The Effect of Color on Perceived Flavor Intensity and Acceptance of Foods by Young Adults and Elderly Adults

Abstract

Decreased taste and olfactory acuity in older adults has been proposed as a factor in food intake ((1)Bidlack W. Nutrition and the elderly.Food Technol. 1986; 40: 81-88Google Scholar, (2)Clydesdale F. Meeting the needs of the elderly with the foods of today and tomorrow. Nutr Today. September/October 1991:13–-20.Google Scholar, (3)Chauhan J. Hawrysh Z.J. Gee M. Donald E.A. Basu T.K. Age-related olfactory and taste changes and interrelationships between taste and nutrition.J Am Diet Assoc. 1987; 87: 1543-1550Google Scholar, (4)Zallen E. Hooks L.G. O’Brien K. Salt taste preferences and perceptions of elderly and young adults.J Am Diet Assoc. 1990; 90: 947-950Google Scholar, (5)De Graaf C. Van Staveren W. Burema J. Psychophysical and psychohedonic functions of four common food flavours in elderly subjects.Chem Senses. 1996; 21: 293-302Google Scholar), although some studies refute a decline in taste sensitivity with age ((3)Chauhan J. Hawrysh Z.J. Gee M. Donald E.A. Basu T.K. Age-related olfactory and taste changes and interrelationships between taste and nutrition.J Am Diet Assoc. 1987; 87: 1543-1550Google Scholar, (6)Kamath S. Taste acuity and aging.Am J Clin Nutr. 1982; 36: 766-775Google Scholar). Some studies have shown that color has an effect on flavor attributes ((2)Clydesdale F. Meeting the needs of the elderly with the foods of today and tomorrow. Nutr Today. September/October 1991:13–-20.Google Scholar, (7)Johnson J.L. Dzendolet E. Damon R. Sawyer M. Clydesdale F.M. Psychophysical relationships between sweetness and color in cherry flavored beverages.J Food Prot. 1982; 45: 601Google Scholar, (8)Maga J. Influence of color on taste thresholds.Chem Senses Flavr. 1974; 1: 115-119Google Scholar, (9)Clydesdale F.M. Changes in color and flavor and their effect on sensory perception in the elderly.Nutr Rev. 1994; 52: 19-20Google Scholar, (10)Dubose C. Cardello A.V. Maller O. Effects of colorants and flavorants on identification, perceived flavor intensity, and hedonic quality of fruit-flavored beverages and cake.J Food Sci. 1980; 45: 1393-1400Google Scholar, (11)Roth H.A. Radle L.J. Gifford S.R. Clydesdale F.M. Psychophysical relationships between perceived sweetness and color in lemon- and lime-flavored drinks.J Food Sci. 1988; 53: 1116-1118Google Scholar, (12)Philipsen D.H. Clydesdale F.M. Griffin R.W. Stern P. Consumer age affects response to sensory characteristics of a cherry-flavored beverage.J Food Sci. 1995; 60: 364-368Google Scholar) whereas other studies have found no effect ((13)Christensen C.M. Effect of color on judgments of food aroma and flavour intensity in young and elderly adults.Perception. 1985; 14: 755-762Google Scholar, (14)Gifford S.R. Clydesdale F.M. The psycho-physical relationship between color and sodium chloride concentration in model systems.J Food Prot. 1989; 49: 977-982Google Scholar). However, several of these studies used simulated food model systems rather than real foods ((7)Johnson J.L. Dzendolet E. Damon R. Sawyer M. Clydesdale F.M. Psychophysical relationships between sweetness and color in cherry flavored beverages.J Food Prot. 1982; 45: 601Google Scholar, (11)Roth H.A. Radle L.J. Gifford S.R. Clydesdale F.M. Psychophysical relationships between perceived sweetness and color in lemon- and lime-flavored drinks.J Food Sci. 1988; 53: 1116-1118Google Scholar, (12)Philipsen D.H. Clydesdale F.M. Griffin R.W. Stern P. Consumer age affects response to sensory characteristics of a cherry-flavored beverage.J Food Sci. 1995; 60: 364-368Google Scholar, (14)Gifford S.R. Clydesdale F.M. The psycho-physical relationship between color and sodium chloride concentration in model systems.J Food Prot. 1989; 49: 977-982Google Scholar, (15)Stillman J. Color influences flavor identification in fruit-flavored beverages.J Food Sci. 1993; 58: 810-812Google Scholar). Obviously, there is a lack of conclusive research on the effect of color on flavor intensity and acceptance by an elderly population. Our study examined the relationship between color and perceived flavor intensity and acceptance of food by young adults and elderly adults using two commonly consumed food products: chicken bouillon and chocolate pudding. A further objective of the study was to determine whether color enhances the perception of sweetness, saltiness, or general flavor of a food. Twenty-nine young adults (20 to 35 years old) were recruited at a consumer products company and 29 elderly adults (60 to 90 years old) were recruited from a senior citizens center in New Jersey. Twenty-eight young adults and 28 elderly adults completed the chicken bouillon test; 29 young adults and 25 elderly adults completed the chocolate pudding test. All of the test subjects were in good health and within 10% of their ideal reference body weight based on the 1983 Metropolitan Height and Weight Tables. None had self-reported color blindness, taste or olfactory problems, dietary restrictions, allergies, or notable medical conditions. This test was approved by the New York University Committee on Activities Involving Human Subjects. Perceived intensity of flavor and acceptance were measured using visual analog scales (VAS) ((16)Hetherington M. Rolls B.J. Methods of investigating human eating behavior.in: Toates F. Rowlands N. Feeding and Drinking. Elsevier Science Publishers, location1987: 77-109Google Scholar). The scales were 10-cm long and anchored at either end with opposing phrases related to the attribute (eg, no salty flavor/extremely salty flavor). Formulations of the test foods were modified using ingredients found in the commercial products. The chicken bouillon (Herb-Ox Chicken Bouillon, Reckitt & Colman, Wayne, NJ) was prepared according to package directions with increasing amounts of turmeric oleoresin (Kalsec Inc, Kalamazoo, Mich) added to yield three levels of yellow color intensity: no color added (Lightness Factor [L]=38.90, Chromaticity coordinates [A,B] A=1.25, B=0.51); standard intensity (commercially available concentration of color [L=39.24, A=0.77, B=1.50]); and high intensity (twice the level of color as the standard intensity [L=37.80, A=0.15, B=3.52]). The chocolate pudding (Royal Pudding, Nabisco Brands, East Hanover, NJ) was prepared according to package directions with increasing amounts of FD&C artificial color (yellow 5 and 6, blue 1, red 40) to yield three levels of brown color intensity: no color added (L=40.95, A=11.70, B=12.25); standard intensity (commercially available concentration of color [L=32.45, A=13.73, B=9.22]); and high intensity (twice the level of color as the standard intensity [L=30.63, A=11.75, B=6.10]). Color measurements were taken with a Minolta chromameter (version CR200, Ramsey, NJ). A perceptual difference in color among the three levels of color intensity for each food was confirmed by a panel of five experts. In a pilot study, triangle tests ((16)Hetherington M. Rolls B.J. Methods of investigating human eating behavior.in: Toates F. Rowlands N. Feeding and Drinking. Elsevier Science Publishers, location1987: 77-109Google Scholar) were conducted to verify that there was no flavor difference in each test food at the three levels of color intensity, and to confirm that the artificial colors did not contribute any flavor. The two test foods were evaluated in separate sessions one week apart. Chicken bouillon was tested in the first session, chocolate pudding in the second session. Samples were served in 1-oz plastic cups and presented to the participants one at a time in random order. After consumption of each sample, subjects marked their response using the VAS for each attribute. The VAS scale responses were converted to numerical values from 0 to 10. Repeated measures analysis of variance and post hoc least significant difference tests were used to determine any difference in attribute ratings by color intensity in each food for the young adults and the elderly group. Table 1 summarizes the results of sensory evaluation of chicken bouillon in the young adult and elderly adult groups. There was a significant effect of color on ratings for intensity of overall flavor (P<.05) and acceptance of appearance (P<.001) by the young adults. The young adults perceived the overall flavor of the commercially available sample (standard intensity) to be more intense than the no color and high intensity samples. The young adults liked the appearance of the chicken bouillon sample with no color added significantly (P<.001) less than the standard intensity and high color intensity samples. In the elderly group there were no significant differences among all attributes. Results of the chocolate pudding test (Table 2) indicate that, again, color significantly affected acceptance of appearance in the young adults (P<.001). They preferred the sample with no color added significantly less than the other two levels of color intensity (P<.001), The elderly adults also showed, to a lesser degree, that color affected their acceptance of appearance (P=.059), and preferred the standard and high color intensity samples. In this study, color did not affect perceived intensity of flavor (chocolate/chicken, sweetness/saltiness) or acceptance of flavor (chocolate/ chicken, sweetness/saltiness) in chicken bouillon and chocolate pudding. Although color significantly affected acceptance of appearance in the young adults in both test foods, no significant effect on the elderly adults was found. This may be explained partly by the large variance in the rating responses given by the elderly adults compared with the young adults. This difference in responses to varying color intensity may suggest that young adults are more sensitive to color than elderly adults in regards to food acceptability.Table 1Attribute intensity and acceptance ratings (mean±standard deviation) of three color intensity levels of chicken bouillon in 28 young and 28 elderly adults where 0=lowest and 10=highest valueAttributeYoung adultsElderly adultsNo coloraNo color=no color added.StandardbStandard=commercially available concentration of color.HighcHigh=twice the level of color as the standard.No coloraNo color=no color added.StandardbStandard=commercially available concentration of color.HighcHigh=twice the level of color as the standard.Intensity of overall flavor5.3±1.8wDifferent letters within an age group indicate significance at P<.05.5.6±1.8xDifferent letters within an age group indicate significance at P<.05.5.5±1.6wDifferent letters within an age group indicate significance at P<.05.3.7±2.14.8±2.55.09±3.1Intensity of chicken flavor4.3±2.05.2±1.84.8±1.92.4±2.14.1±2.64.37±3.0Intensity of saltiness5.5±1.96.1±1.95.1±1.94.5±2.64.2±2.65.32±3.1Acceptance of overall flavor5.2±1.95.0±2.85.6±2.85.7±2.86.2±2.65.54±2.9Acceptance of chicken flavor5.0±2.05.0±2.55.3±2.65.3±2.95.9±2.75.25±2.8Acceptance of saltiness4.8±1.94.7±2.55.3±2.25.3±3.05.7±3.15.56±2.6Acceptance of appearance2.3±2.1yDifferent letters within an age group indicate significance at P<.001.5.4±2.0zDifferent letters within an age group indicate significance at P<.001.5.8±2.6zDifferent letters within an age group indicate significance at P<.001.5.5±2.96.0±2.76.39±2.5a No color=no color added.b Standard=commercially available concentration of color.c High=twice the level of color as the standard.w Different letters within an age group indicate significance at P<.05.x Different letters within an age group indicate significance at P<.05.y Different letters within an age group indicate significance at P<.001.z Different letters within an age group indicate significance at P<.001. Open table in a new tab Table 2Attribute intensity and acceptance ratings (mean±standard deviation) of three intensity color levels of chocolate pudding in 29 young and 25 elderly adults where 0=lowest and 10=highest valueAttributeYoung adultsElderly adultsNo coloraNo color=no color added.StandardbStandard=commercially available concentration of color.HighcHigh=twice the level of color as the standard.No coloraNo color=no color added.StandardbStandard=commercially available concentration of color.HighcHigh=twice the level of color as the standard.Intensity of overall flavor6.1±1.66.5±1.56.1±1.74.2±2.35.2±2.25.6±2.6Intensity of chicken flavor5.9±2.06.5±1.56.0±1.74.0±2.15.0±2.35.6±2.6Intensity of sweetness5.8±1.86.2±1.66.0±1.75.0±2.25.9±1.84.9±2.3Acceptance of overall flavor6.1±2.07.0±1.76.7±2.15.4±2.76.3±2.36.7±2.1Acceptance of chicken flavor6.1±2.06.8±1.86.7±2.05.2±2.66.2±2.66.3±2.6Acceptance of sweetness5.9±2.06.4±1.76.2±2.25.3±2.96.0±2.67.1±2.5Acceptance of appearance3.0±2.0zDifferent letters within an age group indicate significance at P<.001.6.5±2.2yDifferent letters within an age group indicate significance at P<.001.6.2±2.6yDifferent letters within an age group indicate significance at P<.001.5.4±2.86.9±2.16.8±2.2a No color=no color added.b Standard=commercially available concentration of color.c High=twice the level of color as the standard.y Different letters within an age group indicate significance at P<.001.z Different letters within an age group indicate significance at P<.001. Open table in a new tab Previous studies that reported significant differences in flavor attributes were often tested on model food systems and may not be reproducible for complex foods ((7)Johnson J.L. Dzendolet E. Damon R. Sawyer M. Clydesdale F.M. Psychophysical relationships between sweetness and color in cherry flavored beverages.J Food Prot. 1982; 45: 601Google Scholar, (9)Clydesdale F.M. Changes in color and flavor and their effect on sensory perception in the elderly.Nutr Rev. 1994; 52: 19-20Google Scholar, (13)Christensen C.M. Effect of color on judgments of food aroma and flavour intensity in young and elderly adults.Perception. 1985; 14: 755-762Google Scholar, (14)Gifford S.R. Clydesdale F.M. The psycho-physical relationship between color and sodium chloride concentration in model systems.J Food Prot. 1989; 49: 977-982Google Scholar, (15)Stillman J. Color influences flavor identification in fruit-flavored beverages.J Food Sci. 1993; 58: 810-812Google Scholar). Additionally, many of the studies evaluated the effect of atypical colors on flavor identification (eg, red color for lime flavor), rather than varying the intensity of a particular color ((15)Stillman J. Color influences flavor identification in fruit-flavored beverages.J Food Sci. 1993; 58: 810-812Google Scholar). Furthermore, saltiness is often not identified with a specific color because of the large variety of colors associated with salty foods and is a difficult taste to be influenced by color modification ((8)Maga J. Influence of color on taste thresholds.Chem Senses Flavr. 1974; 1: 115-119Google Scholar). Our results did not support the claim that color can significantly influence the flavor of foods and affect the perceived intensity of saltiness or sweetness. We suggest that the effect of color on sour and bitter tastes should also be explored.