BACKGROUND: Since the consumption of fresh blackberries has increased, the demand for new cultivars with extended postharvest quality that meet consumer expectations has increased. OBJECTIVE: The objective of this study was to identify fresh-market blackberry genotypes with high postharvest potential and evaluate changes in physiochemical and sensory attributes. METHODS: Fruit quality, chemical composition and descriptive sensory attributes of five blackberry cultivars (Natchez, Osage, Ouachita, Prime-Ark ® 45 and Prime-Ark ® Traveler) and six advanced breeding selections from the University of Arkansas Fruit Breeding Program were evaluated at harvest and after 7 days of storage (2 • C and 90% RH). Fruit quality (firmness, red drupelets, weight loss and unmarketability) and chemical composition (basic composition and phytochemicals) were evaluated, and a trained descriptive sensory panel (n = 8-9) evaluated blackberry attributes for appearance, basic tastes, feeling factors, aromatics and texture. RESULTS: The blackberries had soluble solids of 6.6-10.9% and titratable acidity of 0.5-1.5% at harvest. 'Natchez' had the lowest percent of unmarketable fruit (2.9%) and A-2418 had the highest (53.6%) after 7 days of postharvest storage. After 7 days of storage, 'Natchez' and A-2453 had low incidence of red drupelets and high uniformity of color and 'Natchez' and A-2491 were associated with the sensory attributes of sweetness and overall aromatic impact. The sensory panelists could not perceive differences in color, uniformity of color, glossiness, firmness or sweetness after storage, but perceived blackberries as more astringent and less sour and bitter after storage. These sensory findings correspond with the fruit quality and chemical composition data that indicated no changes for incidence of red drupelets, firmness or soluble solids of blackberries after storage. However, blackberries had increased total phenolics, flavonols, anthocyanins and ellagitannins, and decreased titratable acidity after storage. After storage, total phenolics and total ellagitannins of blackberries were positively correlated to bitter and sour basic tastes. CONCLUSION: Fruit quality and chemical composition analyses correlated to sensory attributes and may assist blackberry breeders in developing cultivars with extended postharvest storage and superior fruit attributes. 'Natchez', A-2453 and A-2491 showed positive fruit attributes in this study and have potential for the development of future cultivars or used as parents for crosses in blackberry breeding programs.

In subtropical or tropical conditions, the insufficient winter chill accumulation is often a limiting factor to break the dormancy of temperate-climate species such as the blackberry, which requires using products to help break dormancy. This study evaluates the efficacy of compounds in breaking dormancy of blackberry and its consequent influence on phenology and crop yields. The experiment was conducted in São Manuel, State of São Paulo, Brazil, in the 2011/2012 production cycle. The plants used were two-year-old "Tupy" blackberry (Rubus spp.), with 0.6 × 4.0 m spacing (4.166 plants·ha −1 ). Pruning was performed in August, followed by the application of these treatments: control (water); hydrogen cyanamide (Dormex ® ); nitrogen fertilizer (Erger ® ) and mineral oil (Assist ® ). The concentrations of each compound used were: 2.0%, 4.0%, 6.0% and 8.0%. The compounds used influenced the budding, flowering and fruit harvest stages, in addition to providing increased yields depending on the concentration used. For hydrogen cyanamide the recommended concentration is of 4.2% and 5.4% for nitrogen fertilizer; doses above these concentrations may cause phytotoxic effects. For mineral oil the dose recommended is of 8.0%.

Blackberries (Rubus subgenus Rubus Watson) are grown worldwide for commercial fresh markets. Physiochemical and sensory attributes were evaluated on fresh fruit of five blackberry cultivars (Natchez, Osage, Ouachita, Prime-Ark® 45, and Prime-Ark® Traveler) and six advanced breeding selections from the University of Arkansas Fruit Breeding Program. The physiochemical attributes of blackberries were within a commercially acceptable range (soluble solids = 8% to 11%, pH = 3.0–3.6, titratable acidity = 0.7% to 1.4%, berry weight = 6 to 14 g, drupelets/berry = 50 to 150, and pyrenes/berry = 51 to 115). ‘Natchez’ had the highest berry weight, berry length, drupelets/berry, and pyrenes/berry, whereas A-2453 was the lowest for these attributes. The highest nutraceutical levels were found in ‘Osage’ (total flavonols and total anthocyanins), A-2434 (total ellagitannins) and A-2453 (total phenolics). A trained descriptive sensory panel (n = 9) evaluated fresh blackberry attributes for appearance, basic tastes, feeling factors, aromatics, and texture using a 15-point scale (0 = less of the attribute; 15 = more of the attribute in terms of intensity). The descriptive panel identified ‘Natchez’ as having the largest descriptive size of berry with the highest overall aromatics and A-2453 as the smallest, glossiest, and firmest. Although A-2491 had the highest soluble solids, the descriptive panelists could not differentiate sweetness among the genotypes, but found A-2491 the least sour. A consumer sensory panel (n = 74) evaluated appearance, flavor, and texture attributes of blackberries on a 9-point verbal hedonic liking scale (1 = extremely dislike; 9 = like extremely) and 5-point just about right (JAR) scale (1 = not nearly enough; 3 = JAR; 5 = much too much). In terms of overall impression and overall flavor, A-2491 and ‘Prime-Ark® Traveler’ had the highest liking; average attributes for these blackberries were a berry weight of 9.1 g, soluble solids of 10.0%, titratable acidity of 0.95%, and a soluble solids/titratable acid ratio of 11.9. ‘Prime-Ark® Traveler’ also had the highest liking for appearance and berry size. A-2453, the glossiest berry, had the highest liking for berry color. Consumer panelists liked the firmness of the blackberries including those that were very firm, such as A-2453, but did not indicate differences in liking among genotypes. Consumers found the size of ‘Ouachita’, ‘Prime-Ark® Traveler’, and ‘Prime-Ark® 45’ (berry weight ≈8.3 g) JAR, but ‘Natchez’ (14.3 g) too large. Consumers found the sweetness and sourness of A-2491 JAR. Consumer overall impression and flavor of blackberries were positively correlated to consumer liking of berry shape and color and negatively correlated to the descriptive attributes for sourness, bitterness, green/unripe aromatic, and amount of seeds. Consumer liking of appearance was positively correlated with consumer liking of berry size, shape, color, and descriptive uniformity of color and glossiness. To produce a commercially marketed fresh-market blackberry, there are many characteristics that are important, but our data for these genotypes suggest that a desired blackberry should have a berry weight of 8–10 g, soluble solids of 9% to 11%, titratable acidity of 0.9% to 1%, and a soluble solids/titratable acid ratio of 10 to 13. However, optimum sugar and acidity levels require more investigation including other factors in flavor and aromatics. Evaluating the physiochemical and sensory attributes of fresh fruit is an important tool that can be used to determine commercial potential for selections and cultivars.

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Fresh-market blackberries (Rubus subgenus Rubus Watson) have a growing global market, with continued release of cultivars to meet demand for consumer-quality fruit. The release of primocane-fruiting blackberry plants that produce crops on both floricanes and primocanes has expanded blackberry production. This study investigated the physiochemical attributes of fresh-market blackberries harvested from two cane types (floricane and primocane) from four primocane genotypes (APF-238, APF-268, ‘Prime-Ark® 45’, and ‘Prime-Ark® Traveler’) grown at the University of Arkansas Fruit Research Station, Clarksville in 2015 and 2016. Year-to-year differences were evident as blackberries harvested in 2016 were smaller (6 g) and less acidic (0.7% titratable acidity) than berries harvested in 2015 (8 g berries with 0.9% titratable acidity); however, soluble solids in each year were similar (≈10.2%). Differences in genotypes were also a factor. ‘Prime-Ark® Traveler’ (2015) and APF-268 (2016) had the highest berry firmness (7.8–8.3 N). In both years, APF-238 had the lowest firmness (5.7–6.0 N), highest isocitric acid (0.8–1.1 g/100 g), and highest total anthocyanins (239–353 mg/100 g). Floricane fruit harvested from ‘Prime-Ark® Traveler’ had the highest berry weights (8.3–10.4 g) in both years. Blackberries harvested from primocanes were wider (21.3–22.9 mm), had higher soluble solids (11.6% to 12.6%), and had lower titratable acidity (0.6%) when compared with floricane fruit in both years. Major year-to-year differences were found for several variables in this study, indicating that environmental effects can be substantial and growers should be aware of this influence on berries harvested from the different cane types. Evaluation of quality properties of floricane and primocane fruit of primocane plants in other locations would be valuable, particularly from areas where commercial blackberry production is established.