• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.635-641
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• 2000

In order to utilize the protein source from a fish proessing by-product, cod was hydrolyzed with various enzymes such as tuna pyloric caeca crude enzyme (TPCCE), a-chymotrypsin, trypsin, papain and pronase E. The TPCCE hydrolysate acquired the highest sensory properties on taste, odor and color. The resultant cod rfame protein hydrolysate (CFPH) which was hydrolyzed with TPCCE, was separated through a series of ultrafiltration membranes with molecular weight cut-off (MWCO) of 30, 10, 5 and 1 kDa, and four types of permeates in cluding 30 K (permeate from 30 kDa membrane), 10 K (permeate from 10 kDa membrane), 5 K (permeate from 5 kDa membrane) and 1 K (permeate from 1 kDa membrane) were obtained. The natural sauces were prepared with 30 K, 10 K, 5 K and 1 K hydrolysate, and the sauce prepared with 1 K hydrolysate was the best score in sensory evaluations. In addition the mixed sauce prepared with 1 K hydrolysate and commercial soy sauce was similar to commercial sauce in sensory properties. These results suggest that the mixed sauce would be utilized as the substitute of acid-hydrolysis sauce.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.125-133
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• 1983

Red cell glycolytic intermediates, metabolites and metabolic ratios were studied. Glycolytic intermediates were measured in neutralized perchloric acid extracts of red cell suspensions after 3 hr incubation at $37^{\circ}C$ in the presence and absence of saponin. Adenosine triphosphate(ATP), adenosine diphosphate(ADP), pyruvate and lactate were measured by enzymatic procedures involving stoichiometric oxidation or reduction of a pyridine nucleotide. Glucose was determined using glucose oxidase after zinc hydroxide extraction. The redox state was calculated from the lactate dehydrogenase equilibrium. Adenosine triphosphatase activity(ATPase) was measured by determining the amount of phosphate released from ATP by washed erythrocyte membranes(ghost) during 20 min. incubation. Both total hydrolysis and the amount of hydrolysis that occured in the presence of ouabain were measured. The second measurement yields Mg-ATPase and represents nonspecific ATPase activity of the membranes. The difference between total and Mg-ATPase activity can be attributed to Na-K-ATPase. For the measurement of sodium fluxes, human erythrocytes were preincubated in $^{22}Na$ for 3 hr at $37^{\circ}C$, washed and suspended in a tracer-free medium. The amount of $^{22}Na$ transported out of cells at any time was determined by analysis of supernatant samples taken at various time after addition of the labeled cells to isotope-free medium. The cells and medium were separated and the radioactivity appearing in the medium was measured. From the total radioactivity in the suspension and the radioactivity appearing in the medium at known time, the rate constant for sodium release was computed. The results are summarized as follows: 1) ATP and ATP/ADP were found to increase at every concentration of saponin tested whereas ADP declined at every cone. of saponin. The increase in pyruvate and lactate were observed at every cone, of saponin and thus $NAD^+/NADH$ computed from pyruvate/lactate also increased. Glucose utilization was stimulated by saponin. 2) $Na^+-K^+-ATPase$ activities showed a biphasic response to saponin, first increasing in lower concentration and then decreasing in higher concentration of saponin. 3) The efflux of sodium was significantly increased by saponin in the range of 5 to 10 mg%. The stimulatory effect of saponin on the rate constants for active(ouabain-sensitive) sodium efflux was inhibited by addition of ouabain.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.132-138
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• 1998

To improve functional properties and enhance application of FPC in food industry, modified salmon FPC with enzyme treatment was produced and its general properties were investigated. Salmon FPC has over $84\%$ of protein and less than $0.18\%$ of lipid. Solubilities of FPC extracted with IPA and ethanol were very poor as less than $3\%$ in every pH range. In case of enzyme : substrate ratio of 1 : 100, degree of hydrolysis significantly increased until 4 hours and then slightly increased. No considerable differences were observed in general components of hydrolysates. Results of SDS-PAGE showed one unique band in each case and their molecular weight was less than 6,500. The flow properties of hydrolysates showed newtonian flow. Whiteness of hydrolysates were higher than that of salmon FPC as $5\~7$. There was no significant differences in the amount of peptide, but that of free amino acid slightly increased from 0.17 to 0.21 mg/ml.

• Korean Chemical Engineering Research
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• v.56 no.2
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• pp.229-239
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• 2018

The purpose of this study was to effectively produce the biosugar from cell wall of lipid extracted microalgae (LEA) by using microwave-assisted pretreatment without enzymatic hydrolysis process. Response surface methodology (RSM) was applied to optimization of microwave-assisted pretreatment conditions for the production of biosugar based on enzyme-free process from LEA. Microwave power (198~702 W), extraction time (39~241 sec), and sulfuric acid (0~1.0 mol) were used as independent variables for central composite design (CCD) in order to predict optimum pretreatment conditions. It was noted that the pretreatment variables that affect the production of glucose (C6) and xylose (C5) significantly have been identified as the microwave power and extraction time. Additionally, the increase in microwave power and time had led to an increase in biosugar production. The superimposed contour plot for maximizing dependent variables showed the maximum C6 (hexose) and C5 (pentose) yields of 92.7 and 74.5% were estimated by the predicted model under pretreatment condition of 700 w, 185.7 sec, and 0.48 mol, and the yields of C6 and C5 were confirmed as 94.2 and 71.8% by experimental validation, respectively. This study showed that microwave-assisted pretreatment under low temperature below $100^{\circ}C$ with short pretreatment time was verified to be an effective enzyme free pretreatment process for the production of biosugar from LEA compared to conventional pretreatment methods.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.145-149
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• 2016

Thermal acid hydrolysis pretreatment of Kappaphycus alvarezii was carried out with 12% (w/v) seaweed slurry and 180 mM H₂SO₄ at 140°C for 5 min. Utility of the thermotolerant yeast Kluyveromyces marxianus KCTC7150 was evaluated with respect to cell growth and ethanol fermentation at 40°C was close to optimal for enzymatic hydrolysis. This could lead to the integration of both the saccharification and fermentation processes. The levels of ethanol production by simultaneous saccharification and fermentation (SSF) with non-adapted and adapted K. marxianus KCTC7150 were 9.1 g/l with an ethanol yield (Y_EtOH) of 0.24 and 10.2 g/l with an ethanol yield (Y_EtOH) of 0.27 at 156 h, respectively. The two-phase SSF process was employed in this study to improve the efficiency of ethanol fermentation. Adapted K. marxianus KCTC7150 using the two-phase SSF process produced 13.5 g/l with an ethanol yield (Y_EtOH) of 0.35 at 96 h. Development of the two-phase SSF process could enhance the overall ethanol fermentation yields of the seaweed K. alvarezii.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.205-210
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• 1983

Extracellular $\beta$-galactosidase was prepared from a culture of Lactobacillus sporogenes, a spore-forming lactic acid bacterium. The enzyme functioned optimally at pH 6.8 and at 6$0^{\circ}C$ o-nitrophenyl-$\beta$-D-galactopyranoside (ONPG) in 0.05M sodium phosphate buffer. The activation energy of the enzymatic hydrolysis of ONPG was about 16,000 cal/mole below $50^{\circ}C$ and 11,300 cal/mole above the temperature. It was fairly stable over a pH range from 4.0 to 8.0 losing only less than 30% of its activity after hearting at 6$0^{\circ}C$ and pH 6.8 for 3 hours. Metal ions showed no significant effect on the enzyme activity, whereas L-cysteine exerted a slight stimulatory effect at the concentration of 10mM. The km values were 1.48mM for ONPG and 64.5mM for lactose. Hydrolysis of ONPG by the enzyme was product-inhibited by galactose (Ki=13.3mM, competitive inhibition) and by glucose(Ki= 11.4mM, uncompetitive type). The enzyme activity was also noncompetitively inhibited in the presence of lactose (Ki= 17.8mM).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.9-15
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• 2006

As a part of the investigation for utilizing pearl oyster by-products, a rapid salt-fermented pearl oyster using commercial enzyme was prepared and also examined on the characteristics. The salt-fermented pearl oyster prepared by optimal condition, which was prepared by mixing of minced pearl oyster, 15% salt, and 1% $Protamex^\circledR$ and fermented for 4 weeks, was superior in hydrolysis degree (28.7%) and ACE inhibitory activity (92.6%) to salt-fermented pearl oyster prepared by other conditions, such as the use of whole tissue, different enzymes $(Alcalase^\circledR,\;Neutrase^\circledR\;and\;Flavourzyme^\circledR)$, different salt concentrations (20 and 25%), and different fermentation periods (2, 6 and 8 weeks). There were, however, some shortcomings with this product. It showed a dark green color and an unfavorable bitter taste. These shortcomings were improved by the addition of seasoning paste. The calcium and phosphorus contents of the seasoned salt-fermented pearl oyster were 64.2 mg/100 g and 71.6 mg/100 g, respectively, and the calcium content based on phosphorus was a good ratio for absorbing calcium. The total amino acid content of the seasoned and salt-fermented pearl oyster was 7,054 mg/100 g and the major amino acids ware aspartic acid (555.1 mg/100 g), glutamic acid (1,131.2 mg/100 g), alanine (658.2 mg/100 g), and lysine (695.5 mg/100 g). The seasoned salt-fermented pearl oyster, along with angiotensin I converting enzyme (ACE) inhibitory activity (98.3%), also showed a recognizable level (87.5%) of anti-oxidative activity.

• Journal of Life Science
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• v.21 no.2
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• pp.309-315
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• 2011

Rice syrup meal (RSM) was enzymatically hydrolyzed using eight commercial proteases (Protamex, Neutrase, Flavourzyme, Alcalase, Protease M, Protease N, Protease A, Molsin F) for 4 hr at optimum pH and temperature. Proteolytic hydrolysates were examined in supernatant and precipitate using Lowry protein assay, semimicro Kjeldahl method and gravimetric method using weight difference before and after enzymatic hydrolysis. Although RSM contains a high amount of protein (71.2%), only a very small amount of protein was hydrolyzed. Two proteases (Protease M and Protease N) were found to be the most effective in the hydrolysis of RSM protein. In Lowry method, 57.5 and 59.0 mg protein/g RSM were hydrolyzed after Protease M and Protease N treatments, respectively. In gravimetric method, 80.0 and 85.4 mg protein/g RSM were hydrolyzed after Protease M and Protease N treatments. In Kjeldahl method, 67.43 and 70.43 mg protein/g RSM were hydrolyzed after Protamex and Protease N treatments, respectively. For synergistic effect, two or three effective commercial proteases (Protease M, Protease N and Protease A) were applied to RSM at one time. The highest hydrolysis of RSM protein was observed in both Lowry protein assay (80.3 mg protein/g RSM) and gravimetric methods (153.2 mg protein/g RSM) when three commercial proteases were applied at one time, suggesting the synergistic effect of those proteases.

• Journal of Life Science
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• v.23 no.4
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• pp.569-577
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• 2013

Soy sauce is a traditional fermented seasoning in several oriental countries, such as Korea and Japan, and recently it has been reported to have biological activities. In Korean soy sauce, soybeans and wheat are the two main raw materials. Polysaccharides that originate from the cell wall of soybeans are resistant to enzymatic hydrolysis. These polysaccharides remain in the soy sauce even after fermentation and are termed Kanjang polysaccharides (KPS). In this study, polysaccharides were obtained from dialysate of different soy sauces labeled as A~T and manufactured by fermentation or the acid-hydrolyzate method. We investigated anti-inflammatory activities by examining the effects of these KPS on proinflammatory cytokine release and mRNA expression in mast cells. Histamine and ${\beta}$-hexosaminidase release were strongly decreased by the KPS treatment in RBL-2H3 cells. Treatment with KPS clearly reduced mRNA expression and the release of the proinflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor-alpha (TNF-${\alpha}$) in PMACI-stimulated HMC-1 cells. In particular, KPS derived from fermented Kanjang products showed a significant anti-inflammation effect on mast cells compared to the acid-hydrolyzed Kanjang products. This study suggests that KPS appear to be effective in suppressing allergic inflammatory reactions.

• Food Science and Preservation
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• v.24 no.3
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• pp.455-463
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• 2017

In this study, the biological activities and physicochemical properties of polysaccharides from Gloiopeltis furcata were investigated. Polysaccharides were isolated by enzymes treatment (celluclast, flavourzyme, papain, termamyl, viscozyme) followed by ethanol precipitation and lyophilization. The yield of polysaccharides by enzymes treatment group were 52.8-66.4%. The major constituents in viscozyme treatment group were total sugar (71.04%), protein (7.22%), uronic acid (23.18 g/100 g), and sulfate (28.27%), respectively. The DPPH radical scavenging activity and ferric reducing antioxidant potential of the viscozyme treatment group at 5 mg/mL were 23.10% and $218.50{\mu}M$, respectively. The protective effects against $H_2O_2$-induced cytotoxicity in L132 cell of viscozyme treatment group at $1{\mu}g/mL$ was 85.64%. The viscozyme treatment group increased the production of nitric oxide (NO) in a dose-dependent manner. The antitumor activity of viscozyme treatment group (at $25{\mu}g/mL$) in A549, HeLa, SNU719 and MCF7 was 69.57%, 52.74%, 61.06% and 68.64%, respectively. All of data showed that the biological activities and chemical characteristics of enzymes treatment group are higher than that of the control group. The polysaccharides isolated from Gloiopeltis furcata investigated herein are useful as functional materials agents.