Aromatic Impact of Fresh Blackberries Identified by a Descriptive Sensory Panel

The flavor of a product includes aromatics, basic tastes and chemical feeling factors. Aromatics are olfactory perceptions of volatile substances released by a product in the mouth. There is limited information on the aromatics of fresh blackberries (Rubus subgenus Rubus), particularly those derived from eastern United States germplasm. This study aimed to use descriptive sensory analysis to identify and evaluate the aromatic attributes of fresh blackberry genotypes (cultivars and selections) harvested from the University of Arkansas Fruit Research Station, Clarksville. A trained descriptive sensory panel (n=9 ) evaluated sensory attributes of 11 fresh blackberry genotypes including five cultivars (Natchez, Osage, Ouachita, Prime-Ark® 45, and Prime-Ark® Traveler) and six selections. The genotypes had commercially acceptable soluble solids levels of 8% to 11%. Each panelist evaluated four berries for each genotype in duplicate, served monadically and randomized. The descriptive panelists identified and evaluated the aromatics of fresh blackberries using a 15-point scale (0 = less of the attribute and 15 = more of the attribute).  The panel evaluated the overall aromatics and individual aromatics described as blackberry, earthy/dirty, green/unripe, overripe/fermented, chemical, mold/mildew, and metallic. The genotypes evaluated had high overall aromatic impact, with values ranging from 7.6 (A-2434) to 8.2 (‘Natchez’) on a 15-point scale, indicating positive potential for fresh market. Although the panelists identified high levels for the blackberry flavor attribute (6.7–7.2), there were no differences identified among the genotypes. The panelists observed differences for the earthy/dirty aromatic attribute, with values from 1.2 (A-2416 and A-2491) to 2.4 (A-2434). ‘Natchez’ and A-2491 had the lowest green/unripe attribute (1.5 and 1.6, respectively), indicating more perceived ripeness, as opposed to A-2416 that had the highest value (3.0). The overripe/fermented, chemical, mold/mildew and metallic attributes ranged from 0.0 to 1.1 on a 15-point scale. The panelists did not find differences among genotypes for metallic or mold/mildew attributes.  Aromatics play a critical role in the perception of fresh blackberry flavor and can be used to determine commercial potential.