UNIVERSIDADE TECNOLÓGICA FEDERAL DO PARANÁ COORDENAÇÃO DE ALIMENTOS CURSO SUPERIOR DE TECNOLOGIA EM ALIMENTOS

VEIGA, Camila Carolina. Encapsulation of roasted coffee oil in microcapsules of gelatin and gum arabic cross-linked by transglutaminase. 2014. 44 f. Trabalho de Conclusão de Curso (Tecnologia em Alimentos) Universidade Tecnológica Federal do Paraná. Campo Mourão, 2014. 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 byproduct 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). Key-words: roasted coffee oil, microcapsules, complex coacervation, transglutaminase. LISTA DE ILUSTRAÇÕES Figura 1 Exemplo da coacervação complexa (a) dispersão do recheio em solução de gelatina e goma arábica, (b) inicio da coacervação dos polímeros após a adição do agente de coacervação (redução do pH), (c) término da coacervação, (d) formação da casca reticulada na interface entre o óleo e a fase aquosa . 17 Figura 2 – Molécula de gelatina. 18 Figura 3 Compostos voláteis encontrados no óleo de café torrado. 19 Figura 4 Gráfico referente a curva de calibração . 24 Figura 5 Resultado do teste de Turvamento/Precipitação. 27 Figura 6 Micrografias das microcápsulas obtidas nas seguintes condições (a) Exp. 1: 350 RPM e 0,8250 g óleo; (b) Exp. 2: 350 RPM e 0,4125 g óleo; (c) Exp. 3: 500 RPM e 0,4125 g óleo; (d) Exp. 4: 500 RPM e 0,8250 g óleo. 30 Figura 7 Distribuição de tamanho das microcápsulas (a) Exp. 1: 350 RPM e 0,8250 g óleo; (b) Exp. 2: 350 RPM e 0,4125 g óleo; (c) Exp. 3: 500 RPM e 0,4125 g óleo; (d) Exp. 4: 500 RPM e 0,8250 g óleo. 31 Figura 8 Espectros de Infravermelho dos componentes puros utilizados na preparação das microcápsulas. 33 Figura 9 Espectros de Infravermelho das microcápsulas, mistura física dos componentes e óleo do café torrado. 35