Survival of Listeria innocua in Rainbow Trout Protein Recovered by Isoelectric Solubilization and Precipitation with Acetic and Citric Acids†

2011 ◽  
Vol 74 (8) ◽  
pp. 1348-1352 ◽  
Author(s):  
R. A. OTTO ◽  
I. PAKER ◽  
L. BANE ◽  
S. BEAMER ◽  
J. JACZYNSKI ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Rainbow Trout ◽  
Organic Acids ◽  
Glacial Acetic Acid ◽  
Bacterial Load ◽  
Listeria Innocua ◽  
Initial Inoculum ◽  
Acid Ph ◽  
The Impact ◽  
By Products

During mechanical fish processing, a substantial amount of protein is discarded as by-products. Isoelectric solubilization and precipitation (ISP) is a process that uses extreme pH shifts to solubilize and precipitate protein from by-products to recover previously discarded protein. Typically, strong acids are used for pH reduction, but these acids do not have a pasteurization effect (6 log reduction) on bacterial load; therefore, organic acids were used during ISP processing to test the impact on Listeria innocua concentrations. Headed and gutted rainbow trout (Oncorhynchus mykiss) were inoculated with L. innocua, homogenized, and brought to the target pH with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized for 10 min at 4°C, and insoluble components (e.g., skin and insoluble protein) were removed by centrifugation. The remaining solution was pH shifted to the protein isoelectric point (pH 5.5) with sodium hydroxide, and precipitated protein was separated from the water. Microbial cells for each component (proteins, insolubles, and water) were enumerated on modified Oxford agar (MOX) and tryptic soy agar with 6% yeast extract (TSAYE). The sums of the surviving cells from each component were compared with the initial inoculum levels. No significant differences were observed between results obtained from TSAYE and from MOX (P > 0.05). Significant reductions in microbial populations were detected, regardless of pH or acid type (P < 0.05). The greatest reduction was at pH 3.0 with glacial acetic acid, resulting in a mean reduction of 6.41 log CFU/g in the recovered protein and 5.88 log CFU/g in the combined components. These results demonstrate the antimicrobial potential of organic acids in ISP processing.

Effect of by-Products from Wet-Oxidation Explosion on the Growth and Fermentation of Saccharomyces cerevisiae

2013 ◽  
Vol 724-725 ◽  
pp. 1116-1121
Author(s):  
Mei Zhen Gong ◽  
Ru Ming Zhao ◽  
Zhi Jun Li ◽  
Juan Yao ◽  
Da Chun Gong
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Energy Metabolism ◽  
Formic Acid ◽  
Ethanol Fermentation ◽  
Wet Oxidation ◽  
The Impact ◽  
By Products ◽  
Minimum Impact

Effect of by-products from wet-oxidation explosion, such as formic acid, acetic acid, and furfural on the growth and fermentation, glycolysis and energy metabolism, cytomembrane integrality ofSaccharomyces cerevisiaewere studied. The results showed that the maximum tolerated concentra tion ofS. cerevisiaewas 1.8 g/L formic acid , 6.0 g/L acetic acid,2.5g/ furfural, respectively. The inhibition strengths of the typical inhibitors to ethanol fermentation were in the order of formic acid , acetic acid , furfural. When the concentration of these typical inhibitors is 1×IC80, acetic acid has the minimum impact on glycolysis and energy metabolism . When the concentration of these typical inhibitors was 2×IC80, furfural had minimum impact on glycolysis and energy metabolism. However , formic acid can inhibit strongly the glycolysis and energy metabolism ofSaccharomyces cerevisiaewith any concentration . When compared with ethanol, the impact of these typical inhibitors onS. cerevisiae's cytomembrane integrality was not very significant. When the concentration of these typical inhibitors varied from 1×IC80to 3×IC80, the results of the leak of Mg2+was 11%-20% formic acid, 5%-12% acetic acid, 4.5%-8.4% furfural, respectively. However, the result of ethanol that leaded to the leak of Mg2+was 55%.

Behavior of Acid-Adapted and Unadapted Escherichia coli O157:H7 When Exposed to Reduced pH Achieved with Various Organic Acids

1999 ◽  
Vol 62 (5) ◽  
pp. 451-455 ◽  
Author(s):  
JEE-HOON RYU ◽  
YUN DENG ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Citric Acid ◽  
Organic Acids ◽  
Malic Acid ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Ph Values ◽  
Acid Ph

A study was done to determine if various organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted Escherichia coli O157:H7 cells. E. coli O157:H7 strain E0139, isolated from venison jerky, was grown in tryptic soy broth (TSB) and in TSB supplemented with 1% glucose (TSBG) for 18 h at 37°C, then plated on tryptic soy agar (TSA) acidified with malic, citric, lactic, or acetic acid at pH 5.4, 5.1, 4.8, 4.5, 4.2, and 3.9. Regardless of whether cells were grown in TSB or TSBG, visible colonies were not formed when plated on TSA acidified with acetic, lactic, malic, or citric acids at pH values of ≤5.4, ≤4.5, ≤4.2, or ≤4.2, respectively. Cells not adapted to reduced pH did not form colonies on TSA acidified with lactic acid (pH 3.9) or acetic acid (pH 3.9 and 4.2); however, a portion of acid-adapted cells remained viable on TSA containing lactic acid (pH 3.9) or acetic acid (pH 4.2) and could be recovered in TSB. Inactivation of acid-adapted cells was less than that of unadapted cells in TSB acidified at pH 3.9 with citric, lactic, or acetic acid and at pH 3.4 with malic acid. Significantly (P ≤ 0.05) higher numbers of acid-adapted cells, compared with unadapted cells, were detected 12 h after inoculation of TSB acidified with acetic acid at pH 3.9; in TSB containing lactic acid (pH 3.9), the number of acid-adapted cells was higher than the number of unadapted cells after 5 h. In TSB acidified at pH 3.9 with citric acid or pH 3.4 with malic acid, significantly higher numbers of acid-adapted cells survived. This study shows that organic acids differ in their inhibitory or lethal activity against acid-adapted and unadapted E. coli O157:H7 cells, and acid-adapted cells are more tolerant than unadapted cells when subsequently exposed to reduced pH caused by these acids.

scholarly journals HISTOCHEMICAL AZO COUPLING OF PROTEIN HISTIDINE BRUNSWIK'S NITRATION METHOD

1972 ◽  
Vol 20 (11) ◽  
pp. 929-937 ◽  
Author(s):  
R. D. LILLIE ◽  
P. T. DONALDSON
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Alkaline Solution ◽  
Glacial Acetic Acid ◽  
Oxides Of Nitrogen ◽  
Azo Coupling ◽  
Azure A ◽  
Acid Ph ◽  
Water Ph

The xanthoproteic reaction is accomplished with only 20% HNO3 with glacial acetic acid (HAc) as the solvent; in water 40% HNO3 is required. Tyrosine and 3-mononitrotyrosin readily azo-couple in alkaline solution with fresh p-nitrodiazobenzene in vitro; 3,5-dinitrotyrosine does not. In vitro p-nitrodiazobenzene at pH 8.5 does not couple with histidine, tryptophan or tyrosine after overnight nitration in tetranitromethane (TNM)-pyridine-0.1 N HCl 1:20:40. Histochemical nitration of tissue adequate to prevent the p-diazobenzenesulfonic acid, pH 1-0.02% azure A sequence reaction of hair medulla and arterial elastin of man, dog and rodents can be achieved by 40% HNO3 in glacial acetic acid-acetic anhydride (Ac2O) mixtures. Acetic anhydride should be 10% only, to restrict evolution of brown oxides of nitrogen and prevent undue section losses. Exposures of 4 hr at 3°C to 4:5:1 HNO3:HAc:Ac2O are effective and well tolerated. Nitration is also effectively accomplished by 6-hr 25°C exposures to mixtures of 1% tetranitromethane-pyridine and two volumes of water (pH 8.2) or 0.1 N HCl (pH 6.6). Even 10% TNM in dry pyridine and 2.5% in 16.3% pyridine alcohol (6 hr), 3°C exposures gave only partial tyrosine blockades. The pyridine-water TNM mixtures also prevented the Morel-Sisley tyrosine reaction and, with greater exposures, the postcoupled benzylidene indole reaction of tryptophan as well. Sites reactive to diazobenzenesulfonic acid-azure A after the best nitrations are probably assignable largely to histidine, though the presence of some unblocked tryptophan, purines and other reactive substances must be considered.

scholarly journals PENGARUH KONSENTRASI ISOPROPANOL TERHADAP KARAKTERISTIK KARBOKSIMETIL SELULOSA DARI BATANG PISANG

2020 ◽  
Vol 8 (03) ◽  
pp. 253
Author(s):  
Ridwan Santoso
Keyword(s):  
Acetic Acid ◽  
Moisture Content ◽  
Trichloroacetic Acid ◽  
Glacial Acetic Acid ◽  
Raw Materials ◽  
Raw Material ◽  
Preparation Stage ◽  
Material Preparation ◽  
By Products ◽  
Banana Stem

In this study consists of 5 stages, namely preparation of raw materials, cellulose isolation, alkalization, carboxymethylization, and purification. The raw material preparation stage is banana stem powder sieved at mesh 60. Furthermore, cellulose isolation of banana stems is carried out with 90% formic acid with a stirring speed of 300 rpm for 180 minutes at 100 0C. Alkalised using 15% NaOH and varying concentrations of 70%, 80%, 90% and 100% isopropanol solvents in a 100 rpm waterbath shaker for 60 minutes at 300C. The next step is carboxymethylation between alkali cellulose and trichloroacetic acid for 180 minutes at 550C in a 100 rpm waterbath shaker. At the purification glacial acetic acid and ethanol are used to remove unwanted by-products. The results characteristics with the highest degree of substitution value of 0.8 in the composition of 100% isopropanol, the highest purity of 99.7%, pH 4.8 and 5% moisture content.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Synthesis and Caracterization of some New 1H-3-aryl-7-etoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles

2008 ◽  
Vol 59 (1) ◽  
pp. 41-44
Author(s):  
Maria-Daniela Sofei ◽  
Maria Ilici ◽  
Valentin Badea ◽  
Carol Csunderlik ◽  
Vasile-Nicolae Bercean
Keyword(s):  
Mass Spectrometry ◽  
Acetic Acid ◽  
Nmr Spectroscopy ◽  
Sodium Acetate ◽  
Glacial Acetic Acid ◽  
Ir And Nmr Spectroscopy

The synthesis of 1H-3-aryl-7-ethoxycarbonyl-6-methyl-pyrazolo[5,1-c][1,2,4]triazoles (2) was carried out by cyclization of 1H-5-arylidenehydrazino-4-ethoxycarbonyl-3-methyl-pyrazoles (1) in the presence of bromine using glacial acetic acid as solvent and sodium acetate as base. The new nine obtained compounds were characterized by IR and NMR spectroscopy and mass spectrometry.

Coordination state of cobalt(II) ions in solution and on a sulphonated organic polymer

1979 ◽  
Vol 44 (8) ◽  
pp. 2330-2337 ◽  
Author(s):  
Jindřiška Maternová ◽  
Anastas A. Andreev ◽  
Dimitrii M. Shopov ◽  
Karel Setínek
Keyword(s):  
Acetic Acid ◽  
Coordination Sphere ◽  
Glacial Acetic Acid ◽  
Organic Polymer ◽  
Octahedral Complex ◽  
Coordination State ◽  
Tetrahedral Symmetry ◽  
Liquid Acid ◽  
Homogeneous Phase ◽  
Bromide Ion

It was found spectroscopically that cobalt(II) acetate dissolved in glacial acetic acid forms the octahedral complex [Co(OAc)2(HOAc)4] which in the presence of bromide ions gives the octahedral [Co(OAc)Br(HOAc)4] and tetrahedral bromo(acetate)cobalt(II) complexes with the higher number of Br- ions. When attached to an organic polymer cobalt(II) ions are bonded in the form of octahedral [Co(H2O)6]2+ cations which form with acetic acid similar complexes as in homogeneous phase and are able to coordinate one bromide ion. Drying the copolymer possessing octahedral hexaaquocobalt(II) cations leads to tetrahedral aquocomplexes which are solvated by gaseous acetic acid and converted into the acetate complexes with the liquid acid. The latter contain the acid in the inner coordination sphere and have tetrahedral symmetry.

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