Cross-cultural determinants of food acceptability: Recent research on sensory perceptions and preferences

Review Studiesof cross-cultural chemosensofy perceptiuns ancl preSences a m examined from the point of view of their ability to explain differences in food selection in different cultures. It is unclear from the limited literature whether psychophysical judsements of tastu or of other sensory qualities of fonds differ cross-culturally. However, preference for these same qualities appears to be dependent on the context in which they are experienced, and thus cultural preference differences are evident, most probably as a function of the different dietsn/ experiences of differentcultures.

Cultural factors are perhaps the most powerful determinants of which foods w e consume ~. Nevertheless. there has been smprisingly little research on how perceptions of, or preferences for, foods or their taste and flavor components might vary acxqosscultures. This is all the more smprlsing given the motivation of the food industry internationally to produce foods for export, particularly for rapidly growing Asian consumer markets. The primary issue from the standpoint of the food industry is understanding the differences between cultures in preferences for the sensory characteristics of foods. However, ;t is also impotent to determine if the p e ~ p t i o n of food q~n_~il;~ such as tastes, flavors or mxtur~ differs between cultures, as these may underlie differences in food preference. Thus, this review will address, firstly, the cross-cultural perceptual differences that have been identified to date and, secondly, how these differences might explain cross-cultural vari~on in preferences for the sensory properties of foods° The major types of theoretically possible differences are snmmariZ~ in BOX 1.

Psyc~q~nysical responses to sensory qualities In an effort to determine i f the perception of food qualities varies across cultures, a sfaall number of studies have examined jedgements of intensity (known as psychophysical responses) of tastes not in a food context (typically in solution). Differences in psychophysical responses to tastes, flavors or textures p e r s e might explain the presence of similar differences in responses to them within foods. It is possible that such differences may also arise from dietary experiences. However, there is little empirical suppoxt for such a relationship. For example, it has been shown that ~ g dietary sodium intake does not influence psychophysical responses to sodium in solutionz. Comparison of the responses of Taiwanese students living in the USA with those of North American students r(.~'eatledsimilar patterns of response for a ranse of concentrations of bitter, sweet and salty solutions. k l I'mcdt and Grdmmk l areat the Senson/ResearchCenue,CS~RO Oi~sionof FoodScienceand Technology,PO Box 52, NorthKyde,NSW 2113,Australia(fax:+61-2-887..8511;e-mail:presco~csiro.au). Trendsin FoodScience& TechnolosyJune1995 [3/ol.6]

Cr s-cultural determinants of food acceptability: Recent research on sensory perceptions and preferences John Prescottand GrahamB81 althoush them were ~ of ~ . The Taiwm¢~ students rated the sweet sol~'umm as mete ~ amd the weak salty ~lutlons as saltier, but the monger salty solutions as less salty tlma did the North Ameri~m students. In contrast, them were no diffeZl~CeSin lee psy. chophysical responses f0nad betweea N0flh students and those from maktlamd China liv~u~ in the USA to sweet and salty solutioas4.

In a study of psychophysical responses to a variety of sensory qualitiess, subjects in Sweden, the USA, Switzerland, Japan, Australia, the UK, F'miand, France, Germany and Poland evaluated samples of pectin gel whose firmness, aroma, sweetness, sourness and flavor had been manipulated. It was concluded that there were few, if any, differences between countries that could be attributed to fundamental differences in perception. Thus, while differences in psychophysical responses to sensory qualities have been observed, they are not pronounced. Furthermore, there is little evidence, as yet, that dietary differences or other cultural factors influence psychophysicaljudgement for food sensory qualities. Detection and discrimination thresholds Another approach to investigating possible perceptual differences has involved the examination of discriminative abilities. Conceivably, differences in taste sensilivity either at, or above, threshold could account for some variability in food selection. Thus, differences in taste sensitivity to the bitter compounds phenylthiourea (VFC) and 6-n-propylthiouracil (PROP), which are believed to be inbefited~s, are known to vary across cultures8 and also to be associated with food pre~rences9. T~oe few studies that have examined the detection thresholds of other tastants have failed to show differences in thresholds for sweetness, sourness, saltiness and bitterness between subjects from Nigeria, Korea and the USA, all tested in the USA ~°, and also in thresholds fur sucrose, monosodium glutamate (MSG) and NaC! between Japanese and North American subjectsu. Sensitivity to small variations in taste intensities above threshold (also known as differential sensitivity) has also been investigated. Comparisons of the sensitivity of subjects from laboratories in the USA, Sweden, Poland and The Netherlands to differences in low and high cuncenU~_tions of NaCI in solution revealed no differences that could not be accounted for by methodological differences12. A similar comparison of subjects in Sweden, the USA, Poland and Switzerland for sensitivity to variations in sucrose concentration both in water and in orange juice revealed very tittle difference in the case of solutions, but a number of differences for variations in orange-juice sweetuess13. These data suggest that it is unwise to extrapolate perceptual abilities from 'experimental' solutions to real foods, and also that it is possible that previous experience of a food will have an effect on the discrimination of its sensory properties. A later study by this same group also revealed differences between subjects in Sweden, the USA, Poland, Brazil and Japan in their sensitivity to sweetness variations in coifed 4. There have been two recent investigations of the taste sensitivity of Japanese subjects. In a comparison with North Americans, the Japanese subjects damonstra~xi a greater ability to discriminate different intensities of sucrose and of MSG, but no differences in ability to discriminate NaCI intensities15. However, compared with Australian subjects, the Japanese subjects showed no differences in sensitivity t~ ~,~a,:ions in sweetness, nor in saltiness, sourness and bitterucss~'. 202

The cross-cultural data on thresholds appear to suggest that, at least with taste solutions, sensitivity reflects unbiased operations of perceptual mechanisms. Except in the case of genetically determined sensitivity to PROP or PTC, such operations might be expected to show more communalities than differences between cultures, given common perceptual mechanisms. These very Hmited data do, however, raise the possibility that sensitivity to tastes within foods might be influenced by diff~ent dietary experieuces. Psychophysical responses to tastes in foods If scnsitivity to tastes p e r s e can be influenced by different dietary experiences, then it might be reasonable to expect that the influence of the overall food context would also be evident in crose-cultural comparisons of psychophysical judgements of tastes within foods. The findings to date are, however, equivocal. Comparison of the judgements made by North American and Chinese subjects of the saltiness of soup and crackers revealed no differences in psychophysical responses over a variety of NaCl concentrations4. By conWast, however, comparisons of the sweetness judgements of Taiwaneso and native-bom US students for cookies in which the sucrose content had been manipulated over seven different levels found that, as with solutions, the Taiwanese students rated the cookies as uniformly sweeter than the US students. Our own research compared the responses of Japanese and Auslralian subjects to a range of Japanese and Australian foods in which sweetness or saltiness was a prominent component. There was agreement between the Japanese and Australian groups on both the sweethesst~ and saltinessm intensity of the great majority of the foods evaluated. The agreement on psychophysical responses to sweemess and saltiness occurred despite each cultural group being unfamiliar with the sensory characteristics of different subsets of the products drawn from the other culture. This suggests that these responses are relatively unaffected by familiarity. In subsequent studies in which sweetness intensity was manipulated in ice cream, orange juice and breakfast cereal, Japanese and Australian subjects gave almost identical intensity ratings across the four different sweethess intensifies of each food ~9. This level of agreement suggests that the groups from the two cultures perceived the sweetness intensities very similarly. It also suggests, incidentally, that the two groups used the ratings scales in much the same way. Overall, therefore, the evidence points to there being few differences between cultures in the perception of tastes within foods, although this might be a function of the limited data on this issue. Nevertheless, the failure to find reliable differences, especially in those studies using subjects from cultures with very differing diets (e.g. Japan versu~ Australia), is interesting, and suggests that the influence of food context is in fact minimal. An alternative possibility that cannot be ignored, however, stems from the fact that these studios all used populations in urban settings where some consumption of Trendsin FoodScience& TechnologyJune1995 [Vol. 6]

Western foods is likely (Japan) or inevitable (Chinese ethnics living in the USA). This factor may have acted to dilute any perceptual differences that might otherwise have been present.

Cross-cultu~ differences in preference It has been suggested that preferences for basic tastes (particularly sweet and bitter) might be determined genetically, or at least be present before birth2°. However, such preferences in adult populations might still exhibit cross-cultural differences, as dietary experience may influence liking for such tastes. Preferences for sensory qualities A few studies have assessed liking for tastes in solution, in each case comparing Asian and Western populations. Compared with groups of North American students, Taiwanese students living in the USA rated a range of both sweet and salty solutions as more pleasanP, whereas students from mainland China living in the USA rated strong sweet solutions and weak salty solutions as more pleasant, but the stronger salty solutions as less pleasant*. A comparison of Australian and Japanese subjects' liking for tastes in solutionu revealed no cross-culturul differences in hedonic ratings across six intensities of sweet, salty or bitter solutions. Compared with the Australians, however, the Japanese preferred the highest intensity of the umami taste of MSG, the three highest intensities of guanidiue monophosphate (another umami taste) and the two highest intensities of sourness. The origins of culturally-based preferences for tastes in solution are unclear, hut might include differential experience with tastes within foods22 or, in the case of umami, simple familiarity with the taste2L23. Arguing against the influence of differential taste experience in foods, however, is the finding that, despite the differences between the Chinese ethnics and the US students in preference for sweetness and saltiness, these groups had similar caloric, sodium and sucrose intakes4. In addition, manipulations of dietary sodium do not appear to influence preference for NaCI concentrations in solutionz. This does not, of course, rule out the possibility that longerterm dietary expefieuces might exert such an effect. The basic tastes of sweet, sour, salty, bitter and umami are perhaps the most universal sensory characteristics of foods, itreapective of culture. On the other hand, the range and variability of food odors and flavors is enormous and clearly differs across cultures24. Thus, odor and flavor preferences might be expected to be strongly influenced by cultural factors, perhaps mediated by simple familiarity. One study addressing this issue compared 16 population groups in North and Central America, South Africa, Europe and India25. Although some food odors (e.g. orange, chocolate and vanilla) were universally liked, commonalities between cultures in liking for the majority of the other food odors tested were best explained by the geographical proximity of the cultures, rather than their ethnic origin. This suggests the importance of regional food usage in Trendsin FoodScience& TechnologyJune1995 [Vol. 61

determining odor preference - a conelmioa supported by significant positive conelatiem for u majority of the countries between bedonic responses and the freqeoncy with which populations from e~.'h cmmuy expet~nw.ed the odors tested.

Preferences for tastes in foods In the case of tastes within foxls, it might be r e a s ~ able to expect that ptcfeffed levels would depend to a large extent on previous expos~um to a particular level within each food type, as a variety of studies have confirmed the effects of expostffe on preference. For example, increasing salt intake, if it is tasted, leads to higher saltiness preferences in fizxls2-'~-=.This suggests that dietary experience may at least paxtly datennine taste preferences, which could therefore be expected to diverge with differing cultural e x ~ . This is, in fact, suggested by the research to date. Our own studies have shown that, although there were few differences between Japanese and Austral~ subjects in judging the, sweetness and saltiness intensity of the vast majority of products, the extent to which the panels from the two cultures agreed on sweetness or saltiness liking was considerably lower. This lack of agreement on hedonic ratings may reflect the influence of familiarity with the overall food context because, in many cases, each culture gave higher sweetness or saltiness hedonic ratings to products from their own cultures17,ms.Unfortunately, the influence of familiarity with the product on preference for food qualifies limits the extent to which inferences can be made about crosscultural preferences for sensory qualities such as sweetness or saltiness p e r se within ~ food context. A comparison of the hedonic responses of Nigerian and Korean ethnics in the USA with those of North American subjects to locally available tomato juice and apple sauce samples whose sweetness, sourness, saltiness and bitterness had been manipulated revealed that the Nigerians and Koreans generally p~fermd samples whose sweemess had been increasedI°. The North Americans, however, showed a prefereuce for the unaltered samples of the products. As the use of these products may have varied considerably between the three ethnic groups, these data again suggest the importance of familiarity. One method of determining if preferences for tastes within foods differ between cultures is to manipulate tastant levels within foods that are common to all of the cultures involved in a study. This approach was followed in a cross-cultural study of hedonic responses m different levels of sucrose in coffee, a beverage common to Brazil, Japan, Poland, Sweden and the USA '4. The patterns of hedonic response over different sucrose concentrations were found to be dependent on culture. However, the fact that there was tittle agreement on liking for the strength of the coffee suggests that the response to the sucrose solutions may have been considerably influenced by the cultural appropriateness of the coffee strength. This illustrates one of the difficulties in assessing preferences for a component within a complex 203

food in which other sensory aspects may influence the results and therefore need to be taken into a¢connL Varying the sucrose content of cookies produced concamtmtion-dependent bedonlc responses from students of Taiwanese and North American origin3. Compared with US students, the Taiwanese students rated the cookies as more p l ~ t at low sucrose concentrations and less pleasant at higher concentrations. In a comparative study of mainland Chinese students living in the USA and US students, preferences for cookies whose sucrose levels had been manipulated, and also for soup and crackers with different salt concentrations, were evaluated4. There was a tendency for the Chinese students to rate the cookies overall as more pleasant, and a clear p r e f ~ for the crackers, particularly at higher salt concentradons. There were no differences in liking for the soups, however. We have compared hedonic responses to variations in sucrose concentrations in three products that were familiar to both Japanese and Auslrafian subjects, namely orange juice, ice cream and Ixeakfast cereal. Despite diff~ between the Japanese and Australians in their liking for sweetness intensities, there was no consisteat pattern in the differences in preference across the three sweet products19. For example, the Japanese gave higher ratings than the Australians to the two highest sucrose concentrations in orange juice, but not in ice cream nor cereal. In combination with the cross-cultural data on taste solutions3~1, these data clearly show that cross-cultural responses to a tastant are dependent on the context in which it is wesented (see Fig. 1). Thus, the research to date does not support generalizations regarding preferences for tastes within foods; for example, that the Japanese prefer all their foods to be relatively salty. The

other lesson to be drawn from these data is that food producers wishing to export to countries with signilif~ntly different cuisines will undoubtedly need to perform some modification of the sensory qualities of their product before it reaches optimal acceptability.

!rues andfuture direcliem in cross-culturalresearch A n issue c o r n to all cross-cultural studies, but seldom addzessed in studies o f chemosensot7 perception or preference, is that of communicating across different languages. Although the logistical problems involved in actually undertaking sensory evaluations in another cultore can be overcome by employing bilingual staff, the more crucial problem is that of agreement on the nature of the sensory qualities to be measured. The best-studied example o f this is the use of the term nmami by the Japanese to describe the taste of foods rich in glutamate and nucleolides. There is no equivalent term in English, and this taste tends to be described in combinations of the other commonly recognized tastes (sweet, sour, salty, bittery3. Similarly, in studies of Korean consumers, we have encountered the term 'imsu', which again has no English equivalent, yet has e n ~ g e d as an important determinant o f preference for noodles. The problem is not merely one of definition, but rath~ has implications for the actual perception of the qualities themselves. In addition, while the issue of language is, of course, important for consumer preference studies, it becomes critical for. the profiling of sensory qualities, both in terms of the sensory descdptot,s and the methods (so.des) used to measure themz'. One implication of this is that panelist training may be a prerequisite for any cross-cultural study as a means of "concept alisnment'. The relatively small amount of date on cress-cultural factors in sensory aspects of food acceptance reflects the (c)

(b)

(a)

7

~

~6

9oi

80b

j:o[

4

c

70

=

so

$,o

u

20 1o o 40

gO

120

170

280

420

Sucrose concentration (rnM)

0

~)

4

8

Added sucrose (g/lOOml)

3

5

Sucrose content (%)

of groups of Japanese(---) and Australian subjects(--e-) in mean (± SE)liking for sweetnessin: (a), sucrosesolutions; (b), orangejuice; (c), ice cream. Thesedata show that cross-culturaldifferencesin sweetnessliking are dependent upon the context in which sweetnessis judged. For sweet (sucrose)sotutinos,there were no aoss-cultural differencesin ratingsacron a wide rangeof sweetnessintensities.With mange juice, howew% Japaneseand Australian subjectsdiffered in their liking for Ihe sweetnessd three d the four samphs (0, 4, 8g added sucroseper 100 ml); wilh ice cream, the two groups differed in their liking only for the sweelnessof the ice cream d standardsucrosecontent (15%). Adapted from Refs19 and 21. 204

Trends in Food Science & Technology June 1995 Wol. 6]

logistical difficulties in studying groups that are sometimes separated by thousands of kilometers, as well as the potential scope of the field of study. Findings from one culture are not necessarily, or even likely, to be applicable in another. However, what it also reflects is the absence of un~¢d objectives in cunducling crosscultural studies. Clearly needed is a greater empl~sis on investigating the origins of differences in perception and preference. For example, few studies have attempted to correlate dietary intake with c~oss-cultural sensory responses. In pmlicular, with countries in Asia now increasingly open to dietary influences from Europe, North America and Australasia, the influence of a changing diet on the psrceptions of, and preferences for, sensory qualities can be investigated. Another approac~ is to undertake studies on more complex sensory aspects of foods; the information from such studies will assist in food development. Foods are complex systems in which perceptions of, and preferences for, sensory characteristics are interdependent, and cress-cultural research should reflect this complexity. A relatively simple example h e m might be tL,e investigation of preferences for. sugar:acid ratios in fruit-based products. Concurrent manipulations of the intensity of sensory characteristics within both model and real foods can allow an assessment of the relative importance of these categories of sensation across different cultures. One issue that deserves investigation is the role of pungency in food preference in different cultures. Chilli and pepper are some of the most commonly consumed food ingredients worldwide, yet their role in food preference has largely been ignored. One crosscultural investigation of liking for chillP° found that Mexicans were much more likely to find food bland w i t h o u t chilli than N o r t h , ~ f i c a n s .

Tlds issue is im-

portunt 8iven that, for many coumries in Asia, pungency is a key part of the 'flavor principle' of the cuisine. Investigations of the sensory properties of foods also need to be placed in a broader context. To what extent, for example, are there cross-cultural differences in the degree to which sensory factors determine the overall acceptability of a food product? Surveys of Japanse consumers have found that taste, in the generic use of the term, is rated the most hnportant determinant of purchasing decisions in the case of processed foods3t. Does preference for taste, flavor or other sensory characteristics determine food-purchasing decisions in other Asian markets? One of the key questions will be not just what flavors are important for a market in Asia, but what aspects of a food: its flavor, image, packaging, brand, size, 'healthiness', price or origin. Consumer characteristics also need to be considered, and related to perception and preference data. Such characteristics include not only demographic and product usage information, but also individual behavior in relation to food. Examples of this include cultural expectations in relation to foods or food sources, as well as the willingness of consumers to experience new foods~2, which might conceivably be a function of their cnltulal nogms. Trends in Food Science & Technology June 1995 Wol. 6]

In sonmmry, resemch ueeds to a a ~ m lmrc¢lnim~ of, and preferences for, sensory ¢l~u'actm4stics not m isolatlon but as o~e i m p o ~ a t fact0r amo~pt othe~ f l ~ determine coemuner behavim'. e,e f e r e m ~ 1 Rozin,P. and Vo!,.~n~-~%T-A. (1906)Aacm.Rev.NMr. 6, 433-456 2 Bedlno,M., Beauchanp, G.IL and E~dmn, IC (1992)Am. L C//e. Nutr. 36,113,1-1144 3 B~tino, M., 8eax:hanp, G.K.and ~ , |LC (1903)Omn. 5era5 e, 3..15 Berfino, M. and (~n, M.M. (1~61 Clime $emes11,229-241 : Lundg~n, B., ~ , R-M., D a ~ N., Ymidda, M., I_ainlbD.G., McBnde, RJ.., Qiffidm, N., I ~ IL, Sauvql~t F., Padre, IC and ~ P i k i e l n a , N. (1986) Lebmn.-W'~s. TecEno/.19, 66-76 s Krondl, M., Colen~, P., Wnde, J. and Milnm', J. (1993) Hum./~tr. /~o/. N~. 37A, 189-198 7 Glanville, E.V.and Kapbn, A.R. (19651NaUe 205, 851453 ,LS., e Rozin, P. (1975) in Advancesm Ihe 5aJdyoO/ebav/or( ~ Hinde, R.A., Shaw, F- and Beer,C, ed0, pp. 21-76, Academk: Pros Fischer, R., Griffin, F., Ensla~, $. aml C_,am,S.M. (i 961) Nag~ 191,1328 lO Dmz, L.L. and Baldwin, K.E.(! 902) I. Food5cL 47, 551-56], 569 YamaBuchi,5. (1991) PhyS. Bekav.49, 833-841 11 Johamson, B., Drake, B., ~ , R-&L, ~ N. and 12 Koster, EP. (1973)I. Faad~i. 38, 52~1-$27 13 Lundgren, B., Pangbom, R-M., BeffkPPgdelm, N. and Daset, N. (1976) Chem. SensesF/avor2,157-176 14 Lundgren, B., Jonsson,B., ~ , R.M., S o n ~ A.M., Baylko-Pikielna, N., Piel~.a~ E.,dos SaMasC,amJ, P~,Moraes, M.KC. and Yoshida, M. (1978) Chin: 5era. ~ 3 , 24%265 is Ishii, R., Yamasuchi, S. and O'Mahony, M. (1992) Chem. 17, 365-380 It Lalng, D.G., Presco¢ J., B~II,G.K, G i l ~ , IP,.,James,C, Be~t,DJ., Nlen, 5., Yoshida,M. axl Y ~ , IC (1993)Chem.Seines16,161-168 17 Lain~ D.G., P r ~ J., Bell, GA., Gillmoee, R., Allen, 5., Best,D.J., Yoshida, M., Yan~aki, K. and Ishi~Cahews, R. (I 994)L Sere. Slud. 9,131-155 18 Prescott,]., Bell, G ~ , Gillmore, R., Y o s l ~ M., Lain& D.G., Men, 5. and Yamazaki, K. (1993) Chem. Seines18, 616 [abstract] 19 Bell, GA., PrescoU,J., Gillmom, R., Allen, S., Kordc, S., Yoshida, M. and Yamazaki, K. (1994) Chem. ~ 19, 441-442 20 Beauchamp,G.K., Cowart, B.]. and S¢lanidt, HJ. (1991) in 5me//and Tastein HealthandDisease(Gelchell, T.V., B a f l o ~ L.M., Dot,/, R.L. and Snow, J.B.,eds), pp. 405-416, RavenPless 21 Prescott,]., Lain¢ D., Bell, G., Yosl~h, M., Gilknom, R., ABen, S., Yamazaki, K. and fshii, R. (1992) Chem. 5e~es 17, 801-809 22 ~r~kOwitz, H.W., Kumadah,V., Sha~na,K.N., Jacob, H.L. and Sharrna,S.D. (1975) 5c/en¢'e19,1217-1218 23 O'Mahony, M. and Ishii, 17,.(1986) BJ:]. Psycho/.77,161-174 24 Rozin, E. (1983) Etlm~Cuisine:TheFlavorPdncipleC ~ S~ Greene, Battlebom,VI, USA Pansborn, R-M., Guinan:l,FX. and D,wis, R.G. (1988) Food Qua/. Pm£ 1,11-19

26 Shepherd,R., Farleigh,CA. and Land, D.G. (198,1)AppeMe5,

187-197 Bedino, M., Beauchamp,G.K. and Emjelman, K. (1986) Phys/o/.Behav. 27 38, 203-213 2a Mattes, R.D. (1987) in F o o d . 4 c ~ ar,d ~ (Solms,J., Beo~, DA., Panda)m, R.M. and Ratmha~ O., eds), pp. 129-142, Academic Press Cardello, A. (1993) CemaOFoods1 4 / ~ 38, 699--701 Rozin, P. and Schiller, D. (19g0) Moth'. Emo6m 4, 77-101 31 Anon. (1988) PurchaseBehav/orfor roods [,Su~'y reponl, lapanese Minis~' of Agriculture, Foe~t~' and F ~ , Toloto, Japan 19,105-120 32 Wine,r, P. and Hobden, K. ( 1 9 9 2 ) ~ 205