276: Systemic Characterization of Polyphenols in 79 Blackberry Cultivars Grown Throughout Virginia

Introduction

Blackberries are a nutrient dense crop containing high amounts of polyphenols, which have been shown to have desirable health benefits including inflammation reduction, cardiovascular disease prevention, and improved cognitive function. Many blackberry cultivars are grown in Virginia and have been characterized for their agronomic qualities. However, a systematic characterization of the nutritionally beneficial polyphenols in Virginia blackberries has not been undertaken. Thus, the objective of this study is to evaluate the effects of location, harvest date, and cultivar on the phenolic profile of Virginia blackberries.

Methods

A total of 79 blackberry samples, representing 21 unique cultivars, were harvested from 9 locations across Virginia between June 2, 2023 and September 26, 2023. Forty samples were grown in a controlled experimental field, with ripe berries from 6 cultivars harvested weekly throughout the harvest season. The other 39 samples, representing 19 cultivars, were collected from 8 locations across Virginia. Harvested berries were lyophilized, powdered, and extracted using an acidified methanol-water solution. Extracted samples were characterized for total polyphenols via the Folin-Ciocalteu method (quantified as gallic acid equivalents (GAE)), total monomeric anthocyanins (TMA, quantified as cyanidin-3-O-glucoside equivalents (C3G)) via the pH differential method, and a total of 67 individual phenolics via LC-MS/MS. Linear models were used to compare total phenolics and TMA among 9 harvest weeks and 6 cultivars grown at the AREC.

Results

Total phenolics ranged from 12.85-39.44 mg GAE/g (dw) (median: 24.61), while TMA ranged from 4.07-28.58 mg C3G/g (dw) (median: 10.13). The most prevalent individual polyphenols included cyanidin 3-glucoside (2.36-11.98mg/g (dw)), ellagic acid (0.032-0.114mg/g (dw)), and epicatechin(0.013-2.73mg/g (dw)). Among cultivars grown under controlled conditions, Sweetie Pie had significantly higher concentrations of total phenolics and anthocyanins than other cultivars (p < 0.05).

Significance

Polyphenols in Virginia blackberries vary widely based on location, harvest date, and cultivar. These data will be used to help growers select high polyphenol cultivars for their farms and market them to health-conscious consumers.

Authors: Molly E Caron, Virginia B VanHook, Alicia A Surratt, Melissa Wright, Patricia Richardson, Jayesh Samtani, Dennis P Cladis