Correlation Between Sensory and Instrumental Measurements of Crisp Textured Blueberries

The University of Florida blueberry breeding program has been developing Southern highbush blueberry cultivars for over 50 years.  During this period, fruit firmness has been a primary selection trait, and a novel texture most often described as “crisp” was identified.  The anatomical and physiological basis of this trait is not understood, nor the manner of inheritance.  However, two releases from the program, ‘Bluecrisp’, and ‘Sweetcrisp’, possess this crisp fruit texture, and many advanced seedling selections have been subjectively identified.  Prior to fruit evaluation of this large group of seedlings, we are attempting to better understand the anatomical differences leading to a crisp fruit texture, as well as develop a common set of descriptors that align sensory evaluation of fruit texture with instrumental measures that could be used for quantitative measurements during breeding selection.  Therefore, sensory and instrumental characteristics were measured in 36 cultivars and advanced selections considered by breeders at the University of Florida to have the crisp texture.  A trained sensory panel evaluated fresh fruit based on five textural categories:  bursting energy, flesh firmness, skin toughness, juiciness, and mealiness.  The class of crisp berries scored highest among sensory scores for bursting energy, flesh firmness, and skin toughness.  Sensory scores for mealiness and juiciness did not correspond to either the crisp or non-crisp class. Compression and puncture forces correlated with each other, and both instrumental measures were significantly different between crisp and non-crisp cultivars.  Compression and puncture forces correlated with sensory scores for bursting energy, flesh firmness, and skin toughness, but did not correlate with sensory scores for mealiness and juiciness.  Puncture forces were measured for fruit with the skin removed from the berry, but these results did not correlate with sensory ratings.  The results of sensory and instrumental measures support the distinction made between crisp and non-crisp berries, and suggest that crispness is related to the sensory perception of bursting energy, flesh firmness, and skin toughness.