Aronia Melanocarpa: Identification and Exploitation of Its Phenolic Components

Abstract

The phenolic components of Aronia melanocarpa were quantitatively recovered by three successive extractions with methanol. They comprise anthocyanins (mainly cyanidin glycosides) phenolic acids (chlorogenic and neochlorogenic acids) and flavonols (quercetin glycosides). Approximately 30% of the total phenolic compounds are located in the peel and the rest in the flesh and seeds. Peels contain the major part of anthocyanins (73%), while the flesh contains the major part of phenolic acids (78%). Aronia juice, rich in polyphenols, was obtained by mashing and centrifugation, while the pomace residue was dried and subjected to acidified water extraction in a fixed bed column for the recovery of residual phenolics. A yield of 22.5 mg gallic acid equivalents/g dry pomace was obtained; however, drying caused anthocyanins losses. Thus, their recovery could be increased by applying extraction on the wet pomace. The extract was encapsulated in maltodextrin and gum arabic by spray drying, with a high (>88%) encapsulation yield and efficiency for both total phenols and anthocyanins. Overall, fresh aronia fruits are a good source for the production of polyphenol-rich juice, while the residual pomace can be exploited, through water extraction and spray drying encapsulation for the production of a powder containing anthocyanins that can be used as a food or cosmetics additive.

Keywords: anthocyanins; black chokeberry; chlorogenic acid; pomace extraction; spray drying encapsulation.

Figure 1

Total phenolic content (TPC, mg GAE/g_dw) and DPPH radical scavenging capacity (AC, mg TE/g_dw) obtained by successive ultrasound assisted extractions of (A) peels and (B) flesh and seeds of A. melanocarpa with acidified methanol. GAE: gallic acid equivalents, TE: Trolox equivalents.

Figure 2

Chromatogram overlay of the first methanolic extract of aronia berries’ flesh at 520 nm, 360 nm and 320 nm.

Figure 3

Recovery of phenolic compounds through pomace fixed bed extraction, at the exit of the fixed bed (A) and in total (B). The green line represents the wash out stage, and the blue line the diffusion stage of the extraction.

Figure 4

Schematic representation of the fixed bed semi-batch extraction arrangement.