Microencapsulation of <em>Opuntia Ficus-indica</em> Betacyanin by Lyophilization and Effect on Stability and Antioxidant Activity
Keywords:
tara gum, soy protein isolate, betacyanin, stability, antioxidant capacityAbstract
Introduction: Betacyanin is a natural pigment offering health benefits due to its antioxidant, anticancer, antipyretic and antibacterial activities.
Objective: To evaluate the stability and antioxidant capacity of betacyanins present in Opuntia ficus-indica pulp subjected to a microencapsulation process.
Methods: Microencapsulation of Opuntia ficus-indica pulp was performed by freeze-drying and encapsulation with concentrations of tara gum and soy protein isolate. The stability by spectroscopy technique and antioxidant capacity by 2,2-diphenyl-1-picrylhydrazyl free radical inhibition of the betacyanins present in the pulp were evaluated.
Results: Tara gum at 0.1 % w/v increased the half-life of betacyanins 1.19 times more than a sample without encapsulant and soy protein isolate at 1.0 % w/v increased the half-life of betacyanins 1.10 times. Furthermore, the antioxidant activity was observed to be higher for the microcapsules compared to the unencapsulated pigment and 41 % inhibition of 1,1-diphenyl-2-picrylhydrazyl was obtained with 0.1 % w/v tara gum. The external microstructure of the encapsulated soy protein isolate was smooth, not granular, and in the case of encapsulated with tara gum it was irregular. Statistical analysis indicated that the exposure time and the concentration of the wall material has a significant effect on the betacyanin concentration.
Conclusions: The technique of betacyanin microencapsulation by freeze-drying with tara gum and soy protein isolate has a positive effect on the properties of betacyanin and could be used in the food and pharmaceutical industry.
