A heat transfer model aided by experimental research for oleogels during their scale-up

Abstract: The search for new and improved vegetable oil structuring strategies has been progressing since the discovery of the deleterious impacts of partially hydrogenated fats. Although molecular gelators has been proven to be an alternative to traditional hydrogenation methods, efforts are needed to optimize the technology suitable for industrial requirements. A major constraint during the fabrication of oleogels is to achieve consistency in physical properties during scale-up. Experiments showed that gelation fails to occur when larger volumes were prepared based on the minimum gelation concentration (MGC) of gelators, determined using the smallest oil volume (1 mL), a general laboratory practice. This observation was consistent with the select molecular gelators used in this study; sorbitol dioctanoate, mannitol dioctanoate, and 12-hydroxystearic acid. To understand this behavior, a mathematical model was developed since gelator network propagation is governed by the cooling rate. The model indicates that maintenance of a minimal thermal gradient via uniform heat dissipation and gelation time is necessary to achieve homogeneous gel propagation across the vial. With these predictions, we hypothesized and confirmed that oleogels with constant surface area-to-volume ratio could result in identical gelation times and consistent physical properties (MGC, melting temperature, melting enthalpy, yield stress, solid phase content, and oil binding capacity) during scale-up.