• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.320-324
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• 2003

The protein hydrolysis with 6 M formic acid containing 0.3% tryptamine was a superior method for amino acid analysis of standard amino acid and protein than 6 M HCI containing 0.3% tryptamine. The recoveries of standard amino acid after acid hydrolysis were more accurate in the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially recovery of tryptophan showed higher values of 1.5 times than that of 6 M HCI hydrolysis. The results of analysis on the standard protein, bovine serum albumin, showed very similar values compared to the sequence analysis reported in the literature for the 6 M formic acid hydrolysis than 6 M HCI hydrolysis, especially in the tryptophan recovery as standard amino acid recovery. Butylthiocarbamyl - trimethylsilyl (BTC - TMS) derivatives of 22 standard amino acids were successfully resolved DB-17 capillary column. Excellent reproducibility of standard amino acid recovery and composition of bovine serum albumin were obtained with BTC-TMS derivatives.

• KSBB Journal
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• v.20 no.2 s.91
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• pp.106-111
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• 2005

The functional relationship between the number of mole of an i-fatty acid (Si) included in fish oil and the hydrolysis time(t) was expressed as a mathematical model, $S_i=-{\alpha_i}1n(t)+\beta_i$. The average errors of calculated values on the basis of the measured values were distributed in the range of less than $5\%$ for all the 15 fatty aids composing of fish oil. The equation of hydrolysis rate of each fatty acid was deduced as $v_i={\gamma_i}exp(\frac{S_i}{\alpha_i})$ from the above-mentioned $S_i=-{\alpha_i}ln(t)+{\beta_i}$. Therefore the hydrolysis yields of fatty acids were analyzed using the equation of $S_i\;Vs.\;t.$. The 15 fatty acids were categorized into 4groups from the view point of hydrolysis yield. The hydrolysis yields of the first group, including C14:0, C16:0, C16:1, C18:0, C18:1 (n-7) and 1l8:1 (n-9), were higher than $70\%$ at 48 hr of hydrolysis. Those of the second group, C20:1, C22:1, C18:3, C20:4 and C20:5, were distributed from $40\%,\;to\;60\%$, and third group were around $30\%$. The final group containing only C22:6 was very hard to be hydrolyzed and the yield was less than $20\%$ at the same time.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.287-292
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• 2013

Reaction of glucose and xylose to secondary hydrolysis of concentrated acid hydrolysis was quantitatively analyzed by $^1H$-NMR spectroscopic method. Anomeric hydrogen, furan and formic acid peaks were selected for quantitative analysis. The glucose was converted to the formic acid and the levulinic acid via the 5-hydroxymethylfurfural (HMF) but the xylose was converted to the fufural, which further degraded to the formic acid. The conversion to furans was slower for the glucose than the xylose. But the 5-HMF formed from the glucose was unstable in acidic aqueous medium, resulted in fast conversion to the levulinic acid and the formic acid. The furfural was relatively stable than 5-HMF at acidic aqueous medium.

• Journal of Sericultural and Entomological Science
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• v.41 no.1
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• pp.48-53
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• 1999

The study was carried out to investigate the effects of hydrolysis conditions such as treatment times and concentrations on the solubility of insoluble sericin using the hydrochloric acid solution. When insoluble sericin was hydrolyzed by HCl solution, the solubility was increased with the higher treatment concentration. As the results of electrophoresis of sericin powder obtained by the HCl treatment, a distinguishable band was not confirmed. Average degree of polymerizations(A.D.P.) of sericin hydrolyzed by HCl solution were about 4.2~5.9 and average molecular weights(M.W.) were about 470~670. The longer hydrolysis time reduced the whiteness of sericin powder. As the results of amino acid analysis, the amino acid compositions of the sericin powder from HCl treatment were sililar to that of insoluble sericin, but Tyr. and Arg. were not detected in the powder obtained by HCl treatment. In DSC analysis, thermal deformation and pyrolysis peak located at near 220$^{\circ}C$ and 330$^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.77-86
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• 1990

The residue after hot water extraction of blue crab, Portunus trituberculata, was hydrolyzed for utilizing the byproducts as seasonings. The acid(5N HCl) hydrolyzates were then neutralized with $Na_2CO_3$, 5N NaOH or 5N NaOH hydrolyzate, while the alkali hydrolyzates (5N NaOH) were also neutralized with 5N HCl or 5N HCl hydrolyzate. The total nitrogen and formol nitrogen contents increased, and the platability of the hydrolyzates was also enhanced by neutralization. The released amino acid contents from the neutralized hydrolyzates with $Na_2CO_3$, 5N NaOH and 5N NaOH hydrolyzate were $2,274mg\%,\;2,105.0mg\%$ and $2,683.5mg\%$, respectively. Amino acid contents from the neutralized hydrolyzates with 5N HCl and 5N HCl hydrolyzate were $1,352.5mg\%$ and $2,498.8mg\%$, respectively. In the decolorization of hydrolyzates using decolorization agent, powdered active carbon showed good decolorizing effect. Powdered active carbon decreased total nitrogen and formol nitrogen contents in direct relationship to the increase in its concentration. The effective concentration of active carbon used as decolorization agent showed as $1\~2\%$ of the crab hydrolyzate. Salt contents could be decreased at 37 brix by desalination method such as the evaporation of the hydrolyzate contents.

• Journal of Life Science
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• v.19 no.1
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• pp.34-39
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• 2009

Alginate with a MW of 1,283 kDa was hydrolyzed with 0.4 M organic acids at $100^{\circ}C$ for 3 hr. Molecular weights of alginates hydrolyzed with organic acids ranged from 7.5 to 53.2 kDa. There was no significant difference in the molar ratio of mannuronate to guluronate in alginates hydrolyzed with organic acids. Acetic add was found to be the most effective organic acid for hydrolysis of alginate. The MW of alginate decreased with increasing concentration and reaction time with acetic acid as a hydrolyzing agent. The correlations between the MW of hydrolyzed alginate and concentration of acetic acid as well as reaction time with 0.4 M acetic acid were plotted and the relevant equations obtained in this study. Polymannuronate and polyguluronate were isolated by pH adjustment of alginate hydrolyzed with 0.4 M acetic add. The molar percentages of mannuronate in polymannuronates isolated from alginate hydrolyzed with 0.4 M acetic acid at $100^{\circ}C$ were increasing in proportional to the reaction time such as 75% for 1 hr, 90% for 3 hr, and 98% for 5 hr of reaction time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.4
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• pp.13-16
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• 1982

The hydrolytic conversion of sawdust was studied by sulfuric acid-enzymatic and sodium hydroxide-enzymatic treatments. Sugars were identified by paper chromatography and quantified colorimetrically. Sawdust yielded dextrose and xylose in concentrations ranging from 3.01 to 3.64 and 3.48 to 6.61 grams per 100g. Under optimum conditions, the total concentration of sugars was 10.7 grams per 100 grams.

• Korean Journal of Food Science and Technology
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• v.21 no.1
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• pp.1-8
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• 1989

Ten cultivars of malting barley grown at four locations were malted and assayed for six enzymes involved in the degradation of nucleic acids. Among these enzymes were deoxyrinonuclease, ribonuclease, phosphodiesterase, 3'- and 5'- nucleotidases and phosphomonesterase. Activities of all enzymes in five-day malts were significantly affected by variety and location of growth. The average levels of ribonuclease, deoxyribonuclease, 3'-nucleotidase and 5'-nucleotidase of 80 five-day malts were 11.2, 5.7, 5.6 and 1.2 units per gram of malt, respectively. Six-rowed barley malts contained higher levels of deoxyribonuclease, phosphodiesterase and 3'-nucleotidase than those of two-rowed barley malts, while two-rowed barley malts contained significantly higher ribonuclease levels than those of six-rowed barley malts.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.39-45
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• 2002

It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.

• Proceedings of the Korean Society of Life Science Conference
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• 2001.06a
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• pp.3-41
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• 2001

단백질의 부분 가수분해는 산성 음료에서의 용해도 증가, 환자들의 소화력과 알러지 내성의 개선, 다른 기능적 특성의 개발 등을 위하여 식품산업에 널리 이용되고 있다. 그러나 우유 단백질이나 대두 단백질과 같은 몇 가지 단백질들은 가수분해에 의하여 강한 쓴맛을 형성한다, 단백질 가수분해물의 쓴맛에 관한 연구는 1950년대 초에 시작되었으며, 여러 가지 원료로부터 쓴맛물질이 분리되었다. 이들 단백질 가수분해물의 쓴맛 물질은 올리고펩타이드로 알려져 있으며, 펩타이드 분자를 구성하는 소수성 아미노산의 존재와 밀접한 관계가 있는 것으로 보고되고 있다. 본 연구에서는 최근에 발달된 분석기술과 생명공학적 기법으로 E. coli에서 생산한 콩 단백질 단일 subunit를 이용하여 효소적 가수분해물의 분자구조를 확인하고자 하였다. 탈지대두박으로부터 115 glycinin와 E.coli떼서 발현된 proglycinin을 각각 90%, 97%의 정제도로 분리하여 이들 단백질을 trypsin으로 각각 가수분해하였다. 115 glycinin은 효소/기질 비 3%에서 4시간 가수분해에 의해 $14.0{\times}10^{-5}$ M quinine-HCI equivalent의 강한 쓴맛을 나타내었으며, 12%의 가수분해도(DH)를 나타내었다. 대두 단백질의 쓴맛 성분을 확인 위하여 이미 아미노산 서열이 밝혀진 11S glycinin과 proglycinin 가수분해물에서 GP-HPLC, $C_{18}$ RP-HPLC 등을 통하여 쓴맛 peptide들을 분리하였다. 각각의 분획은 다시 21개의 peptide로 분리되어 그 서열이 결정되었으며 이중 RP와 GI는 이미 알려진 쓴맛 dipeptide였고, LAGNQEQE, SAEFG, NALPE, KLHENIAR, GMIYPG 등이 주된 쓴맛 Peptide로 확인되었다. 이들은 11S glycinin의 5개의 subunit 중에서 그 위치가 확인되었다. Proglycinin 가수분해물에서도 11S glycinin과 같은 방법으로 7개의 쓴맛 peptide가 분리되었다. 이들은 $A_{1a}B_{1b}$의 아미노산 서열 중에서 37-42, 103-110, 164-167, 323-327, 367-373의 위치에 분포하고 있었으며, NALKPD, IYPGCPST, SlDT, HNIGQT, NAMFVPH의 서열을 나타내었다. 분리된 쓴맛 peptide 중에서 가장 쓴 두 분회의 peptide를 합성하여 관능 검사한 결과, NALPE는 매우 쓴맛을 내는 peptide로 확인되었다.