Time of harvest affects United States-grown Aronia mitschurinii berry polyphenols, °Brix, and acidity.

The goal of this study was to determine how the date of harvest impacts the quality characteristics of Aronia mitschurinii (A. K. Skvortsov and Maitul.) "Viking" and "Galicjanka" berries. Aronia berries were collected from farms in the Midwestern and Northeastern United States over seven weeks of harvest during 2018, 2019 and 2020. The berries were analyzed for total phenol, anthocyanins, proanthocyanins, sugar, and acid. Aronia berry composition modestly deviated between each year of the study. Berries harvested in 2018 had the highest total phenols and proanthocyanidins, both increasing in content from weeks 1-5 from 15.90±3.15-19.65 mg gallic acid equivalents/g fw, a 24% increase, and 2.22±0.40-2.94 mg (+)-catechin equivalents/g fw, a 32% increase, respectively. Berries harvested in 2019 had the lowest total phenol and proanthocyanidin levels and had increasing anthocyanins until week 4. In 2020, aronia berry proanthocyanidins differed from those in 2018 by having 38% lower levels after the 4...