microstructure of such blends changed dramatically during storage, while the microstructure of the blends with the higher SatSatSat content did not.

Effect of TAG composition on the crystallization behaviour of model fat blends with the same saturated fat content

“…At longer isothermal times the low melting peak and exothermal peak disappeared and the high melting peak was the only remaining peak. Based on Vereecken et al (2009), this behaviour might be explained by a polymorphic transition (as indicated in Fig. 6), but to be completely sure about this, X-ray diffraction is needed.…”

“…In a previous study of our group (Vereecken et al, 2009), the explanation of the mechanism of the two-step crystallization was obtained by looking at the peak maxima in the melting curves obtained from the stop-and-return experiments. Indeed, the peak maxima of the melting curves at different isothermal times will shift when there is a change of the polymorphic form or when there is fractional crystallization.…”

“…Therefore, the objective of this research was focused between these two types of studies by investigating blends of natural fats and oils from a TAG point of view. This kind of research has already been carried out by the authors' group (Vereecken, Foubert, Smith, & Dewettinck, 2009), using fat blends all having a saturated fat content of 30%.…”

Effect of the distribution of saturated fatty acids in the melting and crystallization profiles of high-oleic high-stearic oils

“…Thus, the complex behavior of some fats in terms of crystallization, polymorphic transformation, crystal morphology and aggregation depends directly on the properties of their TAGs (Foubert et al, 2006;Foubert et al, 2007, De Graef et al, 2012. The effects of different tristearin (StStSt) and StOSt ratios in TAGs on the crystallization behavior of different fat blends with the same fatty acid composition has been studied (Vereecken et al, 2009). Accordingly, StStSt does not appear to exert a seeding effect on the other TAGs present in the TAG mixture, unlike fats containing tripalmitin and dipalmitoyl glycerol.…”

Thermodynamic Modeling of Multi‐phase Solid–Liquid Equilibria in Industrial‐Grade Oils and Fats

“…To decrease the complexity of the oil (and thereby increase the calculation speed), the number of TAG was reduced by lumping them into groups, using two criteria: First, one TAG from every TAG-category (see Table 1) should be present in the composition. This was desirable in order to capture the specific features linked to the various TAG categories [23,24]. Secondly, if a TAG comprised less than 1.5 % of the oil, the TAG was removed and the amount added to the most similar TAG included in the Although up to 3 % diacylglycerols were allowed in the oils, these were disregarded in the oil compositions.…”