Preparation of the caseinophosphopeptides using a membrane reactor

• Main Authors: YU CHE-LI, 余哲禮
• Other Authors: Chiang,Been-Huang
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/05211872331726868586

碩士 === 國立臺灣大學 === 食品科技研究所 === 84 === A large scale dietary survey conducted in Taiwan area showed that the most inadequate intake of nutrients was calcium, which only reached 81.9% of the recommended daily allowance(RDA). Hydrolysis of sodium caseinate leads to the production of phosphopeptides containing phosphoseryl residues, which can bind Ca2+ and enhanced absorption of calcium in vito. This reserach inestigated how to hydrolyze sodium caseinate by trypsin in a membrane reactor. Sodium caseinate was hydrolyzed in a continuous stirred tank mem;brane reactor consisted of ultrafiltration hollow fiber and continuous stirred tank reactor. The permeate stream, consisting of peptides, passed through the membrane, while the rejected stream from the retentate side of the membrane was returned to the reaction vessel for further reaction. Five major parameters, including pH, reaction temperature, substrate concentration, enzyme concentration and reaction volume were studied. The initial experiment showed that the substrate concentration of 2% sodium caseinate (w/v), enzyme/substrate ratio 1/1000, pH 7.6, reaction temperature 37℃, operative flow 44.55L/hr and operative pressure 20psi might be are the best operating conditions, but the accumuation of substrate during process due to inactivation of enzyme might reduce the flux. To improve this problem, we investigated the effect of enzyme concentration and reaction volume on the performance of membrane reactor system. When the process was conducted at enzyme/substrate ratio 1/200 with add-back 5% of initial total enzyme hourly in a 500ml reactor, the purity of CPP in permeate was 18.10%. The subsequent purification process by immobilized metal ion affinity chromatography could increased the product purity t0 64.97%. The overall conversion was 13.06%.