Antioxidants in Fruit Fractions of Mediterranean Ancient Pear Cultivars.

BACKGROUND: The genetic diversity of Sardinian pear germplasm has received limited attention regarding its chemical composition. Understanding this composition can aid in the setting up of resilient, extensive groves that offer multiple products and ecosystem services. This research aimed at investigating the antioxidant properties and phenolic compounds of ancient pear cultivars grown extensively in Sardinia (Italy); Methods: the cultivars Buttiru, Camusina, Spadona, and Coscia (as a reference) were compared. Fruit samples were manually peeled and cut. Their flesh, peel, core, and peduncle were frozen separately, lyophilized, and milled before being analysed; Results: The content of total phenolics (TotP), total flavonoids (TotF), condensed tannins (CT), and antioxidant capacity in each fruit part varied significantly among the cultivars. The TotP content was high in the peduncle (42.2-58.8 g GAE kg-1 DM) and low in flesh (6.4-17.7 g GAE kg-1 DM); Conclusions: the highest values of antioxidant capacity, TotP, NTP, TotF, and CT were found in the flesh of the cultivar Buttiru and in the peel of the cultivar Camusina. Chlorogenic acid was the major individual phenolic compound in peel, flesh and core, whereas arbutin was mostly present in the peduncle. Results can contribute to revise target exploitations of underutilized ancient pear cultivars.

Antioxidant Contents in a Mediterranean Population of Plantago lanceolata L. Exploited for Quarry Reclamation Interventions.

Plantago lanceolata L. (plantain) is an interesting multipurpose perennial species whose aerial parts are used in herbal medicine due to its precious phytochemicals and are palatable to animals. Moreover, peculiar traits such as drought tolerance, an extended growth season and a deep root system, make plantain a promising pioneer plant for quarry reclamation based on the use of native species. This study evaluated the effects of different environmental conditions and seasons on the accumulation of the bioactive compounds of its aerial organs. An autochthonous plantain population was grown in three locations in Sardinia (Italy). Leaves, peduncles and inflorescences were collected between October 2020 and July 2021. Phenolic contents and antioxidant capacity were determined. The analysis of the individual phenolic compounds was performed using liquid chromatography. In leaves, the content of total phenolics, antioxidant capacity and total flavonoids were significantly influenced by location and season. Total phenolic content ranged from 65 to 240 g gallic acid equivalent kg-1, whereas total flavonoids were from 16 to about 89 g catechin equivalent kg-1. Neochlorogenic, chlorogenic, cryptochlorogenic acids, verbascoside, diosmin and luteolin were identified in the methanolic extracts of leaves, peduncles and inflorescences. Verbascoside was the main antioxidant isolated from plantain extracts. Results evidenced an increasing accumulation pattern of phenolics from vegetative stage to flowering, followed by a decrement towards the seed ripening as well as site-specific differences with amounts of phenolics even 25% higher for same plantain accession.

Phenolic compounds content and antioxidant capacity in cardoon achenes from different head orders.

Cardoon inflorescences (heads) contain achenes, which are used for the production of edible oil and biodiesel but also represent a phenolic source. This research aimed at determining the level of bioactive compounds and antioxidant capacity of cardoon achenes and investigating their qualitative and quantitative variations in achenes harvested from heads having different insertion order on main stem. The head order significantly affected the number of achenes per head and one thousand weight but did not affect the achene values of antioxidant capacity and concentrations of total phenolic (107.7-117.4 g gallic acid equivalent kg-1 dry weight), as well as the concentration of chlorogenic and 3,5-di-O-E-caffeoylquinic acids. Conversely, the absolute amounts of these metabolites differed significantly among head order when referred to a single achene or head. About 75% of their absolute values per cardoon plant were produced by achenes belonging to secondary and tertiary heads.

Antioxidant Sources from Leaves of Russian Dandelion.

Taraxacum kok-saghyz (TKS) is a dandelion species native to Kazakhstan, Uzbekistan and north-west China, considered as a promising alternative source of natural rubber from its roots. The aim of this study was to investigate the possible exploitation of TKS leaves, a rubber byproduct, as a source of phenolic compounds with antioxidant properties for potential applications in forage, nutraceutical and pharmacological fields. Two accessions (TKS016, TKS018) grown under Mediterranean conditions of Sardinia were evaluated at vegetative and flowering stages. The leaves of TKS018 had the highest antioxidant capacity (19.6 mmol trolox equivalent antioxidant capacity 100 g-1 ), total phenolic (106.4 g gallic acid equivalent kg-1 ), tannic phenolics (58.5 g gallic acid equivalent kg-1 ) and total flavonoid contents (22.9 g catechin equivalent kg-1 ). At both phenological stages, TKS016 showed significantly lower values than TKS018 in 1,1-diphenyl-2-picrylhydrazyl (DPPH), total phenolic and tannic phenolics. Six individual molecules were identified, namely chlorogenic, cryptochlorogenic, caffeic, sinapic, chicoric and 3,4-dimethoxycinnamic acids. Chicoric (8.53-10.68 g kg-1 DW) and chlorogenic acids (4.18-7.04 g kg-1 DW) were the most abundant. TKS leaves represent a valuable source of chicoric acid with potential application as antioxidant to be used as herbal medicine and nutrition for production of healthy food/feed.

Bioactive compounds and antioxidants from a Mediterranean garland harvested at two stages of maturity.

Chrysanthemum coronarium L. (garland) is an herbaceous plant rich in bioactive compounds. The chemical composition, bioactive compounds and antioxidant properties of a Mediterranean garland population were investigated in different organs at two phenological stages. Antioxidant capacity varied from 7.9 (vegetative) to 14.4 (flowering) mmol Trolox equivalent antioxidant capacity 100 g-1 dry weight (DW). A significant correlation between antioxidant capacity and total phenolics and total flavonoids was found at flowering stage. LC-MS/MS analysis revealed that chlorogenic acid reached a maximum of 4.7 µg g-1 DW in leaves; flowers were high in luteolin (2.37 µg g-1 DW), whereas leaves showed a remarkable content of rutin (1.78 µg g-1 DW). Results highlight differences in bioactive compound levels and antioxidant capacity related to plant stages and organs. This research provides new insights into antioxidant activities and chemistry of garland, in view of its exploitation in areas of fodder resources, functional foods and natural antioxidants.