Anthocyanin, Carotenoid, Tocopherol, and Ellagitannin Content of Red Raspberry Cultivars Grown under Field or High Tunnel Cultivation in the Southeastern United States

Abstract

High tunnels have been widely adopted for red raspberry (Rubus idaeus) production in the United States to extend the harvest season and increase yields. In this study, effects of high tunnel production on contents of plant secondary metabolites (anthocyanins, carotenoids, tocopherols, and ellagitannins) in red raspberry fruit were determined for three fall-fruiting cultivars (Autumn Britten, Caroline, and Nantahala) grown at three locations in North Carolina under field and high tunnel cultivation systems. Cultivar was the primary contributing factor to variation in phytochemicals, with minor effects of location and production system. The anthocyanin cyanidin-3-glucoside and the carotenoids α-carotene, β-carotene, lutein, and zeaxanthin were higher in fruit produced in field compared with tunnel cultivation (P < 0.01). Accumulation of total anthocyanins and tocopherols in fruit were unaffected by high tunnel cultivation in comparison with traditional field cultivation. Carotenoid content varied by genotype and production system. ‘Autumn Britten’ and ‘Caroline’ showed no difference, but were higher than ‘Nantahala’ for α-carotene, β-carotene, 9-cis-β-carotene, and lutein + zeaxanthin (P < 0.0001). Phytochemical differences among field and tunnel produced fruit have important implications for breeding with increased nutritional value in mind, and also the understanding of the relationships of plant pigments to light and temperature.