Stability Kinetics of Anthocyanins of Grumixama Berries ( Eugenia brasiliensis Lam.) during Thermal and Light Treatments.

Grumixama ( Eugenia brasiliensis Lam.) are red-colored fruits due to the presence of anthocyanins. In this paper, anthocyanin-rich extracts from grumixama were submitted to different temperatures and light irradiations, with the aim of investigating their stabilities. The thermal stability data indicated that a temperature range from 60 to 80 °C was critical to the stability of the anthocyanins of the grumixama extracts, with a temperature quotient value (Q 10 ) of 2.8 and activation energy (E a ) of 52.7 kJ/mol. The anthocyanin-rich extracts of grumixama fruits showed the highest stability during exposure to incandescent irradiation (50 W), followed by fluorescent radiation (10 W). The t 1/2 and k were 59.6 h and 0.012 h -1 for incandescent light, and 45.6 h and 0.015 h -1 for fluorescent light. In turn, UV irradiation (25 W) quickly degraded the anthocyanins (t 1/2 = 0.18 h and k = 3.74 h -1 ). Therefore, grumixama fruits, and their derived products, should be handled carefully to avoid high temperature (>50 °C) and UV light exposure in order to protect the anthocyanins from degradation. Furthermore, grumixama fruits showed high contents of anthocyanins that can be explored as natural dyes; for example, by food, pharmaceutical and cosmetic industries. In addition, the results of this study may contribute to the setting of processing conditions and storage conditions for grumixama-derived fruit products.