Microencapsulation by spray drying of carotenoid rich extract obtained from guarana peel (Paullinia cupana)

Guarana is a species native from Amazon region, brazilian, known for its stimulating and medicinal properties. The reduction and use of waste generated by industries are a current tendency. Guarana peel is a source of carotenoids with great potential for exploration and application in the food industry. Thus, the aim of this study was to encapsulate by spray drying the extract rich in carotenoids obtained from guarana peels evaluating the efficiency of the process and the stability of the particles. The extraction of carotenoids from guarana peels was carried out at 50 °C for 4 hours, considering the ratio of 1:10 (w/v) peel: absolute ethanol. Using a temperature of 100 °C, three formulations were produced by varying the proportions extracts: gum arabic solution (1: 2, 1: 3, 1: 4, v / v) in triplicate, totaling nine products. The content of total carotenoids, moisture, water activity and color parameters, L, a * and b *, were analyzed every 15 days during three months. The total carotenoid content of the free extract was also analyzed in this period. The particles and the free extract were stored at 25 °C and 33% relative humidity. The particles obtained with the 1: 2 formulation (extract: gum arabic solution, v / v) had a higher carotenoid content, reducing from 97.3 to 62.7 μg / g, while the formulations 1: 3 and 1: 4 (extract: gum arabic solution, v / v) presented a reduction from 60.92 to 40.44 μg / g and 40.66 to 26.41 μg / g, respectively. The results showed that after complete monitoring, the carotenoid content reduced 36, 34, 35 and 44% in the formulations 1: 2, 1: 3, 1: 4 and the free extract, respectively. The moisture and water activity of the particles increased significantly after 15 days and proceeded with small oscillations during storage for all formulations. The particles of the 1: 2 formulation had a stronger yellow-red color than the others. In general, the color parameters showed small variations during storage. The results showed that spray drying is an efficient encapsulation technique to guarantee stability during this period for carotenoids, unstable bioactive compounds, reducing the degradation and increasing its applicability.