Oil migration in chocolate: A case of non-Fickian diffusion

Effect of pre-crystallization process and solid particle addition on microstructure in chocolate model systems

“…Additional quality defects associated with fat migration are shell softening, filling hardening, and sensory deterioration (Ghosh, Ziegler, & Anantheswaran, 2002;Talbot, 1989;Ziegleder, 1997). The fat migration phenomenon has been extensively studied and several theories of its underlying mechanisms have been proposed, based on molecular diffusion (Galdámez, Szlachetka, Duda, & Ziegler 2009;Ghosh et al, 2002;Miquel, Carli, Couzens, Wille, & Hall, 2001;Ziegleder, Moser, & Geiger-Greguska, 1996a,b) or capillary flow (Aguilera, Michel, & Mayor, 2004;Marty, Baker, Dibildox-Alvarado, Rodrigues, & Marangoni, 2005) as the main hypothesis. However, so far neither of these theories has succeeded in fully explaining fat bloom or in identifying ways to prevent it.…”

Diffusion, counter-diffusion and lipid phase changes occurring during oil migration in model confectionery systems

“…Non-Fickian diffusion models, which take into account the changes in chocolate structure by coupling molecular diffusion with the lipid phase behavior, can effectively describe the oil migration process (Ziegler et al, 2004;Galdámez et al, 2009). Recently, McCarthy and McCarthy (2008) described oil migration using a diffusion model while also accounting for the interfacial phenomena involved, indicating that oil migration is a diffusiondominated transport process.…”

Effect of shell microstructure on oil migration and fat bloom development in model pralines

“…Unfortunately, we did not characterise the relative volumes of shell and filling to confirm this hypothesis. However, swelling due to oil migration has been observed previously of CB matrixes in contact with liquid fat (Dahlenborg et al, 2011;Deka et al, 2006;Galdamez et al, 2009;Guiheneuf et al, 1997;Svanberg, Loren, & Ahrne, 2012). When storing white chocolate against a hazelnut filling at a cycled temperatures, Dahlenborg et al (2011) could observe a volume increase in the shells of approximately 40% after 36 weeks.…”

“…When storing white chocolate against a hazelnut filling at a cycled temperatures, Dahlenborg et al (2011) could observe a volume increase in the shells of approximately 40% after 36 weeks. Further, Galdamez et al (2009) observed an increase of approximately 25% in chocolate shell weight after storage against hazelnut oil at 23 8C for one week, which corresponded to an increase of 61 wt% regarding the fat phase of the shell. We suggest that a likely scenario for a swelling could be crystal growth in the CB matrix due to Ostwald ripening and re-crystallisation into more stable polymorphs.…”

“…It has been suggested that non-fat particles such as CP and sugar retard the oil migration rate, mainly due to their contribution to increase of the tortuosity of the diffusion path for migrating lipids (Galdamez, Szlachetka, Duda, & Ziegler, 2009). However, our observations show that after 12 weeks storage at both storage temperatures the amount of migrated BrTAGs had increased for samples containing CP, dCP and sugar compared to the seeded CB samples.…”