Pyrene Attributes and Seediness Evaluation of Blackberry Genotypes

Fresh market blackberries can feel "seedy" when consumed. This "seediness" is associated with the presence of pyrenes which are comprised of a single seed enclosed in an endocarp. Small pyrene size (<3 mg) is preferred in both fresh-market and processed blackberry products. Yet, the proportion of pyrene weight to total berry weight can be more important than pyrene size. The objective of this study was to determine and compare descriptive sensory analysis and pyrene characteristics of blackberry genotypes from the University of Arkansas Division of Agriculture blackberry breeding program. Panelists were trained according to Spectrum (R) methods and evaluated 20 genotypes for overall seediness. Pyrene characteristics, including weight and dimension, were measured. Six of the 22 genotypes had an individual pyrene weight of 3 mg or less. 'Tupy' had low individual pyrene weights and a low pyrene weight/berry weight ratio, which are most likely factors that contribute to its widespread acceptance by consumers. Pyrene weight/berry weight ratio was positively correlated to descriptive overall seediness (r = 0.70) but not to number of pyrenes/berry. Therefore, finding a desirable pyrene weight to berry weight ratio is integral to decreasing perceived seediness in the development of new blackberry cultivars.