Encapsulation of Cherry Laurel (Prunus laurocerasus) Extracts via Spray and Freeze Drying: Effects on Bioactive Compounds, Volatile Profile, and Physicochemical Properties of the Powder

Abstract

This study evaluated the encapsulation of cherry laurel (Prunus laurocerasus) fruit extracts by spray drying and freeze-drying using gum arabic, maltodextrin, and their mixture. Powder yields ranged from 63.57% (MD165) to 98.33% (MD-L), with freeze-dried samples showing higher recovery. Encapsulation efficiencies varied between 23.89% and 83.82%, highest in gum arabic-coated powders. Moisture contents ranged from 2.85% to 7.55%, with water activity below 0.32 for all samples. The highest total phenolic content (469.14 mg GAE/100 g) and antioxidant capacity (514.39 mg TE/100 g) were observed in freeze-dried samples. Thirty-three volatile compounds were identified by GC–MS; alcohols and hydrocarbons were found at higher levels in freeze-dried samples, whereas ketones were primarily formed in spray-dried powders. PCA and heatmap analyses confirmed that drying method and coating material significantly affected volatile profiles. PCA score plots clearly separated freeze-dried and spray-dried groups, with PC1 and PC2 explaining over 60% of total variance. Heatmap clustering showed gum arabic improved retention of acetic acid and esters, while maltodextrin preserved aldehydes like benzaldehyde. SEM images revealed smooth, spherical particles in spray-dried samples and porous, fractured structures in freeze-dried powders. Overall, freeze-drying combined with gum arabic achieved the best retention of bioactive and volatile compounds, while spray drying with maltodextrin produced powders with good morphology and flowability. These results highlight how encapsulation method and wall material selection optimize the functional quality of cherry laurel powders for use in value-added functional food products.