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Edible flowers are rich in bioactive compounds and pigments that are on increasing demand in nutraceutical, medicinal, food, cosmetic and dyeing industries. This study evaluated the anthocyanins, phenolics and antioxidant activity of eight edible flowers (Bellis perennis L., Centaurea cyanus L., Dianthus carthusianorum L., Lavandula angustifolia Mill., Primula vulgaris Huds., Rosa canina L., Rosa pendulina L. and Viola odorata L.) after 24 h of hot drying (50 °C; natural convection stove) or cold drying (CD) (22 °C; heat-pump drying system). The hot-dried and cold-dried materials were then used to prepare ultrasound-assisted extracts, which are used as food additives or as a source of natural colourants, or decoctions (DECs), which are used for herbal teas. The edible flower UAEs and DECs had high amounts of anthocyanins (up to 3,284.6 mg C3G · 100 g-1), phenolics (up to 9,034 mg · 100 g-1) and antioxidant activity (866 μmol TE · g-1, 4,901 mmol Fe2+ · kg-1), with roses having the highest amount. The anthocyanin content and phenolic profile (flavonols, benzoic acids, cinnamic acids and flavanols) of edible flowers are found to be affected by drying and extraction methods. For decoctions, CD was found to be the most efficient drying method for all the parameters. For UAEs, CD resulted in a higher anthocyanin content, while hot drying resulted in a higher phenolic content, particularly flavanols. Overall, the studied edible flower extracts and decoctions can contribute to healthy and coloured substances, which can be used for designing innovative natural products. Rosa pendulina and R. canina are the most promising sources.

The increasing interest in healthy and natural foods has raised the attention towards uncommon or unexplored ingredients, such as edible flowers. These products are proven to be a rich source of bioactive compounds, for example, vitamins or polyphenols that play an important role in health promotion and disease prevention. However, plant species with edible flowers are numerous and most of them still need to be studied with this aim. The high species richness of North-Western Italy provides interesting perspectives in the use of wild edible flowers, which are currently underutilized, but can be a valuable food source or food supplement for healthy diets. In this framework, the phytochemical composition of 22 wild edible flowers was analysed and compared with that of four cultivated species (Borago officinalis L., Calendula officinalis L., Tagetes patula L. and Tropaeolum majus L.) to evaluate their potentiality as sources of bioactive compounds. The total polyphenol content (TPC) and antioxidant activity of the fresh flowers were assessed, together with their phenolic profiles and vitamin C content, through spectrophotometric and chromatographic analyses. The evaluated parameters varied widely among species, with Paeonia officinalis L. and Rosa pendulina L. showing the highest values of polyphenols (1,930 mg gallic acid equivalents (GAE) · 100 g−1 and 1,774 mg GAE · 100 g−1, respectively), followed by Rosa canina L. (1,397 mg GAE · 100 g−1) and Geranium sylvaticum L. (1,268 mg GAE · 100 g−1). The same species also showed the highest antioxidant activity, measured with three different assays [ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS)]. The phenolic profile differed among the studied species, with Dianthus pavonius Tausch and R. pendulina having the highest sum of detected polyphenols (2,522 mg · 100 g−1 and 2,366 mg · 100 g−1, respectively). Vitamin C was identified in all but two flowers (Allium ursinum L. and B. officinalis) and Primula veris L. had the highest amount (45 mg · 100 g−1). The study showed that wild edible flowers outperformed the cultivated species, except for T. majus, providing new insights for the use of wild edible flowers as sources of bioactive compounds.

Lavandula angustifolia Mill. is a part of the Lamiaceae family, which includes aromatic plants used in perfumery, manufactory, food, ornamental, and medicinal sectors. Both fresh and dried lavender flowers can be exploited in different ways; however, post-harvest treatments such as drying processes can help maintain the flowers' properties for a longer period. This study analyzed fresh (F) and dried lavender flower ultrasound-assisted extracts, comparing two different drying methods, i.e., heat-pump drying (HP) and hot-air drying (HA), to assess potential differences in their effect on the phytochemical composition (total phenolic content, total anthocyanin content, and phenolic profile) and antioxidant activity (FRAP, DPPH, and ABTS assays) of flowers, focusing on three lavender selections from north-western Alps (i.e., Susa, Stura, and Tanaro). Results showed that HP-dried flowers are to be preferred over HA-dried flowers, as they contain +66.73% of phenolics and +62.2% of anthocyanins, and they have higher antioxidant activity (from 60.32% to 284.3% more according to the assay). HP-dried flowers, particularly those from the Tanaro selection, showed also higher values in the relative antioxidant capacity index (RACI) and the global antioxidant score (GAS), ranking together with the fresh flowers. Nine bioactive compounds out of thirteen were detected by means of HPLC, seven in F (caffeic acid, hyperoside, quercetin, ellagic acid, catechin, epicatechin, and dehydroascorbic acid), four in HA (ferulic acid, hyperoside, quercitrin, and epicatechin), and two in HP (caffeic acid and hyperoside). The higher temperatures used in HA probably promoted oxidative and biochemical reactions that led to the presence and increase in these compounds. However, many other phenolic compounds may contribute to the antioxidant power of lavender extracts. Overall, HP resulted in an effective and sustainable method for drying lavender flowers and may have interesting applications to obtain final products richer in bioactive compounds and antioxidant activity to be used in the functional food industry. [ABSTRACT FROM AUTHOR]

Soil fungi strongly influence ecosystem structure and functioning, playing a key role in many ecological services as decomposers, plant mutualists and pathogens. Arbuscular mycorrhizal fungi (AMF) establish mutualistic symbiotic associations with plant roots and act as biofertilizers by enhancing plant nutrients and water uptake. Information about the AMF association with Crocus sativus L. (saffron) and their impact on crop performances and spice quality has been increasing in recent years. Instead, there is still little data on the biodiversity of soil microbial communities associated with this crop in the Alpine environments. The aims of this study were to investigate the fungal communities of two Alpine experimental sites cultivated with saffron, and to rank the relative impact of two AMF inocula, applied to soil as single species (R = Rhizophagus intraradices, C.Walker & A. Schüßler) or a mixture of two species (M = R. intraradices and Funneliformis mosseae, C. Walker & A. Schüßler), on the resident fungal communities which might be influenced in their diversity and composition. We used Illumina MiSeq metabarcoding on nuclear ribosomal ITS2 region to characterize the fungal communities associated to Crocus sativus cultivation in two fields, located in the municipalities of Saint Christophe (SC) and Morgex (MG), (Aosta Valley, Italy), treated or not with AMF inocula and sampled for two consecutive years (Y1; Y2). Data analyses consistently indicated that Basidiomycota were particularly abundant in both sites and sampling years (Y1 and Y2). Significant differences in the distribution of fungal taxa assemblages at phylum and class levels between the two sites were also found. The main compositional differences consisted in significant abundance changes of OTUs belonging to Dothideomycetes and Leotiomycetes (Ascomycota), Agaricomycetes and Tremellomycetes (Basidiomycota), Mortierellomycetes and Mucoromycetes. Further differences concerned OTUs, of other classes, significantly represented only in the first or second year of sampling. Concerning Glomeromycota, the most represented genus was Claroideoglomus always detected in both sites and years. Other AMF genera such as Funneliformis, Septoglomus and Microdominikia, were retrieved only in MG site. Results highlighted that neither sites nor inoculation significantly impacted Alpine saffron-field fungal communities; instead, the year of sampling had the most appreciable influence on the resident communities. [ABSTRACT FROM AUTHOR]

Lavandula angustifolia Mill. has a great economic importance in perfumery, cosmetics, food manufacturing, aromatherapy, and pharmaceutical industry. This species finds its phytosociological optimum in the sub-Mediterranean region. Latitudinal and altitudinal gradients are expected to affect species diversification in peripheral alpine populations. In this study, phenotypic traits including morphometric parameters, volatile organic compounds (VOCs) and essential oils (EOs) were analyzed in lavender peripheral populations selected in order to explore different ecological conditions. Plants were cultivated under uniform conditions to observe variations due to the genetic adaptation to native environments and to exclude the short-term response to environmental factors. Results showed qualitatively and quantitatively intra-specific variations in secondary metabolites, mainly along the latitudinal gradient, while minor effect was attributable to the altitude. This latter affected more the morphometric parameters. As the latitude augmented, VOCs showed lower content of monoterpene hydrocarbon (mh) and higher content of oxygenated monoterpenes (om); whereas EOs showed higher content of mh and non-terpene derivatives (nt) and lower content of sesquiterpene hydrocarbons (sh). Lavender aroma and EO composition varied in every population, for a total of 88 and 104 compounds identified, respectively. Eleven and 13 compounds were responsible for 95% of the dissimilarity, with linalool, linalyl acetate and 1,8-cineole as major contributors. As the latitude augmented, linalool decreased and 1,8-cineole increased while linalyl acetate content was unaffected. These results are discussed with regards to the potential adoption of the lavender peripheral alpine populations for the improvement of quality and productivity of lavender cultivations, especially in mountainous areas. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) establish mutualistic symbiotic associations with plant roots and act as biofertilizers by enhancing plant nutrient and water uptake. Moreover, AMF colonization may influence the biosynthesis of plant bioactive compounds in medicinal and aromatic plants. There is limited information on AMF associations with Crocus sativus L. (saffron) roots and their effect on crop performances and spice quality. In the present work we verified the efficiency of root mycorrhization in potted conditions, and then we evaluated the yield and quality of the saffron produced in two Alpine sites during two cultivation cycles with the application of AMF. Two inocula were applied, either a single-species (Rhizophagus intraradices) or a multispecies mixture (R. intraradices and Funneliformis mosseae). The trial conducted in potted conditions confirmed that both AMF commercial inocula established symbiotic relationships with saffron roots. The multispecies inoculation yielded the highest content of arbuscules in colonized portions of the root (100%), while the single-species was slightly less (82.9%) and no AMF were recorded in untreated control corms. In open-field conditions, AMF colonization of the root systems, flower production, and saffron yields were monitored, and bioactive compounds contents and antioxidant activity in the dried spice were analyzed using spectrophotometry and high performance liquid chromatography. Overall, the saffron produced was high quality (ISO category) and had high contents of bioactive compounds, with very high total polyphenol content and elevated antioxidant activity. The use of arbuscular mycorrhizal symbionts as biostimulants positively affected saffron cultivation, improving the crop performances and the content of important nutraceutical compounds. In particular, the inoculum composed by R. intraradices and F. mosseae increased flower production and the saffron yield. R. intraradices alone enhanced the spice antioxidant activity and the content of bioactive compounds such as picrocrocin, crocin II, and quercitrin. Since saffron is the world's highest priced spice, the increases in yield and quality obtained using AMF suggests that farms in marginal areas such as alpine sites can increase profitability by inoculating saffron fields with arbuscular mycorrhiza. [ABSTRACT FROM AUTHOR]