Organic acid profiles of different mushroom species were obtained by ultra-fast liquid chromatography (UFLC), by means of photodiode array detector (PDA). The chromatographic separation was achieved using a SphereClone (Phenomenex) reverse phase C 18 column using an isocratic elution with sulphuric acid (3.6 mM) at a flow rate of 0.8 mL/min. All the compounds were separated in 8 min. The method was optimized usingAgaricus bisporus sample and proved to be reproducible and accurate. Organic acid profiles were quite homogeneous for all mushroom samples; oxalic, malic and fumaric acids were the main organic acids; some samples also presented quinic and citric acids.Sarcondon imbricatus was the species that presented the highest total content (254.09 mg/g dw), while Bovista nigrescens presented the lowest concentration (1.33 mg/g dw). The high amounts of organic acids present in all the species may suggest that they could be related to the antioxidant activity found in these species and previously reported by us.

Cornflower is a flowering weed and ornamental plant whose blue flowers have been used for food, decorative and colouring purposes. In this study, the upper (edible flowers) and lower (non-edible receptacle and involucre) parts of the capitulum were studied and compared for their chemical composition and bioactive properties. The flowers were richer in tocopherols, organic acids, and apigenin derivatives (mainly apigenin-7-O-glucuronide-4′-O-(6-O-malonylglucoside)) than the non-edible bristly part (where syringic acid predominated). Four cyanidin derivatives were identified in the flowers. The extract of the non-edible part was more efficient in inhibiting the formation of thiobarbituric acid reactive substances (TBARS), the bleaching of β-carotene, and the haemolysis of the erythrocytes membrane. In general, the extracts were more active against Gram-positive bacteria and had no cytotoxicity against non-tumour liver PLP2 cells. Therefore, while flowers are a potential source of natural cyanidin-based colorants, the lower part of the capitulum has bioactive properties to be exploited in different food or pharmaceutical formulations.

Analysis of organic acids has become increasingly important due to their role in the physiological activity of plants, and many separation methods have been developed for the simultaneous determination of these compounds in plant samples. Herein, ultra fast liquid chromatography and photodiode array detection (UFLC-PDA) was applied to the analysis of organic acids in young shoots, leaves, aerial parts and flowering shoots, as well as in flowers and fruits, of thirty five plant species, according to their traditional use. The studied plants were divided in three groups: traditionally cultivated food plants, wild edible plants and wild medicinal plants.Most of the species were characterized for the first time. Among all the analysed species, Rumex acetosella leaves and aerial parts revealed the highest content of total organic acids.Overall, the organic acids found in the studied plant species make them suitable to be used as food additives such as antioxidants (e.g. ascorbic acid) or acidulants (e.g. citric and malic acids).

Lovage is a source of nutrients, volatiles and bioactive compounds, and its extracts exhibit interesting antioxidant potential and bacteriostatic activity against several Gram-positive and Gram-negative bacteria.

Due to its coloration, the fig (Ficus carica L.) peel, a by-product of fruit processing and/or consumption, is a potential source of anthocyanin compounds. In the present study different extraction techniques (heat, ultrasound, and microwave) were compared aiming to recover the anthocyanin pigments and optimize its extraction conditions. A response surface methodology tool with three factors and five levels for each factor was used according to a circumscribed central composite design. The variables tested for the heat and microwave extraction methods were time, temperature, and solvent proportion (ethanol/water ratio), meanwhile, for the ultrasound method, the variables tested were the ultrasonic power, time, and solvent proportion. The anthocyanin composition of the extract was determined by HPLC-DAD-ESI/MS, and the used criteria responses were: i) quantification of cyanidin 3-rutinoside (C) in the extracted residue (mg C/g R) and in the dried peel (mg C/g P dw), and the extraction yield of the obtained residue (g R/g P dw). Ultrasound extraction was the most effective method, yielding 3.82 mg C/g R at the optimal global extraction conditions (21 min, 310 W, and 100% of ethanol). Additionally, the solid-to-liquid ratio effect was studied at the optimal conditions, using a dose-response format, in view of its plausible transference to industrial level. For the ultrasound method, an increased non-linear relationship was observed for concentrations in the range 5 to 200 g/L, being the optimal solution close to 150 g/L. In brief, the obtained results show the potential of fig peels as a source of anthocyanin pigments, with potential uses in various industrial fields, such as food, pharmaceutical, and cosmetic.

Centaurea raphanina subsp. mixta (DC.) Runemark is a wild edible species endemic to Greece. This study evaluated the chemical composition and bioactive properties of wild and cultivated C. raphanina subsp. mixta plants. Wild plants had higher nutritional value than cultivated ones, whereas cultivated plants contained more tocopherols. Glucose and sucrose were higher in cultivated plants and trehalose in wild ones. Oxalic and total organic acids were detected in higher amounts in cultivated samples. The main fatty acids were α-linolenic, linoleic and palmitic acid, while wild plants were richer in polyunsaturated fatty acids. Two pinocembrin derivatives were the main phenolic compounds being detected in higher amounts in wild plants. Regarding the antioxidant activity, wild and cultivated plants were more effective in the oxidative haemolysis (OxHLIA) and thiobarbituric acid reactive substances (TBARS) assays, respectively. Moreover, both extracts showed moderate cytotoxicity in non-tumor cell lines (PLP2), while cultivated plants were more effective against cervical carcinoma (HeLa), breast carcinoma (MCF-7) and non-small lung cancer (NCI-H460) cell lines. Finally, wild plants showed higher antimicrobial activity than cultivated plants against specific pathogens. In conclusion, the cultivation of C. raphanina subsp. mixta showed promising results in terms of tocopherols content and antiproliferative effects, however further research is needed to decrease oxalic acid content.

In the present study, the nutritional value of the edible parts (immature capitula) of cardoon plants was evaluated, while further analyses were carried out in order to assess antioxidant properties and phenolic compounds composition of the various plant parts and seed oils. Cardoon capitula (heads) were a rich source of carbohydrates, with the main detected free sugar being sucrose, as well as of macro- and micro-minerals (K, Ca, Mg, and Fe). Heads were also abundant in saturated fatty acids (palmitic, behenic, linoleic, stearic, caproic, and oleic acid), whereas seed oils in unsaturated fatty acids (linoleic, oleic, palmitic, and stearic acid). Total phenolic compounds (TPC) content and phenolics composition differed between the various plant parts, with heads and leaf blades having higher TPC than midribs and petioles. Moreover, heads and leaf midribs and petioles consisted mainly of phenolic acids (5-O-caffeoylquinic and 3,5-O-dicaffeoylquinic acid), with flavonoids being detected in lower amounts. In contrast, the composition of polyphenols in leaf blades consisted mostly of flavonoids (Luteolin-7-O-glucoside and luteolin-7-O-malonylhexoside), whereas phenolic acids were also detected in considerable amounts (5-O-feruloylquinic and 3-O-caffeoylquinic acid). Regarding antioxidant properties, leaf blades and seeds exhibited the highest potency for all the tested assays which could be partly attributed to the synergistic effects of the phenolic compounds present in each sample. In conclusion, cardoon plant parts may find various uses in the food and pharmaceutical industry, since they contain considerable amounts of bioactive molecules, while seed oils can be considered as alternative vegetable oils for human consumption.

Cynara scolymus (artichoke), Silybum marianum (milk thistle) and Cochlospermum angolensis (borututu) are three plants widely used regarding hepatoprotective effects but to the best of our knowledge no anti-hepatocellular carcinoma activity has been studied in the most consumed forms: infusions and dietary supplements. Herein, antioxidant properties, anti-hepatocellular carcinoma activity and toxicity of infusions and dietary supplements of the mentioned plants were evaluated and compared. All the samples revealed antioxidant properties with EC 50 values lower than the daily recommended dose, but infusions showed higher biological activity than dietary supplements.Borututu infusion gave the highest antioxidant activity (EC 50 ≤170 µg/mL), and also revealed anti-hepatocellular carcinoma activity (GI 50 =146 µg/mL) without toxicity in non-tumour liver cells (GI 50 >400 µg/mL). Artichoke infusion also presented antitumour activity (GI 50 =52 µg/mL) but with toxicity for normal cells at a higher concentration (GI 50 =72 µg/mL). The antioxidant and antitumour properties were positively correlated with phenolics and flavonoids content. Overall, among the three studied species, borututu infusion proved to be the most complete sample regarding antioxidant and antihepatocellular carcinoma activity.