• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.211-215
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• 1999

The pure-separation of calcium chloride-treated fibroin hydrolysates could be carried out using gel filtration chromatography. Also, the effect of its enzymatic hydrolysis was investigated in order to find out the enhancement of their functionality. The average molecular weight(Mw), solubility and free amino acid compositions of three hydrolysates samples (calcium chloride, calcium chloride-flavourzyme and calcium chloride-thermoase)were measured to compare their characteristics. The molecular weight of calcium chloride hydrolysate was about Mw 46,800 and it can be reduced to Mw 12,500 and 1,070 upon the enzymatic hydrolysis by flavourzyme and thermoase, repectively. A solubility of calcium chloride-treated samples shows about 60% while calcium chloride/enzyme-treated samples are perfectly soluble (100% solubility). The total amino acid composition of calcium chloride enzymatic hydrolysates are much higher than that of calcium chloride hydrolysate.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.97-102
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• 2021

In this study, enzymes were screened for hydrolysis of defatted perilla seed residue (DPSR) and optimal conditions for enzymatic treatment were determined to produce the hydrolysate of DPSR. Also its antioxidant activity and utilization as a culture medium were examined. The combined treatment of Alcalase and Ceremix is most effective for solubilization of protein and carbohydrate in DPSR. The optimal dosage, pH, and reaction time for enzymatic treatment were found to be 2.0% (w/w), 7.0, and 2 h, respectively. Treatment with optimal conditions of enzymes dramatically increased reducing sugar, soluble protein, and total phenolic content. The hydrolysate of DPSR possessed better scavenging activity against cation and free radicals than enzyme-untreated extract. When Leuconostoc mesenteroides 310-12 was cultured in the hydrolysate of DPSR, cell population rapidly increased compared to enzyme-untreated extract, and titratable acidity increased in proportion to the bacterial growth. In conclusion, these results imply that the hydrolysate of DPSR could be utilized as a bacteria culture medium as well as a physiologically active material with antioxidant activity.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.238-243
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• 2005

This study was carried out to understand hyrolytic characteristics of $\beta-casein$ by enzyme in goat milk and to measure the inhibition effect of the ACE of the hydrolysate. In order to conduct the experiment, $\beta-casein$ of goat milk was separated using Mono S HR 5/5, a cation exchange column. The separated $\beta-casein$ was treated with trypsin of animal hydrolysis enzymes, in an effort to verify the characteristics of hydrolysis. The inhibition activity of ACE was measured and the results are as follows. By analyzing the hydrolysate separated from the trypsin-processed $\beta-casein$ of goat milk, the inhibition effect of the ACE was measured trypsin-hydrolyzed $\beta-casein$ demonstrated a $25.36\pm0.79\%$ of inhibition effect and the $IC_{50}$ of the hydrolysate from the trypsin-processed $\beta-casein$ reached $308.7\pm2.77({\mu}g/mL)$.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.3
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• pp.417-424
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• 2003

Inhibitory activities against angiotensin I-converting enzyme (ACE) of enzymatic hydrolysates of porcine skeletal muscle proteins were investigated. Myosin B, myosin, actin, tropomyosin, troponin and water-soluble proteins extracted from pork loin were digested by eight kinds of proteases, including pepsin, $\alpha$-chymotrypsin, and trypsin. After digestion, hydrolysates produced from all proteins showed ACE inhibitory activities, and the peptic hydrolysate showed the strongest activity. In the case of myosin B, the molar concentration of peptic hydrolysate required to inhibit 50% of the activity increased gradually as digestion proceeded. The hydrolysates produced by sequential digestion with pepsin and $\alpha$-chymotrypsin, pepsin and trypsin or pepsin and pancreatin showed weaker activities than those by pepsin alone, suggesting that ACE inhibitory peptides from peptic digestion might lose their active sequences after digestion by the second protease. However, the hydrolysates produced by sequential digestion showed stronger activities than those by $\alpha$-chymotrypsin, trypsin or pancreatin alone. These results suggested that the hydrolysates of porcine meat were able to show ACE inhibitory activity, even if they were digested in vivo, and that pork might be a useful source of physiologically functional factors.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.5
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• pp.732-737
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• 2008

This study developed a natural ingredient as a functional food possessing properties of attenuation of hypertension and cardiovascular hypertrophy. In a previous study hydrolysates obtained from chicken leg bone protein using Alcalase strongly inhibited angiotensin I converting enzyme (ACE) in vitro. In particular, hydrolysate (A4H) from four hours of incubation exhibited the highest ACE inhibitory activity (IC50 = 0.545 mg/ml). A4H was selected as a potent ACE inhibitor and orally administrated to spontaneously hypertensive rats (SHR) for eight weeks to investigate attenuating effects on age-related development of hypertension and cardiovascular hypertrophy. Results showed that treatment with A4H of SHRs attenuated the development of hypertension as effectively as the clinical antihypertensive drug captopril. Moreover, a significantly lower heart to body weight ratio and thinness of coronary arterial wall was observed in SHRs that had been treated with A4H or captopril. The results suggest that A4H can be utilized in developing an ACE inhibitor as a potential ingredient of functional foods to alleviate hypertension and cardiovascular hypertrophy.

• KSBB Journal
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• v.24 no.5
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• pp.415-419
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• 2009

In this study, the detoxification methods were evaluated for the removal of fermentation inhibitors from synthetic solution containing the composition similar to the lignocellulosic hydrolysate. The enzyme peroxidase and laccase were used as a biological treatment method. The physico-chemical methods such as adsorption and ion exchange were applied by using activated charcoal and ion exchange resins. The enzyme peroxidase showed a excellent removal of phenolic compounds. The 5-HMF and furfural were completely removed by activated charcoal. The anion exchange resin showed a good result for detoxification of acetic acid. The activated charcoal and ion exchange resins lead to a loss of sugars more or less. The choice of detoxification method must be made after considering the composition and inhibitors in hydrolysates.

• Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.393-405
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• 2023

The aim of this research was to enhance the flavor of visceral extracts from skipjack tuna. Flavor precursors and the optimum condition for the Maillard reaction were determined. The flavor extract was prepared from the tuna viscera using Endo/Exo Protease controlled in 3 factors; temperature, enzyme amounts and incubation time. The optimal condition for producing tuna viscera protein hydrolysate (TVPH) was 60℃, 0.5% enzyme (w/w) and 4-hour incubation time. TVPH were further processed to tuna viscera flavor enhancer (TVFE) with Maillard reaction. The Maillard reactions of TVFE were conducted with or without supplements such as xylose, yeast extract and methionine. The Maillard volatile components were analyzed with gas chromatography-mass spectrometry. Sixteen volatiles such as 2-methylpropanal, methylpyrazine, 2,5-dimethylpyrazine, dimethyl disulfide and 2-acetylthaizone were newly formed via Maillard reaction and the similarity of volatile contents from TVPH and TVFE were virtualized using Pearson's correlation integrated with heat-map and principal component analysis. To virtualize aromagram of TVPH and TVFE, odor activity value and odor impact spectrum (OIS) techniques were applied. According to OIS results, 3-methylbutanal, 2-methylbutanal, 1-octen-3-ol 2,5-dimethylpyrazine, methional and dimethyl trisulfide were the potent odorants contributed to the meaty, creamy, and toasted aroma in TVFE.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.3
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• pp.210-219
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• 2003

To develop natural flavoring substances, optimal two stage enzyme hydrolysis conditions and flavor compounds of short-neck clam (Tapes philippinarum) enzyme hydrolysates were examined. The optimal enzyme hydrolysis conditions for two stage enzyme hydrolysate (TSEH) of short-neck clam were revealed in temperature at $55^{\circ}C$ for 4 hours digestion with alcalase at the 1st stage and 4 hours digestion at $45^{\circ}C$ with exopeptidase type neutrase at the 2nd stage. In quality tests of hot-water extracts, steam extracts and 4 kinds of enzyme hydrolysates, TSEH processing method was superior to other methods in yield, nitrogen contents, organoleptic taste such as umami intensity and inhibition of off-flavor formation, and transparency of extract. Total free amino acid contents in hot-water extract, steam extract and TSEH were 1,352.1 mg/100 g, 1,174.1 mg/100 g and 2,122.4 mg/100 g, respectively, Major free amino acids in TSEH were glutamic acid, glycine, alanine, tyrosine, phenylalanine and arginine. As for nucleotides and other bases, betaine, TMAO and creatinine were principal components in TSEH. The major inorganic ions in TSEH were Na, K, P and Cl. TSEH also revealed very higher angiotensin-I converting enzyme inhibition effect $(70.7\%)$ than those of hot-water and steam extract. We conclude that TSEH from short-neck clam was more flavorable compared with the seasoning materials on the market, it could be utilized as the instant soup base and the seasoning substances for fisheries processing.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.565-571
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• 2007

This study was carried out to investigate an optimum condition for the high angiotensin-l converting enzyme (ACE) inhibitory activity and the yield on enzyme concentration, casein concentration, and hydrolysis time. The optimum condition was performed by response surface methodology for acquirement of casein hydrolysate of milk which shows high ACE inhibitory activity, Among 8 tested enzymes, Protamex showed the highest activation degree with 77.03 unit/g from casein. Their hydrolysis degrees of flovourzyme 500MG, protamex, mixture from 1% casein were 85.5, 88.5, and 93.5%, respectively. The ranges of enzyme concentration (0.25-1.25%), casein concentration (2.5-12.5%), and hydrolysis time (20-100 min) as 3 independent variables through preliminary experiments of the yield of casein hydrolysate and ACE inhibitory activity, and it shows optimum response surface at a saddle point. It shows enzyme concentration (0.64%), casein concentration (8.38%), and hydrolysis time (55.81 min) in the yield aspect and showed the highest activity at enzyme concentration (0.86%), casein concentration (5.97%), and hydrolysis time (63.86 min) in ACE inhibitory aspect. The $R^2$ value of a fitted optimum formula on the hydrolysis yield was 0.9751 as the significant level of 1%. The $R^2$ value of a fitted optimum formula on ACE inhibitory activity is 0.8398, and the significance is recognized in the range of 5%.

• Journal of Korean Society of Forest Science
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• v.99 no.5
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• pp.744-749
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• 2010

Enzymatic hydrolysate from non pre-treated biomass of yellow poplar (Liriodendron tulipifera) was prepared and used as resource for bioethanol production. Fresh branch (1 year old) of yellow poplar biomass was found to be a good resource for achieving high saccharification yields and bioethanol production. Chemical composition of yellow poplar varied significantly depending upon age of tree. Cellulose content in fresh branch and log (12 years old) of yellow poplar was 44.7 and 46.7% respectively. Enzymatic hydrolysis of raw biomass was carried out with commercial enzymes. Fresh branch of yellow poplar hydrolyzed more easily than log of yellow poplar tree. After 72 h of enzyme treatment the glucose concentration from Fresh branch of yellow poplar was 1.46 g/L and for the same treatment period log of yellow poplar produced 1.23 g/L of glucose. Saccharomyces cerevisiae KCTC 7296 fermented the enzyme hydrolysate to ethanol, however ethanol production was similar (~1.4 g/L) from both fresh branch and log yellow poplar hydrolysates after 96 h.