An apple a day: the influence of memory on consumer judgment of quality

Abstract Regular consumers of apples are subjected to a high level of variability in sensory experience. This is due to the biological variation between individual apples, and the deterioration in quality that occurs when fruit are stored for many months. Therefore consumer assessment of quality is likely to be strongly influenced by their capacity to remember past experiences. In this study, we examined the ability of untrained participants to detect differences in apple texture (a primary determinant of quality for many consumers) when presented with fruit at daily and ∼1 min intervals. Each day the participants were given an apple that differed in firmness (measured by an instrumental puncture test) by 0, 5, 10, or 15 N from the fruit tasted on the previous day. They were asked whether the apple was harder, the same or softer than the previous apple, and how sure they were of their answer. The results were analysed using a traditional, bipolar, and weighted bipolar R-index. When comparing apples eaten at daily intervals, the participants were able to detect differences in texture when the instrumental firmness of the fruit differed by as little as 5 N (note that consumers might experience apples between ∼50 and ∼85 N during the year). When the participants tasted apples at ∼1 min intervals, they experienced difficulty detecting any difference in texture even when instrumental firmness of the fruit differed by as much as 15 N. The poorer performance of participants at ∼1 min presentation intervals may be explained by the disruption of a memory trace for texture by other similar but interfering memories (i.e. factors akin to ‘proactive interference’ and ‘suffix’ effects found in research on visual and acoustic memory).