Preparation and Characterization of Isolated Soy Protein Hydrolysate – Nanoparticles

• Main Authors: Pai-Hsiu Sun, 孫百秀
• Other Authors: Jin-Hewi Rwan
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/48572221476854677563

碩士 === 東海大學 === 食品科學系 === 99 === Chitosan (Mw 475.5 kDa, deacetylation≧85%) and its hydrolysates (Mw 231.5 and 131.1 kDa, hydrolyzed by cellulase), were dissolved in 1% acetic acid solution and adjusted to pH 4.7, and added with isolated soy protein hydrolysate (ISPH) solutions (Mw 10~30 kDa molecular weights, 1~9 mg/mL concentrations) before mixing with sodium tripolyphosphate (TPP) solution (pH 9.0) to prepare CS-TPP-ISPH nanoparticles. Such effective factors as chitosan molecular weight, ISPH concentration and chitosan / TPP mass ratio on the encapsulation efficiency (EE), loading capacity (LC) , process yield (PY) , particle size, zeta potential and stability (at pH 1.2 and 7.4) of the nanoparticles were investigated. Cross linking among CS, TPP and ISPH, and SEM of the nanoparticles were also determined. As a result, a high EE obtained in the low ISPH concentration, CS/TPP mass ratio at 3/1 and 4/1. LC increased in increasing ISPH concentration and CS/TPP mass ratio. A high PY obtained in the low CS/TPP mass ratio. CS-ISPH-TPP particle size decreased as CS Mw and ISPH concentration decreased. All nanoparticles showed positive charge, but when CS/TPP mass ratio at 2/1 the zeta potential will reduced from +47.6 mV to +24.0mV. The stable increased in increasing CS MW and decreasing CS/TPP mass ratio. ISPH was kept more stable in case of applying CS Mw at 475.5 kDa, CS/TPP mass ratio at 3/1 and ISPH concentration at 5 mg/mL. In a additional, the particle size ＜100nm (SEM) and spherical in shape when prepared by CS Mw at 131.1 kDa, CS/TPP mass ratio at 3/1 and ISPH concentration at 5 mg/mL. FTIR analysis showed that the tripolyphosphoic groups of TPP and the carboxyl groups of ISPH were linked with amino groups of chitosan in nanoparticles, and ISPH physically absorbed by CS-TPP（no band shifts）.