• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.417-426
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• 1997

Rice bran protein hydrolysates were prepared and some of their physicochemical properties were investigated to utilize rice bran as starting material for functional food ingredient. Rice bran proteins (RBP) were prepared from defatted rice bran by alkaline extraction and isoelectric precipitation. The enzyme for hydrolysis of RBP was selected through measuring relative activity by pH-drop method and comparing the degree of hydrolysis (DH) of hydrolysates. The enzymatic hydrolysates prepared by $Esperase^{\circledR}$ treatment were partitioned into two fractions by ultrafiltration(UF) with a 10 kDa molecular weight cut-off membrane. Each fraction was applied to a cholic acid-conjugated ${\omega}-aminohexyl$ Sepharose 4B column and the bile acid-binding components were obtained by eluting with deoxycholate. Gel permeation chromatography on a Sephadex G-50 column revealed that molecular weight of the bile acid-binding fraction of UF permeate was distributed in ranges of $2\;kDa{\sim}10\;kDa$ and $0.2\;kDa{\sim}0.6\;kDa$. Three peaks (R-1, R-2 and R-3) were obtained by prep-HPLC of bile acid-binding fraction of UF retentate and analyzed for total and free amino acid composition. The results showed that proline content of the bile-acid binding polypeptides and peptides was four times as much as that of rice bran protein and that the peak corresponding to higher average hydrophobicity had a higher free amino acid content. Average hydrophobicity slightly increased with enzymatic hydrolysis.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.109-115
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• 2012

The aim of this study was to determine hepatoprotective effects of pig placenta hydrolysates (PLA) on liver damage-induced rats. Sprague Dawley rats were subcutaneously injected with carbon tetrachlorides and divided into 4 groups: negative control (DMSO treated), two PLA treated groups, low dosage of PLA (LPLA; 300 mg/kg body weight) and high dosage of PLA (HPLA; 1000 mg/kg body weight), and silymarin treated group (80 mg/kg body weight). Rats in each group orally received assigned compounds for 3 weeks. For the normal control group vehicle (corn oil) was injected. After 3 weeks, liver and spleen weights were greater in the two PLA and silymarin groups than the negative control group. After bromosulfalein (BSP) treatment, the clearance rates were in the descending order of negative control > LPLA > HPLA = silymarin and serum BSP levels exhibited the opposite trends of the clearance rates. Serum levels of aspartate aminotransferase, alanine aminotransferase, triglyceride, and cholesterol lowered with PLA in a dose-dependent manner. The decrease with HPLA was similar to that with silymarin. In addition, triglyceride, cholesterol, lipid peroxides levels in the liver decreased in HPLA and silymarin compared to the negative control. The liver morphometry was improved in HPLA- or silymarin-treated rats in comparison to the negative control. In conclusion, HPLA administration ameliorated the hepatotoxicity as much as silymarin in rats injected with carbon tetrachlorides.

• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.24-29
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• 2001

This study was conducted to investigate insecticidal activities of Ginkgo biloba (L.) leaves-derived bilobalide and its hydrolysis and oxidation products against adults of Nilaparavata lugens Stal. To find out active insecticidal moiety of bilobalide, decomposed intermediates and derivatives of bilobalide were made by hydrolysis, oxidation, and acetylation. The structures of hydrolysis product by base and oxidation product by acid were identified as cyclopentenone analogues and trilactone sesquiterpene from dehydration of bilobalide, respectively. Insecticidal activities of the decomposed intermediates and the derivatives of bilobalide decreased in the order of bilobalide, monoacetate, ginkgolide C, oxidation product, diacetate, and hydrolysis product. Therefore, trilactone structure of bilobalide may be essential for its insecticidal activity.

• 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 Journal of Food Science and Technology
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• v.22 no.3
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• pp.234-240
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• 1990

Attempts have been made to optimize the hydrolysis conditions of the oyster and the mussel by the commercial proteolytic enzymes. Raw materials were digested with seven different commercial enzymes, and their quality parameters measured in terms of degree of hydrolysis and content of free amino nitrogen, nucleic acid-related substances. and free amino acids as well as sensory evaluation of optimization of their hydrolysis conditions. As a result, following enzymes have been disclosed as effective for enzymatic digestion: MKC-HT proteolytic, alcalase 0.6L and thermease for the oyster whereas MKC-acid fungal protease and thermoase for the mussel, respectively.

• KSBB Journal
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• v.6 no.4
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• pp.327-336
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• 1991

A study on the optimum hydrolysis conditions of fish skin through the aid of enzymes and the development of a natural seasoning using the hydrolysate has been carried out for the effective utilization of fish skin. Using the "pH-drop" techniques the collagenase and pronase were identified as most suitable for this purpose. The $K_m$ and $V_{max}$ values of pronase were 1.82 mgN/ml and 0.06 mgN/mL/min, respectively. The hydrolysis conditions of the cod skin for the pronase were as follows: reaction temperature, $50^{\circ}C$; reaction time, 3hrs; pH 6; enzyme concentration, 0.03%. The degree of hydrolysis at these conditions was 76.8%. But after hydrolyzing cod skin with collagenase for 1hr, when the pronase was treated, the degree of hydrolysis was 83.13%. The molecular weight of the hydrolysate was 8,000 daltons. Among the amino acids in the hydrolysate, glycine(27.95%), glutamic acid(10.94%), proline(7.39%), aspartic acid(9.47%) and serine(7.39%) were responsible for 64.23% of the total amino acids. But valine, methionine, isoleucine, leucine, phenylalanine and histidine having a bitter taste were only 13.05%. From the results of the sensory evaluation, the imitation sauce which was made of 20% fermented soy sauce prepared from the hydrolysate was at least similar to the traditional soybean sauce in product quality. The complex seasoning containing 31.7% of the hydrolysate was nearly equal to complex seasonings on the market, too.

• Analytical Science and Technology
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• v.13 no.5
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• pp.549-557
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• 2000

FRIR-ATR spectrometry has been used to monitor the aqueous reactions of compounds without distinct chromophores in ultraviolet and visible regions. For example, hydrolysis reactions of ${\alpha}$-cyclodextrin and ${\gamma}$-cyclodextrin in acidic aqueous solution were studied. FTIR-ATR method has been used for the monitoring of cyclodextrin hydrolysis in 1.0 M. 0.5 M, and 0.1 M HCl solutions, respectively. We also found that the hydrolysis of ${\alpha}$-cyclodextrin produced glucose, but the hydrolysis of ${\gamma}$-cyclodextrin proceeded further to give more fragmented products than glucose.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.719-726
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• 2006

Bovine whey protein are rich in cysteine, which is the rate limiting amino acid for synthesis of antioxidant glutathione(GSH). Some strains of Lactobacillus caseihas been reported to contain high level of GSH in cell extracts. The objective ofthis study was to determine whether enzymatically hydrolyzed whey protein isolate(WPI) and cell extract of Lb. casei HY2782 could increase intracellular GSH concentrations and protect against oxidant induced cell death in human prostate epithelial cell line (designated as RWPE1, and PC3MMM2 cells). Treatment of RWPE1 cellsandPC3MMM2 cells with hydrolyzed WPI (500g/ml) significantly increased GSH by28.2% and38.4% respectively. Compared with control cells receiving no hydrolyzed WPI(P<0.05). hydrolyzed WPI and Lb casei HY2782 cell extracts significantly protected RWPE1 and PC3MMM2 cellsfrom oxidant induced cell death compared with controls receiving no WPI. DNA damage associated with oxidant treatment was demonstrated by single cell gel (SCG) electrophoresis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.7
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• pp.881-888
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• 2007

For the use of skipjack tuna cooking drip (STC) as a source of functional seasoning, the STC was hydrolyzed with various commercial enzymes, such as Alcalase, Flavourzyme, Neutrase and Protamex, and its hydrolysate was also investigated on the food component characteristics. The hydrolysate incubated with Alcalase for 30 min (HA30) showed 56.8% for angiotensin I converting enzyme (ACE) inhibitory activity and 1.18 for antioxidative activity, which were high or similar compared to the other enzymatic hydrolysates. There were no differences in ACE inhibitory activity and antioxidative activity among HA30, two-step enzymatic hydrolysates, and ultrafilterates (molecular weight cut off, 10 kDa). The HA30 was very stable on the digestive enzymes, such as chymotrypsin, pepsin, trypsin according to the TCA (trichloroacetic acid) soluble index. The results suggested that skipjack tuna cooking drip could be used as a source for preparing functional seasoning sauce.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.221-228
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• 2022

Major egg white proteins and their hydrolysates serve as functional food ingredients that have certain metal-chelating properties. Employing egg white proteins and their hydrolysates to scavenge dietary oxalates is anticipated to have beneficial effect in the prevention of kidney stones. The objective of this study was to determine the biogenic oxalate-chelating activity of ovalbumin, ovomucin, and ovotransferrin and their hydrolysates. To prepare oxalate extracts, 30 mL of 0.25 N HCl was added to separately to 0.5 g of dried spinach and starfruit powders followed by boiling for 15 min, and after cooling, the addition of a further 20 mL of 0.25 N HCl. Having prepared these extracts, ovalbumin, ovomucin, and ovotransferrin and their hydrolysates were separately mixed with oxalate extracts and incubated at 3℃ for 24 h. Following centrifugation, supernatants were analyzed by HPLC using a reverse-phase C18 column coupled with a diode array detector. We found that all assessed proteins and their hydrolysates showed biogenic oxalate-chelating activity against the oxalates of spinach. In contrast, however, only ovalbumin, ovalbumin-hydrolysate, and ovomucin showed chelating activity (57.10%±8.84%, 85.44%±5.30%, 73.20%±4.13%, respectively) against the oxalates of starfruit (P<0.05). Overall, hydrolyzed ovalbumin was identified as the most effective chelator of the oxalates both spinach and starfruit. In this study, we thus established that the assessed egg white proteins and their hydrolysates have oxalate-chelating activity in vitro, thereby indicating that these compounds have potential utility as nutraceuticals for the chelation of dietary oxalate. However, further research will be necessary to verify their oxalate-chelating activities against different fruits and vegetables and under specific in vivo conditions and against purified oxalate.