• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1629-1640
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• 2015

This study was performed to compare carcass traits, sensory characteristics, physiochemical composition, and contents of nucleotides, collagen, and free amino acids among quality grades (QG) and to understand the association between QG and above parameters in loin and rump of Korean cattle steer. Loin and rump samples were obtained from 48 Korean cattle steers with each of four QG (QG 1++, 1+, 1, and 2; average 32 months of age). Carcass weight and marbling score (MS) were highest in QG 1++, whereas texture score measured by a meat grader was highest in QG 2. A correlation analysis revealed that MS (r = 0.98; p<0.01) and fat content (r = 0.73; p<0.01) had strong positive correlations with QG and that texture had a strong negative correlation (r = -0.78) with QG. Fat content in loin was highest but protein and moisture contents were lowest in QG 1++. Our results confirmed that a major determinant of QG is the MS; thus, intramuscular fat content. The International Commission on Illumination $L^*$, $a^*$, and $b^*$ values in loin were highest in QG 1++. Numeric values of shear force in loin were lowest in QG 1++, whereas those of tenderness, juiciness, and overall acceptability tended to be highest in QG 1++ without statistical significance. QG was strongly correlated with juiciness (r = 0.81; p<0.01) and overall acceptability (r = 0.87; p<0.001). All sensory characteristics were higher (p<0.05) in loin than those in rump. Adenosine-5'-monophosphate (AMP) and inosine-5'-monophosphate (IMP) contents in both loin and rump did not differ among QGs. No nucleotide (AMP, IMP, inosine, hypoxanthine) was correlated with any of the sensory traits. Total, soluble, and insoluble collagen contents in loin were higher in QG 1++ than those in QG 1. All three collagens had lower content in loin than that in rump. All three collagens were positively correlated with tenderness, juiciness, and overall acceptability. Glutamic acid content did not significantly differ among the four QGs in either loin or rump. In conclusion, it is confirmed that QG is associated with sensory traits but nucleotide contents in beef may not be a major factor determining meat palatability in the present study.

• Preventive Nutrition and Food Science
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• 제1권1호
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• pp.16-22
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• 1996

Amino acids and ribonucleotides were measured for boiled-dried anchovy to determine the effect of 5 kGy γ-irradiation on its quality stability during storage at ambient and cooling (5∼10℃) temperatures for 12 months in a laminated-film package(Polyethylene 10㎛). The anchovy samples contained about 55%(d.b) of total amino acids and about 1%(d.b) of free amino acids. Although there found a significant change(p<0.01) in the content of leucine and lysine immediately sfter irradiation, the overall content of toral amino acids was little changed in stored anchovy even six months after irradiation at cooling conditions. γ-Irradiation caused a significant reduction(p<0.01) in the total content of free amino acids, showing a similar tendency by storage conditions. However, the ribonucleotides. which were 12.00mg/g(d.b) in inosine-5'-monophosphate and 0.38mg/g(d.b) in guanosine-5'-monophospate, were resistant to 5kGy-irradiation. With the lapse of storage time, it was also shown that storage temperature was more influential than irradiation on the contents of amino acids and taste compounds of dried anchovy.

• 미생물학회지
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• 제31권1호
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• pp.54-62
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• 1993

Intracellular adenosine deaminase (ADA) from Aspergillus oryzae was purified using ammonium sulfate fractionation, a DEAE-Sephadex A-50 anion exchange chromatography, an ultrafiltration using a PM 10 membrane and two times of Sephadex G-100 gel filtration chromatography. The enzyme was purified 151 fold with a 9% recovery. Purified enzyme gave a single protein band with a molecular weight of 105,000 delton. The enzyme was reasonably stable. The enzyme activity was kept even after 1 hr incubation at 55.deg.C, but decreased significantly at 60.deg.C. The pH optimum was found to be from 6.5 to 7.5. Among tested compounds, the substrate activity was found with adenosine, adenine arainofuranoside, formymcin A, 2'-deoxyadenosine, 3'-deoxyadenosine, 2', 3'-isopropylidene adenosine, 2,6-diaminopurine deoxyriboside, .betha.-nicotinamide adenine dinucleotide (reduced form), 6-chloropurine riboside, 2'-adenine monophosphate (AMP), 3'-AMP and 5'-AMP. The values of Km of adenosine and 2'-deoxyadenosine were calculated to be 500 and .$710\mu$m, respectively. ADA was sensitivite to $Zn^{2+}$, $^Cu{2+}$ and $Fe^{3+}$, p-chloromercuribenzoate and mersalyl acid inactivated the enzyme. The activity of enzyme was not changed when ADA was incubated with dithiothreititol, 2-mercaptoethanol, N-ethylmaleimide, iodoacetic acid and iodoacetamide.

• Asian-Australasian Journal of Animal Sciences
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• 제31권1호
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• pp.123-128
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• 2018

Objective: This study was performed to determine effects of different curing salts on the quality of salamis and to assess feasibility of using NaCl-alternative salts. Methods: Various types of curing salts (KCl or $MgCl_2$) as well as NaCl (sun-dried or refined) were incorporated for processing of salamis. The proximate composition, fatty acids, nucleotide-related compounds, and free amino acids of the salamis were analyzed during 40 days of ripening. Results: The substitution of NaCl by KCl caused higher fat and ash content, but lower moisture content of the salami after 20 days of ripening (p<0.05). Compared with the sun-dried NaCl, use of KCl in salami also led to greater inosine 5'-monophosphate whereas refined NaCl had more inosine (p<0.05). KCl-added salami also had a higher C12:0, C17:1, and C20:0 than other types of salami (p<0.05). $MgCl_2-added$ salami had higher content of free amino acids compared to the other salamis (p<0.05). Conclusion: Alternative curing salts such as KCl and $MgCl_2$ could substitute NaCl in consideration of quality factor of a fermented meat product. Especially replacement of NaCl with KCl will be a suitable strategy for developing relatively low sodium salami products without compromising product quality.

• 한국축산식품학회지
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• 제32권4호
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• pp.428-433
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• 2012

The objective of this study was to identify appropriate aging conditions, changes in nucleotide-related compounds, chemical changes, and a sensory evaluation of duck meat during aging at $0^{\circ}C$ for 7 d. Twenty one 45-day-old Pekin white ducks samples were separated into breast and leg meat. ATP was not detected for almost the entire aging period because ATP was depleted immediately after slaughter. Inosine monophosphate (IMP) was highest on day 1 ($26.69{\mu}mol/g$), and then it rapidly decreased to $7.11{\mu}mol/g$ on day 7. However, this level was not different between breast and leg meat. Hypoxanthine (Hx) content of breast meat was $14.88{\mu}mol/g$, whereas that of leg meat was $16.41{\mu}mol/g$. Inosine content of breast meat was double than that of leg meat. The pH values of breast and leg meat were 5.90-6.05 and 6.23-6.73, respectively, during the aging period. Volatile basic nitrogen content of breast and leg meat increased during aging. Breast meat had good sensory evaluation scores for flavor (7.4), juiciness (6.8), tenderness (7.2), and overall acceptance (7.4) on day 3. Similar to breast meat, leg meat also had good sensory evaluation scores. Therefore, it is concluded that the appropriate aging period is 3 d for duck breast meat and 1 day for leg meat at $0^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8호
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• pp.1172-1185
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• 2019

Objective: Meat quality attributes in postmortem muscle tissues depend on skeletal muscle metabolites. The objective of this study was to determine the key metabolic compounds and pathways that are associated with postmortem aging and beef quality in Japanese Black cattle (JB; a Japanese Wagyu breed with highly marbled beef). Methods: Lean portions of Longissimus thoracis (LT: loin) muscle in 3 JB steers were collected at 0, 1, and 14 days after slaughter. The metabolomic profiles of the samples were analyzed by capillary electrophoresis time-of-flight mass spectrometry, followed by statistical and multivariate analyses with bioinformatics resources. Results: Among the total 171 annotated compounds, the contents of gluconic acid, gluconolactone, spermidine, and the nutritionally vital substances (choline, thiamine, and nicotinamide) were elevated through the course of postmortem aging. The contents of glycolytic compounds increased along with the generation of lactic acid as the beef aging progressed. Moreover, the contents of several dipeptides and 16 amino acids, including glutamate and aromatic and branched-chain amino acids, were elevated over time, suggesting postmortem protein degradation in the muscle. Adenosine triphosphate degradation also progressed, resulting in the generation of inosine, xanthine, and hypoxanthine via the temporal increase in inosine 5'-monophosphate. Cysteine-glutathione disulfide, thiamine, and choline increased over time during the postmortem muscle aging. In the Kyoto encyclopedia of genes and genomes database, a bioinformatics resource, the postmortem metabolomic changes in LT muscle were characterized as pathways mainly related to protein digestion, glycolysis, citric acid cycle, pyruvate metabolism, pentose phosphate metabolism, nicotinamide metabolism, glycerophospholipid metabolism, purine metabolism, and glutathione metabolism. Conclusion: The compounds accumulating in aged beef were shown to be nutritionally vital substances and flavor components, as well as potential useful biomarkers of aging. The present metabolomic data during postmortem aging contribute to further understanding of the beef quality of JB and other breeds.

• 한국축산식품학회지
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• 제43권5호
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• pp.767-791
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• 2023

To evaluate the effect of different cooking methods on the physicochemical quality and volatile organic compounds (VOC) of dairy beef round, twelve beef round pieces were divided into four groups: raw, boiling, microwave, and sous-vide. The sous-vide group had a higher pH than the boiling or microwave groups. The boiling group exhibited the highest shear force and CIE L^*, followed by the microwave and sous-vide groups (p<0.05). The sous-vide group received higher taste and tenderness scores from panelists (p<0.05) and showed significantly higher levels of aspartic and glutamic acids than the other groups. The sous-vide and microwave groups had the highest oleic acid and polyunsaturated fatty acid levels, respectively. The sous-vide group had significantly higher hypoxanthine and inosine levels than the other groups. However, the microwave group had higher inosine monophosphate levels than the other groups. The sous-vide group had a higher alcohol content, including 1-octen-3-ol, than the other groups. Octanal and nonanal were the most abundant aldehydes in all groups. (R)-(-)-14-methyl-8-hexadecyn-1-ol, p-cresol, and 1-tridecyne were used to distinguish the VOC for each group in the multivariate analysis. Sous-vide could be effective in increasing meat tenderness as well as taste-related free amino acid (aspartic acid and glutamic acid) and fatty acid (oleic acid) levels. Furthermore, specific VOC, including 1-octen-3-ol, 2-ethylhexanal ethylene glycol acetal, and 2-octen-1-ol, (E)-, could be potential markers for distinguishing sous-vide from other cooking methods. Further studies are required to understand the mechanisms underlying the predominant association of these VOC with the sous-vide cooking method.

• 한국가금학회지
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• 제48권4호
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• pp.239-253
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• 2021

본 연구는 Cobb종 및 Ross 308종 육계가 동물복지 사육환경에 따라 나타내는 대사체학적 변화를 연구하기 위하여 수행되었다. 일반농장과 동물복지농장(사육면적, 사육밀도, 암모니아 농도, 볏짚 등 제공)에 1일령의 Cobb종 및 Ross종 육계를 35일간 사육하고, 도계 후 가슴육과 다리육을 채취하여 분석에 이용하였다. 대사체 분석은 one-dimensional ¹H 핵자기공명분광법을 이용하였고, 직교부분최소자승판별분석(OPLS-DA)과 대사경로 분석을 함께 수행하였다. OPLS-DA 결과 육계 가슴육은 Ross종에 한하여 사육농장간 뚜렷한 구분이 가능하였다. 동물복지농장 유래 Ross종 육계 가슴육은 acetate, anserine, creatine, inosine monophosphate 함량이 일반농장 닭가슴육에 비해 유의적으로 높았다(P<0.05). 반면 육계 다리육은 OPLS-DA 결과 Cobb종 육계에서만 사육농장에 따른 구분이 뚜렷하게 나타났는데, glucose와 lactate를 포함한 5종의 대사체 함량은 동물복지농장에서 사육된 경우에 높았으나 7종의 유리아미노산을 포함한 9종의 대사체 함량은 낮았다(P<0.05). 대사경로 분석 결과 Ross종 육계 가슴육에서는 4종, Cobb종 육계 다리육에서는 glycolysis/gluconeogenesis를 포함한 20종의 대사경로에서 사육농장 간 유의적인 차이(P<0.05)가 나타났다. 동물복지농장에서 사육된 Ross종 육계 가슴육과 Cobb종 육계 다리육은 일반농장에서 사육된 경우와는 다른 대사체학적 특성을 나타냈으며, 특히 풍미 물질에의 뚜렷한 차이를 보여 관능적 특성에 영향을 미칠 수 있으리라 사료된다.

• 한국미생물·생명공학회지
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• 제44권1호
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• pp.55-61
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• 2016

본 연구에서는 $BH_4$를 대체할 수 있는 유용물질인 세피아프테린의 생산성 증대를 위하여 GTP 생합성 경로의 유전자들을 동시에 발현할 수 있는 재조합 대장균을 제작하였다. 세피아프테린을 생산할 수 있는 재조합 대장균에서 gmk, ndk 및 guaA-guaB 유전자를 동시에 발현함으로써 세포 내 GTP의 농도가 대조구에 비해 약 200% 이상 증가하였고 $126.1{\pm}9.3mg/l$의 세피아프테린이 생산되었는데 이 결과는 대조구보다 세피아프테린의 생산량이 약 43% 증가된 것이다. GTP 생합성에 관여하는 개별 유전자의 단독 발현 또는 두 가지 유전자의 동시 발현은 세포 내 GTP 농도 향상 큰 영향을 미치지 못했지만 네 가지 유전자 모두를 동시에 발현하는 경우는 세포 내 GTP 농도를 유의적으로 증가시킨다는 것이 확인되었다. 결론적으로 세포 내 GTP 생합성에 관여하는 guaA-guaB, gmk 및 ndk 유전자를 동시에 발현함으로써 재조합 대장균에서 세피아프테린의 생산성 증가를 달성하였다.

• 한국수산과학회지
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• 제29권1호
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• pp.51-63
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• 1996

한국 동해안에서 어획되는 연어 Oncorhynchus keta에 대한 식품학적인 연구로서 1991년 $10\~12$월에 강원도 양양군 남대천에 올라오는 시료를 대상으로 등육의 일반성분, 엑스분 질소 및 함질소 엑스성분 즉, 유리아미노산, oligopeptide류, 핵산관련물질, guanidino화합물, 4급암모늄염기 등을 분석하여 각 성분조성을 밝히고 이들 각 성분에 대한 질소분포를 살펴보았다. 엑스분 질소 함량은 $478\~648mg$ 범위였고, 암컷은 평균 604mg으로서 수컷 537ing 보다 높았다. 유리아미노산 총량은 $1,049\~1,441mg$ 범위였으며 10월에 어획된 것은 11월, 12월에 어획된것보다 그리고 암컷은 수컷보다 그 함량이 높았다. 함량이 많고 중요한 유리아미노산으로는 anserine, taurine, alanine, glycine, glutamic acid, lysine 등의 순이었으며, 특히 anserine 함량은 $724\~1,242mg$ 범위로서 엑스분 질소의 평균 $38\%$를, 그리고 유리아미노산 총량의 평균 $84\%$를 차지하였다. 또한 anserine 함량은 어획시기에 따라 차이가 많아서 10월에서 11, 12월로 경과됨에 따라 현저히 감소되었다. Oligopeptide류는 anserine이 가수분해로 생성된 $\pi-methylhistidine$과 $\beta-alanine$이 대부분을 차지 하였으며, 그 다음으로는 hydroxyproline, glycine, glutamic acid, aspartic acid, alanine의 순이었으나 함량은 낮았다. 핵산관련물질 총량은 $3.32\~9.22{\mu}mol/g$, 범위였으며, inosine 5'-monophosphate$(61.2\%)$와 inosine$(29.9\%)$이 $90\%$ 이상을 차지하였다. Betaine류로서는 일부시료에서 glycinebetaine $23\~43mg,\;\beta-alaninebetaine\;2\~11mg$, 그리고 homarine이 1mg 이하 검출되었다. TMAO는 $107\~148mg$ 범위였고, TMA는 $6\~11mg$으로 미량이었다. Creatine 함량은 $477\~642mg$으로서 엑스분질소의 평균 $31\%$를 차지 하였으나 creatinine은 $8\~11mg$으로서 낮았다. 엑스분중의 질소분포는 유리아미노산질소가 가장 높고 $(41.5\~50.1)$, 다음이 creatine과 creatinine$(26.0\~35.7\%)$, oligop-eptide류$(5.3\~12.3\%)$, 핵산관련물질$(3.2\~8.8\%)$, TMAO와 TMA$(3.6\~6.1\%)$, betaine류$(0.1\~0.9\%)$의 순이었다. 연어 엑스분중의 질소분포 특징은 모든 시료에서 공통적으로 anserine과 creatine이 중요한 함질소 성분으로서 엑스분 질소에 대한 양 성분질소의 비율은 anserine이 평균 $38\%$, creatine이 평균 $31\%$로서 이 두 성분만으로 엑스분질소의 $60.9\~76.5\%$에 달하였다. 분석된 성분에 의한 엑스분 질소의 회수율은 모든 시료에서 $91.4\~98.1\%$ 범위였다.