Quercetin and p-coumaric acid derivatives in cranberry (Vaccinium macropcarpon) fruit vary in response to cultivation practices and fruit rot-associated diseases

Cranberry (Vaccinium macrocarpon) is a popular fruit due to reported health benefits, such as antioxidant and anti-inflammatory properties, and is therefore important to the local economy, but fruit rot diseases can alter fruit production and quality. To determine the influence of infections, as well as the influence of cultivation conditions that may affect fruit response to pathogenic stress, p-coumaric acid and quercetin derivatives, which contribute to fruit quality, flavor, and health benefits, were analyzed as fruit quality markers in cranberry fruit samples. Several cultivars, including Stevens, Crimson Queen, Howes, and Early Black were sampled in the Massachusetts 2018 and 2019 growing seasons, from conventionally and organically maintained cranberry bogs, along with fruit from wild sites. Analytical methods, using a Waters UPLC-MS/MS system, were applied for the determination of the dry weight content of the fruit markers within each fruit sample. Results indicate a significant increase in p-coumaric acid derivatives, accompanied by a significant decrease in quercetin derivatives in organically grown fruit compared to conventionally grown fruit of the same cultivar for the 2018 growing season. These results were cultivar specific and varied between growing seasons. In addition, a decrease in both p-coumaric acid and quercetin derivatives was found in diseased fruit compared to healthy fruit of the same cultivar. These results were also cultivar specific with variation between growing seasons. There was also indication that quercetin derivatives could be affected to a greater extent than p-coumaric acid derivatives by both fruit rot and cultivation practices. Cultivar, growing conditions, and exposure to fruit rot disease all contribute to variation in the p-coumaricacid and quercetin derivatives content in American Cranberry fruit.