Production and characterization of bioaerogel particles from strawberries and their application as oil structuring ingredient in low-saturated fat cocoa spreads

Bioaerogels bear high potential in the development of fat-replacers, due to their oil-structuring capacity. However, current aerogel preparation from biopolymeric gels requires a complex and resource-intensive process, which might limit their adoption as oil-structuring food ingredients. A simpler and more sustainable process to produce bioaerogels could be based on their direct preparation from plant tissues rather than from biopolymeric gels. Similar to gels, also in plant tissues, water is embedded into a fibrous network, so water removal while preserving tissue structure can lead to porous materials with bioaerogel properties, avoiding biopolymer extraction, purification and sol-gel steps. This work aimed to demonstrate the potential of tissue-derived aerogels as fat-replacement ingredients in cocoa spreads. To this aim, strawberry pulp was subjected to water-to-ethanol exchange, wet milling, and supercritical-CO2-drying. This process resulted in bioaerogel particles with high mesopore volume (0.69 cm3 g−1), low density (0.03 g cm−3) and high surface area (233 m2 g−1). The particles showed an oil absorption capacity higher than 90%, leading to a self-standing material retaining 80% oil upon centrifugation. Strawberry bioaerogel particles were used to formulate low-saturated fat cocoa spreads. A bioaerogel particle amount as low as 0.2–0.4 g/100 gspread was enough to obtain spreads covering a wide range of rheological and spreadability properties. Preliminary techno-economic assessment demonstrated the technical and economic feasibility of the proposed process to produce bioaerogels from plant tissues intended as fat-replacement ingredients.