Progress 07/01/00 to 06/30/05
Outputs
The principal investigator moved to UC Davis in January 2003 and did not do any work on this project during 2003. For informatin on 2003 research related to this investigator and Sensory methodolgy issues please see the Station project for UC Davis.
Impacts
None
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
During the life of this project the following was accomplished: A study on the effects of culture (American, Latin American and Chinese) on descriptive analysis (DA) data. The results indicated that the overall businesss decisions would have been the same regardless of culture but that there are subtle differences among the descriptors used by the three cultures. A study on whether it is possible to train children (4th grde, 8th grade and 12th grade) to perform DA. The results, using peanut butters as the model food, indicated that children in all three grades perform very well in DA and that their results are very similar to those obtained from adults. A study to determine the effect of literacy on a panel's DA performance indicated that it was more difficult to train the illiterate panelists but that once trained they performed as well as the semi-literate and fully literate groups. A study on time-intensity (TI) of ice creams led to the use of a new data analysis
technique (non centered principal component analysis followed by partial least squares analysis) to evaluate the differences among the TI curves.
Impacts
The expected impact of the descriptive (DA) analysis studies is to give practicioners of these tests the ability to use panelists from different cultures and literacy levels to be on their panles and not to be concerned that these panelists will negatively impact their data. The impact of the children's DA study is more subtle. It is unlikely that practicioners will use children in their day-to-day panels but the results of this study allows them to make the assumption that children live in essentially the same sensory space as adults. The impact of the time-intensity data analysis method will hopefully lead to the better understanding of these curves.
Publications
- Norman, J.L., Berg, E.P., Heymann, H. and Lorenzen, C.L. 2002. Pork loin color relative to sensory and instrumental tenderness and consumer acceptance. Meat Science. Accepted.
- Frost, M.B.; Heymann, H; Bredie, W.L.P.; Dijksterhuis, G.B. & Martens M. 2003. Sensory measurement of dynamic flavour intensity in ice cream with different fat levels and flavourings, Food Quality and Preference, accepted.
- Seo-Jin Chung, Hildegarde Heymann, and Ingolf U. Gruen. 2003. Application of GPA and PLSR in Correlating Sensory and Chemical Data Sets. Food Qual. Pref. 6th Sensormetric Meeting Special Issue. (Accepted)
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Progress 01/01/01 to 12/31/01
Outputs
Compounds that elicit an olfactory response (aroma or flavour) vary widely in their physico-chemical properties, e.g. their partition between oil and water phases. In many cases, fat in a food serves as the main solvent for flavour compounds. However, there can be large differences in fat solubility among different groups of compounds. Furthermore, volatility of compounds can also be highly variable. This gives reason to believe that flavour compounds with highly different physicochemical properties will not be affected (e.g. in their flavour release properties) to the same degree by changes in fat level. Ice cream with three different fat levels (3%, 6% and 12% milk fat), but with a fixed total non-fat milk solids level (11%), was used as the food matrix. Four flavour compounds were selected based on the following criteria: 1) To possess large differences in physicochemical properties. 2) To give a fairly good representation of a flavour attribute 3) To have
relevance to ice cream as a product. The selected compounds were: beta-ionone (berry), delta-nonalactone (coconut), isopentyl acetate (banana) and vanillin (vanilla). The concentration of flavour compounds was adjusted, so all four compounds were perceived as approximately equal in intensity at the highest fat level. The 12 different ice creams were analysed for their sensory properties, among those, flavour intensity (descriptive analysis). The dynamics of flavour perception and melt rate was measured by the time-intensity method. Twelve panellists evaluated all products in three replicates, both for descriptive analysis and time-intensity. Results from descriptive analysis showed the expected large textural differences in ice creams with different fat levels. Differences in flavour intensity were also observed for all four compounds. Perceived intensity for coconut and vanilla increased with increasing fat level of the ice cream, whereas intensity of banana only increased from 6%
fat to 12% fat. Lastly, intensity of berry decreased with increasing fat levels. Time-intensity studies showed expected differences in melt rate and dynamic flavour perception as a result of changes in fat level. In 12% fat ice cream the four flavour compounds exhibited similar behaviours. However, the individual flavour compounds were affected differently by changes in fat level, shown by differences in rate of perceived flavour release. The experiment shows that even in a complex food matrix as ice cream undergoing physical changes during consumption (from frozen to liquid), the effect of differences in physico-chemical properties of flavour compounds still plays a role, especially in low fat versions of the product. This has implications for development of lower fat versions of flavoured products. A food manufacturer cannot expect different flavours to behave the same way in a lower fat version of a given food product.
Impacts
This work could lead to the improvement of low fat ice creams.
Publications
- Swaney-Stueve, M. and Heymann, H. 2002. A comparison between paper and computerized ballots and a study of substitution between the two ballots used in descriptive analysis. J. Sensory Studies. (accepted)
- Tang, C. and Heymann, H. 2002. Multidimensional sorting, similarity scaling and free-choice profiling of grape jellies. J. Sensory Studies. (accepted)
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Progress 01/02/00 to 12/31/00
Outputs
The increasing establishment of free trade agreements between nations signifies increased market globalization. As companies increasingly vie for international consumers, product marketing and development pose serious challenges. For example, a food with desirable sensory characteristics for Western cultures may be undesirable in Eastern and Latin cultures. Further, differences in cultural dialect, dietary habits and regional cuisine present difficulties in global food product development. Several studies have used sensory evaluation in cross-cultural arenas but most of these dealt with basic tastants and not actual food systems. Moreover, language issues of translation and meaning were often not addressed nor were studies conducted by the same researcher (instead data were collected from remote sites, using different researchers, and were centralized for analysis). Of interest to us was whether the descriptive sensory spaces derived from different cultures agree
concerning the same product. Moreover, are descriptive panel profiles on the same products interchangeable across cultures? If possible, a product destined for sale overseas could be profiled in the country of export, tested with consumers in the country of import, and the results integrated statistically. In doing so, the attributes responsible for driving consumer liking could be determined and product changes studied for optimum acceptance. In this study subjects representing American, Chinese and Latin American cultures were recruited to participate in descriptive profiling and consumer acceptance testing of 20 fruit and vegetable juices. The American and Chinese descriptive panels (with 10 panelists each) participated in the USA and the Latin American descriptive panel (with 20 panelists) was trained in Costa Rica. Translators were used to assist the panel moderator with the Chinese and Latin American panels. Descriptive data generated by the three panels were integrated with
consumer data gathered from their respective cultures using Canonical Variate Analysis, Generalized Procrustes Analysis and External Preference Mapping. It was apparent that one could have used the American descriptive panel and integrated it with a consumer data set from another country concerning these juices. The results and interpretations would be practically the same for either Latin or Chinese consumers. It was true that one lost subtle nuances identified with a panel originating from the same population. However much more is gained than lost, since one could integrate the American descriptive panel with consumer data collected from other countries and derive the same inferences concerning consumer's drivers of liking.
Impacts
If companies can use US based descriptive panels to integrate with the consumer data collected in other countires it would save a great deal of time and money in bringing products to the market with the appropraite sensory qualities for a specific country or culture.
Publications
- Waichungo, W.W., Heymann, H., and Heldman, D. H. 2000. Using Descriptive Analysis to Characterize the Effects of Moisture Sorption on the Texture of Low Moisture Foods. Journal of Sensory Studies. 15:(1): 35-46.
- Prindiville, E.A., Marshall, R.T. and Heymann, H. 2000. Effect of milk fat, cocoa butter and whey protein fat replacers on the sensory properties of low-fat and non-fat chocolate ice cream. Journal of Dairy Science. 83:2216-2223.
- Liu, Y., Hsieh, F., Heymann, H. and Huff, H.E. 2000. Effect of process conditions on the physical and sensory properties of extruded oat-corn puffs. Journal of Food Science 65(7):1253-1259.
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Progress 01/01/99 to 12/31/99
Outputs
Subjects representing American, Chinese and Latin American cultures were recruited to participate in descriptive profiling and consumer acceptance testing. Three separate descriptive panels representative of each culture were trained. The American and Chinese descriptive panels were conducted at the University of Missouri in Columbia, Missouri. The Latin American panels and consumers were trained at Escuela De Agricultura De La Region Tropical Humeda (EARTH College) in Costa Rica. Translators were used to assist the panel moderator with the Chinese and Latin American panels. The generic descriptive analysis technique was used to train the panels. The data generated from the three distinct descriptive panels was integrated with the consumer data gathered from their respective cultures using Canonical Variate Analysis (CVA), Generalized Procrustes Analysis (GPA) and External Preference Mapping (PREFMAP). It was determined that one could integrate the American
descriptive panel with consumer data collected from other countries and derive the same inferences concerning consumer's drivers of liking. Residual effect analysis of the descriptive data generated from a Modified 20 X20 Williams Latin Square indicated that carry-over effects were present for the Chinese and American data sets. Testing direct and classical product means, using Fishers least significant difference test (LSD), showed that very little change occurred within product groupings indicating the effects to be small compared to product effects. Interestingly, the use the permanent means appeared to highlight the magnitude differences of the attributes among the products when submitted to Principal Component Analysis. Interesting, was the result of no carry-over effect present in the Latin American descriptive data.
Impacts
In a global environment is is financially advantageous to a food company to know whether they can use the descriptive data obtained in one country as the basis for prefeence maps using consumer data obtained in other countries. For this product and these countries it would seem that this is feasible.
Publications
- Li, J., Tan, J., Martz, F.A. and Heymann, H. 1999. Image texture features as indicators of beef tenderness. Meat Science 53, 17-22.
- Prindiville, E.A., Marshall, R.T., and Heymann, H. 1999. Effect of Milk Fat on the Sensory Properties of Chocolate Ice Cream. Journal of Dairy Science. 82:1425-1432.
- Tang, C., Hsieh, F., Heymann, H., and Huff, H.E. 1999. Analyzing and Correlating Instrumental and Sensory Data: A Multivariate Study of Physical Properties of Cooked Wheat Noodles. Journal of Food Quality, 22 (2): 193-212.
- Elmore, J.R. and Heymann, H. 1999. Perceptual maps of photographs of carbonated beverages created by traditional and free-choice profiling. 10(3): 219-228.
- Elmore, J.R., Heymann, H., Johnson, J., Hewett, J.E. 1999. Preference mapping: relating acceptance of "creaminess" to a descriptive sensory map of a semi-solid. 10(6): 465-476.
- Gao, X.; Tan, J.; Shatadal, P. and Heymann, H. 1999. Evaluating expanded-food sensory properties by image analysis. Journal of Texture Studies, 30(3): 291-304.
- Tang, Chen, Heymann, H., and Hsieh, Fu-hung. 1999. Alternatives to data averaging of consumer preference data. Food Quality and Preference, 11 (2000) 99-104.
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Progress 01/01/98 to 12/31/98
Outputs
Are gender and experience important to the results of sensory studies? New technologies in studying brain structure and activity are providing insight into possible reasons for differences in the behaviors of males and females. Some of these behaviors may be meaningful as they may relate to the performance of sensory evaluation of foods.The objective was to determine if gender and experience influence the performance of sensory analyses of products. The relationships between a set of products, as evaluated by sensory panels of different genders and levels of experience, were studied.Products were 16 corn- and potato-based snack chips. Four panels of judges, comprised of experienced males (EM), experienced females (EF), inexperienced males (IM), and inexperienced females (IF) (n=10, 10, 10, and 11, respectively), participated. Descriptive analysis of the snacks chips was conducted, with six replications. Generalized Procrustes Analysis (GPA) was conducted on the
descriptive data for the 16 snacks, as well as to evaluate panel performance. Results indicate that there were more similarities than differences between panels. For corn chips, all four panels made their distinctions based on visual and aroma/flavor/taste attributes. For potato chips, ridges, a visual attribute, was the single greatest determinant in making distinctions between chips. Snack products were separated slightly more by the experienced than the inexperienced panels. Results of the GPA on judge performance shows fairly good integration of judges by panel throughout three-dimensional space.
Impacts
(N/A)
Publications
- Cliff, M. and Heymann, H. 1998. Descriptive analysis of oral pungency. Reprinted in descriptive sensory analysis in practice (Gacula, M. ed). Chapter 6.2, pages 641-652. Food and Nutrition Press, Trumbull. Connecticut.
- Heymann, H. 1998. A comparison of descriptive analysis of vanilla by two independently-trained panels. Reprinted in descriptive sensory analysis in practice (Gacula, M. ed). Chapter 6.13, pages 653-664. Food and Nutrition Press, Trumbull. Connecticut.
- Ohmes, R.L., Marshall, R.T., and Heymann, H. 1998. Whey proteins in nonfat ice cream. Journal of Dairy Science. ACCEPTED.
- Lin, S., Hsieh, F-H., Heymann, H and Huff, H.E. 1998. Effects of lipids and processing conditions on the sensory characteristics of extruded dry pet food. Journal of Food Quality. ACCEPTED.
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Progress 01/01/97 to 12/31/97
Outputs
In this shelf life study we investigated the effect of increased temperature and controlled relative humidity (RH) on shelf-life of tea. Teas were stored at 20C , 20C, 30C (all at ambient RH), and 25C & 50% RH for eleven months. Teas were evaluated by descriptive analysis using deviation from reference scales and by consumer panels. Storage at 25C & 50% RH more adversely affected tea than storage at 30C & ambient RH. Although descriptive analysis panel changes in products, consumers either did not detect or care these changes. GRAPES (a SAS macro by Pascal Schlich) simplifies evaluation of sensory judge performance by computing ANOVAs and producing scatterplots comparing scale use, within and between session error, discrimination and agreement each attribute. We used GRAPES to evaluate performance of judges from four descriptive panels comprised of experienced males (EM), experienced females (EF), inexperienced males (IM), and inexperienced females (IF). Attributes
common to all panels were used. Inexperienced judges used less of scale range and experienced panelists disagreed the most. EF judges were most consistent. Judges made more within and between session errors when scoring visual and flavor/taste attributes than when scoring texture attributes.
Impacts
(N/A)
Publications
- Lawless, H., Heymann, H. 1998. Sensory Evaluation of Food: Practices and Principles. Chapman and Hall, New York. (Despite the 1998 copyright date this book was completed and published in 1997).
- Popper, R., Heymann, H., Rossi, F. 1997. Three Multivariate Approaches to Relating Consumer to Descriptive Data. Relating Consumer, Descriptive, and Laboratory Data. A.M. Munoz (Ed.), pp.
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Progress 01/01/96 to 12/30/96
Outputs
Do hedonic scores change after extensive sensory testing. Experienced (E) males (M), E females (F) , inexperienced (I) M. IF received 15 corn, potato products and scored each from 1 to 9, (1=dislike extremely; 9=like extremely). Then they performed other tests, multidimensional sorting (MDS) and descriptive sensory analysis on same 15 products. Hedonic test repeated after all tests. ANOVA indicated significant differences in product, gender, and time ("before" and "after") and in interactions of experience and gender; experience and time; product, experience, and gender. MDS allows study of perceived relationships between objects. Panelists sort a set of samples into groups based on similarities and differences. Is MDS affected by gender or experience. EM, EF, IM, IF sorted 15 products into no less than 2 and no more than 14 groups. No criteria for sorting given. Two methods used: visual sort (VIS) and taste/touch sort (TTS). Dimension 1 (D1) split corn vs. potato,
with corn split into two groups (light- and dark-colored). Dimension 2 (D2), separated produ ridges, saltiness, oiliness. D1 and D2 varied among groups. In VIS, EM and IF placed nearly equal weight on D1 and D2, EF and IM weighted D2 more. In TTS, IM and IF had tighter groups than EM or EF. E panelists used dimensions differently for VIS and TTS, I panelists used dimensions similarly for both methods.
Impacts
(N/A)
Publications
- GWARTNEY, E. AND H. HEYMANN. 1996. Profiling to describe the sensory characteristics of a simple model menthol solution. J. Sensory Studies. 11(1):39-48.
- FALLER, J.Y. AND H. HEYMANN. 1996. Sensory and physical properties of extruded potato puffs. J. Sensory Studies. 11:227-245.
- HEYMANN, H., C.H. CHANG, E.L. RICKES, G.J. HICKEY, D.H. WALLACE AND H.B. HEDRICK. 1996. Composition and sensory attributes of bacon as influenced by a beta-agonist-674,239 treatment and sex of pig. J. Muscle Foods. 7:403-411.
- HU, L., H.E. HUFF, H. HEYMANN AND F. HSIEH. 1996. Effects of emulsifier and soy fiber addition on sensory properties of corn meal extrudate. J. Food Quality. 19:57-77.
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Progress 01/01/95 to 12/30/95
Outputs
Creaminess is an integrated term with primary characteristics such as thickness,smoothness and fatty mouthfeel. Thus using only creaminess, provides limited insight to characteristics of a creamy product. The overall objective was to obtain descriptive sensory profiles of a model system, instant vanilla puddings. In subsequent research, these profiles will be integrated with consumer evaluations. Focus group interviews showed that "good" puddings were "creamy". Descriptive evaluations (DE) of pudding indicated that thickness, mouthcoating, rate of melt and smoothness were affected by milk- fat level. Puddings were evaluated for appearance, texture and flavor. For texture, increasing fat content increased thickness, decreased rate of melting, increased smoothness and increased mouthcoating. Decreasing sodium salts or using an unmodified corn starch decreased thickness, rate of melt and mouthcoating. Extruded snack foods are important to Americans. The objective was to
produce corn-amaranth extrudates and to use DE to determine effects of added amaranth. Corn meal extrudates with 0, 15, 25, 35, and 50% amaranth flour (dry weight) were made. Samples were evaluated for appearance, texture, and flavor. As amaranth content increased, extrudates became less yellow and more transparent. Diameter of extrudates with amaranth was greater than for extrudates without amaranth. Hardness decreased and fracturability increased with increased amaranth.
Impacts
(N/A)
Publications
- GILBERT, J. and H. HEYMANN. 1995. Comparison of four sensory methodologies as alternatives to descriptive analysis for the evaluation of apple essence aroma. The New Zealand Food Technologist. 24(4):28-32.
- HOWARD, L.R., et al. 1995. Sensory attributes and instrumental analysis relationships for strained processed carrot flavor. J. Food Science. 60(1):145-148.
- GARCIA, R.S., et al. 1995. Lowfat ice creams from freeze- concentrated versus heat-concentrated nonfat milk solids. J. Dairy Sci. 78:2345-2351.
- POPPER, R., HEYMANN H. and ROSSI, F. 1995. "The Use of Multivariate Statistics in Sensory Science" Chapter for ASTM Manual (Editor: Alejandra Munoz). In Press.
- POPPER, R.D. and HEYMANN, H. 1995. Multidimensional scaling of sensory data. In: Multivariate analysis of sensory data. (T. Naes and E. Risvik, eds.). Elsevier Applied Science, London, UK. In Press.
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Progress 01/01/94 to 12/30/94
Outputs
Textural creaminess is a complex, integrated term composed of several primary characteristics such as thickness, smoothness and fatty mouthfeel. Therefore, the use of creaminess alone, provides limited insight to the sensory characteristics of a creamy product. Previous research has failed to integrate sensory descriptive evaluations of the primary characteristics of creamy products with subjective evaluations by consumers. The objective of this study was to obtain descriptive sensory product profiles of semisolid model systems. Exploratory focus group interviews with individuals who consume pudding on a regular basis stated that "good" puddings were considered "creamy". Descriptive evaluations of JELL-0 instant vanilla pudding indicated that the thickness, mouthcoating, rate of melt and smoothness was affected by the milk-fat level. Therefore, eight puddings varying in these were developed by altering the amount and type of starch, amount of milk-fat and amount of
sodium salts. Puddings were evaluated by descriptive analysis for appearance, texture and flavor characteristics using a 10-member trained panel. To ensure consistent production of samples, proximate analyses were conducted on all samples. The eight samples were clearly distinguished on all but two flavor characteristics. Specifically for texture, increasing milk-fat content increased thickness, decreased rate of melting, increased smoothness and increased mouthcoating.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
See MO-FEHC0271 and MO-FEHB0313.
Impacts
(N/A)
Publications
- No publications reported this period.
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