• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.545-551
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• 2019

The purpose of this study was to investigate the effects of protease in kiwi fruit powder after freeze drying which has the ratio of 0%, 1%, 2%, and 3% on the tenderization of the bovine longissimus dorsi muscle. Beef loin chunks were marinated in distilled water (Control), 1% kiwi powder (K1), 2% kiwi powder (K2), and 3% kiwi powder (K3). As a result, the enzyme activities have shown to have higher activity (p<0.001) as the amount of freeze-dried kiwi powder increased. There are significant difference in pH (p<0.01), color of the beef were slightly different between the C (control) group and the sample groups. The cooking loss showed the highest value of K3 (p<0.001), and water holding capacity showed the highest value of K3. Furthermore, the sample groups exhibited lower shear force values compared with the control (p<0.001).

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_2
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• pp.1009-1015
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• 2022

The purpose of this study was to investigate the effects of protease in Letinus edodes, Agaricus bisporus and Pear powder after freeze drying which has the ratio of 3% on the Tenderness of the Beef Eye of Round muscle. It were marinated in distilled water (Control), 3% Letinus edodes powder (L3), 3% Agaricus bisporus powder (A3), and 3% Pear powder (P3). As a result, enzyme activities were highest in Agaricus bisporus (p<0.001). There are significant difference in pH (p<0.001), color of the beef were slightly different between the C (control) group and the sample groups. The cooking loss showed the lowest value in the control and the highest value in the water holding capacity of Agaricus bisporus. In addition, Agaricus bisporus showed the lowest shear force values than the other sample groups(p<0.001).

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.339-346
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• 2007

The MJP1 bacterial strain, which possesses antifungal activity, was isolated from meju and identified as Bacillus subtilis based on its morphological and biochemical properties, as well as its 16S rRNA sequence. Antimicrobial activity was found against various species of Gram-positive bacteria, yeasts, and molds, including food-spoilage microorganisms. The antifungal activity was found to be stable after heat and proteolytic enzyme treatment, and in the pH range of $6.0{\sim}10.0$. The antibacterial activity was stable in the pH range of $6.0{\sim}10.0$, but about 50% of the activity was lost after 24 hr at $30^{\circ}C$. The antibacterial compound was also inactivated by proteolytic enzyme treatment, indicating its proteinaceous nature. The apparent molecular masses of the partially purified antifungal and antibacterial compounds, as indicated by using the direct detection method in Tricine-SDS-PAGE, were approximately 2.4 kDa and 4.5 kDa, respectively. These studies suggest that B. subtilis MJP1 produces two bacteriocin-like substances with antifungal and antibacterial activities.

• 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.

• Microbiology and Biotechnology Letters
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• v.5 no.3
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• pp.153-158
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• 1977

These experiments were conducted to investigate the condition of the production and the heat resistance of the acid protease by Rhizopus japonicus S-62. The results obtained were as follows: 1) The optimum concentrations of sucrose, yeast, ammonium chloride and sodium phosphate monobasic added to the wheat bran medium in the acid protease production were 0.5％, 2.0％, 0.4％, and 0.4％, respectively. 2) KH$_2$PO$_4$ and NaH$_2$PO$_4$ were the most effective as the heat resistant agents. 3) When the enzyme solutions added with KH$_2$PO$_4$ and NaH$_2$PO$_4$ to the concentration of 2％ were heated for 10 min, at 50$^{\circ}C$, their residual activities were 100％, respectively. 4) The heat resistant effects of KH$_2$PO$_4$ and NaH$_2$PO$_4$ were not observed almost above 55$^{\circ}C$.

• Journal of Animal Science and Technology
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• v.44 no.6
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• pp.801-808
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• 2002

Proteolytic activities of some commercial milk clotting enzymes(rennet, trypsin, pepsin, papain W-40, neutrase 1.5 and protease S) in bovine skim milk containing 0.02% $CaCl_2$ were determined by measuring DH(Degree of Hydrolysis), NPN(Non Protein Nitrogen) and by comparing patterns of SDS-PAGE(Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis). The DH of microbial enzymes(neutrase 1.5 and protease S) and trypsin in bovine skim milk were higher than those of pepsin and papain W-40. The amounts of NPN in the milk treated with trypsin and the other animal enzymes(rennet and pepsin) showed the highest and lowest degrees of proteolysis, respectively. SDS-PAGE showed that trypsin and protease S hydrolyzed $\alpha$-lactalbumin and papain W-40 hydrolyzed $\beta$-lactoglobulin slightly, while neutrase 1.5 hydrolyzed both $\alpha$-lactalbumin and $\beta$-lactoglobulin after treating for 90 min. Trypsin and protease S easily hydrolyzed ${\alpha}_s$-casein and $\beta$-casein, which were not hydrolyzed by rennet. Papain W-40 hydrolyzed $\kappa$-casein more than rennet as shown in SDS-PAGE. Based on the results of the experiments, the DH and NPN of trypsin, neutrase 1.5 and protease S were shown to be higher than those of the other enzymes. The SDS-PAGE patterns of papain W-40 and neutrase 1.5 were similar with that of rennet.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.153-159
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• 2000

A 4.4 kb DNA fragment encompassing lacA (galactoside acetyltransferase) and lacZ($\beta$-galactosidase) genes from Lactococus lactis ssp. lactis ATCC 7962 (L. lactis 7962) was introduced ito a Lac strain, Lactococcus lactis ssp. lactis MG1363 (L. lactis MG1363) by using a lactococcal expression vector, pMG36e and expression level of lacZ was examined. Growth rates and $\beta$-galactosidase ($\beta$-gal) activities of MG1363 cells carrying recombinant plasmid, pMLZ3, on M17 broth containing different carbon sources (1%, w/v) were examined. Contrary to the expectations, MG1363 [pMLZ3] grown on lactose showed the lowest enzyme activity (17 units) and cells grown on galactose had the highest $\beta$-gal activity (41 units). Cells grown on glucose had intermediate activity (33 units). These activities are about one tenth of the values observed in L. lactis 7962 where lacZ is present as a single-copy gene in the chromosome. When the cellular concentrations of lacZ transcript were examined using slot blot hybridization, it was found that MG1363[pMLZ3] produced sufficient amounts of transcript. These results indicate that either proteolytic degradation of $\beta$-gal or other regulatory mechanism prevent the translation or accumulation of $\beta$-gal in L. lactis MG1363 cells. In regard to regulation, the presence of the ccpA gene in L. lactis MG1363 was confirmed by Southern blot.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.12-25
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• 2003

L-camitine ($\beta$ -hydroxy-${\gamma}$ -trimethyl-ammoniumbutyric acid) is a small water-soluble molecule important in mammalian fat metabolism. It is essential for the normal oxidation of fatty acids by the mitochondria, and is involved in the trans-esterification and excretion of acyl-CoA esters. In this paper, to investigate the relationship between aging and L-camitine, we investigated the effects of in vitro MMP inhibition and activity and expression of UVA-induced MMP 1 in human skin fibroblasts. Fluorometric assays of the proteolytic activities of MMP-l were performed using fluorescent collagen substrates. ELISA (enzyme linked immuno sorbent assay), gelatin-substrate zymography, and RT-PCR ELISA techniques were used for the effects of L-camitine on MMP expression and activity, MMP mRNA expression in UVA irradiated fibroblast. L-camitine inhibited the activities of MMP-l in a dose-dependent manner and the $IC_{50}$/ values calculated from semi-log plots were 2.45mM, and L-carnitine showed strong inhibition on MMP-2 (gelatinase) activity in UVA irradiated fibroblast by zymography. Also, UVA induced MMP expression was reduced 40% by treated with L-carnitine, and MMP-l mRNA expression was reduced dose-dependent manner. Therefore L-carnitine was able to significantly inhibition the MMP activity, regulation of MMP expression in protein and mRNA level. All these results suggest that L-carnitine may be useful as new anti-aging cofactor for protection against UVA induced MMP expression and activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1709-1714
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• 2004

The changes of microflora and enzyme activities in Alaska pollack sikhae were evaluated in 3 different temperature conditions, 5$^{\circ}C$, 2$0^{\circ}C$ and alternating temperature (stored at 5$^{\circ}C$ after 10 days of fermentation at 2$0^{\circ}C$), respectively. The number of proteolytic bacteria and 2 lactic acid bacteria including Lactobacillus sp. and Pediococcus sp. increased rapidly up to 10 days and composed major portion of total viable cell (TVC) in sikhae fermented at 2$0^{\circ}C$, whereas those of TVC were occupied by Lactobacillus sp., Pediococcus sp. and yeast after 10 days of fermentation. The major species of microflora in sikhae fermented at alternating temperature were, composed of Lactobacillus, Pediococcus and Streptococcus after 10 days of fermentation. Especially, Leuconostoc sp. was kept up to 27 days at 5$^{\circ}C$ than other temperature conditions (16 days). The activities of protease and lipase in acidic region (pH 3.0) were higher at 2$0^{\circ}C$ than at 5$^{\circ}C$ due to sensitivity of temperature, although those of protease and lipase in neutral region (pH 7.0) were not found any differences in both temperatures. Changing temperature condition from 2$0^{\circ}C$ to 5$^{\circ}C$ in alternating temperature inactivated protease activity, whereas lipase activity was still maintained during fermentation.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.211-217
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• 1984

To study affinity of proteolytic enzymes to soy proteins, the physicochemical and functional properties of enzymatically modified protein products, kinetic parameters and degree of hydrolysis were measured using trypsin, alcalase (serine type protease) and pronase. Bacterial alcalase and pronase showed much greater affinity to soy protein than animal intestinal trypsin. This effect was very significant when unheated soy isolate was used as a substrate. Specific activities of these enzymes decreased with the increment of substrate concentration (over 2.0%, w/v) when heat denatured soy protein was used as a substrate. However, the decrease in specific activity was negligible at substrate concentrations lower than 2.0%. Polyacrylamide gel electrophoretic results showed that the pattern of 2S protein band changed distinctly in alcalase hydrolysis as compared with those of trypsin and pronase. Protein solubilities of alcalase and pronase hydrolyzates increased by 25-30%, at their pI (pH 5.0) over the control. Virtually no change was observed in solubility by trypsin hydrolysis. Heat coagulability and calcium-tolerance of the protein increased by enzymatic hydrolysis. No clear tendency, however, was observed for emulsion properties, foam expansion and the amount of free -SH groups. The enzyme treatment considerably decreased foam stability.