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JFS S: Sensory and Nutritive Qualities of Food

Consumer Sensory Analysis of Organicallyand Conventionally Grown VegetablesXIN ZHAO, EDGAR CHAMBERS IV, ZIAD MATTA, THOMAS M. LOUGHIN, AND EDWARD E. CAREY

ABSTRACT: Consumers of organically grown fruits and vegetables often believe that these products taste better thanconventional produce. However, comparison of produce from supermarket shelves does not permit adequate assess-ment of this consumer perception, given potentially confounding cultivar and environmental effects. We used repli-cated side-by-side plots to produce organic and conventional vegetables for consumer sensory studies. In one test,red loose leaf lettuce, spinach, arugula, and mustard greens, grown organically and conventionally, were evaluatedfor overall liking as well as for intensity of flavor and bitterness. Another consumer test was conducted comparingorganically and conventionally grown tomatoes, cucumbers, and onions. Overall, organically and conventionallygrown vegetables did not show significant differences in consumer liking or consumer-perceived sensory quality.The only exception was in tomatoes where the conventionally produced tomato was rated as having significantlystronger flavor than the organically produced tomato. However, overall liking was the same for both organic andconventional samples. As conventional tomatoes also were scored marginally significantly higher in ripeness and apositive correlation was found between ratings of flavor intensity and ripeness, the flavor difference observed couldnot be simply ascribed to the contrasting growing conditions. Consumer panelists in both tests considered organicproduce to be healthier (72%) and more environmentally friendly (51%) than conventional produce, while 28% con-sidered organic produce to have better taste. Covariance analysis indicated that consumer demographics affectedsensory comparisons of organic and conventional lettuce and cucumbers. Future study is needed to substantiate theinfluence of segmentation of consumers on their preference for organic food.

Keywords: consumer demographics, consumer liking, production method, sensory quality

Introduction

Organic food has become a top consumer trend in the UnitedStates (Sloan 2003) and sales of organic food grew over 20%

annually from 1990 (Dimitri and Greene 2002). Although there isno official claim of better quality for organically produced foodthan its conventional counterpart (The U.S. National Organic Pro-gram, www.ams.usda.gov/nop), expanding consumer demand re-flects consumer perceptions of organic foods as more environ-mentally friendly (Goldman and Clancy 1991; Wandel and Bugge1997), safer (Jolly and others 1989), and more nutritious and health-promoting than conventional foods (Makatouni 2002; Magnussonand others 2003). Additionally, many organic buyers believe thatorganic produce tastes better than conventionally grown produce.According to the Hartman Group survey (2000), after health con-sciousness, taste was the 2nd most important factor determiningconsumer choice.

Despite consumer perceptions of superior taste of organic food,sensory evaluations of organically and conventionally grown veg-etables and fruits have yielded inconsistent results. Consumer tastetests on 5 fruits (orange, grapefruit, banana, mango, and white grape)and 4 vegetables (tomato, spinach, carrot, and sweet corn) grown or-ganically and conventionally did not show consistent results andfew significant differences were detected (Basker 1992). Triangle

MS 20060213 Submitted 4/14/2006. Accepted 12/14/2006. Authors Zhaoand Carey are with Dept. of Horticulture, Forestry, and Recreation Re-sources, Kansas State Univ., Manhattan, KS 66506. Authors Chambersand Matta are with Dept. of Human Nutrition, Kansas State Univ., Man-hattan, KS 66506, U.S.A. Author Loughin is with Dept. of Statistics,Kansas State Univ., Manhattan, KS 66506. Direct inquiries to author Carey(E-mail: tcarey@ksu.edu).

tests also failed to distinguish organic from conventional bananas(Caussiol and Joyce 2004). Over a 2-y period, trained panelists con-sistently rated conventionally grown carrots as having better car-rot taste than ecologically grown carrots, which tasted more bitter(Haglund and others 1999). A previous sensory descriptive analysisof carrots had demonstrated that organic or low-rate mineral fertil-ization resulted in higher total flavor strength as compared to high-rate mineral fertilization (Hogstad and others 1997). Apples fromorganic, conventional, and integrated production systems did notdiffer in overall acceptance as rated by untrained sensory panels, butorganic apples were reported to be sweeter and less tart (Reganoldand others 2001).

Studies comparing taste and other quality aspects of organicand conventional produce are subject to a number of potentialconfounding effects from both production and postharvest factors(Bourn and Prescott 2002; Harker 2004). Confounding productionfactors include effects of cultivar, fertilization, soils, and microcli-mates, and postharvest factors include handling, storage, and pro-cessing. Given mixed results from previous studies, well-designedexperiments involving a wide range of vegetables and fruits areneeded.

Consumer hedonic tests typically require 75 to 150 consumers asan appropriate sample size (Lawless and Heymann 1999) and recentdata indicate panels of around 100 provide a panel size necessaryto appropriately determine differences from a statistical standpoint(Hough and others 2006). However, most consumer tests evaluatingorganic and conventional vegetables and fruits have had smallersample sizes (Basker 1992; Wszelake and others 2005). The ob-jective of this study was to use well-controlled experimental pro-duction systems and consumer tests to assess differences in tastebetween organic and conventional vegetables. To provide a broad

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examination of the impact of production method on sensory quality,a variety of vegetables, including lettuce, spinach, arugula, mustardgreen, tomato, cucumber, and onion, were evaluated. As a secondarygoal, we also examined whether some consumer demographics andpreconceptions of panelists influenced assessments of organic ver-sus conventional produce.

Materials and Methods

Vegetable production environmentSix 9.8 × 6.1 m high tunnels with 1.5-m sidewalls (Stuppy, North

Kansas City, Mo., U.S.A.) were used for vegetable production atthe Kansas State Univ. Horticulture Research and Extension Center,Olathe. The soil was a Kennebec silt loam. The tunnels were coveredwith a single layer of 6-mil (0.153-mm) polyethylene. The 6 high tun-nels were divided into 3 groups (blocks), and the 2 high tunnels ineach block were randomly assigned organic or conventional man-agement treatments starting in May 2002. The organic plots wereinspected and certified in 2003. Rates of fertilizer application werebased on soil tests and crop requirements, and organic fertilizer(compost) rates were typically double those of conventional fertil-izer to compensate for lower nitrogen availability, assuming 50% ofthe total nitrogen in compost would be available during the season.

Production of leafy greensLeafy greens were planted on March 11, 2005. Loose leaf lettuce

(Lactuca sativa cv. New Red Fire), spinach (Spinacia oleracea cv.7-Green), arugula (Eruca vesicaria subsp. sativa cv. Arugula), andmustard greens (Brassica juncea cv. Red Giant) were direct seededon 4.6 × 0.6 m beds with a 4-row precision hand seeder (SembdnerMaschinenbau GmbH), with a spacing of 0.06 m between rows. Bedsin organically managed tunnels received preplant incorporated ap-plications of Hu-More 1-1-1 (composted cattle manure and alfalfahay; Humalfa Inc., Shattuck, Okla., U.S.A.) at a rate of 134 kg N/ha,while beds in conventionally managed tunnels received preplantapplications of NPK 13-13-13 fertilizer at a rate of 67 kg N/ha. Start-ing 5 wk after seeding, organic plots were fertigated (application ofnutrients through drip irrigation systems) with fish emulsion 5-1-1(Lilly Miller Brands, Clackamas, Ore., U.S.A.) at a rate of 5.6 kg N/haat 5-d intervals. Conventional plots were fertigated with calcium ni-trate (15.5-0-0) at a rate of 5.6 kg N/ha at 5-d intervals on the samedates. No pesticide was applied in either production system. All 4vegetables were harvested on May 9 at baby size suitable for saladmix, or slightly larger in the case of spinach.

Production of tomato and cucumberTomato (Lycopersicon esculentum cv. Florida 91) was transplanted

in 4-plant plots with black plastic mulch in high tunnels on May 26,2005. Plants were placed at a 0.6-m spacing and supported withcages made from a concrete reinforcing wire. Organically and con-ventionally managed plots received preplant incorporated verimi-compost at a rate of 134 kg N/ha and ammonium sulfate at a rateof 67 kg N/ha. Plots were irrigated as needed. Starting 4 wk aftertransplanting, organic plots were fertigated weekly for 10 wk withfish emulsion at a rate of 3.4 kg N/ha and conventional plots werefertigated with ammonium sulfate at a rate of 3.4 kg N/ha. Tomatofruits used for sensory analysis were harvested on August 12 at thefull-ripe stage. Fruit worms were controlled through applications oforganic or conventional formulations of spinosad.

Cucumber (Cucumis sativus cv. Tasty Jade) was direct seeded in5-plant plots (0.6-m spacing between plants) in organically and con-ventionally managed high tunnel plots on May 26, 2005. Preplantfertilizer and fertigation treatments were the same as for tomato.

Cucumber fruits used for sensory analysis were harvested on August12. Pyrethrin (PyGanic) (McLaughlin Gormley King Co., GoldenValley, Minn., U.S.A.) sprays were used in organic plots, and perme-thrin (Pounce 3.0 EC) (FMC Corp., Philadelphia, Pa., U.S.A.) sprayswere used in conventional plots to control cucumber beetles.

Production of onionOnion (Allium cepa cv. Candy) seedlings were transplanted on

April 1, 2005. Each plot consisted of 40 plants on 4 rows, with 0.15-mdistance between plants. Organic tunnel plots were fertilized withpreplant incorporated verimicompost at a rate of 134 kg N/ha, whileconventional plots were fertilized with preplant incorporated am-monium sulfate at a rate of 67 kg N/ha. Onion plots were irrigatedas needed and fertigated weekly, starting 10 wk after planting, withfish emulsion (organic plots) or calcium nitrate (conventional plots)at a rate of 3.4 kg N/ha each. Bulbs were harvested on July 25.

Sample preparation for sensory evaluationAt harvest, samples from production blocks were combined and

thoroughly mixed to produce bulk organic and conventional sam-ples for consumer tests. For the leafy greens, harvested leaves wereplaced in food storage containers, moistened with water, and imme-diately packed on ice in coolers for transport to the Sensory AnalysisCenter at Kansas State Univ. within 2 h. Upon arrival, samples werestored at 4 oC overnight. The next morning (day of consumer test),samples were gently rinsed under tap water, laid flat and air driedfor about 15 min, and then held in food storage containers at am-bient temperature (22 to 26 oC). At the time of evaluation, 2 to 3leaves with similar size from each sample were placed in 0.163-Lpolystyrene cups labeled with a random 3-digit code.

In the 2nd consumer test, before sampling, harvested onionswere cured for about 2 wk; harvested cucumbers and tomatoes werestored for 4 d at 4 oC and ambient temperature, respectively. On theday of test, cucumbers were peeled and then sliced on a mandolinejust before serving. Tomatoes were cut into thin round slices about6-mm thick and then into halves before serving. The onions werediced into small pieces about 6 mm and placed into a bowl coveredwith a plastic wrap. The serving sizes were 2 slices for cucumber andtomato and a small spoonful for onion. Paired (organic and con-ventional) samples were placed onto polystyrene plates that weredivided in half, labeled with 3-digit codes.

Consumer sensory analysisConsumer tests were carried out at the Sensory Analysis Center

at Kansas State Univ. Consumers were aged 18 to 60 y, had lived inthe United States for at least 10 y, and reported no food allergies. The100 consumers in the test of leafy greens reported consuming leafyvegetables at least 2 to 3 times weekly, and the 106 consumers in theother test met the criteria of eating cucumbers at least 1 to 2 timesweekly and tomatoes and onions 3 to 4 times weekly.

Each consumer test was conducted in several sessions during theday, with a variable number of consumers per session. For the testof leafy greens, each session consisted of 4 rounds, and the othertest had 3 rounds in each session. A round consisted of a pair of or-ganic and conventional samples of one type of vegetable presentedto consumers simultaneously. On the ballot the instruction stated“Taste the sample on your left hand side first. Answer questions be-low under left sample/retaste if necessary. Take a bite of the crackerand rinse your palate with water. Taste the sample on your righthand side. Answer questions below under right sample/retaste ifnecessary.” The left–right serving sequence was counterbalancedfor organic and conventional samples. The serving order of vegeta-bles was also rotated to reduce potential bias caused by positions;

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however, in the leafy green test, arugula and mustard greens werealways tasted after lettuce and spinach because of their strongerflavor. In the other test, onion was always tasted last because of itspungency.

Consumers were asked to score (1) overall liking on a 9-pointhedonic scale, that is , 9 = like extremely, 5 = neither like nor dis-like, 1 = dislike extremely; (2) intensity of overall flavor on a 7-pointscale, that is, 7 = extremely strong, 1 = barely any flavor; and (3)intensities of bitterness/sweetness on a 7-point scale, that is, 7 =extremely bitter/sweet, 1 = not bitter/sweet at all. In the case oftomatoes, ripeness instead of bitterness/sweetness was rated on a7-point scale, that is, 7 = extremely ripe, 1 = not ripe at all. Differ-ent lengths of scales were used to help the consumers differentiateliking from intensity scales.

After sensory evaluation, consumers were asked to answer de-mographic questions (multiple choice), which included gender, age,frequency of fresh vegetable consumption, perceptions of organicfruits and vegetables, and frequency of organic food consumption.

Statistical analysisData from consumer testing were analyzed using SAS� (Version

9.1, Cary, N.C., U.S.A.). To take into account potential carryover ef-fects due to left–right position for each vegetable, or due to the serv-ing order of vegetables, position and serving order data were incor-porated into the analysis of the consumer data. Analysis of variancewas performed for each vegetable individually using the GLM pro-cedure, where effects of production method, serving position, andserving order, and interactions among these effects, were includedin the model. Significant differences were determined at the 95%confidence level (P < 0.05). Partial correlation was also computedbetween the ratings of flavor intensity and ripeness for tomatoes, ad-justing for all model effects, to explore inherent relationships amongpanelists’ responses. In addition, a post hoc analysis of covariancewas performed to explore relationships between demographic in-formation and the consumer ratings of overall liking.

Results and Discussion

Consumer sensory analysis of organically and conventionallygrown lettuce, spinach, arugula, and mustard greens did not

show any significant difference with respect to overall liking, overallflavor intensity, and bitterness intensity (Table 1). A stronger flavor(Hogstad and others 1997) and more bitter taste (Haglund and oth-ers 1999) in organically grown carrots have been reported. In our

Table 1 --- Mean rating scores (least square means fromthe model) from a consumer panel comparing organicallyand conventionally grown leafy greensa

Production Overall Flavor BitternessVegetable method likingb intensityc intensityc

Lettuce Organic 5.0 4.5 4.4Conventional 5.4 4.2 3.9

P-value (N = 100) 0.11 0.16 0.10Spinach Organic 6.3 3.8 2.3

Conventional 6.3 3.7 2.2P-value (N = 100) 0.94 0.72 0.75

Arugula Organic 2.9 6.3 5.5Conventional 2.8 6.5 5.7

P-value (N = 100) 0.70 0.15 0.37Mustard green Organic 2.7 6.6 5.3

Conventional 3.0 6.5 5.2P-value (N = 100) 0.42 0.70 0.56

aSamples were scored by 100 consumers.bOn a 9-point hedonic scale, that is, 9 = like extremely, 1 = dislike extremely.cOn a 7-point scale, that is , 7 = extremely strong or bitter, 1 = barely any flavoror not bitter at all.

data, we consistently found no significant difference in acceptanceand no statistical differences in strength of flavor properties. Inspec-tion of results with relatively low, but nonsignificant P-values (lowerthan 0.20) did not show consistent tendencies, with slightly highervalues in flavor strength for organically grown lettuce, but the re-verse for arugula. It should be noted that both arugula and mustardgreens were disliked by consumers. The special biting pungency ofthose greens, which clearly was not appreciated by consumers in thisstudy, may influence the ability of consumers to focus on potentialdifferences.

In the test of tomato, cucumber, and onion, in addition to over-all liking and flavor intensity, ripeness of tomato, bitterness of cu-cumber, and sweetness of onion were scored by consumers. Com-parisons of organic cucumbers and onions with their conventionalcounterparts did not yield any significant differences (Table 2). Withregard to tomatoes, although the degree of overall liking was thesame for organic and conventional samples, conventional tomatoeswere scored significantly higher in overall flavor intensity, which wasconsistent with the marginally significantly higher consumer ratingsof ripeness for conventional samples (P = 0.06). Partial correlationanalysis showed a significant positive correlation between flavor in-tensity and ripeness; however, it was low (r = 0.24, P < 0.01). Furtherstudy involving tagging of flowers at anthesis and repeated samplingduring ripening would be required to determine whether the differ-ential ripeness scores between organic and conventional tomatoeswere due to production methods. Tomatoes are subject to multi-ple physiological disorders during the fruit developmental process(Swiader and Ware 2002), some of which are poorly understood, so itis possible that differences in production environment could affectrate of ripening. It has been demonstrated that ripening stage of fruitcan markedly influence the perceived flavor of tomato. Comparedwith tomatoes picked when fully ripened, tomatoes harvested ear-lier followed by after ripening were tasted to have less tomato-likeflavor and even more off-flavor (Kader and others 1977). A previousconsumer study comparing an array of organic and conventionalfruits and vegetables observed that the optimum maturity of testedsamples could possibly direct the consumer preference irrespectiveof growing conditions (Basker 1992).

Various factors could affect sensory analysis of organic comparedwith conventional produce. Sensory attributes of carrots were foundto be affected by variety and year in addition to growing conditions(Haglund and others 1999). The influence of variety on sensoryattributes of tomatoes was actually greater than that of produc-tion methods (Johansson and others 1999). Lower fertilizer rates,

Table 2 --- Mean rating scores (least square means fromthe model) from a consumer panel comparing organi-cally and conventionally grown tomatoes, cucumbers,and onionsa

Production Overall Flavor OtherVegetable method likingb intensityc attributecd

Tomato Organic 7.0 4.6 4.7Conventional 7.0 5.0 5.0

P-value (N = 106) 0.90 0.02 0.06Cucumber Organic 7.1 4.1 2.3

Conventional 7.0 4.0 2.2P-value (N = 106) 0.73 0.59 0.66

Onion Organic 6.7 5.7 3.6Conventional 6.7 5.9 3.5

P-value (N = 106) 0.82 0.41 0.65

aSamples were scored by 106 consumers.bOn a 9-point hedonic scale, that is , 9 = like extremely, 1 = dislike extremely.cOn a 7-point scale, that is , 7 = extremely strong, ripe, bitter, sweet, 1 = barelyany flavor, not at all ripe, bitter, sweet.dOther attribute: tomato = ripeness; cucumber = bitterness; onion = sweetness.

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irrespective of fertilizer type, resulted in increased flavor intensityof carrots (Hogstad and others 1997). Postharvest factors may alsomatter. Based on a preliminary study we conducted, any poten-tial differences in overall liking between organic and conventionalsamples tended to diminish after 1 wk of storage. Moreover, giventhe variance of organic farming systems within and across regions,sensory comparisons between organic and conventional vegetablesand fruits become far more complicated.

After each sensory test, consumers were requested to answer de-mographic questions. When asked about the perception of organicvegetables and fruits, on average 72.4% in both consumer panelsbelieved that organic produce was more nutritious and healthy, and51.4% related environmental benefits to organic produce (Table 3).This was not unexpected as consumer surveys have demonstratedthat perceptions of health benefits outweighed environmental con-cerns as the primary reason for pursuing organic foods (Magnussonand others 2003; Shepherd and others 2005). Better taste ranked3rd among characteristics of organic produce perceived by con-sumers in our study, but with lower numbers of consumers havingthis perception. Exploratory covariance analysis identified differ-ential impacts of consumer demographics on the degree of overallliking in the tests on lettuce and cucumbers (Tables 4 and 5). Forlettuce, consumers younger than 25 significantly preferred the con-ventional sample, whereas other consumers expressed similar likingfor both samples (data not shown). For cucumber, the interactionof consumer gender by growing method was marginally significant(P = 0.06). Male consumers tended to favor conventionally growncucumber (P = 0.19), while females liked organic cucumber better(P = 0.15) (data not shown). Consumers who believed that organicproduce had better taste (based on the demographic questionnaire)actually tended to score conventional cucumbers higher in overallliking (P = 0.12), while organic cucumbers tended to be liked moreby consumers who did not initially believe organic produce tastedbetter (P = 0.13) (data not shown). A recent sensory analysis of dif-ferent varieties of organically grown edamame-type soybean sug-gested that consumer hedonic ratings may be gender-dependent(Wszelaki and others 2005). Given relatively low numbers (less than

Table 3 --- Demographic information about consumers par-ticipating in sensory analyses comparing organically andconventionally grown vegetables

(percent)

Characteristic Category Panel 1a Panel 2b

Gender female 64.0 56.6male 36.0 43.4

Age >50 10.0 19.840–50 23.0 23.625–40 26.0 17.0<25 41.0 39.6

Fresh vegetable once or more daily 38.0 32.1consumption 4–6 times/week 45.0 47.2

2–3 times/week 17.0 20.7Organic food daily 3.0 3.8

consumption more than once a week 14.0 23.6once a week 16.0 18.91–3 times a month 36.0 35.8never 31.0 17.9

Perception more nutritious and healthy 74.0 70.8of organic better taste 20.0 36.8vegetables better for environment 50.0 52.8and fruitsc fresher, longer shelf life 4.0 8.5

same as conventional 18.0 13.2

a100 consumers participated in the taste test on leafy greens.b106 consumers participated in the other taste test on tomatoes, cucumbers,and onions.cConsumers were allowed to have multiple answers to this question.

100) for each specific consumer segment, our results must be con-sidered exploratory at this point. Indeed, given the large number(63) of tests performed in the covariance analysis, the occurrenceof some false significant results is to be expected. In future studiesit may be advisable to increase panel size in order to provide largernumbers for specific consumer segments when comparing organicversus conventional fruits and vegetables.

In our experiment, consumers conducted blind tests with no pre-vious information about the samples to be tasted. However, label-ing effects may affect evaluation of consumer preference for or-ganic and conventional products. Sensory studies combining blindtests, and tests when samples were marked with information ofproduction method, or labeled with correct and false information,respectively, indicated that the organic label can lead to a signif-icant increase of consumer ratings (Schutz and Lorenz 1976; vonAlvensleben and Meier 1990). The influence of product informationon consumer preference may also be conditional as shown by a con-sumer study on ecologically and conventionally grown tomatoes.The positive impact of ecologic labeling was less effective for toma-toes that received high ratings in a blind test (Johansson and others1999).

Conclusions

Consumer sensory analysis of a number of different types of veg-etables produced in our carefully managed, replicated plots did

not show significant differences between organically and conven-tionally grown vegetables in overall liking or for intensity of overall

Table 4 --- P-values showing significance of differential im-pact of consumer demographics on consumer overall lik-ing of organic versus conventional leafy greens

MustardLettuce Spinach Arugula green

Characteristics of consumersGender 0.62 0.76 0.87 0.75Age 0.05 0.90 0.66 0.97Fresh vegetable 0.79 0.48 0.99 0.88

consumptionOrganic food consumption 0.53 0.59 0.88 0.85

Perception of organic vegetables and fruitsMore nutritious and healthy 0.97 0.74 0.73 0.45Better taste 0.82 0.37 0.75 0.83Better for environment 0.70 0.61 0.98 0.41Fresher, longer shelf life 0.62 0.51 0.80 0.96Same as conventional 0.49 0.58 1.0 0.55

aData presented are P-values for interactions of consumer characteristic bygrowing method in the analysis of covariance.

Table 5 --- P-values showing significance of differential im-pact of consumer demographics on consumer overall lik-ing of organic versus conventional tomatoes, cucumbers,and onions

Tomato Cucumber Onion

Characteristics of consumersGender 0.46 0.06 0.59Age 0.39 0.09 0.78Fresh vegetable consumption 0.15 0.18 0.26Organic food consumption 0.53 0.42 0.38

Perception of organic vegetables and fruitsMore nutritious and healthy 0.43 0.45 0.78Better taste 0.97 0.03 0.47Better for environment 0.68 0.33 0.99Fresher, longer shelf life 0.98 0.98 0.92Same as conventional 0.19 0.14 0.98

aData presented are P-values for interactions of consumer characteristic bygrowing method in the analysis of covariance.

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flavor and bitterness (or sweetness) in most vegetables tested. Sig-nificant results for flavor intensity occurred only in the evaluationof tomatoes, an effect that appeared to be related to differences inripeness between organic and conventional. Demographic charac-terization of our consumer panel showed that panelists perceivedhealth and environmental benefits as the 2 major characteristicsof organic produce, followed by taste. Covariance analysis indicatedpossible influences of consumer demographics on sensory compar-isons of organic and conventional lettuce and cucumbers. Furtherstudies are needed to confirm and investigate the extent to whichconsumer segments have higher preference for organic products.

AcknowledgmentsThis work was supported by the grant from the U.S. Organic FarmingResearch Foundation. Contribution number 07-30-J of the KansasAgricultural Experiment Station. We also thank Alisa Doan for herassistance with the consumer sensory study on tomato, cucumber,and onion.

ReferencesBasker D. 1992. Comparison of taste quality between organically and conventionally

grown fruits and vegetables. Am J Altern Agric 7:129–36.Bourn D, Prescott J. 2002. A comparison of the nutritional value, sensory qualities,

and food safety of organically and conventionally produced foods. Crit Rev Food SciNutr 42:1–34.

Caussiol LP, Joyce DC. 2004. Characteristics of banana fruit from nearby organic versusconventional plantations: a case study. J Hortic Sci Biotechnol 79: 678–82.

Dimitri C, Greene C. 2002. Recent growth patterns in the U.S. organic foods mar-ket. USDA Economic Research Service Agriculture Information Bulletin No. AIB777.September. Available from: www.ers.usda.gov/publications/aib777/aib777.pdf.

Goldman BJ, Clancy KL. 1991. A survey of organic produce purchases and relatedattitudes of food cooperative shoppers. Am J Altern Agric 6: 89–96.

Haglund Å, Johansson L, Berglund L, Dahlstedt L. 1999. Sensory evaluation of carrotsfrom ecological and conventional growing systems. Food Qual Pref 10:23–9.

Harker FR. 2004. Organic food claims cannot be substantiated through testing of sam-ples intercepted in the marketplace: a horticulturalist’s opinion. Food Qual Pref 15:91–5.

Hogstad S, Risvik E, Steinsholt K. 1997. Sensory quality and chemical compositionin carrots: a multivariate study. Acta Agric Scandinavica Section B, Soil Plant Sci47:253–64.

Hough G, Wakeling I, Mucci A, Chambers EIV, Gallardo IM, Alves LR. 2006. Num-ber of consumers necessary for sensory acceptability tests. Food Qual Pref 17:522–6.

Johanson L, Haglund Å, Berglund L, Lea P, Risvik E. 1999. Preference for tomatoes,affected by sensory attributes and information about growth conditions. Food QualPref 10:289–98.

Jolly DA, Schutz HG, Diaz-Knauf KV, Johal J. 1989. Organic foods: consumer attitudesand use. Food Technol 43:60–6.

Kader AA, Stevens MA, Albright-Holton M, Morris LL, Algazi M. 1977. Effect of fruitripeness when picked on flavor and composition in fresh market tomatoes. J AmSoc Hortic Sci 102: 724–31.

Lawless HT, Heymann H. 1999. Introduction and overview. In: Lawless HT, HeymannH, editors. Sensory evaluation of food: principles and practices. New York: KluwerAcademic/Plenum Publishers. p 1–27.

Magnusson MK, Arvola A, Koivisto-Hursti UK, Åberg L, Sjoden PO. 2003. Choice oforganic foods is related to perceived consequences for human health and to envi-ronmentally friendly behavior. Appetite 40:109–17.

Makatouni A. 2002. What motivates consumers to buy organic food in the UK? Resultsfrom a qualitative study. Br Food J 104:345–52.

Reganold JP, Glover JD, Andrews PK, Hinman HR. 2001. Sustainability of three appleproduction systems. Nature 410: 926–30.

Schutz HG, Lorenz OA. 1976. Consumer preferences for vegetables grown under ”com-mercial” and ”organic” conditions. J Food Sci 41:70–3.

Shepherd R, Magnusson M, Sjoden P. 2005. Determinants of consumer behavior re-lated to organic foods. Ambio 34:352–9.

Sloan AE. 2003. Top 10 trends to watch and work on: 2003. Food Technol 56:30–50.Swiader, JM, Ware GW. 2002. Producing Vegetable Crops, 5th ed. Danville, Ill.: Interstate

Publishers.The Hartman Group. 2000. The Organic Consumer Profile. Bellevue, Wash.: The Hart-

man Group.von Alvensleben R, Meier T. 1990. The influence of origin and variety on consumer

perception. Acta Hortic 259:151–61.Wandel M, Bugge A. 1997. Environmental concern in consumer evaluation of food

quality. Food Qual Pref 8:19–26.Wszelaki AL, Delwiche JF, Walker SD, Liggett RE, Miller SA, Kleinhenz MD. 2005. Con-

sumer liking and descriptive analysis of six varieties of organically grown edamame-type soybean. Food Qual Pref 16: 651–8.

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