Dimyristoylphosphoethanolamine Addition During Chocolate Manufacture Promotes Proper Tempering under Simple Cooling Conditions without Shear

Abstract

We report a practical application of using 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) to temper dark chocolate. Building upon prior research where 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) was used to direct CB crystallization into the desired Form V polymorph, we investigated whether DMPE could achieve superior results without the structural defects observed with DMPC-tempered chocolate. Chocolate samples containing 0.1 wt % DMPE were prepared and compared to chocolates tempered with DMPC, as well as commercially tempered and statically cooled controls. Small-angle X-ray scattering (SAXS) revealed that the DMPE addition induced the formation of the Form V polymorph, with no detectable amounts of Form IV polymorph, which is often associated with reduced shelf life and fat bloom in chocolate products. Unlike the DMPC-tempered samples, the DMPE chocolate exhibited no blooming or structural defects such as cracks upon prolonged storage. Small-angle neutron scattering (SANS) experiments showed no evidence of micelle formation by DMPE, suggesting a mechanism distinct from that of DMPC. Fourier transform infrared (FTIR) spectroscopy and attenuated total reflectance imaging indicated no significant chemical interactions between DMPE and the main triacylglycerol (TAG) in CB, 1-palmitoyl-2-oleoyl-3-stearoyl-sn-glycerol (POS). We propose that DMPE acts as a unique tempering particle, which facilitates the formation of the stable Form V polymorph and the correct chocolate microstructure through physical interactions with the crystallizing TAGs on its surface. Moreover, DMPE addition also prevents localized material contraction and bloom development due to the absence of induced lattice strain. Crystallization kinetics of the cocoa butter component of chocolate shows an acceleration of crystallization induced by DMPE at 28 °C, relative to both the native refined cocoa butter and the refined cocoa butter containing DMPC. Polarized light micrographs supported this observation. Isolated seed crystals from cocoa butter showed an enrichment in POS and POP in DMPE chocolate, and a characteristic Form V polymorphism for these seeds, in contrast to both native refined cocoa butter and refined cocoa butter with DMPC, where Form IV was identified at the onset of crystallization. The addition of DMPE to chocolate simplifies the tempering process, potentially reducing production costs and energy consumption, and enhancing the quality and stability of the final product, benefiting both artisanal chocolatiers and large-scale manufacturers.