Improving powder performances of natural extracted lutein with spherulitic growth control

Abstract

Lutein tends to form tiny lamellar crystals which result in poor powder performances in uniformity of particle size and flowability. Spherulitic growth technology is developed to obtain uniform lutein spherulites with diameter around 250 μm to improve the powder performances. Operation conditions concerning initial concentration, stirring speed, temperature and cooling rate for spherulitic crystallization of lutein from solution without additives are studied. Lab-scale crystallization process analysis by on-line Raman confirms the critical effect of temperature on spherulitic growth control, and temperature related molecular conformation disorder induced spherulitic growth above 303.15 K is revealed. Particle growth kinetic study using in-situ HSM reveals that lutein spherulites result from spherulitic growth effect. Kinetic coefficients ( k ) and growth rate order (g) of the spherulitic particle are calculated to be 7.7 × 10 −6 cm/s and 0.78. It provides a new strategy to improve the crystal powder performances of carotenoid compounds through spherulitic growth control. • Spherulitic growth technology without additives is established for natural extracted pigment lutein. • Designed products show much better powder performances. • On-line analyzing the crystallization processes are performed. • Mechanism of molecular disorder induced spherulitic growth is investigated. • Growth kinetic of lutein spherulitic particles is calculated.