A deracemization technique using periodic temperature fluctuations on a conglomerate forming system undergoing a swift racemization in solution is demonstrated. The method uses heating and cooling periods of the suspension in order to create cycles of partial dissolution of the crystal phase followed by crystal regrowth: this enables symmetry breaking in the solid phase. The technique is an effective, simple, and cheap operation, and can promote understanding of the effects of dissolution and recrystallization on chiral symmetry breaking in the solid phase. The heating period leads to the decrease of the size of crystals and the destruction of small crystals; the surviving crystals can then grow during the cooling period. A succession of such cycles allows the autocatalytic transformation from a racemic suspension into pure enantiomer, with an enantiomeric excess (ee) > 99% within a few days. The results demonstrate a possible mechanism for the emergence of homochirality of molecules of biological significance on Earth.

Cocoa butter equivalent (CBE) was produced from a blend of mango kernel fat (MKF) and palm oil mid-fraction (PMF). Five fat blends with different ratios of MKF/PMF (90/10, 80/20, 70/30, 60/40 and 50/50 (%wt)) and pure MKF, PMF and cocoa butter (CB) were characterized. Similar to CB, all fat blends contained palmitic (P), stearic (S) and oleic (O) acids as the main fatty acid components. The triglyceride compositions of all blends were significantly different from CB. However, blend 80/20, which contained higher content of SOS, similar content of POP and lower content of POS compared to CB, exhibited a slip melting point, crystallization and melting behavior most similar to CB and hence it was recommended as CBE. The chosen CBE was then mixed with CB in a ratio of 1:5.64 (wt), mimicking that of typical dark chocolate where 5 % of CBE is added to the finished product. The crystallization behavior, the crystal morphology and bloom behavior of the mixture was investigated and was found to be not significantly different from CB.

An improved process for the deracemization of a racemic conglomerate suspension of enantiomorphs has been created based on principles developed in an earlier method using temperature fluctuations. The method consists of circulating the suspension between two vessels, each controlled at a specific temperature in order to make the process more effective and faster to achieve a homochiral solid state. Crystals in the suspension were partially dissolved in the hot vessel, and the remaining crystals were regrown in the cold vessel. The crystals in the cold vessel have a longer residence time than those in the hot vessel to allow more time for the crystal growth process. The results show that complete deracemization can be achieved via this process far more rapidly than by using the previous temperature cycling (one-vessel) process. Moreover, the new process could easily be scaled up to an industrial scale. The current process can be an effective alternative to currently used enantiopurification methods, with simple processing implementation and low cost.

The effect of a crystal's growth rate history on the current growth behavior was investigated as a cause of crystal growth rate dispersion (GRD), which is a significant problem in crystallizer design and modeling. The solute used in the experiments was sucrose, a high production commodity still crystallized mainly in batch crystallizers, where GRD is most significant. The results show that the growth history of a crystal has a significant effect on the crystal growth rate of that crystal. In particular, a history of rapid crystal growth under high supersaturation causes a roughening of the crystal surface, apparently due to poor surface integration, and subsequent growth occurs at lower rates than would be expected without this growth history. The process of crystal surface healing occurs at low levels of supersaturation over periods of several hours of growth and results in the crystals again reaching their normal growth rate levels. The growth layer formed to heal the surface of the crystal is greater than 100 µm thickness, far in excess of the scale of the apparent surface roughness. This study shows that the crystal perfection near the growing surface of the crystal may be a more significant indicator of crystal growth rate than the overall average perfection in the entire crystal.

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