| Summary: | 碩士 === 東海大學 === 食品科學系 === 90 === The purpose of this study was to investigate the flavoring production from porcine plasma by Enzyme. After centrifugation, porcine plasma was sterilized by pass through 0.45 μm membrane. The sterilized plasma subject to hydrolysis（at 50℃/16hr）with four different commercialized protease respectively. Analysis of hydrolysis degree , it was found that the order of enzymatic activity was : Umamizyme＞Protease A＞Protease M＞Alcalase. 2﹪addition of Umamizyme was used to prepare plasma hydrolysate. After extended hydrolysis for 3 day, the degree of hydrolysis (DH) of plasma was found around 32﹪. The plasma protein precipitated by 80% (NH4)2SO4 had a higher DH by Umamizyme compared with the other plasma protein precipitated by 40%、60%(NH4)2SO4 and 60% ethanol. The DH of the plasma protein precipitated by 80% (NH4)2SO4 was found around 67﹪.
Test pannel result showed no obvious bitter of plasma hydrolysate by Umamuzyme and obvious bitter test of hydrolysate of precipitated plasma protein. After the second hydrolysis by Flavorzyme, the bitterness was greatly reduced.
Result of sensory evaluation showed the plasma hydrolysate by Umamizyme could be not accepted due to its strong odor of hog smell. Addition of diatomaceous earth or active carbon to hydrolysate was found to slightly reduce the bad smell. The recovery of product was obviously reduced by the decoloring treatment. In order to remove bad smell from enzymatic hydrolysate , concentration with heat(room temp, 55℃, 85℃) was conducted. The order of plasma hydrolysate by concentration with heat at 85℃ was better than heat treatment. But the hog smell was still found unacceptable to test panel. Extraction of plasma hydrolysate by organic solvent did not improved the smell, too. The viscosity of plasma hydrolysate would decrease gradually with DH , whereas color change was not obvious. The viscosity and color of the hydrolysate of precipitated protein was found to change slightly.
0.45μm filtering disc was used to remove microbial contamination effectively. Before and after passing through 0.45μm disc, total plate counts of blood plasma was found to be 7.2 × 102 CFU/mL and N.D. respectively.
The HPLC analysis of hydrolysate by Umamizyme, the major molecular weight (MW) was found to be below 1000. The average length of hydrolysate MW was around ten amino acids residue. Low MW fractions were increased with increasing hydrolysis time. Change in area (%) of chromatogram showed that the hydrolysate product centered on small MW.
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