Characterization of Plum Procyanidins by Thiolytic Depolymerization

Abstract

The phenolic compounds of 'Green Gage' (GG) plums (Prunus domestica L.), "Rainha Clá udia Verde", from a 'protected designation of origin' (PDO), in Portugal, were quantified in both flesh and skin tissues of plums collected in two different orchards (GG-V and GG-C). Analyzes of phenolic compounds were also performed on another GG European plum obtained in France (GG-F) and two other French plums, 'Mirabelle' (M) and 'Golden Japan' (GJ). Thiolysis was used for the first time in the analysis of plum phenolic compounds. This methodology showed that the flesh and skin contain a large proportion of flavan-3-ols, which account, respectively, for 92 and 85% in GJ, 61 and 44% in GG-V, 62 and 48% in GG-C, 54 and 27% in M, and 45 and 37% in GG-F. Terminal units of procyanidins observed in plums are mainly (+)-catechin (54-77% of all terminal units in flesh and 57-81% in skin). The GJ plums showed a phenolic composition different from all of the others, with a lower content of chlorogenic acid isomers and the presence of A-type procyanidins as dimers and terminal residues of polymerized forms. The average degree of polymerization (DPn) of plum procyanidins was higher in the flesh (5-9 units) than in the skin (4-6 units). Procyanidin B7 was observed in the flesh of all GG plums and in the skin of the Portuguese ones. Principal component analysis of the phenolic composition of the flesh and skin of these plums obtained after thiolysis allowed their distinction according to the variety and origin, opening the possibility of the use of phenolic composition for variety/origin identification.

Comparison between microwave hydrodiffusion and pressing for plum juice extraction

“…Polyphenols were analyzed independently in the flesh and skin from 'Najbolja' fruit, with marked differences in composition as expected from Nunes et al (2008). The anthocyans and flavonols were present exclusively in the skin.…”

“…Plums were chosen for experiment as they are rich in antioxidants (Kim et al, 2003;Los et al, 2000;Nunes et al, 2008;Wang, Cao, & Prior, 1996), four times the concentration in apple (Wang et al, 1996), and the optimization of enzyme treatment for the production of plum juice was one of the aims of ISAFRUIT project.…”

Kinetics of Polyphenol Losses During Soaking and Drying of Cider Apples

“…(+)-Catechin benzylthioethers and (−)-epicatechin benzylthioethers were produced as previously described by Guyot et al (1998). Procyanidins B1, B2, and B5 were available from INRA UR117 (Le Rheu, France) and were prepared as previously described by Nunes et al (2008).…”

“…Phenolic compounds are important to the visual appearance (browning), taste (bitterness and astringency), and health-promoting properties of fresh fruits and their derived products (Nunes et al 2008). Several polyphenols have been identified in apples.…”

Anti-allergic Properties of a Fruit Extract of Prune (Prunus domestica L.) in Mite-sensitized BALB/c Mice

“…The molecular masses of procyanidin C1 and quercetin 3-glucoside are 867 and 465, respectively. Prune contains procyanidins, quercetin 3-rutinoside and quercetin 3-glucoside (Nunes et al, 2008;Slimestad et al, 2009). Therefore, the anti-allergic effect of prune extract observed in this study may be partly attributable to polyphenols, such as procyanidins, quercetin 3-rutinoside and quercetin 3-glucoside.…”