Flavanol–anthocyanin condensed pigments in plant extracts

Abstract

Pigments resulting from the direct condensation of anthocyanins and flavanols are usually associated with reactions taking place during processing and storage of plant-derived foods and beverages and have been particularly studied in aged red wines. In this paper, small amounts of flavanol-anthocyanin condensed pigments are found in different plant extracts. Structures are suggested for 10 such condensed pigments detected in extracts of strawberry, runner beans, purple corn and grape skins, based on their MS n fragmentation patterns, following analyses by electrospray tandem mass spectrometry. All of them correspond to dimers containing a flavan-3-ol [either (epi)afzelechin, (epi)catechin or (epi)gallocatechin] as the upper unit carbon-carbon linked to a lower anthocyanin unit consisting of different delphinidin, cyanidin, pelargonidin, peonidin or malvidin derivatives. The detection of these pigments in plant extracts may suggest that they are natural pigments and not products exclusively formed during storage and ageing of processed foods and beverages, as was previously assumed.

Anthocyanin pigments in strawberry

“…That was the first evidence of the occurrence in a natural plant source of this type of condensed pigments, whose formation was associated to reactions taking place during maturation and ageing of red wines (Jurd, 1969;Salas et al, 2004;Somers, 1971; Vivar-Quintana, Santos-Buelga, Francia-Aricha, & Rivas-Gonzalo, 1999). Further evidence about the presence of anthocyanin-flavanol condensed pigments in strawberry fruits and other plants has also been recently contributed by our group (Gonza´lez-Parama´s et al, 2005).…”

“…Compound 4 (i.e. (epi)afzelechin-(4-8)-Pg 3-rut) was not reported by those authors, but firstly described by our group (Gonza´lez-Parama´s et al, 2005).…”

New Materials Derived from Heterocyclic Systems

“…Several examples of anthocyanidins are present in nature such as the brilliant red pelargonidin (5), responsible for the color of geranium petals [4], and the crimson cyanidin (6) found in apples [5] and raspberries [6]. Other examples are blue to dark purple delphinidin (7), which colorizes some types of grapes [7], and dark purple malvidin (8) as the main pigment of red wines (Figure 27.3) [8]. A combination of different anthocyanidins results in a wide range of colors in flowers such as tulips [9].…”

Anthocyanin Recovery from Mangosteen (Garcinia mangostana L.) Hull using Lime Juice Acidified Aqueous Methanol Solvent Extraction

“…The latter protocol is more commonly used by researchers probably due to it being simple, fast and effective. It involves maceration or soaking of plant material in methanol containing a small concentration of mineral acid such as hydrochloric acid (HCl) (Burin et al, 2011;Du and Francis, 1977;González-Paramás et al, 2006;Koh et al, 2011;Palapol et of the mangosteen fruits change from green to purple black as they ripen (Du and Francis, 1977;Palapol et al, 2009). The preparation of dried mangosteen hull was as described by Cheok et al (2012) where small pieces of mangosteen hulls were dried under a fan at an ambient temperature of 28℃ for at least two days to achieve a moisture loss of about 48.5% from the initial weights measured.…”

“…Although the use of a HCl acidified extraction solvent enhances the anthocyanin yield, it may result in pigment degradation, as noted by a few researchers during the evaporation process to concentrate crude extracts for analytical needs (Froehlicher et al, 2009;Garzón and Wrolstad, 2009;González-Paramás et al, 2006). Hence, in reducing pigment degradation, weaker organic acids, namely acetic acid (Kirakosyan et al, 2009;Özgen et al, 2009), formic acid (Sun et al, 2009), and trifluoroacetic acid (Baublis et al,1994) have been tried.…”