From biorefinery of microalgal biomass to vacuum impregnation of fruit. A multidisciplinary strategy to develop innovative food with increased nutritional properties

A multi-disciplinary approach based on the biorefinery of microalgae biomass (Chlorella sorokiniana) to remove the lipid fraction responsible of the green color and the ‘fishy’ aroma and vacuum impregnation technique to create innovative apple snacks with improved nutritional properties has been investigated. The pressure (150 mbar – 650 mbar), vacuum time (1–7 min) and relaxation time (3–13 min) were modulated by using a Box-Behnken experimental design. The filling of apple pores occurred with a maximum gaining weight of 19.5% and a reduction of porosity fraction from 15.32% to less than 5% but only the pressure and relaxation time significantly affect the level of impregnation. While the texture did not show any difference compared to fresh apples, the color of impregnated apple was affected with minor change in comparison. Industrial relevance: Results positively fuel the food chain sustainability by proposing multidisciplinary tools that combine microalgae cultivation, biorefinery and vacuum impregnation processing capable to improve the nutritional quality of fruit products. Biorefinery is proved to be an essential technology for fractionating chemical compounds from raw microalgae and improving their potential use in food industry as source of nutrient by eliminating some undesired components such as lipid fractions related to the fishy aroma. Finally, the obtained results may be used as basic protocols for the optimization of VI treatments aiming to enrich fruit product of proteins and micronutrients.