Encapsulamento de óleo de café em microcápsulas de gelatina/goma arábica reticuladas por transglutaminase

Abstract

Coffee is one of the most consumed beverages in the world mainly due to its pleasant aroma when recently prepared. However, the components that are responsible to promote coffee aroma are highly volatile being lost after coffee preparation. The instant coffee production process causes great aromatic losses leading a negative impact when compared to the conventionally prepared coffee. An alternative way to recover the lost aroma is the direct incorporation of roasted coffee oil on instant coffee. The roasted coffee oil is a coffee industry by product composed by a great number of compounds including the volatiles, responsible by coffee aroma. Nevertheless, some researches have already showed the difficulty in obtaining good results due to the oil high volatility and by lipid oxidation. To minimize this losses many works have been developed using microencapsulation techniques to aroma recovery. In this way, the main objetive of the present works to produce gelatin and arabic gum microcapsules enzimatically cross-linked containing roasted coffee oil by complex coacervation technique. The microcapsules were obtained in four experimental conditions with the intent to verify the effect of the roasted coffee oil amount used and the stirring rate on the average diameter, oil recovery and encapsulation efficiency. The microcapsules obtained presented average diameter up to 21 μm with narrow size distributions. The percent recovery and encapsulation efficiency were more affected by stirring rate and oil amount than the average diameter. The results varied from 80 to 100 % (recovery) and 33 to 68% (encapsulation efficiency). Finally, the interaction of roasted coffee oil with the polymeric shell as well as the cross-linking reaction were investigated by Fourier Transform Infrared Spectroscopy (FTIR).