Variation in Chemical, Textural and Sensorial Traits Among Remontant Red Raspberry (Rubus idaeus L.) Cultivars Maintained in a Double-Cropping System

Remontant raspberry cultivars originally produce fruit in the upper part of primocanes in the fall, but if retained over winter, they can produce a second crop in the lower part of the floricanes the following spring. Maintaining remontant cultivars to yield twice during the cane's growth cycle corresponds to a double-cropping system, which enables an increase in the total yield and the extension of the fruiting season. To date, there is little information on changes in fruit quality between primocane and floricane crops. The aim of this study was, therefore, to investigate variations in the content of sugars and organic acids, fruit weight, color and textural and sensorial attributes among five newly introduced remontant raspberry cultivars ('Dafne', 'Kokanee', 'Paris', 'Versailles' and 'Primalba') and the control cultivar 'Enrosadira'. The specific aim was to evaluate how a double-cropping system in each cultivar may affect the variability in quality traits between primocane and floricane crops. The results showed a significant increase in fruit weight and individual and total sugar content in primocane crops, while significantly brighter red-colored and firmer fruits were observed in floricane crops. Cultivars did not differ from the control regarding total sugar content and sweetness index, while the content of individual sugars caused greater variations. The highest content of citric, malic and total acid (9.74, 1.42 and 11.25 mg 100 g^-1 FW, respectively) were recorded in 'Paris', by which this cultivar was the only one distinguished from the control. 'Dafne' and 'Versailles' exhibited better internal and external fruit quality on primocanes, having significantly larger fruits (6.83 g and 6.37 g, respectively) and twice the increased sugar content. The lowest fruit weight was observed in 'Kokanee' for both primocane (4.63 g) and floricane (3.65 g) crops. 'Kokanee' and 'Primalba' also performed worse than the control for most sensory attributes in both seasons. Based on the analysis of the overall fruit quality linked to the appearance-, texture- and taste-related attributes that affect consumer preference, cultivars 'Enrosadira', 'Versailles' and 'Dafne' stood out, while 'Paris' showed high uniformity in fruit quality between crops, but scored the worst according to the total quality index.