University of North Florida
Browse the Citations

Contact Info

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

View Stuart Chalk's profile on LinkedIn


Classification: Agricultural -> grain -> malt

Citations 14

"Determination Of High Molecular Weight β-glucan In Malt By Post-column Calcofluor Flow Injection Analysis"
J. Am. Soc. Brew. Chem. 2000 Volume 58, Issue 4 Pages 198-199
H. Maeba

Abstract: The collaborative study was carried out to evaluate the post-column Calcofluor flow injection analysis method for the determination of b-glucan in malt by eight collaborators. Repeatability coefficients of variation and reproducibility coefficients of variation were acceptable. This method was included in Methods of Analysis of BCOJ. The collaborative work was completed this year.
β-d-Glucan Fluorescence

"Automated Flow Injection Extraction Method For Determination Of Bittering Compounds In Beer"
Anal. Chim. Acta 1986 Volume 187, Issue 1 Pages 339-342
Ylva Sahleström, Sigrid Twengström and Bo Karlberg

Abstract: The flow injection procedure described is an adaptation of a standard manual method. A 100 µL portion of degassed beer is injected into a 0.1 M HCl carrier stream (1 mL min-1), which, after passing through a 50-cm mixing coil, is mixed with 2,2,4-trimethylpentane (0.5 mL min-1). The resulting stream is passed through a 200-cm mixing coil and thence into a phase-separation unit equipped with a PTFE membrane (cf. Ibid., 1986, 179, 315), and the absorbance of the separated organic phase is measured at 275 nm in a flow-through spectrophotometer. Results for 22 products agreed well with those obtained by the manual procedure. The sampling rate is 60 h-1.
Acids, bitter Isohumulone Isocohumulone Isoadhumulone Spectrophotometry Sample preparation Extraction Method comparison Organic phase detection Phase separator Tecator Teflon membrane

"Quantification Of High Molecular Weight (1->3)(1->4)-β-D-glucan Using Calcofluor Complex Formation And Flow Injection Analysis. II Determination Of Total β-glucan Content Of Barley And Malt"
Carlsberg Res. Commun. 1988 Volume 53, Issue 5 Pages 287-296
Kim G. Jørgensen, Sten Aastrup

Abstract: Complete solubilisation of barley or malt β-glucan was obtained by extraction with dilute acid. Investigation of the extraction procedure by high performance size exclusion chromatography indicates that originally water insoluble high molecular weight β-glucan is solubilized by degradation to smaller fragments. The fluorescence emitted by the specific complex formed between Calcofluor and β-glucan in solution was used to measure the total β-glucan content of barley and malt samples. Examination of the residues after the extraction with dilute acid by degradation with (1 fwdarw 3)(1 fwdarw 4)-β-D-glucanase and by fluorescence microscopy of Calcofluor stained residues confirmed the complete extraction of the β-glucan. Comparison between the Calcofluor-FIA method and the enzymatic method of McCleary and Glennie-Holmes (20) revealed a high correlation between the values obtained by the two methods. 39 barleys and 57 malts analyzed for β-glucan content with the two methods and linear correlation coefficients of r = 0.977 and r = 0.986, respectively, were found. The system enables a large number of barley or malt-β-glucan determinations to be performed within a short period of time with a minimum of manpower. The method is suitable for standard routine analysis in quality control laboratories.
β-d-Glucan Fluorescence Biotechnology

"Application Of The Calcofluor Flow Injection Analysis Method For Determination Of β-glucan In Barley, Malt, Wort, And Beer"
J. Am. Soc. Brew. Chem. 1988 Volume 46, Issue 3 Pages 76-81
Sten Aastrup, and Kim G. Jørgensen

Abstract: Mixed linkage (1?3)(1?4)-?-d-glucan, the main constituent of barley endosperm cell walls, has been known for decades to be a troublesome compound in malting and brewing. Great efforts have therefore been made in order to assay ?-glucan. A new convenient and simple method of extracting the total ?-glucan in barley and malt is described in this paper. The ?-glucan in solution is subsequently assayed using flow injection analysis, by which ?-glucan and the fluorochrome, Calcofluor, are mixed. ?-Glucan in wort and beer can be assayed directly. The increase in fluorescence intensity is observed using a spectrofluorimeter. This method offers advantages over other methods with respect to the number of operational steps involved and the number of samples that can be analyzed per day. High correlation was found between the new method and enzymatic methods recently described.
β-Glucan Fluorescence Sample preparation Extraction

"Analysis Of β-glucans In Barley And Malt: A Comparison Of Four Methods"
J. Am. Soc. Brew. Chem. 1991 Volume 49, Issue 3 Pages 110-115
S. E. Ullrich and J. A. Clancy J. G. Cuti, Jr., and C. M. Tompkins

Abstract: Interest in analyzing β-glucans in barley and malt has been increasing. β-Glucan analyzes are time-consuming and expensive. However, newer, faster methods are being developed. The present study compared four methods of measuring β-glucans in barley and malt flour, including three enzymatic procedures developed at Washington State University (WSU), Cornell University (CU), and Biocon (Australia), and the flow injection analysis (FIA) system using the fluorochrome Calcofluor. Two- and six-row barleys were analyzed, providing a range of β-glucan levels of 3.5-10%. Fully malted to partially malted flours had a range of 0.2-2.5%. Accuracy and precision varied among methods. Absolute β-glucan percentage differed considerably among methods. The rank among methods was consistent for barley (CU gt FIA gt WSU gt Biocon) and different for malt (CU gt WSU gt Biocon = FIA). The methods were in generally good agreement for relative β-glucan values, (r gt 0.98 for comparison of any two methods over all barley and malt samples). However, r values ranged lower within barley (r = 0.89-0.95) and malt (r = 0.81-0.98) subsets. Choice of method will depend on the importance of cost, speed, accuracy, precision, and the type and intended use of the material being analyzed.
β-d-Glucan Method comparison

"Utility Of Automation In Malt Quality Assurance"
J. Am. Soc. Brew. Chem. 1997 Volume 55, Issue 2 Pages 35-37
M.-J. S. Maurice, M. J. Munar, and B. R. Sebree

Abstract: In the past, individual malthouses maintained on-site laboratories, capable of handling limited numbers of samples on a daily basis. Cost-effectiveness dictated the streamlining and centralization of quality assurance laboratories, which must be prepared to analyze more samples for more parameters. The availability of reference-quality automated methods allows precise analysis with minimization of cost and turnaround time. The various capacities in which a company may benefit from automating their laboratory systems will be discussed. 5 References
Automation Calibration

"Relationships Among The β-glucan Contents Of Barley, Malt, Malt Congress Extract, And Beer"
J. Am. Soc. Brew. Chem. 1998 Volume 56, Issue 4 Pages 164-168
M. J. Edney, D. E. LaBerge, and D. E. Langrell

Abstract: Malting barley breeders have directed a sustained effort toward reducing β-glucan problems through selection of lines exhibiting low barley β-glucan content. This study determined β-glucan contents in barley, malt, and Congress ext. in an effort to define this relationship and to determine which best predicts levels obtained in beer. The impact of environment and genotype on this relationship and prediction was also considered. In total, 60 samples of barley and the corresponding malts, Congress fine-ground extracts, and beers were analyzed for β-glucan content using the Calcofluor-flow injection method of anal. β-Glucan contents of malt and Congress ext. were highly correlated with levels detected in the beer produced from those malts. The correlation between the β-glucan content of barley and beer was significantly lower. This study also demonstrated the strong influence of environmental growing conditions of the β-glucan contents of barley, malt, Congress ext., and beer, although the genetic component was also significant for malt, Congress extract, and beer.
β-Glucan Fluorescence

"Determination Of β-glucan In Wort And Beer By Its Binding With Calcofluor, Using A Fluorimetric Flow Injection Analysis Method"
J. Inst. Brew. 1989 Volume 95, Issue 5 Pages 327-332
José M. Sendra1, José V. Carbonell, Maria J. Gosalbes, Victoria Todo

Abstract: Previous fluorimetric methods for determination of β-glucan in worts and beers were studied and modified to improve their performance. Fluorescence was measured at 425 nm (excitation at 338 nm). By increasing the I of the carrier solution (by adding 1% of NaCl), the mol. wt. range of β-glucans which were effectively bound by calcofluor was increased. Low-mol.-wt. components of beer had no effect on the analysis. Recommendations are presented to overcome the interference caused by the color of wort and beer. Results are presented for 36 beers, and the possible use of the method to detect addition of exogenous β-glucanases is discussed.
β-Glucan Fluorescence Interferences

"Several New Factors Influencing The Measurement Of β-glucan Content Using Calcofluor Flow Injection Analysis Method"
J. Inst. Brew. 1995 Volume 101, Issue 5 Pages 371-374
Izawa, By Masayuki; Takashio, Masachika; Koshino, Shohei

Abstract: Factors such as temperature, calcofluor concentration, sample injection volume, void volume of the mixing tube and other factors have been reported to influence the calcofluor flow-injection analysis (FIA) of β-glucan. In addition to these factors, we revealed the following factors and elucidated their effects on the FIA of β-glucans: the inside diameter and arrangement of the mixing tube, calibration method using peak area or peak height of the edition patterns, and the quality of the calcofluor reagent. An apparently lower value was obtained when (1) the mixing tube had a smaller inside diameter, (2) the mixing tube was looped in a ring of smaller diameter, or (3) the mixing tube was wound as double coils in a figure eight instead of a loop. Furthermore, it was indicated that the peak area calibration produced higher measures values than the peak height calibration. The reagent also affected the results; a calcofluor reagent from Sigma Chemical Co. gave a higher value than one from Polyscience Inc. It was concluded that these troublesome phenomena were derived from the difference between the test sample and the standard solution of β-glucan, that is, the molecular weight distribution of β-glucans and/or the sugar and ethanol in the sample solutions. Based on these findings, it is suggested that international standardization of the FIA method for β-glucan be made.
β-d-Glucan Fluorescence Optimization Temperature

"EBC Methods For Determination Of High-molecular-weight β-glucan In Barley, Malt, Wort And Beer"
Monatsschr. Brauwiss. 1989 Volume 42, Issue 4 Pages 162-166
Munck, L., Jorgensen, K.G., Ruud-Hansen, J., und Hansen, K.T.

Abstract: Two methods were evaluated in a collaborative test with 14 participating laboratories. The methods were; (i) that described by, e.g., Joergensen (Carlsberg Res. Commun., 1988, 53, 277), involving flow injection analysis with fluorimetric detection by using the fluorichrome Calcofluor, which binds specifically to β-glucan; and (ii) that described by, e.g., McCleary and Nurthen (J. Inst. Brew., 1986, 92, 168), involving enzymatic hydrolysis. Barley, malt and beer samples were analyzed for six concentration. of β-glucan. Acceptable levels of repeatability and reproducibility were achieved for both methods in the collaborative test and results for the two methods correlated well. Both methods are accepted by the Analytical Committee as Standard Methods.
β-Glucan Fluorescence Standard method Method comparison

"Evaluation Of The Dissolving Properties Of Malts Using The Friabilimeter, Calcofluoride And FIA Method"
Monatsschr. Brauwiss. 1996 Volume 49, Issue 7-8 Pages 220-225
Wackerbauer, K., Hardt, R., Hirse, U.

Abstract: This article describes the most common methods for the determination of the cytolytic dissolving of brewing malts in current usage. On the basis of malting tests and the study of trade malts, the authors assess the information provided from the friabilimeter and calcofluoride method and the determination of beta glucanes in the congress wort using flow injection. The benefits and drawbacks of the various methods are compared.

"An Update Of Analytical Procedures For The Determination Of Malt Modification And Malt Homogeneity. 4"
Monatsschr. Brauwiss. 1997 Volume 50, Issue 1-2 Pages 49-57
Moll, M.

Abstract: More than 40 different methods of analysis allowing the evaluation of malt modification and 4 methods for homogeneity have been described (part 1 to 4) with their strengths and weaknesses and their limits. A perspicacious brewer should be able to make the best choice from these methods of analysis with the objective of predicting malt behavior during the brewing process. Ancestral methods, nearly centenarian, must be revised at an international level. The accumulation of analytical methods in malt specifications should be avoided for economical reasons and to avoid overlapping. 291 References

"α-Amylase And Diastatic Power In Malt By Automated Flow Analysis"
J. Am. Soc. Brew. Chem. 1994 Volume 52, Issue 4 Pages 175-177
A. Pranke; S. Chan; V. Coonce; P. Gualdoni; M. Joyce; G. Laycock; P. Schwartz; M. Munar

Abstract: Automated flow analysis gave unacceptable repeatability coefficients of variation for a-amylase in malt. There was a significant improvement in a-amylase reproducibility with predefined calibration samples. Automated flow analysis gave acceptable repeatability and unacceptable reproducibility coefficients of variation for diastatic power.
α-Amylase Method comparison

"β-Glucan In Barley, Malt, And Congress Wort By Fluorescence"
J. Am. Soc. Brew. Chem. 1990 Volume 48, Issue 4 Pages 145-146
J. Cuti; J. Dufour; S. Home; M. Izawa; B. Jones; W. Ladish; S. Lie; S. Paeschke; and D. Thomas

Abstract: (1->3)(1->4)b-D-Glucan was determined in barley, malt, and congress wort using the fluorochrome Calcofluor and flow injection in collaborative anal. The repeatability standard deviation was acceptable but the reproducibility coefficient of variation was unacceptably high.
β-Glucan Fluorescence Method comparison