Binary Phase Behavior of 1,3-Distearoyl-2-oleoyl-sn-glycerol (SOS) and Trilaurin (LLL)

Abstract

This paper reports the precise analysis of the eutectic mixing behavior of 1,3-distearoyl-2-oleoyl-sn-glycerol (SOS) and trilaurin (LLL), as a typical model case of the mixture of cocoa butter (CB) and cocoa butter substitute (CBS). SOS was mixed with LLL at several mass fractions of LLL (wLLL); the mixtures obtained were analyzed for polymorphic phase behavior using differential scanning calorimetry (DSC) and synchrotron radiation X-ray diffractometry (SR-XRD). In melt crystallization with constant-rate cooling, SOS and LLL formed eutectics in their metastable polymorphs, allowing the occurrence of a compatible solid solution at wLLL ≥ 0.925. With subsequent heating, the resultant crystals transformed toward more stable polymorphs, then melted in a eutectic manner. For mixtures aged at 25 °C after melt crystallization, eutectics were found in the extended wLLL region, even at wLLL = 0.975. These results indicate that phase separation between SOS and LLL progressed in their solid solution under stabilization. The crystal growth of the separated SOS fraction may cause fat-bloom formation in compound chocolate containing CB and CBS. To solve this problem, the development of retardation techniques against phase separation is expected.

Solid phase behavior of mixture systems based on tripalmitoyl glycerol and monounsaturated triacylglycerols forming a molecular compound

“…Understanding the mixing properties of TAGs in their metastable polymorphs is of practical value since obtaining specific forms and preserving their shelf life is the aim in many industrial applications, such as oil fractionation or fat structuring. 23,24 In the present work, the kinetic phase behavior of PPP/PPO mixtures was evaluated during a thermal process consisting of cooling from the melt to −30 °C and next heating at a rate of 2 °C min −1 .…”

Interactive Polymorphic Crystallization Behavior in Eutectic Triacylglycerol Mixtures Containing Molecular Compound Crystals

“…This concave-shaped line is typical of eutectic mixtures and is referred to as the liquidus line . Such eutectic relationships were previously reported for TAG mixtures of POP/ rac -OOP, LLL/SOS, and others. As for the melting of MC SOS/OSO β-2, the horizontal and straight solid line connecting the corresponding symbols over the W SOS/OSO = 0.50–0.80 range can be regarded as the solidus line, while the curved solid line ascending upward to the right between W SOS/OSO = 0.10 ( T p = 32.4 °C) and 0.50 ( T p = 34.5 °C) can be regarded as the solvus line; these lines are also characteristic of eutectic mixtures.…”