Changes in pomegranate juice pigmentation during ripening

Abstract

Six anthocyanin pigments were found to be responsible for the red colour of pomegranate juice (cv 'Mollar'). These were analysed quantitatively and qualitatively by HPLC and identified as delphinidin 3-glucoside and 33-diglucoside, cyanidin 3-glucoside and 3,5-diglucoside and pelargonidin 3-glucoside and 3,5-diglucoside. The fruit skin contained only the cyanidin and pelargonidin derivatives. Generally, there is an increase in juice pigmentation with fruit ripening. During early maturation stages the 3,5-diglucosides were the main pigments and the delphinidin-based derivatives were the predominant compounds. In late maturation stages the proportion of monoglucosides increased to reach values similar to or higher than those of the diglucosides, and the cyanidinbased derivatives were the predominant substances. The concentration of pigments in juice obtained from mature pomegranates ranged between 50 and 100 pg of anthocyanin per gram fresh weight of arils. The development of anthocyanins was also tested in fruits produced in two different orchards, and in fruits from different locations in the tree. Red coloured fruits, located in the outer parts of the tree, and yellow fruits, on the inner branches, were analysed. The juices obtained with the seed coats of both fruit types, and from the two orchards selected, showed the same anthocyanin profile. However, the total amount of pigments in the juice was generally smaller in those fruits with reddish skins (outer fruits), than in those with yellow skins (inner fruits). As juice pigmentation is one important quality factor in pomegranate, these results could be used in on-line determinations of the pomegranate quality by non-destructive physical methods.

Thermal Post Harvest Treatments for Improving Pomegranate Fruit Quality and Shelf Life

“…The increasing of anthocyanin concentration after harvest was reported previously in pomegranates (Gill et al, 1995 andHolcroft et al, 1998) and that was correlated with the activity of the enzymes of the anthocyanin biosynthetic pathway. …”

Salinity effects on colour and health traits in the pomegranate (Punica granatum L.) fruit peel

“…Our results indicate that salinity markedly affects the accumulation and composition of anthocyanins and non-pigment phenolics, as well as the antioxidative capacity, in the fruit peels, thus influencing the two commercially most important traits of the pomegranate fruit, i.e., the internal red colour intensity (Gil et al, 1995a(Gil et al, , 1995bHernandez et al, 1999) and the health potential (Gil et al, 2000;Murthy et al, 2002;Seeram et al, 2004;Seeram et al, 2005aSeeram et al, , 2005b.…”

“…The anthocyanins detected in 'Wonderful' and 'SP-2' fruit peels, i.e., mono-and di-glucosides of cyanidins, pelargonidins and delphinidins, are typical to pomegranates (Du et al, 1975;Gil et al, 1995a;Noda et al, 2002;Fischer et al, 2011). Salinity affected the peel anthocyanin composition, thereby influencing the external colour hue of the fruit.…”

“…Other important constituents are present in smaller amounts and include anthocyanins, gallic acid and gallotannins, and flavonols (mostly kaempferol derivatives). The anthocyanins convey the red colour to the fruit (Gil et al, 1995a(Gil et al, , 1995bHernandez et al, 1999). Six pigments particularly characteristic to pomegranate are the 3-mono-and 3,5-diglucosides of cyanidin, delphinidin and pelargonidin (Du et al, 1975;Gil et al, 1995a;Noda et al, 2002;Fischer et al, 2011).…”

Influence of storage temperature and duration on postharvest physico-chemical and mechanical properties of pomegranate fruit and arils

“…The intense coloration was evident by increases in the CIE a* and C* values as well as by decrease in the h°. The increase in C* values could be as a result of biosynthesis and accumulation of anthocyanin pigments in the peel, resulting in intense red coloration (Gil, García-Viguera, Artés, & Tomás-Barberán, 1995). However, fruit external appearance deteriorated after 3 months up till the end of the storage trials (5 months), possibly as a result of breakdown or browning of the husk.…”