Ultrasound-assisted extraction of oilseeds-sustainability processes to obtain traditional and non-traditional food ingredients: A review.

Oilseeds are sources of not only major compounds such as oil and meal but also of bioactive compounds. Their conventional extraction is related to long extraction time, large non-renewable solvent consumption, high temperature, and therefore, high energy consumption. Ultrasound-assisted extraction (UAE) has emerged as a new and green technology, which can accelerate and/or improve the extraction process of these compounds. Moreover, the possibility of using renewable solvents in the UAE enhances its application and allows obtaining both extracted and remaining products more compatible with current human consumption requirements. This article examines the mechanisms, concepts, and factors that impact oilseeds' UAE with an emphasis on the extraction yield and quality of oil, meal, and bioactive compounds. Furthermore, the effects of combining UAE with other technologies are addressed. Gaps detected in the analyzed literature about oilseed treatment and quality and properties of products, in addition to perspectives about their uses as food ingredients, are also included. Moreover, it highlights the need for increasing research on process scalability, on environmental and economic impacts of the whole process, and on the phenomenological description about the effect of process variables on extraction performances, which will be a key tool for process design, optimization, and control. Understanding ultrasound processing techniques for the extraction of different compounds from oilseeds will serve as useful information for fats and oils and meal scientists in academia and industry to explore the possibility of employing this sustainable approach during the extraction treatment of various crops.

Effects of cooling temperature profiles on the monoglycerides oleogel properties: A rheo-microscopy study.

The oleogelation process has become in a great interest area for the food sector. The aim of this study was to understand the effect of cooling temperature profiles (CTP) applied during oleogelation on microstructure and some macroscopic properties of monoglycerides (MG) oleogels. To this purpose, oleogels from MG and high oleic sunflower oil were produced using programed CTP corresponding to the actual temperature evolution of the samples when they are left at rest to progress in a specific ambient temperature (AT). In order to evaluate the crystal formation during the gelation process, a torsional rheometer equipped with a rheo-microscope (RM) module was used. This allowed us to carry out simultaneously rheological measurements and record images of the gels during their formation process. Overall, microstructural characteristics were determined: fractions of crystalline material and oil, crystal length and shape, the Avrami index, and the fractal dimension. Although crystal formation took place during a similar range of temperatures (~55-46 °C), significant morphological differences in the distribution and size of crystal and aggregates were observed depending on the applied CTP, and the area occupied by the crystals and oil phase did not depend on CTP used. RM images were useful to follow the kinetics of crystallization as well as to identify a more restricted time domain in the rheological behavior allowing to find more accurate Avrami index values. Furthermore, the analysis of RM images turned out to be an efficient approach to obtain accurate measurements of the fractal dimension. High fractal dimension values were associated with gels exhibiting high number of homogeneous small crystals. Oleogels composed by this network generated a material with high capacity to retain oil. A weak-link regime approach applied to the dynamic systems was appropriate to describe the relationship between the elastic modulus and the crystal formation during the oleogels structuration. In conclusion, these findings may serve to the food industry to achieve a better understanding of the oleogelation process that allows it to control the quality of obtained oleogels, which could be utilized to replace and/or reduce the trans and saturated fats in food formulations.