J. T. 'STUBBY' PARKER CHAIR IN DAIRY FOODS
REPORT OF FIVE YEARS OF PROGRESS

W. James Harper
October 1, 1993 - August 18, 1998

This report is a summary of the activities of Dr. W. James (Jim) Harper as the J. T. "Stubby" Parker Chair in Dairy Foods for the past five years.

MAJOR RESEARCH ACCOMPLISHMENTS:

Research areas given specific attention include:

Low fat and full fat Swiss cheese flavor and texture Determination of the efficacy of electronic noses in differentiating aroma in foods and evaluation as a research tool Improvement of the baking quality of milk fat through glycerolysis Flavor and flavor improvement of whey protein concentrates Functionality of 34% WPC in food systems and factors controlling functionality Control of microflora in accelerated ripening of cheese through the use of high pressure processing Functionality of milk protein concentrates, a new milk protein ingredient, in foods and processing effects on functionality Effect of feeding soy beans on milkfat composition and off-flavor development Whey proteins as functional food ingredients

Swiss Cheese Research:

Ohio is #1 in Swiss Cheese production in the USA and the Parker Chair has a continuing Swiss Cheese Research program since October, 1993. The J.T. Parker Chair, with expenditures of approximately $200,000, primarily funds the program. One M. S. recipient, two Ph.D. recipients and 1 Post Doctoral researcher have completed Swiss Cheese research. Much of the work was accomplished in collaboration with the Brewster Dairy Company, as the company provided most of the cheese used in the research (a minimal amount of cheese was processed in the OSU pilot plant).

Major results of this research:

Provided a basis for the improvement of commercial low fat Swiss cheese flavor.

Developed a procedure for making low fat Swiss cheese with a Body similar to full fat cheese. This is accomplished without changing the make procedure or increasing the moisture content of the cheese.

Elucidated the key aroma components of Swiss cheese. By using the Electronic Nose and SPME/GC in combination, it was shown that the major components differentiating the aroma of Swiss cheese are five fatty acids (acetic, propionic, butyric, isovaleric and caproic acids). An Electronic Nose containing various ratios of the five fatty acids differentiated thirteen Swiss cheeses. The thirteen cheeses were provided by the Swiss Cheese Consortium and tested different during sensory evaluation.

Showed the importance of starter organisms in the ripening process. The lactobacillus starter culture used in the manufacture of Swiss cheese proves to be important in the flavor development of the cheese and modifies the fatty acid profile during ripening.

Failed to improve accelerated ripening through high pressure processing of cheese slurries. High-pressure treatment of Swiss cheese slurries succeeded in eliminating undesirable organisms, but failed because the ripening process was blocked through a mechanism not fully understood.

A brief summary of the various research areas are presented in the following table:

Electronic Nose Research:

Aroma and taste are among the most important attributes that consumers use in assessing the acceptability of food products. A need exists for objective methods to supplement human sensory evaluation. Specific Instruments were reported as capable of differentiating food aroma and became commercially available four years ago. The Chair predicted these "Electronic Noses" would either become significant tools for food aroma evaluation or "this is one of the largest scams going." The three instruments available at that time differed in respect to sensors, methods for operation and methods for analysis. With no clear indication of which, if any, of the instruments would truly differentiate aromas, negotiation with the three manufacturers led to the purchase of all three pieces at a 50 -66% reduction in cost. The first two years were spent evaluating the electronic nose’s technology potential. The past two years have assessed the electronic nose’s value as a research tool and its application to ongoing research projects.

Major findings:

	Proved the technology is valid and provide a useful tool for quality control, supplementing human sensory evaluation by screening a large number of samples in one day (up to 12 in triplet). Established the factors that need to be controlled for successful differentiation of food aromas. Showed that all three instruments, when operated properly, can differentiate the aromas of a range of dairy foods. Determinedthe differences between the instruments and which were easiest to use. Demonstrated that the nose differentiated aroma of Swiss cheese on the basis of the ratios of 5 fatty acids (acetic, propionic, butyric, isovaleric and hexanoic) Illustrated that for 30 compounds with different chemical structures, the electronic nose had a threshold value similar to that reported for human sensory aroma thresholds. Demonstrated the differences observed by human sensory panels could be similar to electronic nose results in cheese, milk proteins, baked goods, lipid oxidation and milk. Found the electronic nose is a useful tool in a wide range of applications. These included:
	High pressure treatment of cheese slurries, where the use of human sensory panels was excluded because of the potential for growth of pathogens in the slurry.
	Differentiation of aroma in Swiss cheese, enzyme modified cheese and Cheddar cheese.
	Differentiation of aroma in whey protein concentrates and the EN showed the loss of volatiles through treatment with cyclodextrins.
	The effect of different starter adjuncts on aroma differences in the ripening of Cheddar cheese.
	Differentiation of commercial cheese crackers made by different manufacturers.
	Demonstration of changes in aromas during the storage of orange oil at elevated temperatures.

Whey Protein Concentrate Research:

Whey, long considered a waste product, has been converted to whey proteins and lactose through the application of ultrafiltration. Of these, whey proteins have proven to give the greatest financial return. Whey protein concentrates (WPC) are accepted as an ingredient in a wide range of food products. However, the lack of understanding of factors controlling functionality and the presence of off flavors in WPC have limited their application as food ingredients.

Flavor Research:

Flavor research on WPC has looked at the identification of volatile compounds associated with different types of WPC, origins of off flavors and methods for improving the flavor of WPC. Particular attention was directed to 34% WPC, which is the major WPC made in the USA, but has received little research attention.

Major findings include:

The Electronic nose was successful in differentiating WPC from different manufacturers and with different flavor characteristics. Solid phase micro-extraction combined with capillary GC was superior to other methods for measuring the volatile compounds in WPC. More than 70 volatile compounds were identified in WPCs that could potentially influence flavor. These included fatty acids, aldehydes, sulfur compounds, esters, alcohols, aromatic compound, pyrazines and suggested the flavor of WPC could arise from a variety of sources. Cyclodextrins removed up to 90% of the volatile compounds in WPC, but only reduced a portion of the off flavors. This suggests that non-volatile compounds cause much of the off flavor in WPC. For 34% WPC: Electronic nose data indicates that different lots of product from the same factory are generally, but not always, similar. However, differences in aroma exist in samples from different factories. A combination of GC and EN suggest that at least four different sources contribute to the aroma portion of the flavor of 34% WPC: (a) feed; (b) lipolysis; (c) lipid oxidation and (d) Maillard reaction. The contribution of each appears to vary between factories. SMPE/GC shows that chemical markers can be used to determine the sources of off flavors in 34% WPC. The markers also indicate the relative significance of a given source to the overall flavor character of the product.

Functionality Research:

Functionality research was focussed primarily on 34% WPC, which has received little attention in respect to its functionality and is generally assumed to be much less functional than high protein (>60%) WPC.

Major findings of this research include:

	A study of over 70 low protein WPCs from six different U.S. manufacturers shows that the 34% WPC has the potential for having excellent solubility, foaming, emulsion, gelation and food ingredient characteristics. Variations exist in functional properties of products made by different companies and within products of the same company. However, the data suggest that good control was achieved for the characteristics the company found to be important, such as solubility in the case of all 70 products.
	The 34% WPC was also found to have good potential for application as a food ingredient in all model systems investigated. This included infant formula, acid beverage, cake, whipped topping, coffee whitener and processed cheese food and spread.
	The factory source of the WPC had no statistically significant effect on the application of the 3% WPC in cake, infant formula and whipped topping. However, the factory source was important for application in acid beverages and processed cheese food. Product from at least one (not the same one) factory made very good product. Bad product was made from at least one factory.
	Functionality of 34% WPC could be predicted by its solubility. Low solubility results in unstable acid beverages and increases the hardness of processed cheese food.
	There was a significant correlation between solubility and the size of particles in hydrated WPC.
	Investigation continues into the specific reasons for the differences observed. Preliminary data suggest that functionality of 34% WPC is controlled by the extent of protein denaturation during processing

Milk Protein Concentrate Research:

Milk protein concentrates (MPC) are a new family of milk protein ingredients developed by building on the membrane processing technology successful for making whey protein concentrates. Like many new products, MPCs are not well understood regarding where they are most useful as ingredients or what factors need to be controlled to provide uniform functionality. The work has shown:

Currently availalbe commercial MPCs are highly variable in functionality and therefore not able to reach their market potential as food ingredients at the present time. Variability is especially high in respect to the viscosity of 10% protein solutions, which ranges from 100 to 15,000 cP. The variability in MPCs from different manufactures is likely related to the characteristics of the particles in the MPCs after one hour of hydration. Overall, the study shows that basic differences in the characteristics of casein aggregates in the MPCs appear to relate to variability in functionality.

Characterization of the particles in the hydrated MPCs shows:

The particle size increased as the protein content of the sample increased (e.g., 77 um for MPC85 versus 0.42um for MPC42). Ultrasonication effect of reducing the particle size increased as the protein content decreased (e.g., 56% for MPC85 versus 98% for MPC56). The effects of the treatment were similar within the samples made by the same manufacturer. Among all the treatments, ultrasonication and 2-mercaptoethanol affected the samples at a higher degree, while EDTA and urea had relatively fewer effects on the samples. In some cases, none of the treatments could dissociate the aggregates, suggesting possible protein polymerization during processing. The characteristics of the particles in the MPC appear to be affected primarily by the conditions used in drying. Control of drying inlet and outlet temperatures can control the heat induced interactions during drying and provides a basis for control of the functional properties of MPCs.

Milk Fat Research:

The major benefit of milkfat in baked products is the formation of butter flavor during baking, which has never been duplicated. The loss of market share for butter as a bakery ingredient has been its lack of functionality in comparison to vegetable fat products with added emulsifiers. Lipase, in the absence of water and with an excess of glycerol, is able to convert tri-glycerides to mono- and di-glyceride. This research investigated the partial conversion (glycerolysis) of milkfat to mono- and di-glycerides and the application of the modified milk fat as a bakery ingredient.

Partial glycerolysis (10-25%) produced primarily di-glycerides, whereas full glycerolysis produced mostly mono-glycerides. Removal of lipase and excess glycerol from the modified milk fat was necessary to avoid off flavors in baked products. Partially modified milkfat (10-20% mono- & di-glycerides) was used in bread, cakes, muffins and cookies. Butter flavor was formed during the baking of all the products investigated. The partially modified milk fat had no significant effect on the textural characteristics of the baked products, except for cakes. In the case of cakes, the cake volume was increased and tenderness was improved. The cost of partial glycerolysis was $0.20 per pound of finished product without recovery and re-use of the lipase. A simple procedure was developed for lipase recovery permitting re-use up to 20 times, reducing the cost to $0.01 per pound of finished product. The partially modified milkfat is useful in providing both flavor and improved texture to cakes, but has little benefit to other baked goods.

Effect of Feeding Soybeans on Milk Fat Composition and Flavor:

The Parker Chair is a Co-Investigator with Don Palmquist of the Department of Animal Science on a study determining the effect of feeding animals whole soybeans on fatty acid composition and the potential for development of oxidized flavor of milk. Major findings to date include:

Feeding animals whole soybeans increases the unsaturated fatty acid content substantially, with the linoleic acid values increasing 2-3 fold. The increase in unsaturated fatty acids is accompanied by a decrease in C-12, 14 and 16 unsaturated fatty acids. There is no indication of oxidized flavor development in the milk within the first 6-12 hours after milking for either the control tallow fed or soybean fed animals. Pasteurized, unhomogenized milks from cows fed soybeans become oxidized after 3 days of refrigerated storage. After 8 days of refrigerated storage all pasteurized samples of milk showed some evidence of oxidized flavor. The level of oxidized flavor was much higher in the milk from cows fed soybeans. There was no correlation between the hexanal content of the milks and oxidized flavor scores. Further investigation is in progress.

Functional Food (Nutriceutical) Research:

At the suggestion of the Parker Chair advisory board, attention is now being directed to the investigation of milk components as ingredients in functional (nutriceutical) foods.

A paper was prepared regarding the biological properties of whey proteins and the current state of knowledge of their potential role in functional foods. This paper is currently being reviewed by the American Dairy Products Institute for possible publication as a monograph.

The possibility that modified beta-lactoglobulin from heated milk may have different physico-chemical and biological properties from normal beta-lactoglobulin is a current investigation. In 1994, other researchers reported finding proteins in the proteose-peptone fraction (proteins remaining soluble after heating to 95 °C and adjustment of the pH to 4.6) of heated milk which interacted with E. coli toxin. These proteins had the amino acid sequence of beta-lactoglobulin and alpha-lactalbumin. The proteins were thought to be lactosylated. Recently, heat treatment was shown by French and New Zealand researchers to cause a Maillard type reaction between beta-lactoglobulin and lactose in milk. An investigation is in progress to determine the characteristics of glycated (lactosylated) beta-lactoglobulin with attention to its functional and biological properties.

Previous research showed that an acceptable beverage could be made with tomato juice and yogurt. The potential functional food benefits of this product are being considered. Special attention will be given to potential anti-cancer benefits.

Miscellaneous Areas of Research:

Cheese Cracker Research:

Research was undertaken using a one year industrial grant to determine the reason why it takes so much cheese (20-40% of flour weight) to give a "cheesy" character to cheese crackers. The study investigates ways to provide cheese flavor with less cheese.

The four factors found to be associated with the loss of cheese flavor during the manufacture of cheese crackers include: (a) interaction of volatile flavor components with starch and gluten during dough preparation; (b) some masking of cheese flavor by the volatile components in the dough itself; (d) volatilization of volatile compounds and (e) thermal induced changes in the cheese volatiles during baking.

The literature reports it necessary to have salt and a pH of less than 5.5 to detect a cheese note in the crackers. Use of different types of cheese at 25% of flour weight resulted in crackers having a "cheesy" note, but gave no indication of the type of cheese used.

Attempts to improved cheese flavor through "encapsulation" of cheese with a variety of proteins, starches and gums was not successful, and generally resulted in even less cheesiness in the cracker.

Neural Net Research:

A commercial program designed for the optimization of manufactured product properties was evaluated for possible use with the Electronic Nose and as a product development tool. The program (ChemCad) was not easily adapted to the electronic nose. However, ChemCad was very useful as a research tool to establish designs for optimization and optimization of process and product formulations.

Support of research by other faculty:

The chair has provided support to research being conducted by other faculty. Five % release time was provided for the past two years to assist Dr. Zhang's Nattick project on pulsed electric field (PEF) treatment of products to be evaluated for suitability in army rations. The role of the Chair was to provide assistance in the formation of foods designed specifically for PEF.

GRADUATE DEGREES COMPLETED:

Nine M.S. and five Ph.D. degrees have been completed under the direction of the Chair. Seven additional students are currently working toward completion of degrees.

M.S.

Kuen Da Jou, M.S. 1994. The effect of added sugars on the thermal behavior of a low lactose whey protein concentrate.

Joseph P. Kleinhenz, MS. 1995. Lower molecular weight fatty acids in full fat and low fat Swiss Cheese.

Wen Lin Li M. S. 1995. Determination of fatty acids and other volatiles in whey protein concentrates.

Tina M. Knisley, M.S. 1995. Comparison of flavor compound detection level by sensory panel versus Aroma Scan.

Mahmut Seker M.S. 1996. Bovine/soy milk blends in natural and processed cheese.

Poppy Susanto, 1997. The functionality of enzyme modified milkfat in bakery products.

Judy Atkinson, M,S. 1997. Assessment of the Sensory Quality of a Medical Nutritional Powder using trained profession panelists and the Alpha MOS Electronic Nose.

Cynthia S. Neal, M.S. 1997 The quantitative versus qualitative evaluation of the organoleptic quality of canola oil.

Stephen French, M. S. 1997. The effect of milk proteins and emulsifying salts on the characteristics of processed cheese food.

Ph.D.

Ming-Ju Chen, Ph.D. 1993. Factors affecting consumer acceptance and shelflife of a fermented milk flavored tomato juice product.

Stephen Pao, Ph.D. 1994. Halophylic organisms in Sufu, a Chinese cheese.

Sungmi Sohn, Ph.D. 1996. Factors affecting the textural properties of low fat Swiss Cheese.

Michelle Yang, Ph.D. 1996. The use of cyclodextrins to removed volatile compounds from selected protein products.

Kuen Da Jou, Ph.D. 1997. Integrated analysis and pattern recognition of Swiss cheese aroma by SPME/GC/MS and electronic noses.

CURRENT GRADUATE STUDENTS

Stephen French, Expected Ph.D. 2000. Investigation of Beta-lactoglobulin as a functional food component.

Monica De Castro, Expected Ph.D. 1998. Milk protein concentrate research.

Sudarat Jianyangyuen, Expected Ph.D. 2000. Research to be determined.

Joseph Klenhenz, Expected Ph.D. 2000. Flavor research.

Joesphine Kuo, Expected Ph.D. 1999. Milk protein concentrate research.

Kwok Man Lee, Expected Ph.D. 1998. 34% whey protein concentrate functionality research.

Sarit Seth, Expected M.S. September, 1998. 34% whey protein concentrate flavor research.

PRESENTATIONS AND PUBLICATIONS:

Since becoming the Parker Chair in Dairy foods, W. J. Harper has given 31 presentations and published 14 technical papers.

Presentations:

Harper-WJ (1995) Functional properties of whey protein ingredients. IFT Annual Meeting 1995 Book of Abstracts p 45.

Kleinhenz-JP; Harper-WJ (1995) Comparison of capillary electrophoresis and capillary gas chromatography analysis of water soluble fatty acids in full fat and low fat Swiss cheese. 1995 IFT annual meeting: book of abstracts, p. 224.

Jou-KD; Harper-WJ (1995) The effect of additional disaccharides on thermal behavior of whey protein concentrates determined by DSC. IFT Annual Meeting 1995: book of abstracts p 121.

Sohn-S; Harper-WJ (1995) Young's modulus in relation to the textural evaluation of cheese. IFT Annual Meeting 1995:book of abstracts p 123.

Sohn-S; Harper-WJ (1995) Comparison of textural characteristics of lowfat and full fat Swiss cheese in relation to microstructure. IFT Annual Meeting 1995: book of abstracts p 123.

Tamaro-AC; Harper-WJ; Chism-GW (1995) A rapid method to assess rebodying potential of Swiss-style yogurt gels using a cone and plate viscometer. IFT Annual Meeting 1995: book of abstracts p. 120.

Jin-Z; Harper-WJ (1996) Differentiation of enzyme-modified cheese slurries by electronic noses. 1996 IFT annual meeting: book of abstracts, p. 218.

Jou-KD; Harper-WJ (1996) Differentiation of seven cheeses using an Electronic Nose. 1996 IFT Annual meeting: Book of abstracts, p. 184.

Sungmi-Sohn; Harper-WJ (1996) Modifications of processing procedures to improve the textural properties of low-fat baby Swiss cheese. 1996 IFT annual meeting: book of abstracts, p. 214.

Yang-MH; Harper-WJ (1996) Effect of various cyclodextrins on volatile compounds in whey protein concentrate 1996 IFT annual meeting: book of abstracts, p. 151.

Yang-MH; Harper-WJ (1995) Effect of beta-cylcodextrin on volatile flavor compounds in whey protein concentrate. IFT Annual Meeting 1995:book of abstracts p 190.

De Castro, M. and Harper, W. J. (1997) Basic functional characteristics of milk protein concentrates. IFT Annual Meeting. Book of Abstracts p 227.

Harper, W. J. (1997) Seminar presented to the New Zealand Dairy Research Center. The Electronic Nose as a research tool for evaluating food aromas. February 1997.

Harper, W. J. (1997) Whey Protein Work Shop. University of Campinas, Campinas, Brazil July 7-11, 1997.

Harper, W. J. and Lee, K. M. (1997) Functional Properties and Applications of 34% WPC. Proceedings 1997 International Whey Conference. October 27-29, 1997 International Dairy Federation Bulletin. In Press.

Jou, K. D. and Harper, W. J. (1997) Pattern recognition of GC chromatographs of five Swiss cheeses using artificial neural networks and comparison of GC and Electronic Nose Discriminate Plots. IFT Annual Meeting. Book of Abstracts p 225.

Lee, K. M. and Harper, W. J. (1997) The function value of 34% whey protein concentrates. IFT Annual Meeting. Book of Abstracts p 226.

Sohn, S. and Harper, W. J. (1997) The role of volatile compounds in the flavor of Swiss cheese. J.Dairy Sci. 80:Suppl 1: 133.

Susanto, P. and Harper, W. J. (1997) Determination of Mono- and Di-glycerides in milkfat by thin-layer chromatography and densiometric analysis. IFT Annual Meeting. Book of Abstracts p 126.

Harper, W. J. (1998) Functional properties of milk protein concentrates. Seminar presented to the New Zealand Dairy Research Center. February 1998.

Harper, W. J. (1998) Functional properties of whey protein concentrates. Seminar presented to the New Zealand Dairy Research Institute. February 1998.

Harper, W. J. (1998) Factors affecting the functionality of milk proteins in food products. Seminar presented to M&M Mars, Elizabeth Town, PA June 18, 1998.

Ruhlman, K. T., Jin, Z. T., Chism, G. W., Harper, W. J. & Zhang, Q. H. (1998) The Development of Cheese Sauce and Salsa to be treated by pulsed electric fields. . IFT Annual Meeting. Book of Abstracts p137.

French, S. J. and Harper, W. J. (1998) Effects of milk protein concentrates and emusifier salts on the characteristics of a processed cheese product. IFT Annual Meeting. Book of Abstracts p173.

Kuo, C. J. and Harper, W. J. (1998) Effects of dissociating agents on the particle size of milk protein concentrates. IFT Annual Meeting. Book of Abstracts p 205.

De Castro, M. and Harper W. J. (1998) Effect of heat treatment on particle size distribution of high protein milk protein concentrates. IFT Annual Meeting. Book of Abstracts p 208.

Lee, K. M. and Harper, W. J. (1998) The functionality of 34% whey protein concentrates (WPC) on selected model food systems. IFT Annual Meeting. Book of Abstracts p 211.

Huffman, L.H. and Harper, W. J. (1998) Isolating the value of milk through the application of separation technologies. American Dairy Science Annual Meeting. J. Dairy Sci. Supl I. P 73

Harper, W. J. (1998) The electronic nose as a tool in cheese research. Seminar presented to Kraft Foods, Glenview, IL August 21, 1998.

Harper, W. J (1998) The of milk proteins on the characteristics of processed cheese. Seminar presented to Kraft Foods, Glenview, IL August 21, 1998.

Harper, W. J. (1998) Strengths and Weaknesses of Electronic Noses.

Technical Publications:

Harper, W. J. (1993) Dairy Substitutes. In Kirk-Othmer Encyclopedia of Chemical Technology. Fourth Edition. Volume No. 7. John Wiley & Sons Inc., N. Y. pp 877-905.

Yang, B., Harper, W. J. and Parkin, K. (1993). Control of Lipase-Mediated Glycerolysis Reactions with Butteroil in Dual Liquid Phase Media Devoid of Organic Solvents. J. Agr. Food Chem 41 1905-1909.

Yang, B., Harper, W. J. and Parkin, K. (1993) Control of Lipase-Mediated Glycerolysis Reactions with Butteroil in Single liquid phase media with 2-methyl-2-propanol. J. Agr. Food Chem 41:1899-1904.

Yang, B., Harper, W. J. and Chen, J. P. (1994). Screening of Commercial Lipases for Production of Mono- and Diacylglycerols from Butter Oil by Enzymatic Glycerolysis. Int. Dairy J. 4:1-13.

Jou, K. and Harper, W. J. (1996) Effect of disaccharides on the thermal properties of whey proteins determined by differential scanning calorimetry (DSC). Milchwissenschaft-; 51 (9) 509-512.

Jou, K. and Harper, W. J. (1996) Effect of disachharides on the thermal properties of whey proteins determined by various means. Int. J. Dairy Sci. Submitted for Publication. 1997.

Mangino, M.E. and Harper, W. J. (1996) Factors affecting application of native and modified proteins in food product. In "Surface Activity of Proteins: Chemical and Physicochemical Modifications. Ed. Shlomo Magdassi. Marcel Dekker, Inc. N.Y. pp 285-322.

Harper, W. James, Sohn, Sungmi and Kleinhenz J. (1996) Flavor of Swiss cheese and the Electronic Nose Proceedings Biennial Cheese Symposium August 1996, Utah State University, Logan. Utah.

Kleinhenz, J. E. and Harper, W. J. (1997) Comparison of direct capillary electrophoresis and gas capillary chromatographic methods for the determination of lower molecular weight fatty acids in Swiss cheese. Milchwissenschaft 52(4): 200-204.

Kleinhenz, J. E. and Harper, W. J. (1997) Lower molecular weight free fatty acids in full fat and low fat Swiss cheese. Milchwissenscaft. 82(11): 622-625.

Harper, W. James, Michelle Yang, Sumgmi Sohn (1997) Comparison of three electronic noses for the analysis of aromas of selected dairy products. Proceedings 3^rd International Symposium on olfaction and electronic noses. November 4-5, 1996, Miami, Florida. pp 154-164.

Harper, W. James, Kuen Da Jou, Sungmi Sohn (1997) The role of fatty acids in the aroma profiles of Swiss cheese as determined by an electronic nose. Proceedings 3^rd International Symposium on olfaction and electronic noses. November 4-5, 1996, Miami, Florida. pp 176-185.

Yang, M. and Harper, W. J. (1998) Use of solid phase micro extraction of volatile compounds in whey protein concentrates. Milchwissenscaft 53(4): 208-212.

Jou, K.D. and Harper, W. J. (1998) Pattern recognition of Swiss cheese aroma compounds by SPME/GC and an electronic nose. Milchwissenschaft 53(5):159-263.

TEACHING:

The chair has developed and taught four courses in the department:

FST 401 Introduction for food processing 1992-present(202 students)

FST 541 Physical properties of foods 1992-1994 (87 students) FST 696 Technical problem solving 1994-present (155 student) FST 650 Food product development 1997-present (10 students) This course is co-taught with Dr. Ron Harris, former VP of Kraft Foods.

FST 401, 696 and 650 utilize groups in the learning process and emphasize teamwork, communication skills and critical thinking.

As a member of the college's Academy of Teaching and participant in the Kellogg Foundation supported Student Centered Learning Initiative (SCLI), the chair is involved in activities aimed at improving student learning within the college. SCLI includes approximately 50 faculty in the college willing to devote five years toward improving student learning. During Spring quarter of 1998, FST 696 was used as a showcase example of student centered learning.

OUTREACH:

Primary outreach activities are to provide technical support to food companies in Ohio on request and to support extension activities in dairy foods. Over the past five-years, more than 50 requests for assistance were received.

Technical support to the food industry includes:

Assistance in improving the flavor of low fat Swiss cheese (technology transfer). Assistance in improving the texture of low fat Swiss cheese (technology transfer). Assistance in improving the functionality of 34% WPC (technology transfer). Helping to eliminate problems in the manufacture of Cheddar cheese from Amish milk (direct assistance). Elimination of problems with loss of viscosity in chocolate pudding (direct assistance). Providing better understanding of the causes of shrinking in ice cream (technology transfer). Improving the quality of whey cream butter (direct assistance). Providing updates on new technology for manufacture of long life milk (technology transfer). Assistance in researching the off flavor development in milk powder when it is used as an ingredient in food products (direct assistance).

Copyright © August 1998