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Siebert, Karl Joseph
Cornell Faculty Member
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- Professor, Food Science & Technology at Geneva
I worked in the brewing industry for 18 years before I became an academic, holding positions from Research Associate to Director of Research (the last 8 years) at the Stroh Brewery Co. in Detroit. I joined Cornell at the Geneva Experiment Station in 1990 as a Full Professor. I served as Chair of the Food Science & Technology Dept. for the first five years (two terms). Since then I have mainly been engaged in research with some teaching and extension; my current effort distribution officially includes research, teaching and extension. I teach the brewing part of FD SC 4300 (Understanding Wine and Beer) each spring and I teach FD SC 6080 (Chemometric Methods in Food Science) in the Fall of alternate years.
Research Areas
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- Extension
- Research
- Publications
- Teaching
- Service
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Affiliations
other Cornell affiliations
Extension
has primary specialization area
Research
research overview
- In terms of disciplines, my program is spread across food chemistry, food microbiology and sensory analysis and it is largely tied together with chemometrics (the application of multivariate math and statistics). The focus of the chemistry part of the program is largely on the manner in which macromolecules interact with small molecules to produce phenomena that people can directly perceive. This includes interactions of proline-rich proteins with polyphenols that produce visible turbidity in beverages and astringency in the mouth, interactions of proteins with hop bitter compounds that are involved in beer foam and gushing (uncontrolled overfoaming upon opening a container), and binding of flavor compounds by proteins and other macromolecules. I am also interested in how the molecular properties of organic compounds determine their flavor intensity (perception thresholds) and how the amino acid composition of proteins determines their physicochemical and functional properties. In the microbiology area I am interested in a number of mathematical approaches to microbiological problems. This has included work in simulation modeling of the microbial sampling of liquids, modeling how the molecular properties of organic acids result in different degrees of inhibition of different species of bacteria, and the use of pattern recognition approaches for characterizing and identifying bacteria. In the sensory area, in addition to several previously mentioned items, my group has pioneered the use of proper sensory tests (for determining perception thresholds, estimating haze intensity and describing appearance) to observe the effects of sample properties (solution color and particle size and concentration) and viewing conditions (illumination intensity and background contrast) on human visual response to turbidity. In terms of commodities my program is concentrated in beverage technology, particularly brewing, but also including fruit juice, wine, tea and coffee. Work has included fundamental studies of particle formation in beverages, mechanisms of action of various haze stabilization approaches and analytical approaches to measuring haze-active constituents.
area(s) of concentration/expertise
keywords
- Astringency Perception
- Beverage Technology
- Brewing Science
- Chemometrics
- Modeling
- Predictive Microbiology
- Visual Perception of Turbidity
submitted impact statement
Publications
individual publications
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academic article
- Adventures in Brewing Science. Master Brewers Association of the Americas Technical Quarterly. 49:87-98. 2012
- Chemometric investigation of barley and malt data. Journal of the American Society of Brewing Chemists. 70:163-175. 2012
- Elements of Analytical Measurement in Brewing. Journal of the American Society of Brewing Chemists. 69:100-107. 2011
- The effects of green tea drinking on salivary polyphenol concentration and perception of acid astringency. Food Quality and Preference. 22:157-164. 2011
- The effect of beer pH on colloidal stability and stabilization. Master Brewers Association of the Americas Technical Quarterly. 47:1-5. 2010
- Modeling physicochemical properties and activity of aspartyl proteinases based on amino acid composition. Journal of Agricultural and Food Chemistry. 57:2536-2543. 2009
- Process for production of tilapia retorted skin gelatin hydrolysates with optimized antioxidative properties. Process Biochemistry. 44:1152-1157. 2009
- On the mechanisms of adsorbent interactions with haze-active protein and polyphenol. Journal of the American Society of Berwing Chemists. 66:48-54. 2008
- Taste-odor integration in espresso coffee. Chemosensory Perception. 1:147-152. 2008
- Modeling bovine serum albumin binding of flavor compounds (alcohols, aldehydes. esters and ketones) as a function of molecular properties. Journal of Food Science. 73. 2008
- The relationship between expectorant pH and astringency perception. Journal of Sensory Studies. 23:222-233. 2008
- Turbidimetric titration of haze-active polyphenol in beer. Journal of the American Society of Berwing Chemists. 66:271-79. 2008
- Visual versus instrumental perception of haze – A review. Master Brewers Association of the Americas Technical Quarterly. 45:90-98. 2008
- Comparison of methods for degassing beer for analysis. J. Amer. Soc. Brew. Chem. 65:229-231. 2007
- Modeling Production of Antifungal Compounds and their Role in Biocontrol Product Inhibitory (2) Activity. Journal of Agricultural and Food Chemistry. 55. 2007
- The effect of beer pH on colloidal stabilization with adsorbents. J. Amer. Soc. Brew. Chem. 65:52-58. 2007
- Comparison of methods for assessing polyphenols in beer. J. Amer. Soc. Brew. Chem. 64:127-134. 2006
- Effect of viewing background on visual perception of turbility. Journal of Sensory Studies. 21:34-53. 2006
- Haze formation in beverages. LWT Food Sci. & Tech.. 39:987-994. 2006
- Study of colloidal instability of millet wine. J. Amer. Soc. Brew. Chem.. 64:86-93. 2006
- Comparison of methods for assessing colloidal stability of beer. Tech. Q. Master Brew. Assoc. Am.. 42:7-12. 2005
- Comparison of methods for measuring protein in beer. J. Amer. Soc. Brew. Chem. 63:163-170. 2005
- Effect of illumination intensity on visual perception of turbidity. Food Quality and Preference. 16:536-544. 2005
- Multivariate analysis of routine beer analysis results. J. Amer. Soc. Brew. Chem.. 63:113-120. 2005
- Response surface modeling of factors influencing the production of chitinolytic and b-1,3 glucanolytic enzymes in Trichoderma atroviride strain P1. Enzyme & Micro Tech. 37:82-92. 2005
- pH and (3) beer colloidal stability. Cerevisia- Belgian J. Brew. Biotech. 30:189-194. 2005
- Chemometric analysis of proteolysis during ripening of Ragusano cheese. Journal of Dairy Science. 87:3138-3152. 2004
- Organic acid inhibition models for Listeria innocua, Listeria ivanovii, Pseudomonas aeruginosa and Oenococcus oeni. Food Microbiology. 21:67-72. 2004
- Quantitative structure-activity relationship modeling of alcohol, ester, aldehyde and ketone flavor thresholds in beer from molecular features. J. Agric. Food Chem.. 52:3057-3064. 2004
- An alternate mechanism for the astringent sensation of acids. Food Quality and Preference. 15:13-18. 2003
- Effects of alcohol and pH on protein-polyphenol haze intensity and particle size. J. Amer. Soc. Brew. Chem. 61:88-98. 2003
- Modeling protein functional properties from amino acid composition. Journal of Agricultural and Food Chemistry. 51:7792-7797. 2003
- Validation of bacterial growth inhibition models based on molecular properties of organic acids. International Journal of Food Microbiology. 86:249-255. 2003
- Characterization of haze-active proteins in apple juice. Journal of Agricultural and Food Chemistry. 50:3828-3834. 2002
- Chemometric analysis of Ragusano cheese flavor. Journal of Agricultural and Food Chemistry. 50:1143-1149. 2002
- Chemometrics in brewing - a review. J. Am. Soc. Brew. Chem. 59:147-156. 2001
- Comparison of three pattern recognition techniques for classification and identification of lactic acid bacteria. J. Appl. Micro. 91:225-236. 2001
- Development of a method for assessing haze-active protein in beer by dye binding. J. Am. Soc. Brew. Chem. 59:172-182. 2001
- Quantitative structure-activity relationship modeling of peptide and protein behavior as a function of amino acid composition. Journal of Agricultural and Food Chemistry. 49:851-858. 2001
- Apple cultivar and maturity affect haze-active protein and haze-active polyphenol concentrations in juice. Journal of Food Science. 65:1386-1390. 2000
- Effect of protein/polyphenol ratio on the size of haze particles. J. Am. Soc. Brew. Chem. 58:117-123. 2000
- Evaluation of a model of organic acid flavor thresholds in beer. J. Am. Soc. Brew. Chem. 58:94-96. 2000
- Relationship of particle size to light scattering. J. Am. Soc. Brew. Chem. 58:97-100. 2000
- Effects of protein-polyphenol interactions on beverage haze, stabilization, and analysis. Journal of Agricultural and Food Chemistry. 47:353-362. 1999
- Human visual perception of haze and relationships with instrumental measurements of turbidity. Thresholds, magnitude estimation and sensory descriptive analysis of haze in model systems. Food Quality and Preference. 10:421-436. 1999
- Modeling the flavor thresholds of organic acids in beer as a function of their molecular properties. Food Quality and Preference. 10:129-137. 1999
- Modeling the inhibitory effects of organic acids on bacteria. International Journal of Food Microbiology. 47:189-201. 1999
- Protein-polyphenol haze in beverages. Food Technol. 53:54-57. 1999
- Visual perception of haze. Food Technol. 53:50-52. 1999
- Comparison of polyphenol interactions with PVPP and haze-active protein. J. Am. Soc. Brew. Chem. 56:24-31. 1998
- Development of a signal measurement technique for application in multianalyte liposome immunomigration assays. Food Agric. Immunol. 10:195-202. 1998
- Haze-active protein and polyphenols in apple juice assessed by turbidimetry. Journal of Food Science. 62:79-84. 1997
- Mechanisms of adsorbent action in beverage stabilization. Journal of Agricultural and Food Chemistry. 45:4275-4280. 1997
- Mechanisms of beer colloidal stabilization. J. Am. Soc. Brew. Chem. 55:73-78. 1997
- Formation of protein-polyphenol haze in beverages. Journal of Agricultural and Food Chemistry. 44:1997-2005. 1996
- Nature of polyphenol-protein interactions. Journal of Agricultural and Food Chemistry. 44:80-85. 1996
- Computer simulation of microbiological sampling of liquid foods. Journal of Food Protection. 56:518-524. 1993
- The sensory and chemical basis of beer flavor. Cerevisia & Biotechnology. 18:29-39. 1993
- Evaluation of multinitrogen source media for wild yeast detection in brewing culture yeast. J. Am. Soc. Brew. Chem. 50:134-138. 1992
- Applications of microcomputers in breweries - Data base management system programs. Brew. Dig. 65:20-23. 1990
- An investigation into hop fractions leading to hoppy aroma in beer. Tech. Q. Master Brew. Assoc. Am. 26:62-69. 1989
- Applications of microcomputers in breweries - Spreadsheet programs. Brew. Dig. 64:32-35. 1989
- Correlation of sensory and instrumental data in elucidating the effect of varietal differences on hop flavor in beer. J. Am. Soc. Brew. Chem. 47:18-26. 1989
- Differentiation of lager culture yeast strains by selective dye inhibition. Brew. Dig. 64:16-19. 1989
- Evaluation of a colorimetric method for determination of ascorbates in beer. J. Am. Soc. Brew. Chem. 47:57-61. 1989
- The relationship of beer high molecular weight protein and foam. Tech. Q. Master Brew. Assoc. Am. 26:139-146. 1989
- The use of multivariate analysis of beer aroma volatile compound patterns to discern brand-to-brand and plant-to-plant differences. J. Am. Soc. Brew. Chem. 47:93-101. 1989
- A data base management system for flavor threshold information and an evaluation of strategies for identifying new flavor-active substances in beer. J. Am. Soc. Brew. Chem. 46:82-91. 1988
- Applications of microcomputers in breweries - Introduction. Brew. Dig. 63:12-14. 1988
- Applications of microcomputers in breweries - Word processing. Brew. Dig. 63:12-15. 1988
- A new medium for the detection of wild yeast in brewing culture yeast. J. Am. Soc. Brew. Chem. 45:135-140. 1987
- Filtration difficulties resulting from damage to yeast during centrifugation. Master Brewers Association of the Americas Technical Quarterly. 24:1-8. 1987
- The determination of ascorbates in beer by liquid chromatography with electrochemical detection. J. Am. Soc. Brew. Chem. 45:33-37. 1987
- A new calibration procedure for the determination of dimethyl sulfide in beer using gas chromatography with a flame-photometric detector. J. Am. Soc. Brew. Chem. 44:57-66. 1986
- Brewing process dimethyl sulfide measurements using a new calibration procedure for gas chromatography with flame-photometric detection. J. Am. Soc. Brew. Chem. 44:66-69. 1986
- Determination of oxygen and nitrogen in packaged beer via gas chromatography. J. Am. Soc. Brew. Chem. 44:72-77. 1986
- The effect of trub (and other particles) on fermentation. Tech. Q. Master Brew. Assoc. Am. 23:37-43. 1986
- The semi-routine use of capillary gas chromatography for analysis of aroma volatiles in beer. J. Am. Soc. Brew. Chem. 43:203-208. 1985
- Application of ion chromatography to beer, wort, and brewing water. J. Am. Soc. Brew. Chem. 42:65-70. 1984
- Application of pattern-recognition techniques to the essential oil of hops. J. Am. Soc. Brew. Chem. 42:54-61. 1984
- Assessment of filterability of beer and wort. Tech. Q. Master Brew. Assoc. Am. 21:112-123. 1984
- Microcomputer automation of titration. J. Am. Soc. Brew. Chem. 42:29-36. 1984
- Yeast counting by microscopy or by electronic particle counting. J. Am. Soc. Brew. Chem. 42:71-79. 1984
- Application of instrumental techniques in brewing chemistry - past, present, and future. J. Am. Soc. Brew. Chem. 41:4-9. 1983
- High performance liquid chromatographic analysis of hop bittering components in hops, hop extracts, wort and beer. J. Am. Soc. Brew. Chem. 41:51-57. 1983
- Brewing laboratory automation. A review with special emphasis on the use of microcomputers. J. Am. Soc. Brew. Chem. 40:9-14. 1982
- Characterization of amorphous-particle haze. J. Am. Soc. Brew. Chem. 39:1-11. 1981
- Factors affecting dissolved oxygen analysis in beer and water. J. Am. Soc. Brew. Chem. 39:147-153. 1981
- Factors affecting dissolved oxygen analysis in beer and water. J. Am. Soc. Brew. Chem. 39:147-153. 1981
- Microcomputer automation of the conductometric titration of hop alpha-acids. J. Am. Soc. Brew. Chem. 39:124-130. 1981
- An improved system for the conductometric determination of hop alpha-acids. J. Am. Soc. Brew. Chem. 38:119-125. 1980
- Routine use of a programmable calculator for computing alcohol, real extract, original gravity, and calories in beer. J. Am. Soc. Brew. Chem. 38:27-33. 1980
- Gas chromatographic determination of beer volatiles by carbon disulfide extraction: Improved methodology, data handling, and interpretation. J. Am. Soc. Brew. Chem. 34:4-13. 1976
- High-performance liquid chromatography of hop compounds in brewing. J. Am. Soc. Brew. Chem. 34:79-96. 1976
- Origin and formation of 2-nonenal in heated beer. Tech. Q. Master Brew. Assoc. Am. 13:227-232. 1976
- Determination of trans 2-nonenal in beer. Tech. Q. Master Brew. Assoc. Am. 11:110-117. 1974
- The influence of various storage conditions on the formation of 2-nonenal in bottled beer. Proc., Am. Soc. Brew. Chem. 32:47-49. 1974
- Brewing applications of high performance liquid chromatography. Tech. Q. Master Brew. Assoc. Am. 9:205-214. 1972
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booksection
-
chapter
- Using chemometrics to classify samples and detect misrepresentation. Progress in Authentication of Food and Wine. 39-65. 2011
- Haze in Beverages. Advances in Food and Nutrition Research. 53-86. 2009
- Control Systems: Chemical Analysis in Brewing. New Technologies to Improve Brewing Performance and Beer Quality. 372-390. 2006
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conference paper
- Applications of chemometrics in brewing. European Brewery Convention, Congress 28th. 801-810. 2001
- The effect of pH on protein-polyphenol particle size. European Brewery Convention, Congress 28th. 791-800. 2001
- Beer clarity stability. 6th Scientific and Technical Convention. 67-74. 1997
- Analysis of haze-active polyphenols and proteins in grape juices and wines. 4th International Cool Climate Symposium on Viticulture and Enology. 1996
- The relationships between instrumental and human visual perception of turbidity in clear and colored samples simulating wines and grape juices. 4th International Cool Climate Symposium on Viticulture and Enology. 1996
- Sensory analysis of hop oil-derived compounds in beer; flavor effects of individual compounds. Quality control. Monograph XXII E.B.C. Symposium on Hops. 198-215. 1994
- The sensory and chemical basis of beer flavor. Centenary International Congress. 1-15. 1993
- Applications of computers in brewing research and quality assurance laboratories. 18th Convention. 196-210. 1984
- Application of pattern recognition techniques to essential oil of hops. IUFOST Symposium on Food Research and Data Analysis. 424. 1982
- Advanced methods of sensory evaluation. European Brewery Convention Monograph VII, Flavor Symposium. 33-42. 1981
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document part
- Factors influencing haze formation in fruit juices 1996
featured in archived article
Teaching
teaching overview
- I teach the brewing part of the course FDSC4300 Understanding Wine and Beer each spring. I teach the graduate course FDSC6080 Chemometrics in Food Science in alternate years in the fall semester. Chemometrics is the application of statistical and mathematical methods as well as the principles of good measurement science to efficiently extract useful information from chemical data. It has broad application across many disciplines and this is reflected in the attendees.
teaching activities
- FDSC-4300: Understanding Wine and Beer - Spring 2013
- FDSC-5000: Master of Professional Studies (Agriculture) Project - Spring 2013
- VIEN-4300: Understanding Wine and Beer - Spring 2013
- FDSC-6080: Chemometric Methods in Food Science - Fall 2012
- FDSC-4300: Understanding Wine and Beer - Spring 2012
- FDSC-5000: Master of Professional Studies (Agriculture) Project - Spring 2012
- VIEN-4300: Understanding Wine and Beer - Spring 2012
Service
outreach overview
- I am responsible for Cornell's brewing extension program. Occasionally I respond to contacts from media or correspond with media on brewing or beverage related topics. Beer brewing and brewing science.
- I make presentations on producing alcohol from grains in distillation workshops.
- I train and advise students/faculty members from my department, and occasionally those from other departments, on statistical experiment design and chemometrics/ multivariate data analysis. I respond to information requests from industry in NY and beyond.
service to the profession
- American Society of Brewing Chemists Foundation Board Board Member 2008 -
- International Chemometrics Society, North American Chapter Webmaster 2004 -
- International Chemometrics Society, North American Chapter Member 1990 -
- Institute of Food Technologists Member 1989 -
- American Society of Brewing Chemists Technical Committee Chairperson 1986 -
- Master Brewers Association of the Americas Member 1984 -
- Sigma Xi Member 1980 -
- American Society of Brewing Chemists Member 1971 -
- AMERICAN CHEMICAL SOCIETY Member 1970 -
- Multistate Project S-1033 Control of food-borne pathogens in pre- and post- harvest environment
- Omicron Delta Kappa
- University of Hawaii at Manoa External Evaluator for faculty promotion 2010
- Dept. of Human Nutrition, Food and Animal Sciences, Univ. of Hawaii at Manoa External Evaluator for Faculty Promotion & Tenure Decision 2009
- Sigma Xi -Geneva Chapter Officer, President/Elect/Past 2004 - 2006
- American Society of Brewing Chemists Technical Committee Committee Member 1983 - 1989
reviewer or editor for
Background
education and training
- Ph.D. in Biochemistry, Pennsylvania State University 1970
- M.S. in Biochemistry, Pennsylvania State University 1968
- B.S. in Biochemistry, Pennsylvania State University 1967
awards and honors
- Award of Merit, 2011
- Eric Kneen Memorial Award, 2004
- Eric Kneen Memorial Award, 1999
- Award of Distinction, 1999
- Eric Kneen Memorial Award, 1998
- Honorary Professor, 1996
- Presidential Award, 1990
- Presidential Award, 1986
- National Science Foundation Fellowship, 1967
Other
college
- CALS
research keyword
- Astringency Perception
- Beverage Technology
- Brewing Science
- Chemometrics
- Modeling
- Predictive Microbiology
- Visual Perception of Turbidity
name prefix
- Professor