• KSBB Journal
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• v.10 no.5
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• pp.510-517
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• 1995

The hydrolysates of three kinds [FSEH(first step enzymatic hydrolysate), SSEH(second step enzymatic hydrolysate), and TSEH(third step enzymatic hydyolysate)] were prepared by continuous hydrolysis of Alaska pollack(Theragra chalcogramma) skin gelatin with three-step membrane enzyme reactor. The molecular weight distributions of FSEH, SSEH, and THSE are 9,500∼4,800Da, 6,600∼3,400Da, and 2,300∼900Da, respectively. The contents of amino acid having sweet taste (glycine, proline, serine, alanine, hydroxyproline, glutamic acid, and aspartic acid) were about 70% of total amino acid being in the three kind hydrolysates. We also tried preparing of natural seasonings (complex seasoning and enzymeatic hydrolysale sauce) using the hydrolysates. From the results of sensory evaluations, complex seasoning containing TSEH was nearly equal to shellfish complex seasoning on the market. The mixture sauce which was made by mixing of 80% enzymatic hydrolysis sauce and 20% fermented soy sauce, was at least similar to the tradition soybean sauce in product quality, too.

• Korean Chemical Engineering Research
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• v.52 no.2
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• pp.226-232
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• 2014

In this study, we investigated kinetic model for the acid-catalyzed xylan hydrolysis at temperature $120{\sim}150^{\circ}C$. Also, we analyzed the kinetic parameters for xylose production and furfural decomposition. The hydrolysis of xylan and the degradation of xylose were promoted by high reaction temperature and acid concentration. The optimal hydrolysis condition for the highest reaction rate constants ($k_1$) was different depending on the acid catalysts. Among sulfuric, oxalic and maleic acid, the xylan reaction rate constants ($k_1$) to xylose had the highest value of $0.0241min^{-1}$ when 100 mM sulfuric acid was used at $120^{\circ}C$. However, sulfuric acid induced more xylose degradation compared to oxalic and maleic acid hydrolysis. The activation energy for xylan degradation was the highest when sulfuric acid was used.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.129-132
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• 2005

This work was a method that used an acid hydrolysis for increasing the efficacy of decreasing alcohol concentration from Hovenia dulcis extract. For acid hydrolysis, the best pH was 2.0 to obtain a maximum alcohol dehydrogenase activity at fixed reaction temperature and time. At pH 2.0, reaction temperature $80^{\circ}C$ and reaction time 4 hr gave the highest activity which was $124\%$ of control. The bioactive compound, (+)-dihydromyricetin, content increased to $30\%$ after acid hydrolysis. This is very simple and efficient method to increase the efficacy of decreasing alcohol concentration from Hovenia dulcis extract.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.84-89
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• 2009

This paper was conducted to evaluate aglycones and carbohydrates produced by acid hydrolysis of three potato glycoalkaloids [(PGA); ${\alpha}$-chaconine, ${\alpha}$-solanine, and demissine] in potatoes. Standard solanidine and demissidine were dissolved in 1N HCl and then heated at $100^{\circ}C$ for 10-120 min. Solanidine was rapidly decomposed during acid hydrolysis and one peak that was identified as solantherene ($M^+$=379) by GC-MS was detected. The transformation solanidine to solanthrene was approximately 50% complete after 10 min, approximately 90% complete after 60 min and 100% complete after 120 min. Demissidine was hydrolyzed using the same method that was used to hydrolyze the solanidine. However, demissidine produced only one peak upon GC-MS ($M^+$=399) analysis and was found to be very stable at increased temperatures. Acidy hydrolysis of ${\alpha}$-chaconine, ${\alpha}$-solanine and demissine resulted in the decomposition of ${\alpha}$-chaconine and ${\alpha}$-solanine to solanidine and solanthrene, respectively. Therefore, this hydrolysis method should not be utilized to produce PGA combining with solanidine as aglycone. The individual carbohydrates produced by the two PGAs by hydrolysis were very stable at increased temperatures; therefore, it was possible to quantify these PGAs based on calculation of the individual carbohydrate content. Conversely, because demissidine produced by the hydrolysis of demissine was extremely stable at increased temperatures, it was possible to quantify the PGA based on the aglycone produced by hydrolysis.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.315-319
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• 1994

Use of a solid superacid (Nafion) in hydrolysis of rice straw was investigated focusing on the fermentability of the hydrolyzates by Pichia stipitis CBS 5776. Comparisons were made with the hydrolyzates produced by a conventional method of sulfuric acid treatment. The Nafion-catalyzed hydrolyzates of rice straw exhibited low level of inhibition for both cell growth and fermentation in comparison to the hydrolyzates produced by sulfuric acid. Pichia stipitis cells were able to produce ethanol by fermentation of Nafion-catalyzed hydrolyzates when the inoculum level exceeded 3.2 g dry cells/l.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.168-171
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• 2005

한우의 Myosin B 단백질을 단백질 가수분해 효소인 pepsin으로 처리한 다음 단백질의 함량과 혈압상승 펩티드 생성효소인 angiotensin-I converting enzyme(ACE)에 대한 저해활성을 측정하였다. 등심이 우둔에 비해 단백질의 함량이 높았으며, 가수분해 처리 후 우둔과 다르게 등심은 3시간 가수분해 처리구에서 단백질의 함량이 높게 나타났다. ACE 저해활성은 등심에서는 3시간, 우둔에서는 6시간동안 가수분해시켰을 때 ACE 저해율이 유의적으로 가장 높게 나타났으며, 3, 6시간동안 가수분해시켰을 경우 부위 별로 유의적인 차가 있었으나(p<0.05), 0, 1시간동안 가수분해 시켰을 때는 부위간의 유의적인 차는 없었다(p>0.05). ACE 저해율이 가장 좋은 가수분해 처리구를 ultrafiltration시킨 결과, 저분자 peptide 상태의 가수분해물이 고분자에 비하여 ACE 저해율이 높은 것으로 나타났다. 차후 ACE 억제활성도가 높은 단백질을 분리하여 가장 우수한 분획을 찾아 아미노산 염기서열을 밝혀 고혈압 억제제로 합성 개발하는 연구를 추진할 예정이다.

• Journal of Life Science
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• v.18 no.11
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• pp.1617-1624
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• 2008

Chitin and chitosan, which is deacetylated form of chitin, are one of the most abundant biomass on the earth. They showed various biological activities including antimicrobial activity, heavy metal chelating, immune system activation, and have very diverse applications in food, pharmaceutical, medicinal, and environmental industry. There have been reported many chitin/chitosan-hydrolyzing enzymes, their structures and genes from three domains, archaea, bacteria, and eukarya. Carbohydrate hydrolyzing enzymes are classified in CAZy (Carbohydrate Active Enzymes) database according to their amino acid sequence similarity. Interestingly, chitinases and chitosanases are classified in various glycosyl hydrolase(GH) families, GH2, GH5, GH7, GH8, GH18, GH19, GH20, GH46, GH48, GH73, GH75, GH80, GH84, and GH85. Here, we review characteristics and structures of chitin/chitosan hydrolyzing enzymes according to glycosyl hydrolase families in order to provide information about gene mining.

• Food Science and Preservation
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• v.23 no.3
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• pp.413-421
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• 2016

The aim of this study was to investigate physicochemical properties of porcine blood hydrolyzed by proteases under various conditions for utilization as a food source. Five kinds of proteases (Alcalase, Neutrase, Protex-40L, PTPF-1430, and KMFP-15) were tested at different concentrations (0.1, 0.2, and 0.3%, w/v) during hydrolysis at 55 for 4 hr. Hydrolysis with $^{\circ}C$ KMFP-15 showed the lowest pH by 7.3. The highest soluble solid ($24.3^{\circ}Brix$) and free amino acid (4,944 mg%) contents were obtained by hydrolysis with KMFP-15 (w/v) at 0.2% addition level, which was not significantly different from the sample hydrolyzed at 0.3% level. Under the optimal condition of KMFP-15 at 0.2%, porcine blood was hydrolyzed at 60 up to 8 hr. The $^{\circ}C$ free amino acid content reached the highest at 4 hr, and then decreased with longer hydrolysis time. Under the optimal hydrolysis conditions, porcine blood hydrolysis powder had plenty of crude proteins, amino acids, and minerals, including iron, potassium, and zinc. The results showed that porcine blood could be utilized as an useful source of food supplement. The optimum conditions of hydrolyzing porcine blood, using 0.2 KMFP at $60^{\circ}C$ for 4 hr, can be used in the commercial production of protein supplements, amino acid sources, and iron fortifying agents.

• Korean Journal of Food Science and Technology
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• v.47 no.6
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• pp.772-778
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• 2015

Hydrolysis of isolate soybean protein (ISP) using subcritical water (SCW) was conducted to study the feasibility for producing protein hydrolyzate. SCW hydrolysis of SPI suspension (5-15%) was conducted in an electrically heated batch reactor (2 L). The effects of temperature (230 to $270^{\circ}C$) and holding time (10 to 50 min) on the degree of hydrolysis (DH) and the production of amino acids were studied by surface response method. The DH was determined by derivatizing the hydrolyzates with ortho-phthalaldehyde (OPA) solution. It was confirmed that reaction temperature and holding time affected the hydrothermolysis of soybean protein. However, the holding time was less effective on amino acid yield when the temperature was higher than $230^{\circ}C$. In order to achieve optimal yields of amino acids exceeding 43%, the temperature should be within the range between 256 and $268^{\circ}C$ with holding time from 29 to 41 min, respectively. A maximum estimated amino acid yield of 43.5% was obtained at $268^{\circ}C$ for 35 min.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.226-233
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• 1993

Enzymatic hydrolysates of food proteins (defatted soybean cake, egg albumin and casein) were tested for inhibitory activity against angiotensin-I converting enzyme (ACE). Food proteins were hydrolysed with complex enzyme, bromelain, alcalase, $\alpha$-chymotrypsin, trypsin, papain and pepsin by heating method. The hydrolysates obtained from the treatment of complex enzyme and bromelain showed the higher ACE inhibitory activity. ACE inhibitory activity of hydrolysates exhibited a tendency to be increased until 8hrs and increased with increment of concentration. The activity was also stable by heat treatment at 10$0^{\circ}C$ for 20min. Molecular weight of active fraction was about 1, 400 and defatted soybean cake hydrolysate below 1, 400 in case of defatted soybean cake hydrolysate treated with alcalase. Amino acid of the active fractions was abundant in Asp, Glu, Lys, lle, Leu, Ala and Val.