Characterization and Preservation of Edible Flowers Fresh Characterization and Preservation of Edible Flowers Luana Fernandesa,b,c, Elsa Ramalhosaa, José A. Pereiraa, Susana Casalb, Jorge A. Saraivac aCIMO-Instituto Politécnico de Bragança, Escola Superior Agrária, Bragança, Portugal.; bLAQV@REQUIMTE-Laboratório de Bromatologia e Hidrologia, FFUP, Porto, Portugal; cQOPNA- Departamento de Química, Universidade de Aveiro, Aveiro, Portugal. 1. Edible flowers: nutritional, antioxidant, antimicrobial properties and effects on human health NUTRITIONAL Few studies have been carried out on the nutritional composition of edible flowers (Figure 1), but most of them reported that the content of common components is not different from the composition of other plant organs. Water: the main constituent, varying between 70 and 95% . Carbohydrates: the most abundant macronutrient in edible flowers, ranging between 42.4 and 90.2 g/100 g dry weight for Erythrina caribaea and Rosa micrantha, respectively, followed by the other parameters (proteins, ash and lipids). Fibers: between 6.1 and 55.4 g/ 100 g dry weight was observed for Alium schoenoprasum and Spilanthes oleracea/Tagetes erecta, respectively. Lipids: between 1.3 to 6.1 g/100 g dry weight for R. micrantha (petals) and Madhuca indica, respectively. Minerals (ash): the components with the highest variability on the total content (varying between 2.6 and 15.9 g/100 g dry weight), as well as individually. Potassium, phosphorus, calcium and magnesium are the major components. Furthermore, edible flowers are richer in potassium than in sodium, which is of benefit for cardiovascular diseases prevention. Figure 1- Examples of edible flowers ANTIOXIDANT PROPERTIES ANTIMICROBIAL PROPERTIES A substantial number of studies have been made on the antioxidant activity and bioactive compounds of edible flowers. Several studies have been performed such as: Inhibitory effect against: Staphylococcus aureus, Shigella flexneri, Salmonella typhi, Escherichia coli and Vibrio cholera Anthocyanidins: cyanidin, delphinidin and pelargonidin Flavonols: quercetin, kaempferol, myricetin and rutin Flavones: apigenin and luteolin, Flavan-3-ols:catechins and epicatechins Methanolic extracts of Sesbania grandiflora Antioxidant activity methods DPPH, ABTS, ORAC, FRAP Bioactive compounds Flavonoids Phenolic compounds Micrococcus luteus (strongest activity), E. coli (lowest activity) and Candida (moderate activity) Tamarix gallica Staphylococcus epidermidis, S. aureus, Bacillus subtilis, M. luteus, E. coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis, Candida albicans and C. parapsilosis Methanolic extracts of Rose rugosa Streptococcus mutans and Streptococcus sanguinis Hydroxybenzoic acids: vanillic, chlorogenic, protocatechuic and syringic Hydroxycinnamic acids: ferulic, caffeic and p-coumaric Methanolic extracts of Jasmium sambac EFFECTS ON HUMAN HEALTH Lipid peroxidation inhibition (e.g. Rosa rugosa, Chrysanthemum morifolium) Anti-inflammatory properties (e.g. Hibiscus, Chrysanthemum indicum) Cell proliferation inibition (treatment and prevent tumors diseases) (e.g. Hibiscus on liver cancer; Chrysanthemum on human colon and brain cancers) Fernandes, L., Casal, S., Pereira, J.A., Saraiva, J., Ramalhosa, E. (2017). Edible flowers: A review of the nutritional, antioxidant, antimicrobial properties and effects on human health. Journal of Food Composition and Analysis, 60, 38-50. 3. Effect of high hydrostatic pressure (HHP) on the quality of four edible flowers: Viola × wittrockiana, Centaurea cyanus, Borago officinalis and Camellia japonica 2. Effect of High Hydrostatic Pressure (HHP) treatment on edible flowers’ properties Fernandes, L., Casal, S., Pereira, J.A., Pereira, E., Ramalhosa, E., Saraiva, J., (2017). Effect of high hydrostatic pressure (HHP) on the quality of four edible flowers: Viola × wittrockiana, Centaurea cyanus, Borago officinalis and Camellia japonica. International Journal of Food Science & Technology: In press. (http://dx.doi.org/10.1111/ijfs.13530) Fernandes, L., Casal, S., Pereira, J.A., Ramalhosa, E., Saraiva, J. (2017). Effect of High Hydrostatic Pressure (HHP) treatment on edible flowers’ properties. Food and Bioprocess Tecnhology, 10(5), 799-807. (http://dx.doi.org/10.1007/s11947-017-1887-2). Acknowledgments:The authors acknowledge the Portuguese Foundation for Science and Technology (FCT, Portugal) for the financial support provided by the research grant SFRH/BD/95853/2013 and FCT/MEC for the financial support to QOPNA research Unit (FCT UID/QUI/00062/2013), through national funds and where applicable co-financed by the FEDER, within the PT2020 Partnership Agreement, CIMO through the Project PEst-OE/AGR/UI0690/2014 and REQUIMTE through the Project PEst/UID/QUI/50006/2013 and “Project NORTE-07-0124-FEDER-000069”.