• Korean Journal of Agricultural Science
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• v.25 no.1
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• pp.107-117
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• 1998

Ths studies was carried out to investigate the processing possibility of pheasant meat extracts treated with proteases. The crude protein, aminonitrogen, degree of hydrolysis, yield and amino acid composition of pheasant meat extracts when it was treated with proteases at various temperature and reaction time were analyzed. The crude protein contents of pheasant meat extracts processed in $130^{\circ}C$ were more than when it was done in $100^{\circ}C$, but the contents of aminonitrogen were not quite different between two processing temperature. The content of crude protein and aminonitrogen when pheasant meat was hydrolyzed with protease NP and prozyme A. The yields of pheasant meat extracts, when pheasant meat were treated at $100^{\circ}C$ and $130^{\circ}C$, were from 2.24 to 7.10% and from 5.51 to 10.45%, respectively. And the yield of extraction depended on extraction temperature, kinds of enzyme, amount of enzyme, extraction time. The content of aminonitrogen in pheasant meat extracts treated with enzyme was much higher than any other treatments. And it depended on amount of enzyme, extraction time and temperature. The amount of the amino acids in pheasant meat extracts treated by protease NP were eminently higher than by heat at $100^{\circ}C$ or $130^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.198-204
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• 2000

In order to utilize by-products which would normally be discarded in marine processing plants, cod teiset protein was hydrolyzed and antioxidative actiTity of the hydrolysate was investigated. AntioxidatiTe peptide was isolated using ultrafiltration membrane, ion-exchange chromatography on a SP-Sephadex C-25 column, gel filtration on a Sephadex G-15 column, high performance liquid chromatography on an ODS column, and capillary electrophoresis chromatography. Antioxidative activities of the cod teiset hydrolysate were compared with ${\alpha}-tocopherol$, one of the commercial antioxidant. The hydrolysate passed through a membrane with molecular weight cut-off (MWCO) 1 kDa was shown the strongest antioxidative activity, and the activity was higher $10{\%}$ as compared with ${\alpha}-tocopherol$. In addition, the peptide isolated by ion-exchange chromatography, gel filtration, and HPLC, respectively, was higher $53{\%}$ as compared with ${\alpha}-tocopherol$, and the amino acid sequence was Ser-Asn-Pro-Glu-Trp-Ser-Trp-Asn.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.715-721
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• 2021

Cognitive impairment and Alzheimer's disease are serious social problems associated with the rising elderly population in Korea. 1,2,3,4,6-Penta-O-galloyl-β-ᴅ-glucopyranose (PGG) is a gallotannin isolated from medicinal plants such as Rhus chinensis. This study was performed to evaluate the effect of PGG on biomarkers related to cognitive function in human neuroblastoma SK-N-SH cells. Inhibition of acetylcholinesterase (AChE) activity is considered to be one of the main therapeutic strategies. PGG inhibited AChE activity in the test tube as well as in SK-N-SH cells. In addition, PGG induced protein and mRNA expression of brain-derived neurotrophic factor (BDNF), which is a mammalian neurotrophin that plays major roles in the development, maintenance, repair, and survival of neuronal populations. As one of the underlying molecular mechanisms that induce BDNF expression, PGG induced the activation of Ca²⁺/calmodulin (CaM)-dependent protein kinase II (CaMKII)-cAMP response element binding protein (CREB) pathway. In conclusion, PGG may be an useful material for improving cognitive function.

• Food Science and Preservation
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• v.10 no.1
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• pp.80-88
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• 2003

In order to establish the enzymatic hydrolysis system improving of taste and flavor in the preparation of soy protein hydrolysates using the enzymes with excellent hydrolytic ability and different hydrolysis pattern of soy protein, Degree of hydrolysis(DH) and surface hydrophobicity under the optimal conditions of enzyme reaction, hydrolysis patterns by the SDS electrophoresis and sensory evaluation of soy protein hydrolysates by enzyme reactions were investigated. Four enzyme reactions were highly activated at pH 7.0, 45$^{\circ}C$ under the optimal conditions. As result of changes on the pattern of soy-protein hydrolysates by SDS-electrophoresis, high molecular peptides of hydrolysates by No. 5(Mucor circinelloides M5) and No. 16(Bacillus megaterium B16) enzymes were slowly decrease and 66KD band of these were remained after 3hours reaction. Production of low molecular peptides of hydrolysates by No. 4(Aspergillus oryzae M4) and No. 95(Bacillus subtilis YG 95) enzymes were remarkably detected during the proceeding reactions. As results of HPLC analysis, low molecular peptides of 15∼70KD were mainly appeared during the proceeding enzyme reactions. And, the more DH was increased, the more SDS-surface hydrophobicity was decreased. Hydrolysates by No. 4 enzyme was not only the highest DH of all hydrolysates, but the strongest bitter taste in a sensory evaluation. Sweat taste among the hydrolysates showed little difference. But, when combinative enzymes were treated, combinative enzyme of No. 4(Aspergillus oryzae M4)and No. 16(Bacillus megaterium B16) showed the strongest sweat taste. In conclusion, we assumed that it will be possible to prepare the hydrolysates having functionality when soy-protein were hydrolyzed by these specific enzymes.

• Food Science and Preservation
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• v.14 no.3
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• pp.301-307
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• 2007

To efficiently use Korean mung beans, the functional characteristics of mung bean powder(A), unhydrolyzed mung bean flour(B), and mung bean flour hydrolyzed under optimum conditions(C), were compared. The contents of protein, fat, carbohydrate, ash, and water, did not vary greatly with different treatment methods. The color values of (B) and (C) were similar, while the L value of (A) was higher than those of the other samples. Thereducing sugar content of (C) was highest at 292.63 mg%, while the total phenol contents of (A) and (C) were similar at 38.63 mg% and 38.38 mg%, respectively. The molecular weight of (A) was under 17 kDa by SDS-PAGE, and was lower than the molecular weights of the other samples (B, C), which generally ranged from 17 kDa to 72 kDa. The free sugar content of (C) was highest at 1,125.16 mg%, while (A) and (B) yielded values of 86.36 mg% and 54.20 mg%, respectively. Total free amino acid contents were in the order(C)(B)(A), and were 22,116.35 mg%, 2,731.29 mg%, and 578.54 mg%, respectively. The amino acid content of (C) was 8,231.42 mg% and was higher than those of (A) or(B). The DPPH free radical scavenging abilities of (A) and (C) were high, at 62.1% and 57.63%, respectively, while (B) showed a lower value at 19.26%. Fibrinolytic activity was highest(24.01%) in (C), and was 20.69% in (A) and 18.06% in (B). The above results indicate that mung bean flour hydrolyzed under optimal conditions (C) had the highest functional and quality characteristics, in comparisonh with unhydrolyzed flour (B) and mung bean powder (A). Diverse applications of hydrolyzed mung bean flour are anticipated.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.59-65
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• 2002

This study was carried out to evaluate the effect of whey protein concentrate-80%(WPC-80) and whey protein isolate(WPI) on the growth of B. bifidum Bb-11. Whey proteins($\alpha$-lactalbumin, $\beta$-lactoglobulin) were digested with trypsin, then their hydrolyzates were separated into three fractions (>10,000Da, 3,000∼10,000Da, <3,000Da) by two-step ultrafiltration process with Centriprep 10 and Centricon-30. These three fractions by molecular weight were evaluate growth-promoting effects for the B. bifidum Bb-11. The results obtained were summarized as follows; The growth rate of B. bifidum Bb-11 tended to increase by supplementation of WPC-80 to basal medium, but decreased by supplementation of WPI. Two whey proteins were hydrolyzed by trypsin at 40$\^{C}$ for 6 hrs, and three fractions were collected by UF treatment and concentrated by Centricon-30. Collected concentrations of protein of F-I and F-II and F-III from $\alpha$-lactalbumin were 11.53mg, 7.79mg, and 5.21 mg and those of protein from $\beta$-lactoglobulin were 4.13mg, 5.30mg, and 9.351mg, respectively. Three fractions of $\alpha$-lactalbumin hydrolyzates promoted the growth rate of B. dbifidum Bb-11. Growth promoting activities of hydrolyzates(F-I and F-II) with molecular weight below 10,000Da were stronger than that of hydrolyzate(F-III) above 10,000Da. However, there was no significant difference between the hydrolyzate F-I and F-II. Three fractions of $\beta$-lactoglobulin hydrolyzates improves the growth rate of B.bifidum Bb-ll. The growth of B.bifidum Bb-ll was decreased after 24 hr incubation by supplementation of either F-II or F-III fraction compared to basal Whey medium, but maintained the enhancement by supplementation of F-I.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1277-1280
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• 2004

The effect of duodenal infusion with feed oligo-peptide solution on portal absorption of amino acids was investigated in poultry under unanaesthetized conditions. Four peptide solutions were used in the experiment: enzymatic hydrolysates from fish meal, soybean meal, cottonseed meal and rapeseed meal proteins with average molecular weights less than 3,000 Da and 1,000 Da, respectively. Intestinal absorptions of these oligo-peptide solutions were compared by determining the concentration of free amino acid (FAA) in portal blood after the duodenal administrations of oligo-peptide solutions. Absorptive intensity and balance were used to estimate the intestinal absorption rate of amino acids. The absorptive intensities of amino acids were highest for the fish and soybean meal oligo-peptides. The ratios of amino acids absorbed in the portal blood from fish and soybean meal oligo-peptides were more similar to the composition of the infused amino acids than that observed from the cottonseed and rapeseed meal oligo-peptides. A positive correlation was found between absorption rate and proportion of PAA in the oligo-peptides. The higher absorption rate could be contributed to the higher proportion of peptide bound amino acids (PAA). The results suggest that fish and soybean meal protein are significantly more easily hydrolyzed into oligo-peptides (p<0.05) in the gastrointestinal tracts of poultry and as such can be utilized more effectively by body tissues.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.503-511
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• 2008

An edible marine red alga, Grateloupia filicina, collected from Jeju Island of Korea was hydrolyzed by cheap food-grade carbohydrases (Viscozyme, Celuclast, AMC, Termamyl, and Ultraflo) to investigate its anticoagulant activity. Among the tested enzymatic extracts of G. filicina, a Termamyl extract showed the highest anticoagulant activity. Anion-exchange chromatography on DEAE-cellulose and gel-permeation chromatography on Sepharose-4B were used to purify the active polysaccharide from the crude polysaccharide fraction of G. filicina. The purified sulfated polysaccharide (0.42 sulfate/total sugar) showed ${\sim}1,357kDa$ molecular mass and was comprised mainly of galactose(98%) and 1-2% of glucose. The sample showed potential anticoagulant activity on activated partial thromboplastin time (APTT) thrombin time (TT) assays. The purified G. filicina anticoagulant (GFA) inhibited the coagulation factor X (92%), factor II (82%), and factor VII (68%) of the coagulation cascade, and the molecular interaction (protein-polysaccharide) was highly enhanced in the presence of ATIII (antithrombin III). The dissociation constant of polysaccharide towards serine proteins decreased in the order of FXa (58.9 nM) >FIIa (74.6 nM) >FVII (109.3 nM). The low/less cytotoxicity of the polysaccharide benefits its use in the pharmaceutical industry; however, further studies that would help us to elucidate the mechanism of its activity are needed.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.323-328
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• 2009

Cryotin F could be used for hydrolyzing shrimp byproducts into bioactive ingredients, which could be used as value-added products. The objective of this study was to investigate the optimum condition for antioxidative activities of the enzymatic hydrolysate produced with Cryotin F using response surface methodology with central composite rotatable design. Shrimp byproducts (shells and heads) were hydrolyzed with Cryotin F. The experimental ranges of the independent variables for 20 experimental runs were 28.2-61.8${^{\circ}C}$ reaction temperature, pH 6-10 and 0.5-5.5% enzyme concentration. The degree of hydrolysis for the reaction products was measured. Their antioxidative activities were measured using 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging activity and Fe-chelating activity. The experimental method with central composite rotatable design was well designed to investigate the optimum condition for biofunctional ingredients with antioxidative activities using Cryotin F because of their high R2 values of 0.97 and 0.95 for DPPH-scavenging activity and Fe-chelating activity, respectively. Change in enzyme concentration did not significantly affect their antioxidative activities (p<0.05). Both DPPH scavenging activity and chelating activity against Fe for the enzyme hydrolysates were more affected by the pH of enzyme hydrolysis than by their action temperature. DPPH-scavenging activity was higher at acidic pH than alkali pH, while chelating activity against Few was inversely affected. Hydrolysate of shrimp byproducts showed high antioxidative activities depending on the treatment condition, so the optimum treatment of enzymatic hydrolysate with Cryotin F and other proteases can be applied to shrimp byproducts (shells) and other protein sources for biofunctional ingredients.

• Korean Journal of Microbiology
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• v.21 no.2
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• pp.51-60
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• 1983

Cultural characteristics of Strptomyces griseolus isolated from the soil were investigated. This strain was disclosed to utilize D-xylose, and D-glactose in preference order as a carbon source with the formation of glucose isomerase. The addition of sweet potato starch also proved effective promoting the total enzyme activity measured at 29% higher than the control. Corn cob, one of waste agricultural resources, was hydrolyzed in 2~3% $H_2SO_4$ solution at $100^{\circ}C$, 3~5 hours to produce a xylose syrup which gave rise to the recovery of 19.9% in a batch system and 28.2% in a repeated system. By the addition of both 2% of xylose syrup(Be'28) prepared by and us 65% of corn steep liquor (total nitrogen 1.2%), enzyme induction was maximized. The enzyme activity was stimulated by the xylose and the cell growth by the C.S.L. Also, remarkable increase of enzyme activity was noticed by the addition of protein acid hydrolysate 86.2% higher than the control. $QO_2$ of the biomass cultured in 30L capacity jarfermentor recorded low oxygen requirement of 251.2 1/hr. Maximum activity of glucose isomerase was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery was observed noted at the 9th hour after inoculation which is 2 hours faster than the stationery phase of the biomass growth. Glucose isomerase from the strain was activated by adding the $Co^{++}\;and\;Mg^{++}$ with optimum temperature of $73^{\circ}C$ and pH of 7.2. Conversion ratio of 60% glucose to frutose was 42.5% after 70 hours reaction.