ROASTED COFFEE OIL MICROPARTICLES: COMPARISON BETWEEN PRODUCTS OBTAINED BY SPRAY DRYING AND COMPLEX COACERVATION

Roasted coffee oil, a co-product of the soluble coffee industry, could be used in several products as a flavoring agent and to deliver bioactive compounds. Undesirable changes as oxidation may occur if the oil is directly exposed to the environment, so the use of microencapsulation can minimize the loss of nutritional quality and sensory characteristics. The aim of this research was to produce and compare microparticles of roasted coffee oil obtained by spray drying (MSD) and complex coacervation (MCC) techniques regarding their characteristics and sensory impact. Gelatin and gum arabic (for MCC) and starch (for MSD) were used as wall material. The microparticles were applied in soluble coffee, and the intensity of aroma during coffee brew preparation and preference between beverages were also compared. Stable emulsions were obtained by ultrasound-assisted emulsification. High encapsulation efficiency (above 80% for both methods) was observed, and both microparticles had a continuous wall and similar glass transition temperature (49°C). MSD microparticles presented lower oil content (10.2%); lower surface oil content (1.62%); higher interaction with water observed by high values of water activity, moisture, and solubility); yellowish and lighter color; and more spherical than the MCC. MCC partciles were characterized by higher oil content (42.8%) and encapsulation efficiency (91%); higher bulk density; larger diameter (125 μm); and more saturated color. The sensory evaluation by Time-intensity method showed that the microparticles conferred coffee aroma when dissolved in water; the perception of coffee aroma intensity during the preparation of a soluble coffee using MSD and MCC (standardized by oil content) was similar, but MCC beverage was preferred. In summary, both types of roasted coffee oil microparticles presented suitable stability and physical characteristics and can provide coffee aroma, with potential for application in diverse products.