Less common tropical fruits have been the subject of little research, leaving a vast field to be explored. In this context, a comprehensive study was carried out on the bioactive compounds and antioxidant capacity of 51 non-traditional fruits consumed in Ecuador. Vitamin C, organic acids, carotenoids, and phenolic compounds were evaluated using microextraction and rapid resolution liquid chromatography (RRLC) techniques, while antioxidant activity was measured using microplate readings. The results showed high levels of vitamin C (768.2 mg/100 g DW) in Dovyalis hebecarpa, total organic acids (37.2 g/100 g DW) in Passiflora tripartita, carotenoids (487.0 mg/100 g DW) in Momordica charantia, phenolic compounds (535.4 mg/g DW) in Nephelium lappaceum, Pourouma cecropiifolia (161.4 µmol TE/g DW) and Morus alba (80.5 µmol AAE/g DW) in antioxidant activity. Effective extraction of carotenoids was also observed using a mixture of methanol: acetone: dichloromethane (1:1:2) with an extraction time of 2 min, while an 80% solution of 0.1% acidified methanol with hydrochloric acid with an extraction time of 3 min was highly effective for phenolics in fruit. These results provide a valuable basis for optimising future extraction processes of bioactive compounds from non-traditional fruits, with significant implications for their potential use in various nutritional and pharmaceutical contexts.

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.

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.

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.

The biodiversity of the Amazon rainforest includes little-known cocoa species, which are essential resources for local communities. This study evaluated the bioactive compounds and antioxidant and antimicrobial activity of seeds and mucilage of four non-traditional cocoa species (Theobroma subincanum, T. speciosum, T. bicolor and Herrania nitida). Physico-chemical properties, minerals, vitamin C, organic acids, phenolics, and carotenoids were analysed by spectrophotometric and chromatographic techniques. The antioxidant activity was measured by ABTS and DPPH, along with the antimicrobial activity against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Streptococcus mutans, as well as Candida albicans and Candida tropicalis. T. subincanum seeds scored high in titratable acidity, magnesium, sodium, syringic acid, chlorogenic acid, caffeic acid, rutin, and quercetin. In contrast, the mucilage scored high in calcium, m-coumaric acid, ferulic acid, kaempferol, quercetin glycoside, and antimicrobial activity against Streptococcus mutans. T. speciosum mucilage excelled in malic acid, tartaric acid, naringenin, and antioxidant capacity. T. bicolor seeds excelled in lutein and antimicrobial activity against Staphylococcus aureus and Candida albicans, and mucilage in iron, potassium, vitamin C, citric acid, gallic acid and 4-hydroxybenzoic acid, zeaxanthin, β-carotene, and antioxidant capacity by ABTS. The mucilage of H. nitida has a high soluble solids content. These results highlight the potential of these species as sustainable sources of functional compounds and nutraceuticals.

Sulphate reducing bacteria (SRB) offer promise for the treatment of mine waste due to their effectiveness removing toxic heavy metals as highly insoluble metal sulphides and their ability to generate alkalinity. The main objective of this study was to develop a treatment composed of a sulphate-reducing bioreactor with a limestone precolumn for the removal of Cu(II) from a synthetic ARD. The purpose of the limestone column was to increase the pH values and decrease the level of Cu in the effluent to prevent SRB inhibition. The system was fed with a pH-2.7 synthetic ARD containing Cu(II) (10–40 mg/L), sulphate (2000 mg/L) and acetate (2.5 g COD/L) for 150 days. Copper removal efficiencies in the two-stage system were very high (95–99%), with a final concentration of 0.53 mg/L Cu, and almost complete removal occurred in the limestone precolumn. In the same manner, the acidity of the synthetic ARD was effectively reduced in the limestone precolumn to 7.3 and the pH was raised in the bioreactor (7.3–8.0). COD consumption by methanogens was predominant from day 0–118, but SRB dominated at the end of the experiment (day 150) when the average COD removal and sulphide production were 74.8% and 61.7%, respectively. Study of the microbial taxonomic composition in the bioreactor revealed that Methanosarcina and Methanosaeta were the most prevalent methanogens while the genera Desulfotomaculum and Syntrophobacter were the dominant SRB. Among the SRB identified Desulfotomaculum intricatum (99% identity) and Desulfotomaculum acetoxidans (96%) were the most abundant sequences of bacteria capable of using acetate. GRAPHICAL ABSTRACT