University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

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Classification: Meat -> beef

Citations 7

"Data For The Examination Of The Mercury (Hg) Content Of Certain Groups Of Meat Products Of Slovak And Czech Republic Origin"
Magy. Allatorv. Lapja 2001 Volume 123, Issue 5 Pages 290-291
J. Golian, M. Pavelka

Abstract: The mercury (Hg-) content of 120 meat product samples from the different producers of the Slovak and the Czech Republic was analyzed by cold-vapor generated atomic absorption spectrometry. The minimal mercury content was 0.0001 mg/kg. Comparing to the Siovakian Hg-tolerance limit for meat products (0.05 mg/kg) no violation was found, (In Hungary the related Hg-maximum permissible tolerance limit is 0.03 mg/kg,) The correlation coefficient of the selected meat products concerning their Hg-content was demonstrated and evaluated.
Mercury Spectrophotometry

"Estimation Of Lactate In Meat Extracts By Screen-printed Sensors"
Anal. Chim. Acta 1999 Volume 386, Issue 1-2 Pages 7-12
A. L. Hart, C. Matthews and W. A. Collier

Abstract: Various facets of sensor technology: platinum dispersed on carbon, a second blank working electrode, polymer matrices for enzymes and diffusion-limiting membranes, were integrated using screen-printing to produce lactate sensors. The enzyme was lactate oxidase. The polymer matrices were hydroxyethyl cellulose, GafQuat/lactitol and hydroxyethyl cellulose/polyethyleneimine. The outer membrane was of known composition: polyvinyl chloride co-polymer/cellulose acetate butyrate. When the sensors were mounted in a flow injection analyzer., estimates were obtained of the lactate concentration in simple buffer extracts of cattle meat. The most accurate estimates were obtained from sensors in which the enzyme was embedded in a matrix of GafQuat/lactitol or hydroxyethyl cellulose/polyethyleneimine. The currents generated by the enzyme in the matrices containing GafQuat or polyethyleneimine were higher than when hydroxyethyl cellulose alone was used as a matrix. The activity of the sensors under dry storage (over silica gel at 25°C) varied over eight months, but remained at a functional level. Every step in these relatively simple sensors was achieved by screen-printing; the use of a blank working electrode avoided the necessity of additional layers or membranes to reject interferents and the flow injection analyzer. provided a constant hydrodynamic environment for sensor function.
Lactate Sensor Electrode Electrode Interferences

"Enzymatic Determinations With Rotating Bioreactors: Determination Of Glutamate In Food Products"
Anal. Chim. Acta 1998 Volume 369, Issue 1-2 Pages 147-155
Chitra Janarthanan and Horacio A. Mottola*

Abstract: The benefits of using rotating bioreactors for online or inline determination in food analyzes are illustrated with the determination of L-glutamate. Two enzymatic approaches have been implemented and samples used to illustrate the approaches included: beef and chicken bouillon cubes, soy sauce, chicken broth, seasoning salt, fruit and vegetable juices, and skim milk. One of the methods uses glutamate dehydrogenase (EC in the main enzymatic reaction and diaphorase (EC in the indicator reaction, which involves NADH and hexacyanoferrate(III). The monitored species, amperometrically detected at a platinum-ring electrode, is the hexacyanoferrate(II) produced by the indicator reaction. The second method utilizes a single enzyme, glutamate oxidase (EC, and amperometric monitoring of a product of the enzymatic reaction, H2O2, also at a platinum-ring electrode. Interference by ascorbate present in some samples is eliminated by inline use of a packed reactor containing ascorbate oxidase (EC The relative merits of both systems when using continuous-flow/stopped-flow/continuous-flow processing are discussed.
Glutamate Amperometry Electrode Interferences Immobilized enzyme Stopped-flow Manifold comparison

"Simultaneous Assay Of Nitrite, Nitrate And Chloride In Meat Products By A Flow Injection Method"
Analyst 1996 Volume 121, Issue 10 Pages 1393-1396
I. M. P. L. V. O. Ferreira, J. L. F. C. Lima, M. C. B. S. M. Montenegro, R. Pérez Olmos and A. Rios

Abstract: Sample was homogenized and extracted with hot water and the extract was purified and filtered. A portion (100 µL) of the filtrate was injected into a carrier stream (2.9 ml/min) of 50 mM Na2SO4/0.02 mM NaCl of a flow injection manifold (schematic shown). Chloride (I) was determined potentiometrically a tubular ISE (cf. Ferreira et al., Fresenius' J. Anal. Chem., 1993, 374, 314). The carrier was mixed with a buffer stream (0.5 ml/min) of NH4Cl/sodium tetraborate/Na2EDTA and split into two. One stream passed through a Cd/Cu column to reduce nitrate (II) to nitrite (III). The two streams subsequently passed through a confluence point and were mixed a reagent stream (1 ml/min) of acidified sulfanilamide/N-(1-naphthyl)ethylenediamine dihydrochloride and the absorbance was measured (wavelength not given). As each channel had a different residence time, two peaks were obtained, one for nitrite III and one for total N: II was measured by difference. The calibration graphs were linear from 0.01-0.1 M I, up to 104 ppm II and from 0.03-0.2 ppm III. RSD (n = 10) were 2.5, 0.7 and 1.1%, respectively, for I, II and III.
Chloride Nitrate Nitrite Potentiometry Electrode Electrode Reduction column Buffer Sample splitting

"Evaluation Of Beef Aging By Determination Of Hypoxanthine And Xanthine Contents: Application Of A Xanthine Sensor"
Food Chem. 1995 Volume 52, Issue 4 Pages 439-445
Yukio Yano, Nobuko Kataho, Mino Watanabe, Toyoo Nakamura and Yasukazu Asano

Abstract: The changes of ATP-related compounds were measured during the aging of sirloin meat of eight bullocks, together with changes in myofibrillar fragmentation index (FI) and inosine-5-monophosphate (IMP) content. The increase in hypoxanthine (Hx) content, (Hx + 1/2 Xanthine (X)) content and K value correlated well with the observed increase in FI (R2 = 0.804, 0.819 and 0.801, respectively) and decrease of IMP content (R2 = 0.809, -0.839 and -0.965, respectively). An immobilized xanthine oxidase biosensor was tested for its usefulness as a convenient method for measurement of (Hx + 1/2X) content. Also, organoleptic evaluation and measurement of FI, free amino acids and ATP-related compounds were carried out. The findings suggested that the xanthine sensor could provide accurate measurements of the (Hx + 1/2X) content, and was useful for assessing the progress of aging by the estimation of the changes in tenderness and IMP content.
Hypoxanthine Xanthine Sensor Process monitoring

"Monitoring Of Beef Aging Using A Two-line Flow Injection Analysis Biosensor Consisting Of Putrescine And Xanthine Electrodes"
Food Res. Int. 1995 Volume 28, Issue 6 Pages 611-617
Yukio Yano, Nobuko Miyaguchi, Mino Watanabe, Toyoo Nakamura, Takeshi Youdou, Jinkichi Miyai, Manami Numata and Yasukazu Asano

Abstract: A two-line flow injection analysis biosensor was developed which can simultaneously detect bacterial spoilage and the progress of aging. This FIA biosensor was composed of a putrescine oxidase immobilized electrode and a xanthine oxidase immobilized electrode as detectors. The putrescine electrode measures putrescine and cadaverine which are produced by bacteria, and the xanthine electrode measures hypoxanthine and xanthine which accumulate in meat with aging. The analytical conditions for this system were set as follows; flow rate, 1 ml/min; water bath temperature, 30°C; flow buffer, 0.1 M phosphate buffer (pH 7.0); injection volume for putrescine electrode, 200 µl; injection volume for xanthine electrode, 40 µl; and measurement cycle, 2 min. The linear relationship for standard solution was between 20 and 800 nmol/ml in the putrescine electrode and between 0.1 and 3.0 µmol/ml in the xanthine electrode. The coefficients of variation in standard solutions were 2.14% with the putrescine electrode and 2.83% with the xanthine electrode. The coefficients of variation values in the specimen solution were 3.22% and 3.76%, respectively. This two-line FIA biosensor was applied to the vacuum-packed beef stored at 0, 5 and 10°C. The progress of aging could be monitored at all temperatures, and the bacterial spoilage could be detected before the appearance of putrid odor at 5 and 10°C. However, at 0°C the putrid odor did not appear during storage, and neither putrescine nor cadaverine was detected. Thus, this FIA biosensor was confirmed to be useful for the quality control of beef aging at 5 and 10°C, but not at 0°C. A two-line flow injection analysis biosensor was developed which can simultaneously detect bacterial spoilage and the progress of aging. This FIA biosensor was composed of a putrescine oxidase immobilized electrode and a xanthine oxidase immobilized electrode as detectors. The putrescine electrode measures putrescine and cadaverine which are produced by bacteria, and the xanthine electrode measures hypoxanthine and xanthine which accumulate in meat with aging. (22 References)
Hypoxanthine Xanthine Sensor Immobilized enzyme Process monitoring

"Evaluation Of An HPLC Method For The Determination Of Phylloquinone (vitamin K1) In Various Food Matrices"
J. Agric. Food Chem. 1994 Volume 42, Issue 2 Pages 295-300
Sarah L. Booth, Kenneth W. Davidson, and James A. Sadowski

Abstract: Phylloquinone was extracted from vegetable juice, cows milk, spinach, bread and beef with propan-2-ol/hexane (details given) with 2,3-dihydrophylloquinone or 2-methyl-3-(3,7,11,15,19-pentamethyl-2-eicosenyl)-1,4-naphthalenedione added (internal standards; details given). The extracts under went solid-phase extraction on silica columns (described) with elution effected by hexane/ethyl ether (93:3). Beef extracts were further purified by HPLC on a C18 column (described). The purified extracts were dissolved in methanol containing 10 mM ZnCl2, 5 mM acetic acid and 5 mM sodium acetate (milk extracts were dissolved in 10 mM ZnCl2, 5 mM acetic acid and acetonitrile) and analyzed on an Hypersil ODS (3 µm) column (15 cm x 4.6 mm i.d.) with a mobile phase (1 ml/min) of methanol/CH2Cl2 (9:1) containing 5 ml/l of 2 M ZnCl2, 1 M acetic acid and 1 M sodium acetate with fluorescence detection at 418 nm (excitation at 244 nm) after post-column derivatization in an online chemical reactor (50 mm x 2 mm) with Zn metal (200 mesh). Intra- and inter-day RSD were 6.6-13.6% with between sample RSD (n = 10) of 7.8% (milk), 32.6% (spinach) and 44.6% (vegetable juice).
Vitamin K1 HPLC