| Summary: | 碩士 === 東海大學 === 食品科學系 === 104 === Chitosan (CS, High Mw 740 kDa, deacetylation ≥ 85%) was degraded by O3 oxidation into different molecular weight (Medium Mw 250-200 kDa and Low Mw 50 kDa), then dissolved in 1 % acetic acid, at 0.2% (w/v) concentration and adjusted to pH 4.7, and individually mixed with curcumin solution of different concentrations (40-200 μg/mL).The mixed solutions were added dropwise with sodium tripolyphosphate (TPP) solution (pH 9.0) at different CS/TPP mass ratios of 3:1, 4:1, 5:1 and 6:1 to prepare CS-TPP-Curcumin nanoparticles. Such effective factors as curcumin concentration, chitosan molecular weight and CS/TPP on the encapsulation efficiency(EE), process yield(PY), loading capacity(LC), particle size, zeta potential were investigated. Stability of the nanoparticles in the simulated gastric fluid(pH1.2, with pepsin) for 2 hrs and simulated intestinal fluid(pH7.4, with pancreatin ) for 6 hrs were determined. SEM of nanoparticles were also determined.
As a result, the high curcumin EE ,was obtained at a curcumin concentration of 120 μg/mL(32.3 %), decreased as CS/TPP mass ratio increased, while CS Mw was insignificantly affected. PY of the nanoparticles increased as curcumin concentration increased and CS Mw decreased, but significantly decreased with increasing CS/TPP mass ratio. LC of the nanoparticles, showed increasing in range of 2-11% with both increasing curcumin concentration and CS/TPP mass ratio, but decreased as CS Mw decreased. CS-TPP-Curcumin nanoparticles size increased(686~879 nm) as curcumin concentration and CS/TPP mass ratio increased, but decreased (807~546 nm) with the decreasing CS Mw. Zeta potential of CS-TPP-Curcumin nanoparticles, increased (+41~+25 mV) with the decreasing CS Mw and CS/TPP mass ratio. Simulated gastrointestinal stability of CS-TPP-Curcumin nanoparticles (prepared with curcumin concentration of 200 μg/mL, medium Mw CS (229 kDa), CS/TPP mass ratio of 3/1) released about 5% of curcumin in the simulated gastric fluid and cumulative release about 31% of curcumin in the simulated intestinal fluid. SEM showed that CS-TPP-Curcumin nanoparticles were spherical shape.
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