Design Optimization of emulsions based on fine fraction of durum wheat oil cake: Structural and rheological properties

The production and stabilization of food-grade emulsions by using plant-derived particles have gained great attention due to the increasing demand for sustainable and plant-based alternatives. This study aims to explore the feasibility of using durum wheat oil and durum wheat oil cake, micronized and dry-fractioned (ff-DWOC), with no further chemical treatments, to produce emulsion gels. The emulsions obtained through a design of experiments (DoE) for mixture were analysed for their textural properties. The results of the textural parameters were subsequently modelled according to quadratic model. The nine emulsions were then characterized for their creaming index during 14 days of storage. The three most promising emulsions in terms of textural properties and creaming stability, were then characterized for their microstructure and rheological properties. The formulations with higher proportions of ff-DWOC and durum wheat oil affected the textural parameters, minimizing syneresis phenomena and serum phase separation, then resulting in excellent creaming stability over 14 days of storage. The emulsions containing 25% of ff-DWOC and 20 and 30% of oil displayed homogenous distribution of the oil droplets and a well-developed network, while emulsion with 15% ff-DWOC and 40% of oil (E7) showed a dense and compact continuous phase. According to the rheological results, the emulsions mentioned above exhibited a gel-like structures with G' > G''. E7 had the highest G ' and G '' values, indicating a marked solid-like behaviour. These emulsions demonstrated compelling attributes, positioning them as strong contenders for incorporation into the food industry as innovative ingredients.