Screening for Innovative Sources of Carotenoids and Phenolic Antioxidants among Flowers

Wild Edible Flowers of Indian Himalayan Region, Their Traditional Uses and Potential Health Benefits: A Way Forward for Food and Nutritional Security

Wild edible flowers (WEFs) have long been an integral part of the diets and cultures of various communities worldwide. WEFs have untapped potential for use in human diets as food, supplements, or additives. These flowers contain compounds like flavonoids, carotenoids, nutrients, and minerals that contribute to their health-promoting properties. The Indian Himalayan Region (IHR), known for its biodiversity, hosts a wide array of underutilized WEFs with significant potential as food sources. Indigenous communities have long recognized the nutritional and medicinal benefits of these flowers, incorporating them into traditional medicine and culinary practices. However, systematic research on the nutritional and phytochemical properties of WEFs in this region remains limited. Therefore, gaining novel insights into the nutraceutical compounds of these flowers is crucial, highlighting their significance in promoting consumption. This review article focuses on the nutritional and phytochemical profiles of WEFs and their associated health benefits.The review also addresses the issue of toxicity in wildflowers, as well as various limitations on their consumption. Additionally, it explores the traditional and contemporary uses of these flowers in the IHR, highlighting the importance of preserving traditional knowledge and biodiversity.

Bioactive Composition of Tropical Flowers and Their Antioxidant and Antimicrobial Properties

This study evaluated tropical flower petals' bioactive compounds and antioxidant and antimicrobial properties. The physicochemical characteristics, carotenoids, phenolics, anthocyanins, organic acids, and antioxidant activity of 67 flowers were analyzed. In addition, the antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus mutans, Candida albicans, and Candida tropicalis of 35 species was determined. A 2 × 3 experimental design was used for the extraction of carotenoids and phenolics, including solvents and ultrasonic agitation times. The mixture of methanol-acetone-dichloromethane (1:1:2) and acetone-methanol (2:1) resulted in the highest concentration of carotenoids, while acidified 80% methanol favoured phenolic extraction. Renealmia alpinia was extremely rich in carotenoids (292.5 mg β-carotene/g DW), Pleroma heteromallum in anthocyanins (7.35 mg C-3-gl/g DW), while a high content of citric acid was found in Hibiscus rosa-sinensis (17,819 mg/100 g DW). On the other hand, Thibaudia floribunda showed the highest antioxidant activity (7.8 mmol Trolox equivalent/g DW). The main phenolics were m-coumaric acid in Acalypha poiretii (12,044 mg/100 g DW), 4-hydroxybenzoic acid in Brugmansia arborea (10,729 mg/100 g DW), and kaempferol in Dahlia pinnata (8236 mg/100 g DW). The extract of Acalypha poiretii, Brownea macrophylla, and Cavendishia nobilis showed antibacterial activity, while the extract of Pleroma heteromallum was the only one active against Candida albicans. These findings highlight the potential health benefits from certain tropical flowers.

Functional, Antioxidant, Antibacterial, and Antifungal Activity of Edible Flowers

Edible flowers have been used since ancient times, but their potential for improving human health has not been explored. This study aimed to evaluate the profile of bioactive compounds (organic acids, phenolics, and carotenoids) and the antioxidant and antimicrobial activity of nine flower varieties with high concentrations of carotenoids or total phenolic compounds. Ninety-three edible flowers were analysed for physicochemical characteristics, total phenolic and carotenoid concentrations, and antioxidant activity (ABTS). Bioactive profiles were determined by rapid resolution liquid chromatography (RRLC), and antimicrobial activity was determined against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Streptococcus mutans, and Candida albicans and Candida tropicalis. Chrysanthemum x hybrid orange, Helianthus annuus yellow, Tagetes patula orange, Canna indica red, and Hibiscus rosa-sinensis (orange1 and yellow) showed significant concentrations of total carotenoids. In contrast, Pelargonium hortorum orange2, Hibiscus rosa-sinensis red1, and Rosa x hybrid variety medium yellow showed high levels of total phenolics. The predominant compounds in these species were citric acid (991.4 mg/g DW in Hibiscus rosa-sinensis red1), 4-hydroxybenzoic acid (936.2 mg/100 g DW in P. hortorum orange2), kaempferol (971. 9 mg/100 g DW in T. patula orange), quercetin glucoside (958.8 in C. x hybrid), quercetin (919.3 mg/100 g DW in T. patula), α-carotene, and β-carotene in T. patula orange (989.5 and 601.2 mg/100 g DW, respectively). Regarding antimicrobial activity, T. patula orange and P. hortorum orange2 inhibited bacterial growth, while C. x hybrid orange and P. hortorum orange2 inhibited Candida albicans, and the latter inhibited Candida tropicalis. These results indicate the potential of edible flowers as a natural source of bioactive compounds and as a tool in the fight against antimicrobial resistance.

Bioactive Compound Profiling and Antioxidant Activity of Phytelephas tenuicaulis and Other Amazonian Fruits

The Amazon region is home to many plant species, many of which have not been studied. The objective was to evaluate the physicochemical properties, bioactive compounds, and antioxidant activity of Phytelephas tenuicalis (tintiuk), Grias neuberthii (apai), Euterpe oleracea (acai), and Mauritia flexuosa (brown moriche). Physicochemical analyses were carried out on fresh fruit from local markets. Bioactive compounds (carotenoids, phenolics, vitamin C, and organic acids) were quantified in the freeze-dried pulp by rapid-resolution liquid chromatography (RRLC), and antioxidant activity was determined by ABTS and DPPH assays. The results showed high soluble solids (10.7 °Brix) and ascorbic acid (67.3 mg/100 g DW) in tintiuk; β-carotene (63.4 mg/100 g DW) and malic acid (19.6 g/100 g DW) in brown moriche; quercetin (944.2 mg/100 g DW) and antioxidant activity by ABTS (6.7 mmol ET/100 g DW) in apai; and citric acid (2.1 g/100 g DW) in acai. These results indicate interesting bioactive properties that could increase the consumption of these fruits nationally and internationally, benefiting local farmers and stimulating the development of new products in functional food, medicine, and cosmetics.

Exploring Plants with Flowers: From Therapeutic Nutritional Benefits to Innovative Sustainable Uses

Flowers have played a significant role in society, focusing on their aesthetic value rather than their food potential. This study's goal was to look into flowering plants for everything from health benefits to other possible applications. This review presents detailed information on 119 species of flowers with agri-food and health relevance. Data were collected on their family, species, common name, commonly used plant part, bioremediation applications, main chemical compounds, medicinal and gastronomic uses, and concentration of bioactive compounds such as carotenoids and phenolic compounds. In this respect, 87% of the floral species studied contain some toxic compounds, sometimes making them inedible, but specific molecules from these species have been used in medicine. Seventy-six percent can be consumed in low doses by infusion. In addition, 97% of the species studied are reported to have medicinal uses (32% immune system), and 63% could be used in the bioremediation of contaminated environments. Significantly, more than 50% of the species were only analysed for total concentrations of carotenoids and phenolic compounds, indicating a significant gap in identifying specific molecules of these bioactive compounds. These potential sources of bioactive compounds could transform the health and nutraceutical industries, offering innovative approaches to combat oxidative stress and promote optimal well-being.

Functional and Antioxidant Evaluation of Two Ecotypes of Control and Grafted Tree Tomato (Solanum betaceum) at Different Altitudes

Tree tomato (Solanum betaceum) is susceptible to nematode attack; for this reason, grafting is used as an alternative to reduce this impact. In this study, the bioactive compounds of the fruit (shell, pulp, and seed jelly) of two tree tomato ecotypes ('giant orange' and 'giant purple') were evaluated in both control and grafted plants grown at different altitudes (2010-2250, 2260-2500, 2510-2750 and 2760-3000 masl). Commercial quality, vitamin C, organic acids, phenolics, carotenoids and antioxidant activity were determined by microextraction and quantified by liquid chromatography (RRLC) or spectrophotometry (microplate reader). The results showed high concentrations of vitamin C, organic acids and antioxidant activity in the seed jelly, organic acids in the pulp and phenolic compounds, carotenoids, and antioxidant activity in the shell. The main phenolics were ferulic acid, caffeic acid and luteolin, while the main carotenoids were lutein, B-cryptoxanthin and B-carotene. Multivariate analysis showed that tree tomato quality was mainly influenced by altitude and fruit part and that grafting positively affected soluble solids for both ecotypes and all altitudes.

Physicochemical characteristics and antioxidant capacity of Ecuadorian paramo flowers

Ecuador is a megadiverse country with a wide variety of floral species that have been little studied. In this context, the study's objective was to evaluate the physicochemical characteristics and the antioxidant activity of several floral species of paramo of Pichincha Province in Ecuador. Thus, the weight, size, color, pH, soluble solids, moisture and ash of fresh flower was quantified. In addition, carotenoids, phenolic compounds and antioxidant activity were quantified in lyophilized powder. The results obtained showed that the flowers of Werneria nubigena were the longest (43,80 cm); Brugmansia x candida the widest (9,88cm) and heaviest (9,22g); Tristerix longebracteatus presented high soluble solids content (21,5 °Brix), Lupinus microphyllus high pH (14,00), Ceanothus maritimus high titratable acidity (0,26%), Castilleja integrifolia high ash content (6,42%) and Bidens ferulifolia high moisture content (95,73%). In addition, the highest ranges of total carotenoids and total phenolics were presented by yellow Bidens ferulifolia (24,81 µg β-carotene/g PS) and Fuchsia vulcania (531,77 mg EAG /g PS), respectively. Finally, it was found in Bomarea multiflora high values of antioxidant capacity (182,08 trolox eq. µmol/ g PS). These results suggest that the paramo flowers contain essential bioactive compounds that could be used for food, medicinal and cosmetic purposes. Keywords: Bioactive compounds, carotenoids, phenolic compounds, Andean flowers

Effect of Modified Solar Dryers on Colorimetric and Physicochemical Properties of Pumpkin Flower (Cucurbita maxima)

This study aimed to evaluate the solar dryers' cover material effects on the colorimetric and physicochemical properties of pumpkin flowers (Cucurbita maxima). A direct cabinet solar dryer was designed using three cover types: polycarbonate, polyethylene, and aluminum with selective surface (titanium oxide coating). A unifactorial experimental design with three levels was adopted. Pumpkin flower stability was assured by reducing the initial moisture content (95.22%) and water activity (0.989) to 3.15% and 0.276 in the polycarbonate dryer, to 3.03% and 0.279 in the selective surface dryer, and 5.19% and 0.364 in the polyethylene dryer. The drying kinetics showed that the drying time needed to achieve the moisture equilibrium was 480, 540, and 720 min in the respective dryers, depending on the ambient conditions. The initial pumpkin flower hue angle was 76.52°; however, this value decreased to 74.81, 69.52, and 70.23° in the dryers with polycarbonate, polyethylene, and the selective surface respectively; this behavior indicates a pumpkin flower tendency to orange color. The dryer with the selective surface obtained the best properties in pumpkin flowers. The pumpkin flower showed an initial total soluble solid of 1.5°Brix increased to 30°Brix in the polycarbonate and polyethylene dryers and 39°Brix in the selective dryer. The titanium oxide dryer observed an increment in ascorbic acid content from 3.5 to 8.806 mg/100 g, whereas 6.45 and 5.87 mg/100 g in the polycarbonate and polyethylene dryer, respectively.

Color Variation and Secondary Metabolites' Footprint in a Taxonomic Complex of Phyteuma sp. (Campanulaceae)

In the genus Phyteuma, the taxonomic delimitation of some species is difficult since a high variability of morphological traits, such as flower color, is present, probably due to high levels of hybridization. Historic descriptions and the morphological traits used in the taxonomic keys are sometimes unclear and lead to misinterpretations. Here, a detailed analysis of flower color variability in different populations of sympatric P. spicatum, P. ovatum, and P. persicifolium constitutes a new approach to clarifying the taxonomic statuses. The numeric analysis of color, providing colorimetric variables, together with the detailed description of the metabolic profiles of populations with different flower colors, constitute a unique chemical fingerprint that identifies species and subspecies with clear markers. This study is the most complete metabolic research on genus Phyteuma, since we identified and quantified 44 phenolic compounds using HPLC-MS, comprising 14 phenolic acids, 23 flavonols and flavones, and, for the first time in the genus, 7 anthocyanins involved in flower color variability. This approach contributes to clarifying the differences between species, which is particularly relevant in taxonomic complexes such as the present, where morphology fails to clearly differentiate taxa at specific and intraspecific levels.

The Content of Phenolic Compounds and Organic Acids in Two Tagetes patula Cultivars Flowers and Its Dependence on Light Colour and Substrate

The main focus of the study was to determine the content of phenolic acids, flavonoids, and organic acids in the flowers of Tagetes patula ‘Petite Gold’ and ‘Petite Orange’. The growth of the plants was assessed depending on the cultivation conditions. The above plants were illuminated with white light, whereas the ‘Petite Gold’ ones with white light enhanced with blue or red light. Both cultivars grew in a two-level-mineral compounds organic substrate. The research showed that the French marigold flowers were rich in phenolic compounds and organic acids. The ‘Petite Gold’ flowers had more bioactive compounds compared with the ‘Petite Orange’ flowers. Three flavonoids, 10 phenolic acids and seven organic acids were found in the ‘Petite Gold’ flowers. The artificial lighting used during the cultivation of the plants showed diversified influence on the content of organic compounds in their flowers. The measurements of the plants’ morphological traits and the number of inflorescences showed that illumination with red light resulted in a better effect. Large plants with numerous inflorescences grew in the substrate with a lower content of nutrients.