Physical and bloom stability of low-saturation chocolates with oleogels based on different gelation mechanisms

Oleogels are being increasingly used as solid fat alternatives in food. Low-saturation chocolates (referring to chocolates with low content of saturated fat) were prepared by replacing 50 g/100 g cocoa butter with three oleogels (monoglyceric stearate, beta-sitosterol + lecithin, and ethyl cellulose oleogel), which were fabricated through different gelation mechanisms (crystalline particles, self-assembly fibers, and polymeric strands, respectively). The physical characteristics and microstructures of oleogel-based chocolates during isothermal (4 and 20 degrees C) and fluctuating (20 degrees C for 17 h and 29 degrees C for 7 h) storage conditions were evaluated for 60 d, including whiteness index, hardness, thermal behavior, and crystal polymorph. We found that oleogel-based chocolates exhibited bloom delaying property through assessing whiteness index and polarized light microscopy images, especially under fluctuating temperatures. Among three oleogel-based chocolates, beta-sitosterol + lecithin oleogel-based chocolate maintained the lowest whiteness index. Differential scanning calorimetry and Xray diffraction revealed that oleogel-based chocolates showed sustained thermal and polymorphic stability throughout the storage period. Crystal morphology of fat phase observed by polarized light microscopy confirmed the existence of stable beta crystals in oleogel-based chocolates. Collectively, oleogel-based chocolates not only lower the degree of saturation but also exhibit high physical and bloom stability during isothermal and fluctuating storage.

Automated summary

Oleogel-based chocolates with low saturation levels, particularly those made with beta-sitosterol + lecithin oleogel, showed delayed blooming properties and maintained stable thermal and polymorphic characteristics throughout the storage period.