Chemical Composition and Potential Health Effects of Prunes: A Functional Food?

Abstract

Prunes are dried plums, fruits of Prunus domestica L., cultivated and propagated since ancient times. Most dried prunes are produced from cultivar d'Agen, especially in California and France, where the cultivar originated. After harvest, prune-making plums are dehydrated in hot air at 85 to 90 degrees C for 18 h, then further processed into prune juice, puree, or other prune products. This extensive literature review summarizes the current knowledge of chemical composition of prunes and their biological effects on human health. Because of their sweet flavor and well-known mild laxative effect, prunes are considered to be an epitome of functional foods, but the understanding of their mode of action is still unclear. Dried prunes contain approximately 6.1 g of dietary fiber per 100 g, while prune juice is devoid of fiber due to filtration before bottling. The laxative action of both prune and prune juice could be explained by their high sorbitol content (14.7 and 6.1 g/100 g, respectively). Prunes are good source of energy in the form of simple sugars, but do not mediate a rapid rise in blood sugar concentration, possibly because of high fiber, fructose, and sorbitol content. Prunes contain large amounts of phenolic compounds (184 mg/100 g), mainly as neochlorogenic and chlorogenic acids, which may aid in the laxative action and delay glucose absorption. Phenolic compounds in prunes had been found to inhibit human LDL oxidation in vitro, and thus might serve as preventive agents against chronic diseases, such as heart disease and cancer. Additionally, high potassium content of prunes (745 mg/100 g) might be beneficial for cardiovascular health. Dried prunes are an important source of boron, which is postulated to play a role in prevention of osteoporosis. A serving of prunes (100 g) fulfills the daily requirement for boron (2 to 3 mg). More research is needed to assess the levels of carotenoids and other phytochemicals present in prunes to ensure correct labeling and accuracy of food composition tables in order to support dietary recommendations or health claims.

Plum pomaces as a potential source of dietary fibre: composition and antioxidant properties

“…The main groups of polyphenols were proanthocyanidins, hydroxycinamic acids, quercetin glycosides and anthocyanins. The same groups of polyphenols were previously found in plum fruits (Balasundram et al 2006;Chun et al 2003;Dimitrios 2006;Nakatani et al 2000;Stacewicz-Sapuntzakis et al 2001;Tomas-Barberan et al 2001;Walkowiak-Tomczak et al 2008;Cevallos-Casals et al 2006;Donovan et al 1998;Łoś et al 2000;Usenik et al 2009;Kim et al 2003a, b).…”

“…of all sugars. High content of sorbitol in plum fruits is also attributed to mild laxative effect (Stacewicz-Sapuntzakis et al 2001). As it was found in previous research (Fastyn et al 2010) fruits of 'Promis' cultivar contained sorbitol on high level and in sensory analysis of juices 'Promis' cultivar had too violent laxative effect and therefore the cultivar should be excluded from a single variety juice production.…”

“…Malic and citric are the main organic acids (Walkowiak-Tomczak et al 2007;Usenik et al 2009). Plums are a rich source of polyphenols, there are most of all flavonols, and caffeic acid derivatives: neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid as well as anthocyans and flavonols (Balasundram et al 2006;Chun et al 2003;Dimitrios 2006;Nakatani et al 2000;Stacewicz-Sapuntzakis et al 2001;Tomas-Barberan et al 2001;Walkowiak-Tomczak et al 2008). The content of anthocyans depends on cultivar and is caused by size differences of fruits and the ratio of peel mass to flesh mass.…”

Yoghurt containing galacto-oligosaccharides, prunes and linseed reduces the severity of mild constipation in elderly subjects

“…Their efficacy in elderly subjects has been reported in a few early studies in which prunes in yoghurt (Ferrer and Boyd, 1955) or prunes with cascarin (Stern, 1966) or fibre (Hull et al, 1980) have been ingested. The laxative action of prunes could be explained by its relatively high fibre and sorbitol content (Stacewicz-Sapuntzakis et al, 2001). Prunes also contain phenolic compounds, mainly in the form of neochlorogenic and chlorogenic acids, which may aid the laxative action (Stacewicz-Sapuntzakis et al, 2001).…”

“…The laxative action of prunes could be explained by its relatively high fibre and sorbitol content (Stacewicz-Sapuntzakis et al, 2001). Prunes also contain phenolic compounds, mainly in the form of neochlorogenic and chlorogenic acids, which may aid the laxative action (Stacewicz-Sapuntzakis et al, 2001).…”