Enrichment desired quality chitosan fraction and advance yield by sequential static and static-dynamic supercritical CO2.
This study aimed to establish the sequential static and static-dynamic supercritical carbon dioxide (SDCO2) fractionation conditions to obtain a higher yield and desired chitosan with lower polydispersity index (PDI) and higher degree of deacetylation (DD). The yield increased with increasing DD of used chitosan and amount of cosolvent. The yield of acetic acid cosolvent was higher than those of malic and citric acid cosolvents. SDCO2, compared to static supercritical carbon dioxide, has higher yield. The yield of extracted chitosan was 5.82-14.70% by SDCO2/acetic acid, which increases with increasing pressure. The DD of fractionated chitosan increased from 66.1% to 70.81-85.33%, while the PDI decreased from 3.97 to 1.69-3.16. The molecular weight changed from 622kDa to 412-649kDa, which increased as density of supercritical carbon dioxide increases. Hence, higher DD and lower PDI extracted chitosan can be obtained through controlling the temperature and pressure of SDCO2.
Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan, ROC.
Yi-Yin
YY
Hsieh
Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan, ROC.
Hui Yen
HY
Chin
Department of Food Science, National Taiwan Ocean University, 2 Pei-Ning Road, Keelung 20224, Taiwan, ROC. Electronic address: tml@mail.ntou.edu.tw.
Min-Lang
ML
Tsai
D000107:Acetylation; D002245:Carbon Dioxide / Q000737:chemistry*; D005591:Chemical Fractionation / Q000379:methods*; D048271:Chitosan / Q000737:chemistry / Q000302:isolation & purification*; D019343:Citric Acid / Q000737:chemistry; D008970:Molecular Weight; D012995:Solubility; D012997:Solvents / Q000737:chemistry
D012997:Solvents; D002245:Carbon Dioxide; D019343:Citric Acid; D048271:Chitosan
Chitosan; Degree of deacetylation; Molecular weight; Polydispersity index; Static–dynamic supercritical carbon dioxide