Soft-Drinks Prepared with Pulp, Ultrafiltrated and Nanofiltrated Purple Cactus Pear Microparticles: Betalains Stability

摘要

The aim of this research was to determine the betalain stability in soft-drinks prepared with microparticles from purple cactus pear pulp (P), ultrafiltrated (UF) and nanofiltrated extracts (NF). Capsul (C) and K-4484 (K) were used as encapsulating agents. The microparticles of the six systems (P-C, P-K, UF-C, UF-K, NF-C and NF-K) were obtained by spray drying, and characterized. Soft-drinks were formulated with microparticles of each system. The soft-drinks were stored (30 days, 4-5°C) and kept indark. The betalains stability, the degradation rate constants, and the colour change index (AE) were measured. The results were analyzed by ANOVA and Tukey. The betacyanins (BE)) and betaxanthins content (IE) of microparticles, ranged between 0.312-0.361mg BE/g and from 0.140-0.160 mg IE/g for the systems studied. High encapsulation efficiency (EE) for betacyanins and betaxanthins, 99.1-99.5 and 98.3-99.7%, respectively, was observed. The degradation rate in the soft-drinks, for betacyanins as for betaxanthins, followed a first-order kinetic, showing rate constants among (1.8-3.5) x 10"5 min"1 and (1.1-2.2) x 10"2 min"1, respectively. The beverage prepared with the P-K microparticles showed the higher stability, with a constant of 1.8 x 10"5 and 1.1 x10s min"1, for betacyanins and betaxanthins, respectively. Besides, this formulation showed also the lower colour change index during the storage period. The betalains from microparticles prepared with cactus pear pulp showed higher stability than those from ultra or nanofiltrated extracts.