Abstract
The research reported in this thesis used a Consumer Inspired Quality approach and sought to define the consumer acceptance ranges for Philadelphia Light Cream Cheese directed at the European consumer market. This research involved a comparison of methodologies to determine which method produced the best understanding of Consumer Inspired Quality.
Specifically, this study investigated logistical factors associated with the use of three different consumer hedonic testing methods from an industry perspective when assessing cream cheese and the outcomes from the small scale pilot tests were that two of the mentioned methods were selected and the instructions for the method protocols were refined to improve clarity and ease of understanding.
Assessment of new methods were carried out to enable us to better differentiate or define consumer acceptance ranges based on Philadelphia Light compared to the benchmark method ‘Consumer Acceptance Test’. Consumer Inspired Quality of light cream cheese products was evaluated by 100 consumers by applying two newly developed sensory testing methods along with the benchmark consumer testing method. A Quantitative Descriptive Analysis was used to give a complete sensory profile of the light cream cheese samples. The application of the consumer hedonic testing methods, Boundary of Acceptance with Check-All-That-Apply, Preference Ranking with Open Comments and a Consumer Acceptance Test found all three methods being effective at differentiating the cream cheese samples. On the selected Philadelphia light cream cheese sample set, the consumer acceptance ranges could be identified based on the results of the Consumer Acceptance Test and Preference Ranking with Open Comments due to there being three groups differentiating the samples. From the Consumer Acceptance Test, samples with Cold Stevens lower than 75g were too soft and samples with Cold Stevens higher than 90g were too firm and this would be the cut-off ranges. From the Preference Ranking with Open Comments, samples with Cold Stevens lower than 75g were too soft while samples with Cold Stevens higher than 99g were too firm. From the Boundary of Acceptance, there were only two groups differentiating the samples hence determining the consumer acceptance ranges was slightly more complicated. Based on the results from all three consumer hedonic methods, samples 6 and 7 with the highest Cold Stevens (90g and 99g) were already significantly less liked in comparison to best performing prototypes, samples 2 and 3 (Cold Stevens of 75 and 77g). The consumer acceptance ranges could not be defined for even softer samples as the samples with lower Cold Stevens (<70g) were not included in the study. Correspondence Analysis (CA) demonstrated similarity in explained variance between the three consumer hedonic methods suggesting that the comments and CATA statements could discriminate the cream cheese samples similarly. The samples were differentiated based on overall liking scores and preference ranking scores, however the Check-All-That-Apply statements or liked and disliked comments need to be used in conjunction with this.
Participants’ perceptions of the three consumer hedonic tests were also investigated and the participants’ perceptions exit questionnaire showed there was no significant difference in how the participants liked or disliked the three methods. There was a significant difference between the three methods in terms of difficulty/easiness. Boundary of Acceptance with Check-All-That-Apply and Consumer Acceptance Test were significantly easier than Preference Ranking with Open Comments, but not significantly different from one another. There was a significant difference in the participants opinions of the sample amounts evaluated. Preference Ranking with Open Comments was evaluated to have significantly too many samples compared to the Consumer Acceptance Test and Boundary of Acceptance with Check-All-That-Apply which were not significantly different from one another. There was no significant difference in clearness of instructions for the three methods or in the ease of understanding of the task; however there was a significant difference in how easy the task was to complete. Preference Ranking with Open Comments was significantly less easy to complete than both the Boundary of Acceptance with Check-All-That-Apply and Consumer Acceptance Test. There was no significant difference in the question structure or in the understanding of the questions.
More research is necessary to further clarify important aspects of the two newly developed methodologies (Boundary of Acceptance with a Check-All-That-Apply ballot and Preference Ranking with Open Comments), including the effect of the size of the sample set, the differences in the samples and objectives of the research. Although the trained Quantitative Descriptive Analysis panel detected sensory differences in the light cream cheese samples, the magnitude of the differences in the sensory properties may have been insufficient to enable good sample differentiation in the three consumer methodologies and so a product set with larger differences in sensory profiles may have been useful.