Castanea sativaMill. Flowers amongst the Most Powerful Antioxidant Matrices: A Phytochemical Approach in Decoctions and Infusions

Abstract

Infusions and decoction of chestnut tree flowers have been used for different medical purposes, but their phytochemical profile and antioxidant activity are still mostly unknown. Herein, decoctions and infusions of flowers from the two most appreciated chestnut cultivars (longal and judia) in Trás-os-Montes, Portugal, were prepared and characterized with regard to their content in free sugars, organic acids, and phenolic compounds, such as flavonoids and hydrolyzable tannins, and their antioxidant activity. Overall, the decoction of the cultivar judia was the sample with both the highest quantity of flavonoids and antioxidant activity. The phenolic compound with the highest abundance in all samples was trigalloyl-HHDP-glucoside, followed by pentagalloyl glucoside. The sample with the highest quantity of total phenolic compounds was judia infusion, closely followed by longal decoction, which also gave the highest quantities of ellagitannins. Regarding sugars and organic acids, the profiles were more similar. These results corroborate ancestral claims of the health benefits of infusions and decoctions of chestnut flowers.

Infusions and decoctions of Castanea sativa flowers as effective antitumor and antimicrobial matrices

“…While the decoctions had better effect as antibacterial agents, the infusions proved to be more effective against fungi, especially the cultivar Longal. In terms of phenolic composition, antioxidant activity and presence of organic acids, the infusions were quite poor when compared to the decoctions (Carocho et al, 2014), which means the fungicidal compounds could be sensitive to heat extraction (lower periods of heat for infusions) and other studies should be carried out with cold extractions. These results are in line with other natural plant matrices, like Laurus nobilis, which had very similar activity against the same species of fungi (Dias et al, 2014).…”

“…Our research group has been working with chestnut fruits (Carocho et al, 2012), flowers (Barros et al, 2010) and leaves, with very good results regarding antioxidant (Carocho et al, 2014) and anti-candida activity of the flowers. Recently, we have also reported the profile in phenolic compounds and antioxidant properties of flower decoctions and infusions, in which the most prevalent molecules were trigalloyl-HHDP-glucoside and pentagalloyl glucoside (Carocho et al, 2014).…”

Chestnut flowers as functionalizing agents to enhance the antioxidant properties of highly appreciated traditional pastry

“…Regarding the solvent type, due to the known toxicity of methanol, opting for aqueous extracts was a better choice, among which decoctions were reported as containing the highest amounts in phenolic compounds 3 .…”

“…The phenolic composition of C. sativa flower decoctions is known to include flavonols (quercetin, isorhamnetin, kaempferol and myricetin derivatives), hydrolysable tannins (galloyl and hexahydroxydiphenol derivatives) and flavanols ((+)-catechin) 3 , compounds that might explain the antioxidant activity observed in the final products. In Figure 1, it might be seen that, neither the exterior, nor the interior appearance, were changed by adding dried flowers (the decoctions were lighter than flowers).…”

“…Still, some of the ancient claims 2 of the benefits of the consumption of infusions and decoctions of these flowers have been recently related to their antioxidant, antimicrobial and antitumor effects 3,4 .…”