Use of preference testing to identify tolerance limits for fruit visual attributes in apple breeding

Sensory evaluation methods were used to establish tentative guidelines for screening apple (Malus x domestica Borkh.) breeding selections for four visual attributes. A panel of 42 regional consumers rated sample selections for fruit size on the 7-point "Just Right" (JR) scale, for fruit shape on a 7-point hedonic (liking) scale, and for the appearance of lenticels and stem bowl russet (SBR) on a 7-point affective (acceptability) scale. The panel most preferred a fruit about 7.5 cm in diameter. No evidence was found for range bias or for differences between yellow and red apples in size preference. Women and panelists over 55 years of age tended to prefer a slightly smaller apple. Panelists liked all the most common apple shapes. Lenticels generally became unacceptable when they exceeded 1.0 mm in diameter, but lenticel density was not related to acceptability. For red or yellow apples, SBR was acceptable on average, provided its maximum extent did not exceed about 55% of the fruit diameter. The panel's tolerance to SBR resembled that of a larger regional population, and their fruit size preferences resembled those reported elsewhere for European consumers. Similar methods could be used by other breeders to assess the preferences of their target consumer population.