Preparation And Properties Of Phycobiliprotein Microcapsules

Phycobiliprotein has many biological activities, and can be used as a natural pigment infood and cosmetics industries. It is also a feed source for fish, shrimp, shellfish, and a healthfood or drug used in the medical field. However, phycobiliprotein is hard to be used because ofits poor stability and highly sensitivity to heat, light and pH. Microcapsule can separate theexternal environment from the sensitive components, and is of great significance in theimprovement of stability. The present study prepared the phycocyanin microcapsules andphycoerythrin microcapsules by spray method，studied the effect of sodium alginate, CaCl2,spray pressure, feed velocity and phycobiliprotein concentration on the particle size andembedding rate of the microcapsules, determined the optimal conditions of the preparation of thetwo microcapsules, and studied the stability and antioxidant activity of the two microcapsules,which would be used for the research and development of phycobiliprotein.The preparations of phycocyanin microcapsules and phycoerythrin microcapsules werestudied in the present dissertation. The results indicated that sodium alginate concentration andspray pressure had significant influence on the particle size of microcapsule (P <0.05), and theconcentrations of sodium alginate, CaCl2, phycocyanin/phycoerythrin and spray pressure hadsignificant effect on the embedding rate (P <0.05). Based on multi-index orthogonal experiment,the optimal condition for the preparation of phycocyanin microcapsule was determined as below:0.02g/ml sodium alginate,0.5g/ml CaCl2,1.0mg/ml phycocyanin, and0.11MPa spray pressure.Under this condition, the particle size of phycocyanin microcapsule was (264.2±63.5) μm, andits embedding rate was (25.2±2.3)%. The optimal condition for the preparation of phycoerythrinmicrocapsule was determined as below:0.02g/ml sodium alginate,0.6g/ml CaCl2,0.4mg/mlphycocyanin, and0.11MPa spray pressure. Under this condition, the particle size ofphycocyanin microcapsule was (352.9±66.6) μm, and its embedding rate was (19.0±0.4)%.The thermal stabilities of phycocyanin solution, phycocyanin microcapsule, phycoerythrinsolution and phycoerythrin microcapsule were studied. The preservation rates of phycocyaninsolution, phycocyanin microcapsule, phycoerythrin solution and phycoerythrin microcapsulewere97.5%,98.2%,97.3%and97.7%respectively at40℃for5hours,57.0%,80.9%,59.9%and90.9%respectively at70℃for5hours, and16.6%,68.8%,33.9%and65.7%respectivelyat100℃for5hours, suggesting that the microencapsulation of phycocyanin and phycoerythrin could improve their thermal stabilities.The stability of optical radiation of phycocyanin solution, phycocyanin microcapsule,phycoerythrin solution and phycoerythrin microcapsule were studied in the present dissertation.The preservation rates of phycocyanin solution, phycocyanin microcapsule, phycoerythrinsolution and phycoerythrin microcapsule were99.2%,99.2%,98.8%and99.2%respectively indark environment for5hours,97.6%,99.0%,91.3%and97.6%respectively at the irradiation by6000lux fluorescent lamp for5hours, and80.2%,98.4%,55.2%and80.2%respectively at theirradiation by15w ultraviolet light for5hours, which suggesting the microencapsulation ofphycocyanin and phycoerythrin could improve their optical radiation stabilities.The antioxidant activities of the two kinds of phycobiliprotein and its microcapsules werestudied in the present dissertation. The results showed that the clearances of ultra oxygen anionof phycocyanin and phycoerythrin did not decrease significantly (P>0.05) aftermicroencapsulation of the two phycobiliproteins. After microencapsulation, the reducibilities ofphycocyanin and phycoerythrin decreased significantly (P<0.05), but most of their reducibilitieswere still remained.