Effect of temperature on the stability of Cosmos bippinatus pigments encapsulated by freeze-drying

Abstract

Color is one of the most important attributes, especially in the food industry. Currently, alternative sources are being sought to obtain plant pigments, due to their bioactive properties. Cosmos bipinnatus is a plant known for its high content of anthocyanins, molecules that give it color and have antioxidant properties. However, once they are extracted from the plant matrix they present instability problems, which is why their protection is necessary. In this work, the extraction of C. bipinnatus pigments was carried out, which were encapsulated by freeze-drying as a protection method. During encapsulation, two wall materials (gum arabic (GA) and maltodextrin (M)) were evaluated alone and in combination. The microencapsulated were characterized to determine the encapsulation efficiency and performance. In addition, pigment release kinetics were carried out at three temperatures (4°C, 25°C, and 65°C) to find the conditions at which the pigments are best preserved. It was found that encapsulation by freeze-drying is an efficient method, that the wall materials work better when combined, and that the plant pigments obtained from C. bipinnatus (PPCb) are better preserved at temperatures below 25°C.