• The Korean Journal of Food & Health Convergence
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• v.6 no.6
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• pp.1-7
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• 2020

We compared the fermentation of 0 to 4 weeks by manufacturing a rapid low salt-fermented seahorse with a commercial Protamex added to the functional food, Hippocampus abdominalis. We studied amino acid composition, content and major amino acids related to flavor during the fermentation process of salt-fermented seahorse. In the enzyme-free group, it showed little change in the content of non-protein nitrogenous compounds, the content of amino acids and degree of hydrolysis. The Protamex enzyme treatment group was rapidly hydrolyzed in one week of ripening, resulting in increased non-protein nitrogenous compounds content, amino acid content and degree of hydrolysis, and minimal changes in the four weeks. The total amino acid contents ratio showed the highest content of glutamic acid in the enzyme additive group, glycine, alanine, which indicates sweet taste, and serine, the content of glycine, alanine, serine, and lysine, indicating sweet taste, has increased significantly over the enzyme-free group. Twenty species of free amino acid in the four-week of salt-fermented seahorse were detected. It detected 43.0% (6 species) in the enzyme-free group and 63.96% (7 species) in the enzyme additive group.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.36-50
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• 2021

This study aimed to evaluate the biological potential of functional food, i.e., specific peptides obtained from the hydrolysis of milk protein, by assessing their antioxidant and antibacterial properties. For the preparation of casein hydrolysates, commercial enzymes were added to 10% casein solution in a 1:200 (w/v) ratio, and samples were collected each hour. Based on the assessment of the degree of hydrolysis (DH) of casein hydrolysates, it was observed that the concentration of all enzymatic hydrolysates increased rapidly from 30 to 40 minutes. However, no change was observed in their concentrations after 150 minutes. Protamex® and Neutrase® exhibited the highest DH when compared to other enzymes. Furthermore, SDS-PAGE was performed for analyzing the proteolytic pattern of each enzyme, except for Flavourzyme®, and peptides in the size range of 20-25 kDa were identified. Subsequently, peptides produced by two enzymes were isolated using a preparative liquid chromatography system. Overall, NF3, NF4, PF5, and PF6 showed higher antioxidant potential than other peptide fractions. Moreover, NF7 and PF3 exhibited the highest antibacterial activity. In this study, we evaluated the biological potential of novel casein-derived peptides that may find application in the food and healthcare industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.1
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• pp.194-199
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• 2009

An efficient production method of food-grade heamatococcus extract was developed based on stepwise enzymatic hydrolysis. In the first step, Haematococcus pluvialis cells hydrolysis carried out with commercially available exopeptidase(Flavourzyme) and endopeptidase (Alcalase), resulted in increased astaxanthin content. In the second step, proteolytic hydrolyzed H. pluvialis cells treated with hetero-polysaccharides hydrolytic enzyme (Viscozyme). By two-stage treatments using Alcalase and Flavourzyme and Viscozyme, the highest astaxanthin content was obtained. The astaxanthin content was remarkably enhanced by 320% $(529{\mu}g/g\rightarrow2,256{\mu}g/g)$ than that of the non-treated extract. And then, antioxidative activities determined by DPPH method were increased with increasing the astaxanthin content in haematococcus extract prepared by enzymatic hydrolysis.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.488-492
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• 1988

The physicochemical properties of viscosity, color, acidity and volume of anchovy extract were measured for their changes during extraction with alkali solution and/or proteolytic enzymes. The dried anchovies were ground in 0.3N NaOH solution followed by hydrolysis with neutral or alkaline protease and centrifuged to obtain anchovy extract. The results showed that the volume of supernatant after centrifugation increased from 70% of water only extraction to 89% by combined alkali-enzyme treatment. Titratable acidity of the extract showed a tendency of a little increase while viscosiy decreased with prolonged enzymic hydrolysis. Changes in Hunter value of 'L', 'a', 'b' showed that the extract became darker and less yellowish as protease treatment prolonged.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.398-406
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• 1992

In order to develop a new flavourant using the fish skin gelatin, the proteolytic renditions for the gelatin hydrolysate of the alkali (B-type) and Alcalase (E-type) pretreated flounder (Limanda aspera) skin gelatin were investigated, and some physical properties, molecular weight and amino acid compositions of the hydrolysates were, also, compared with each other. The proteolytic conditions of the gelatins (B-type and E-type) by trypsin were as follows : reaction temperature, 55$^{\circ}C$ : pH, 9.0 : enzyme concentration, 0.1% : re-action time, 4hrs for B-type and 1 hr for E-type. The degrees of hydrolysis of the B-type and E-type gelatin un-der the renditions stated above were 63% and 82%, respectively. The rnajor molecular weights of the hydrolysates were 15,000 dalton for B-type and 12,400 dalton for E-type. Among the amino acids in the hydrolysates, glycine, alanine, proline, hydroxyproline and serine having a sweet taste were responsible for 57% of the total amino acid. But valine, leucine, phenylalanine, tyrosine, methionine, arginine and histidine having a bitter taste were only 18%.

• BMB Reports
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• v.37 no.1
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• pp.59-74
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• 2004

The study of whole patterns of changes in protein expression and their modifications, or proteomics, presents both technological advances as well as formidable challenges to biological researchers. Nutrition research and the food sciences in general will be strongly influenced by the new knowledge generated by the proteomics approach. This review examines the different aspects of proteomics technologies, while emphasizing the value of consideration of "traditional" aspects of protein separation. These include the choice of the cell, the subcellular fraction, and the isolation and purification of the relevant protein fraction (if known) by protein chromatographic procedures. Qualitative and quantitative analyses of proteins and their peptides formed by proteolytic hydrolysis have been substantially enhanced by the development of mass spectrometry technologies in combination with nanoscale fluidics analysis. These are described, as are the pros and cons of each method in current use.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.139-144
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• 1999

Lipoprotein lipase (LPL) I san enzyme that catalyzed the hydrolysis of triacylglycerols of chylomicrons and VLDL to produce 20acylglycerols and fatty acids. The enzyme, LPL, is localized on the surface of the capillary endothelium and is widely distributed in extrahepatic tissues including heart, skeletal muscle and adipose tissue. LPL has been isolated from boving milk by affinity chromatography on heparin-separose in 2 M NaCL, 5mM barbital buffer, pH 7.4. To elucidate the lipid-binding regin, LPL was digested with trypsin and then separated by gel filtration. Lipid binding region of LPL has been investigated by recombining LPL peptides with DMPC vesicles. Proteolytic LPL fragments with DMPC were reassembled and stabilized by cholate. Lipid-binding region of LPL was identified by a PTH-automated protein sequencer, as AQQHYPVSAGYTK. The analysis of the secondary structure of the lipid-binding peptides revealed a higher probability of $\alpha$-helix structure compared to the whole LPL protein. The prediction of hydrophobicity of lipid -binding region was highly hydrophobic (-1.1) compared to LPL polypetide(-0.4).

• Journal of Microbiology
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• v.41 no.1
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• pp.58-62
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• 2003

An extracellular pretense of Bacillus amyloliquefaciens S94 was purified to apparent homogeneity. The enzyme activity was strongly inhibited by general inhibitor for serine protease, PMSF, suggesting that the enzyme is a serine pretense. The purified enzyme activity was inhibited by leucine peptidase inhibitor, bestatin, suggesting that the enzyme is a leucine endopeptidase. The maximum proteolytic activity against different protein substrates occurred at pH 10, 45$^{\circ}C$ (protein substrate) and pH 8, 45$^{\circ}C$ (synthetic substrate). The purified enzyme was specific in that it readily hydrolyBed substrates with Leu or Lys residues at P$_1$ site. The pretense had characteristics of a cold-adapted protein, which was more active for the hydrolysis of synthetic substrate in the range of 15$^{\circ}C$ to 45$^{\circ}C$, specially at low temperature.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.39-45
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• 1993

The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.155-160
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• 1975

The study was carried out to investigate the effects of various compositions of artificial diet for silkworms on the cocoon shell fibroin-hydrolyzing with the proteolytic enzyme. The obtained results are summarized as follows： 1. It was found that the fibroin-hydrolyzing ratio of the cocoon shell made by silkworms fed with artificial diets was lower than that of the cocoon shell made by silkworms fed with natural diet (mulberry leaf) 2. The amount of soybean meal in the artificial diet was negatively related to the sericin content of cocoon shell but it scarcely affected on the fibroin-hydrolyzing ratio. 3. The increase of sucrose in the artificial diet reduced the sericin content of cocoon shell but it didn't influence on the fibroin-hydrolyzing ratio. 4. A significant difference between male and female silkworms fed with artificial diets was found in the sericin content of cocoon shell but it was not approved in tile fibroin-hydrolyzing ratio. 5. The artificial diet containing 8 per cent of mulberry leaf powder increased the fbroin-hydrolyzing ratio more than that containing 10 per cent of mulberry leaf powder or that containing 8 per cent of mulberry leaf powder and a little of methionine did. 6. The artificial diet for all instars of silkworms increased the fibroin-hydrolyzing ratio more than the artificial diet for 1st to 3rd instars and natural diet (mulberry leaf) for the rest instars did.