Panelist selection and evaluation scenarios

Panelists were untrained consumers, who are suitable for spontaneous, fast responses unconditioned by previous training^14-16. Tests were done in three scenarios, each an event which attracts different kinds of attendees. The Gourmet Show (GS) is held every year at the World Trade Center in Mexico City and is aimed at bringing together the suppliers of quality cooking products with potential consumers. The National Rural Culture Fair (FCR) is held annually at the Autonomous University Chapingo and brings together local producers from all over Mexico. Local handcraft and food products are on exhibit and for sale, and there is a food court for the sale of prepared food from all the participating states. The annual Gastronomic Exhibition (MG) of the Institute of Agricultural and Rural Sciences (ICAR) of the Autonomous University of the State of Mexico commemorates The International Day of Food. Attendees are largely university students, teachers and administrative personnel. Scenario choice was done for convenience, given the ease of access to apply sensory tests.

Recommended panel size for this kind of sensory test is 50 to 500 panelists. These are usually recruited because they are product users or are familiar with the products to be evaluated^15,17. A total of ninety (90) panelists were interviewed among the three scenarios: 34.4 % in the GS; 30 % in the FCR; and 35.6 % in the MG. Although most had no prior knowledge of QBO, they were chosen under the assumption that attendees at food events are more likely to be open to trying handmade local products. This was also an advantage because QBO is not widely known nationwide so the spontaneous responses of the untrained panelists were more probable to approximate those of the general population¹⁵.

Cheese samples

In an effort to avoid process-related biases, the QBO samples used in the evaluations were taken from cheeses prepared in the same factory. Three QBO types were tested: 1) fresh cheese, curd acidified for three days before wrapping, 17- to 19-day total production time (hereinafter “fresh cheese”); 2) aged cheese, 21-d curd acidification prior to wrapping, 35- to 37-day total production time (hereinafter 21-d cheese); and 3) aged cheese, 45-d curd acidification before wrapping, 59- to 61-d total production time (hereinafter 45-d cheese).

Tests were done by placing randomly-coded QBO samples on a plate (to prevent any preconceptions based on ageing time), along with water, bread and fruit (green apples) to clean the panelists´ taste buds prior to evaluating the samples, and between samples.

Tests

Acceptance and preference tests were applied. The first measures perception of sensory characteristics using a scale while the second merely requires selection of the most pleasing sample¹⁵. After evaluating the samples panelists were asked for information on their place of origin, gender, age and income to facilitate statistical analyses.

Acceptance was evaluated considering ten attributes: external and internal appearance; external and internal color; texture in hand; smell; texture in mouth; taste; aftertaste; and price. Each attribute was graded on a five-point scale (1: Do not like; 2: Like somewhat; 3: Indifferent; 4: Like; and 5: Like very much); this was accompanied by a visual scale to expedite the evaluation process and avoid any discrimination against panelists lacking formal education¹⁸.

Preference was determined by panelists indicating their order of preference of the evaluated samples. After both tests were done panelists were informed of the characteristics of each cheese type and how it is made and asked about their disposition to buy each type and to pay a different price for their preferred cheese (range was ± 60 % of base price per 300 g piece).

Statistical analysis

Validation of question reliability was done with the Cronbach alpha coefficient, considering the thirty attributes included in the three evaluations. The resulting value (0.935) indicated the questionnaire to be reliable for gathering data on cheese characteristics. This analysis was done with the SPSS ver. 16 statistical package.

Data were analyzed using various statistical techniques, all applied with the Infostat statistical package^19,20. Comparison of attributes between cheeses was analyzed with the Friedman test since each panelist in all three scenarios tested three samples and evaluated each attribute, meaning they are related samples. Results presentation was facilitated by classifying attributes as visual (external and internal appearance, external and internal color) or other (texture in hand, smell, texture in the mouth, taste and aftertaste). Perception of price was presented separately because it is not a sensory attribute, but is still fundamental to generating a complete product evaluation^21,22. A Kruskal-Wallis test was applied to compare differences between the three scenarios in terms of cheese attributes. Parametric and non-parametric statistical tests, based on variable measurement scale, were used to identify cheese preferences. Quantitative variables were compared using an analysis of variance (ANOVA), with a Tukey test to identify differences between means, and a chi-square test for differences between nominal values. Finally, a Kruskal-Wallis test was applied to identify any differences between scenarios in willingness to pay a price other than the base price.

Panelist socioeconomic profile

Most attendees at the GS were from Mexico City and had the highest education and income levels of the three scenarios. Those at the FCR were from different parts of Mexico and had the lowest average education level. At the MG, almost all attendees were students from the State of Mexico, and this group had the lowest average age (Table 1).

Attribute perception by cheese type and evaluation scenario

Overall consumer perception by cheese type did not differ between types (Table 2). Because QBO is a sui generis product among Mexican artisanal cheeses¹¹, it was attractive to the panelists, which influenced their positive evaluation of its attributes.

Visual attributes received better overall evaluations, probably reflecting the fact that the panelists placed more importance on the most easily perceived characteristics. This could be an effect of the global food supply model which is based on symbols and signals to more easily bridge the gap between producer and consumer^1,23. Otherwise, this absence of differences between samples may also be attributed to QBO being an unconventional and striking cheese (only 15.6% of panelists had prior knowledge of it), which would coincide with the largely positive evaluation of all attributes. Since the participants had no previous experience as food evaluation panelists, they failed to detect sensory differences between samples. Similar results have been reported in a study in which goat cheeses aged for different periods were sensory evaluated, and in which consumers who were unfamiliar with cheeses of intense aroma and flavor could not easily recognize sensory differences between samples²⁴.

Comparison of evaluations by scenario and cheese type identified differences between the different cheese samples for visual attributes. However, for other attributes and perception of price only the 45-d cheese differed from the other types (Table 3).

Among the scenarios, FCR attendees gave the lowest evaluations to all three cheeses, much like MG attendees, who found visual attributes to be more important for all cheese types. At the GS, however, attendees gave better evaluations to the other attributes and perception of price for the 45-d cheese. The GS panelists also exhibited more consistent evaluations, with higher ratings as cheese age increased. Trends were not as clear in the MG and FCR scenarios because the most positive ratings were generally given the fresh cheese with ratings decreasing with cheese age. These differences in cheese attribute perception based on cheese age may be explained by variations in panelist characteristics and the possibility that some panelists may have had more regular access to this type of product.

Panelists in the FCR were the most diverse and had the lowest education level while the MG panelists were mostly students and the youngest group on average. Both these groups had lower income than the GS panelists (Table 1). That panelists from lower-income levels may place greater value on the characteristics of fresher cheeses is plausible since fresh cheeses are common in Mexico and are generally cheaper^25,26. Even though the MG panelists were all studying degrees involving evaluation of local products (e.g. tourism, gastronomy), they still placed more importance on visual attributes. Perhaps this was because they were younger and may not have had the experience necessary to distinguish and evaluate products based on intrinsic properties. Panelists at the GS, in contrast, had higher education and income levels, better fitting the profile of consumers who search for and value unique, quality foods. Consumers of this type typically appreciate “fine foods” and seek sensory experiences not offered by mass-produced foods (although these can be made with high quality raw materials). Often they purchase their food at markets selling only specialty or artisanal products. It is this greater contact with differentiated products that most probably allows these consumers to evaluate products based on attributes beyond the visual.

Two types of consumers can apparently be identified among the panelists. The first make choices based on intrinsic attributes associated with a certain degree of knowledge of and experience with a product or similar products; this type is best represented by the GS panelists. The second type largely consider visual aspects, including product appearance, as a kind of codification for making purchase decisions; the MG and FCR panelists best represent this type^6,22.

Perception of price differed notably for the 45-d cheese (Table 3). Taking into account that all three cheese types were assigned the same price, the GS panelists gave a lower valuation to the price of the fresh cheese and a higher one to the 45-d cheese. The latter provided them with a richer sensory experience and they therefore felt it had better value for price than the other types. Among the FCR and MG panelists, the opposite was true in that they gave better valuations to the price of the fresh and 21-d cheeses than to the 45-d cheese. They are presumably not accustomed to products with strong aromas and flavors, meaning the 45-day cheese seemed them expensive.

Comparison of preference results by scenario

An important component of the present study was to evaluate if the perception of attribute results support panelist preference. The preference results suggest the existence of specific consumers for each cheese type. Preferences differed between scenarios (χ²=8.121; P=0.087), particularly between the GS and FCR panels (Figure 1). The former clearly preferred the 45-day cheese while the latter preferred the fresh cheese; the MG panel exhibited no clear preference.

GS= Gourmet Show; FCR= National Rural Culture Fair; MG= Gastronomic Exhibition.

Figure 1: Overall preference by scenario 

Consumer preference can also be explained by considering demographic characteristics, consumer accessibility to and frequency of contact with differentiated products, and the influence of the evaluation scenarios on panelist’s individual experiences². The preference for a particular cheese was linked with education and income levels (Table 4).

A preference for 45-d cheese clearly coincided with higher education and income levels. The preference per scenario results also support the acceptance tests results, suggesting the existence of two consumer types: one of lower education and income level which accepts and prefers the fresh cheese, these panelists were in a scenario in which gastronomy was presented as an aspect associated with general culture (i.e. FCR); and another of higher education and income levels which accepts and prefers more mature cheeses, these were panelists in a gourmet food event who likely had more specialized sensibilities (i.e. mainly GS panelists). In the MG scenario the preference results did not tend towards a particular type, suggesting that panelists were a mixture of consumer types.

Food choices are also influenced by consumer experience²². Considering this the panelists that preferred the fresh cheeses are probably consumers who prefer milder cheeses because they are commonly found in the markets were they shop²⁴. Due to the nature of the FCR, the attendees were probably consumers who share characteristics similar to average Mexican consumers; that is, they are more inclined to consume fresh cheese due to its lower price and greater availability²⁶. The preferences of the GS panelists highlight that consumption of aged cheeses is more likely limited to those regions of the country where they are produced, making them a traditional food stuff, and to gourmet markets in large urban areas where specialized fairs play a key role in product exposure.

The evaluation scenarios themselves, as an element in the social context that produces individual expectations and experiences, may have influenced the results. They can contribute previous codification that provides indirect information on the expected quality of the products on offer in a specific scenario^2,27. This may explain why consumers at the GS placed more value on intrinsic attributes and preferred the most aged cheese; they are at an event centered on differentiated gastronomy and they hope to find products offering rich sensory experiences. The FCR, in contrast, is a more general and diverse event including cultural events such as a book fair, food exhibition and handcrafts, and attracted consumers that preferred fresh cheeses. Acceptance of the three cheese types at the MG did not differ, perhaps because the students at the event studied degrees such as tourism and gastronomy, and are thus sensitized to local products, but lacked the knowledge and experience needed to perceive the differences between the cheese samples.

The attribute perception and cheese preference results reflect important aspects of QBO and its potential consumers. These can be analyzed to identify areas of opportunity and improve QBO marketing strategies; for instance, considering cheese maturation days, regional origin and promoting local products at food-agriculture fairs and gastronomic events ²⁸.

Panelists from an apparently higher socioeconomic class preferred the 45-day cheese, highlighting the potential for marketing to this consumer sector within the region where QBO is produced; for instance, the tourist destination of San Cristóbal de las Casas is relatively near Ocosingo²⁸. The other two groups tended to appreciate QBO for its visual attributes and freshness, and were apparently from lower socioeconomic classes, much like the greater part of Mexico’s population. This consumer sector can be offered a fresher cheese that also happens to be cheaper, an appealing quality according to the perception of price results.

Purchase intention and willingness to pay a different price for the preferred cheese type

Before information on QBO was provided the panelists they gave the lowest ranking to perception of price (Table 3). Providing product information can transform consumer perception, a tendency reflected in willingness to purchase the product and to pay a preferential value^21,29. This was observed in all three scenarios; panelists were more willing to buy their preferred cheese type after they had received information on how it is produced (93.5 % in the GS; 87 % in the MG and 74 % in the FCR). Of note is that the GS panelists were willing to pay more than the market price of QBO, those at the MG were willing to pay near the market price and those at the FCR less than the market price. The differences between the willingness of the different groups to pay for their preferred cheese was significant for the fresh and 21-d cheeses and highly significant for the 45-d cheese (Table 5).

Willingness to pay a higher price was at least partially associated with panelist purchasing power (Table 5), but could also be attributed to educational level and access to differentiated quality products. Only the GS panelists were willing to pay additional value for any of the three tested cheese types, particularly for the 45-d cheese (18 % additional, on average). In the other two scenarios, in which the lowest income levels were recorded (Table 1), panelists did express willingness to pay for this same cheese type, but at a price below the base price.

Although price and income level clearly influenced purchase decision in the present study, other factors intrinsic to the product may have a greater influence on purchase decision, but this implies that the consumer has the possibility of acquiring knowledge on the product. Flavor is reported to be the most important attribute when determining product quality and willingness to buy a local food as long as the consumer can live the sensory experience. However, when sensory information is not available on a product other factors such as price, brand, packaging and the property of being artisanal or local come into play^2,30,31. Once panelists had chosen their preferred cheese and expressed their intent to purchase, they were asked about their principal reasons for buying it. Flavor was the main reason for 55.4 % of the panelists, the properties of its being unique and artisanal for 20.7 %, appearance, curiosity and its being a local product for 24 %, and price for just 6.5 %. Overall, for the panelists participating in the sensory evaluation, taste was more important than price, although the prospect of paying added value was conditioned by socioeconomic variables and individual experiences.