Monitoring Solidification and Storage Stability of Well-Tempered Chocolates Obtained Through Various Pre-crystallization Techniques

Seeding (SD) is a chocolate pre-crystallization technique (PT) that serves as a more efficient alternative to conventional tempering (CT), yielding equivalent characteristics within the category of well-tempered chocolate. However, variability in macroscopic quality attributes may persist. This study aims to discern variations among well-tempered chocolates obtained through various configurations of PTs: CT, SD, and a combination of both (CS), focusing on changes during pre-crystallization, solidification, and subsequent storage at 20 °C. The increased yield stress (> 1.2 Pa) of pre-crystallized chocolate in comparison to non-tempered chocolate, melting peak alignment with the β V cocoa butter (CB) polymorph (29–34 °C) after 6-h storage and fat-bloom resistance up to 9 months, affirm the successful integration of different PTs within the well-tempered chocolate category. However, distinct melt⟶2L⟶3L lamellar packing transition mechanisms for each PT were identified in the first hour of solidification through synchrotron-assisted time-resolved X-ray scattering. Varied polymorphic transition and microstructural growth kinetics were also observed over 28 days of storage, as indicated by melting profiles. CS chocolate exhibited limited transition, remaining stable as β V . In contrast, CT and SD underwent rapid microstructural growth with an indication of a small fraction of CB polymorph transitioning to the undesirable β VI CB polymorph (> 34 °C), linked to fat bloom development. Surface topography observation through accelerated shelf-life test at 26 °C over 9 months marked the link with CB crystal microstructural growth, with fat bloom occurring faster on SD chocolate, then CT chocolate, and finally the CS chocolate. These findings highlight the potential to tailor crystallization kinetics by adapting PT to achieve improved product qualities, such as extended fat-bloom resistance or accelerated solidification while remaining within the well-tempered category.