Effect ofSpirulina(Arthrospira platensis) microencapsulated in alginate and whey protein concentrate addition on physicochemical and organoleptic properties of functional stirred yogurt

BACKGROUND Consumption ofSpirulina-based functionalized food is usually unpleasant due to its specific sensorial properties. Therefore,Spirulinawas encapsulated using alginate and whey protein concentrate (WPC) by emulsification method, and the effect of adding free and microencapsulatedSpirulina(MS) to non-fat stirred yogurt was investigated during storage. RESULTS Scanning electron microscope investigated microcapsules morphology and their mean particle size that was 52 mu m, and electrostatic interaction between wall materials was illustrated by Fourier- transform infrared spectroscopy. The microspheres had appropriate encapsulation efficiency (44.54 +/- 0.06%). Complete release ofSpirulinafrom the microcapsules was observed in simulated intestinal fluid, which is favorable forLactobacillusgrowth in human intestinal tract. Encapsulation caused meaningful differences in colorimetric factors, markedly inL*. Moreover, free and MS were added to yogurt samples, and the results showed that the physicochemical properties (pH, color, viscosity, water holding capacity and susceptibility to syneresis) and sensorial assessment of MS yogurt were positively affected. During the storage, MS yogurt had higher pH value than the others; furthermore, it showed the lowest syneresis and a constant increase in viscosity. Finally, the sensory evaluation results of MS yogurt, in comparison with the free form ofSpirulinautilization, indicated improved acceptance of the produced functional food. CONCLUSION Results showed an obvious impact of encapsulation on the physicochemical properties of yogurt containing MS. The sensory evaluation showed that encapsulation could generally enhance the customer's satisfaction. It can be stated that masking microalgae color and flavor by microencapsulation could be used for dairy products fortification by microalgae. (c) 2020 Society of Chemical Industry