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Aronia is a group of deciduous fruiting shrubs, of the Rosaceae family, native to eastern North America. Interest in Aronia has increased because of the high levels of dietary antioxidants in Aronia fruits. Using Illumina RNA-seq transcriptome analysis, this study investigates the molecular mechanisms of polyphenol biosynthesis during Aronia fruit development. Six A. melanocarpa (diploid) accessions were collected at four fruit developmental stages. De novo assembly was performed with 341 million clean reads from 24 samples and assembled into 90,008 transcripts with an average length of 801 bp. The transcriptome had 96.1% complete according to Benchmarking Universal Single-Copy Orthologs (BUSCOs). The differentially expressed genes (DEGs) were identified in flavonoid biosynthetic and metabolic processes, pigment biosynthesis, carbohydrate metabolic processes, and polysaccharide metabolic processes based on significant Gene Ontology (GO) biological terms. The expression of ten anthocyanin biosynthetic genes showed significant up-regulation during fruit development according to the transcriptomic data, which was further confirmed using qRT-PCR expression analyses. Additionally, transcription factor genes were identified among the DEGs. Using a transient expression assay, we confirmed that AmMYB10 induces anthocyanin biosynthesis. The de novo transcriptome data provides a valuable resource for the understanding the molecular mechanisms of fruit anthocyanin biosynthesis in Aronia and species of the Rosaceae family., (© 2022. The Author(s).)

Interest in nutrient-rich berry juices is growing, but their high polyphenol levels render them sensorily unappealing. Fifty adults, who were assessed for sensory phenotype and dietary behaviors, provided sensory and palatability ratings of juices from 'Viking' aronia berries for each of seven harvest weeks. By peak harvest, juice preference increased two-fold, averaging neither like/dislike. This hedonic shift was associated with: increases in juice sugars paralleling increases in perceived sweetness (maximum = weak); reductions in percent acidity paralleling reductions in sourness (minimum = moderate), astringency (minimum = to just above weak) and bitterness (minimum = just below weak). About 25% of adults liked the aronia juice, including adults who also liked an aqueous citric acid solution (average rating = moderately sour) or those who reported adventurous eating behaviors. Bitter taste phenotype, measured by propylthiouracil or quinine bitterness, failed to explain significant variation in juice sensation or preference. We also collected sensory and preference ratings from juice collected at peak harvest blended with sugar and/or sweet olfactory flavoring (10 ppm ethyl butyrate). Increasing juice sweetness by adding 5% sucrose decreased sourness and improved preference from weak dislike to weak like. Adding sweet olfactory flavoring decreased juice sourness without changing preference. Adding sweet flavoring and 3% sucrose resulted in reduction of sourness and improvements in preference ratings comparable to 5% added sucrose. Neither added sugar nor flavoring blocked juice astringency. In summary, these findings suggest that aronia juice, even from berries picked at peak harvest, appealed to only a few adults (sour likers or adventurous eaters). Although enhanced sweetness, with added sugar and sweet olfactory flavoring, improved aronia juice preference, broader sensory approaches are required to blunt astringency for greater consumer appeal., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

The goal of this work was to characterize how the date of harvest of 'Viking' aronia berry impacts juice pigmentation, sugars, and antioxidant activity. Aronia juice anthocyanins doubled at the fifth week of the harvest, and then decreased. Juice hydroxycinnamic acids decreased 33% from the first week, while proanthocyanidins increased 64%. Juice fructose and glucose plateaued at the fourth week, but sorbitol increased 40% to the seventh harvest week. Aronia juice pigment density increased due to anthocyanin concentration, and polyphenol copigmentation did not significantly affect juice pigmentation. Anthocyanin stability at pH 4.5 was similar between weeks. However, addition of quercetin, sorbitol, and chlorogenic acid to aronia anthocyanins inhibited pH-induced loss of color. Sorbitol and citric acid may be partially responsible for weekly variation in antioxidant activity, as addition of these agents inhibited DPPH scavenging 13-30%. Thus, aronia polyphenol and non-polyphenol components contribute to its colorant and antioxidant functionality., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Polyphenols from underutilized black, purple, and red aronia (Aronia melanocarpa, Aronia prunifolia, and Aronia arbutifolia) and 'Viking' (Aronia mitschurinii) berries were characterized. Anthocyanin and nonanthocyanin flavonoids were quantitated by UHPLC-DAD-MS and proanthocyanidins by normal-phase HPLC. On a dry weight basis, anthocyanins were mainly cyanidin-3-galactoside, highest in black aronia (3.4-14.8 mg/g) and lowest in red aronia (0.5-0.8 mg/g) as cyandin-3-galactoside equivalents. Berries from 'Viking' and the red accession UC021 had substantially more proanthocyanidins than the other accessions, with 3.3 and 3.8 mg catechin equiv/g, respectively. Chlorogenic acids and quercetin glycosides were most abundant in purple UC047 berries, at 17.3 and 1.3 mg/g, respectively. In contrast to anthocyanin content, total phenol values were highest in berries from red and purple accessions and attributed to phenolic acid and proanthocyanin content. Thus, red, purple, and black aronia berries are rich sources of polyphenols with various levels of polyphenol classes.