• Title/Summary/Keyword: free acid

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Functional Properties of a Interspecific Protoplast Fusant from Lactobacillus bulgaricus and Lactobacillus helveticus (유산균의 이종간(異種間) 세포융합균주의 기능특성)

  • Jun, Hong-Ki;Park, Hyun-Jeong;Song, Jae-Chul;Baik, Hung-Suk
    • Microbiology and Biotechnology Letters
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    • v.21 no.4
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    • pp.310-315
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    • 1993
  • An interspecific fusant was made from the protoplasts of two strains of Lactobacillus genus (L. bulgaricus and L.helveticus). And in order to test the applicability of the fusant in manufacturing the cheddar cheese, functional properties of the strain was examined by determining acid-producing activity, three important enzyme activities and volatile free fatty acid-producing activity. The recombinant strain did not exhibit greatly increased acid-porducing activity. Lipase and volatile free fatty acid-porducing abilities of the fusant, however, were remarkably higher than those of the two parental strains. The fusant actually porduced the cheese porduct of the highest ammount of total volatile free fatty acid after 7 days ripening at 10$^{\circ}C$. Finally, the cheddar cheese ripened with this strain was also evaluated to be high preference and flavor intensity by organoleptic panel tests.

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INTRACELLULAR AMINO ACID PROFILE OF RUMEN BACTERIA AS INFLUENCED BY UREA FEEDING AND ITS DURATION

  • Kobayashi, Y.;Wakita, M.;Hoshino, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.6 no.4
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    • pp.619-622
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    • 1993
  • Rumen bacterial amino acids in sheep on urea diet were monitored to assess a possible change in amino acid synthesis as a long term response to high rumen ammonia environment. A sheep was fed a semipurified diet with soybean meal, followed by a diet with urea as a main nitrogen source. Mixed rumen bacteria were harvested from ruminal fluid taken 3 h after feeding (twice in soybean meal feeding and 6 times in urea feeding) and fractionated as cell wall, proteins and protein-free cell supernatant of monitor amino acids in each fraction. Ruminal ammonia concentration at the sampling ranged from 5.7 to 39.5 mgN/dl. Cell wall and protein fractions of mixed rumen bacteria were stable in their amino acid composition regardless of nitrogen sources of diet and the feeding duration. However, protein-free cell supernatant fraction showed a higher alanine proportion with urea feeding (18.6 and 28.2 molar % of alanine for samples from sheep fed soybean meal and urea, respectively) and its duration (20.6 and 32.9 molar % for samples from sheep on urea diet for 1 and 65 days, respectively). Total free amino acid level of bacteria was depressed in the initial period of urea feeding but restored on 65th day of the feeding. These results suggest that an alanine synthesizing system may develop in rumen bacteria as urea feeding becomes longer.

Process Development for the Enzymatic Hydrolysis of Food Protein: Effects of Pre-treatment and Post-treatments on Degree of Hydrolysis and Other Product Characteristics

  • Chae, Hee-Jeong;In, Man-Jin;Kim, Min-Hong
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.3 no.1
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    • pp.35-39
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    • 1998
  • An enzymatic process was developed to produce protein hydrolysater form defatted soya protein. Various unit operations were tried, and the effects of pre- and post-treatments on the product characteristics such as degree of hydroylsis (DH), free amino acid content (%FAA) and average molecular weight (MW) were investigated. The use of acid washes showed no difference in %DH. Increasing pH during pre-cooking gave lower %DH. Alkaline cooking made too much insoluble protein, thus the protein yield was too small. A better hydrolysis with more acceptable taste was obtained when the combination of Neutrase/Alcalase/Flavourzyme was used in place of Alcalase/Flavourzyme combination; Untoasted defatted soya was more effective on the proteolysis than toasted one. The MW of the evaporated and spray dried product was higher than that of undried product, due to precipitation of low-solubility components. When ultrafiltration and the product concentration carried out the product separation by reverse osmosis, the solubility and the taste of the product were improved. The difference between enzyme hydrolysate and acid hydrolysate was significant in free amino acid composition, especially in tyrosine, phenylalanine, glutamine and asparagine.

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Characteristics of Conversion Coating of AZ31 Magnesium Alloy Formed in Chromium-Free Cerium-Based Solution (크롬 프리 세륨 용액에 의한 AZ31 마그네슘 합금의 화성 피막에 대한 특성 평가)

  • Kim, Myung Hwan;Lee, Dong Uk;Kwag, Sam-Tag;Moon, Myung-Jun
    • Journal of the Korean institute of surface engineering
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    • v.49 no.1
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    • pp.62-68
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    • 2016
  • A chromium-free Ce-based conversion coating formed by immersion in a solution containing cerium chloride and nitric acid on AZ31 magnesium alloy has been studied. The effects of acid pickling on the morphology and the corrosion resistance of the cerium conversion coating were investigated. The corrosion resistance of the conversion coating prepared on AZ31 Mg alloy after organic acid pickling was better than that of inorganic acid pickling. The morphology of the conversion-coated layer was observed using optical microscope and SEM. Results show that the conversion coatings are relatively uniform and continuous, with thickness 1.0 to $1.1{\mu}m$. The main elements of the conversion coating of AZ31 Mg alloy are Mg, O, Al, Ce and Zn by EDS analysis. The electrochemical polarization results showed that the Ce-based conversion coating could reduce the corrosion activity of the AZ31 Mg alloy substrates in the presence of chloride ions.

Egg Quality and Amino Acid Composition of Fertilized Eggs of Red Spotted Grouper, Epinephelus akaara (사육환경에 따른 붉바리 Epinephelus akaara 수정란의 난질 및 아미노산 조성)

  • Jong-Youn, Park;Jae-Kwon, Cho;Kyeong-Ho, Han;Chang-Gi, Hong
    • Journal of Marine Life Science
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    • v.7 no.2
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    • pp.139-144
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    • 2022
  • This study aims to investigate egg quality changes and free amino acid composition. Factors that can affect egg quality about farming conditions were investigated through biochemical analysis of egg by red spotted grouper, Epinephelus akaara. As a result, the buoyant, fertilization embryonic survival and hatching rate were better when reared in sea cage than in tank. And the content of free amino acid in fertilized eggs reared in sea cage was higher then in tank. In conclusion, fertilized eggs with good egg quality can be produced when farming sea cage, and contained more free amino acid.

Quality Characteristics of Commercial Fermented Skates (시판 발효 홍어의 품질특성)

  • Cho, Hee-Sook;Kim, Kyung-Hee
    • Journal of the Korean Society of Food Culture
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    • v.23 no.3
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    • pp.397-402
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    • 2008
  • This study was conducted to evaluate the quality characteristics of domestic as well as imported fermented skate. Three types of fermented skate products were analyzed for proximate composition, pH, VBN, ammonia-N, free amino acids, and fatty acids. The results indicated that the domestic fermented skate contained large amounts of TMAO. Also, the domestic and imported fermented skates each contained approximately 7.1 log CFU/g and $5.8{\sim}6.5$ log CFU/g of aerobic bacteria, respectively, and 585.9 mg and $384.1{\sim}398.5$ mg of total free amino acids, respectively; all samples contained high levels of taurine, anserine, lysine, alanine, glycine, proline, and ${\beta}-alanine$. For fatty acid composition, the domestic fermented skate contained 11 different types of saturated fatty acid and 16 types of unsaturated fatty acid, whereas the imported skate contained 8 types of saturated fatty acid and $10{\sim}15$ types of unsaturated fatty acid. Overall, the results suggest that domestic fermented skate is a better source of amino acids and essential fatty acids and contains more aerobic bacteria than imported fermented skate.

Analysis of Free Amino Acids and Polyphenol Compounds from Lycopene Variety of Cherry Tomatoes (방울토마토 라이코펜 품종의 유리아미노산 및 폴리페놀 화합물의 분석)

  • Kim, Hyen-Ryung;Ahn, Jun-Bae
    • Culinary science and hospitality research
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    • v.20 no.3
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    • pp.37-49
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    • 2014
  • In order to elucidate the usefulness of Lycopene, a cherry tomato variety, as a food material, the compositions of free amino acids, amino acid metabolites and polyphenol compounds were analyzed using HPLC and LC-MS/MS method. Lycopene contained eighteen free amino acids except for L-Cys and L-Try. L-Glu was the most abundant free amino acid, followed by L-Gln and L-Asp. The percentages of L-Glu, L-Gln and L-Asp of total free amino acid were 55.5%, 15.9% and 9.9% respectively. Lycopene contained essential amino acids with the exception of tryptophan. The following amino acid metabolites were found : ${\gamma}$-aminobutyric acid(GABA), carnitine(L-Car), o-phosphoethanolamine(o-Pea), hydroxylysine(Hyl) phosphoserine (p-Ser), N-methyl-histidine(Me-His), ethanolamine($EtNH_2$). Especially, GABA known as a neurotransmitter was present at a high level(305.99 mg/100 g dry weight). We identified the following polyphenol compounds in the cherry tomatoes : caffeic acid-hexose isomer I (CH I), caffeic acid-hexose isomer II (CH II), 3-caffeoylquinic acid(3-CQA), 5-caffeoylquinic acid(5-CQA), caffeoylquinic acid isomer(CQAI), quercetin-hexose-deoxyhexose-pentose(QTS), quercetin-3-rutinoside(Q-3-R), di-caffeoylquinic acid(di-CQA), tri-caffeoylquinic acid(tri-CQA), naringenin chalcone(NGC). Large quantities of Q-3-R and NGC known as bioactive compounds were found. These results revealed that Lycopene variety contained various nutritional and bioactive compounds and would be a potent functional food material.

Fatty Acid Compositions of the Free and Bound Lipids in Ginseng and Its Related Crude Drugs (인삼(人蔘) 및 유연(類緣) 생약류(生藥類)의 유리(遊離) 및 결합(結合) 지방질(脂肪質)의 지방산(脂肪酸) 결성(結成))

  • Choi, Kang-Ju;Kim, Man-Wook;Lee, Hyeong-Kyu;Kim, Dong-Hoon
    • Korean Journal of Pharmacognosy
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    • v.14 no.2
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    • pp.44-50
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    • 1983
  • An attempt was made to investigate free and bound lipid contents and fatty acid compositions of ginseng and its eveven kinds related crude drugs. Contents of free and bound lipids of ginseng were 1.23% and 0.47%, and those of the related crude drugs were $0.31{\sim}13.05%$ and $0.26respectively. Fourteen even-numbered and 4 odd-numbered fatty acids were identified by GLC in those lipids from ginseng, and the major fatty acids were linoleic, palmitic, oleic and linolenic acids. The crude drugs are notably different from ginseng in kinds and compositions of fatty acids of free and bound lipids. Composition ratios of unsaturated fatty acids were higher in free lipids from ginseng than those of the crude drugs except 'Won-ji' Polygalae Radix.

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Glutathione Sulphydryl Contents and Antioxidant Activities of Lactobacillus spp. and Bacillus coagulans (Lactobacillus spp.와 Bacillus coagulans의 Glutathione Sulphydryl 함유율과 황산화 활성)

  • Byun, Jeong-Yeol;Yoon, Yeong-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.22 no.2
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    • pp.91-97
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    • 2004
  • The antioxidative ability on the basis of reduced glutathione sulphydryl(GSH) level, the inhibition activities of linoleic acid peroxidation of cell free extract of Lactobacillus spp. and Bacillus spp. have been determined; Lactobacillus casei CU4114 contained the highest level of GSH among the probiotic strains with 25.15 ${\mu}$mole/g. Significantly high level of GSH occured in the intracellular cell free extract of Lactobacillus rhamnosus CU4201, Lactobacillus plantarum CU4203. The antioxidant activity and inhibition of linoleic acid peroxidation of cell free extract of Lactobacillus spp. and Bacillus spp. by thiobarbituric acid(TBA) assay have been shown to be significantly differed depending on the strains(P>0.01). Intracellular cell free extracts of L. acidophilus CU4111, L. casei CU4114, and strains of Bacillus coacillus revealed a significantly intensive inhibitory activity in the linoleic acid peroxidation reactions. Spearmans' rank correlation between inhibitory activity on linoleic acid peroxidation and cellular GSH levels of Lactobacillus spp. was analysed and the correlation quotient was 0.65 which means a significant positive correlation.

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