Investigating the stability of encapsulated phycocyanin at acidic conditions using whey protein isolate as a wall material

Abstract

Phycocyanin is a natural blue pigment derived from cyanobacteria and is usually used as a food colorant. However, phycocyanin is unstable in acidic conditions. In this research, we investigated the effect of encapsulation of phycocyanin using whey protein isolate (WPI) as the wall material to improve the stability at various pH and storage periods. Phycocyanin was extracted from dried Spirulina using a cold maceration method and subsequently encapsulated with 0.25, 0.50, 0.75, and 1.00% of WPI. Results showed that microencapsulation with WPI significantly reduced phycocyanin degradation compared to the control sample under acidic conditions ranging from pH 3.0 to 6.0. The control sample had 81.51±0.70% concentration degradation at pH 3.0. While 0.50% WPI had 50.48±1.27% degradation. Furthermore, microencapsulation exhibited a protective effect against phycocyanin degradation for 10 days of storage at 4°C in pH 4.0 and 5.0. Samples with 1.00% WPI demonstrated a lower concentration degradation each day compared to the control. WPI also demonstrated its efficacy in delaying concentration degradation at pH 4.0 and 5.0 for 8 to 10 days. Our result concluded that microencapsulation using WPI could improve the stability of phycocyanin in acidic conditions and storage periods.