Spray-drying microencapsulation of β-carotene by polysaccharide from yeast cell walls

Abstract

It is well known that β-carotene plays an important role in human health. However, it is susceptibly degraded by environmental conditions including temperature, light and oxygen, due to its natural structure of conjugated double bonds chain. Polysaccharide (PS) from the yeast cell walls has appeared to be an excellent choice of encapsulating agent that can be used to encapsulate biologically active substances. Objective of this study was to investigate the effects of PS concentration (20, 30, 40 and 50%) compared to MD, high pressure homogenization time (5, 10, 15, 20 min) and inlet air temperature of spray drying (130, 140, 150, 160oC) on microencapsulation yield (MEY), microencapsulation efficiency (MEE), moisture content (MC) and antioxidant capacity. The results showed that the highest values of MEY (354.4 µg/g) and MEE (90.2%), the low value of MC (7.0%) and antioxidant capacity (69.07%) were successfully obtained at PS concentration of 30% (w/v), homogenization of 15 min and inlet air temperature of 150oC. Under those conditions, the encapsulated β-carotene powder was examined by scanning electron microscopy (SEM) and it is confirmed that the micro-particles had various sizes which are a typical characteristics of spray dried powders, spherical shapes and were free of cracks and pores. As a result, it can be concluded that β-carotene was successfully encapsulated in the PS and MD matrix and could then be easily incorporated into various foods