The native berries of South America present promising marketing opportunities owing to their high antioxidant content, notably rich in anthocyanin and phenolic compounds. However, Ecuador's endemic fruits, primarily found in the wild, lack comprehensive data regarding their phytochemical composition and antioxidant capacity, underscoring the need for research in this area. Accordingly, this study evaluated the total phenolic, anthocyanin, flavonoid, resveratrol, ascorbic acid, citric acid, sugars, and antioxidant content of three native Ecuadorian fruits: mora de monte (Rubus glabratus Kunth), mortiño (Vaccinium floribundum Kunth), and tuna de monte (Opuntia soederstromiana). Determination of resveratrol, ascorbic acid, citric acid, and sugars was determined by HPLC analysis, and UPLC analysis was used to determine tentative metabolites with nutraceutical properties. Antioxidant capacity was assessed using cyclic voltammetry and the DPPH method; differential pulse voltammetry was used to evaluate antioxidant power. Analysis of results through UPLC-QTOF mass spectrometry indicated that R. glabratus Kunth and V. floribundum Kunth are important sources of various compounds with potential health-promoting functions in the body. The DPPH results showed the following antioxidant capacities for the three fruits: R. glabratus Kunth > O. soederstromiana > V. floribundum Kunth; this trend was consistent with the antioxidant capacity results determined using the electrochemical methods.

We report on two new electrochemical sensors which, coupled to differential pulse voltammetry, constitutes a useful tool for diagnosis of heavy metal pollution. The electrochemical sensors AgHgNf/Cu and the AgBiNf/Cu were obtained by deposition of bimetallic particles of AgHg or AgBi on copper electrodes covered with a Nafion (Nf) film, respectively. Micrographs of the electrode’s surface showed evenly scattered bimetallic particles, with an approximate diameter of 150 nm, embedded in the Nafion (Nf) film. In order to test the electrodes, the hydrogen evolution signal according to the Brdička reaction was measured for the determination of cysteine-rich peptides (CRp) produced by plants. To check the accuracy of the electrodes, real samples of Nicotiana tabacum cells exposed to cytotoxic levels of cadmium were tested. The AgHgNf/Cu electrode produced detection limits (DLs) of 0.088 µmol L⁻¹ for Cysteine and 0.139µmol L⁻¹ for Glutathione, while for the AgBiNf/Cu electrode DLs were 0.41 µmol L⁻¹ for cysteine and 0.244 µmol L⁻¹ for glutathione. Thus, the new electrodes could be a useful analytical electrochemical system very convenient for fieldwork. The electrodes were capable of direct, accurate, and sensitive detection of synthesized peptides, despite the complex matrix where the Nicotiana tabacum cells were grown.

Long-term cadmium intake can be very dangerous to human health due to its toxic effects. Although people can be contaminated with this element from different sources, contaminated food is probably the most important one. Foods such as vegetables and fruits can become contaminated with cadmium existing in soils, irrigation water, or chemical fertilizers. Some plants produce an excess of cysteine-rich peptides (CRp) when affected by high concentrations of heavy metals such as cadmium, thus indicating the presence of this type of contamination. Among these plants is tamarillo (Solanum betaceum), which is locally known as “tree tomato”. This is a native plant widely consumed in the Ecuadorian Andes because of its abundance, low cost, and high content of vitamin C and fiber. The fact that Solanum betaceum produces CRp upon contamination with heavy metals means that this plant may be able to accumulate heavy metals. If this is the case, the plant can possibly be used as an indicator of metal pollution. The main goals of the present work were to evaluate the possibility of using Solanum betaceum as an indicator of metal contamination in plants and to examine its capability to accumulate metals. Both goals were met by determination of the amounts of CRp produced by Solanum betaceum cells cultivated in vitro in the laboratory under controlled conditions in the presence of different concentrations of cadmium. The CRp determination was carried out by means of electrogeneration of iodine in an iodide solution containing reduced glutathione as a biological thiol model. Solanum betaceum cells were grown in a Murashige and Skoog solution enriched with a 30 g L⁻¹ sugar aqueous solution and 1 mg L⁻¹ 2,4-dichlorophenoxyacetic acid. The results of these experiments confirmed the following: (1) CRp production is a function of the amount of cadmium present as a contaminant up to a limiting value after which cell apoptosis occurs; (2) Solanum betaceum accumulates cadmium; (3) the analytical method used is appropriate for CRp determination; and (4) CRp determination is a valid alternative to detect contamination by heavy metals in plants.

The production and isolation of secondary metabolites through in vitro plant culture techniques represent a sustainable and versatile alternative to traditional cultivation. This review provides an integrative overview of the principles, methods, and advances in in vitro systems—such as callus and suspension cell cultures, hairy root cultures, micropropagation, somatic embryogenesis, and protoplast culture—highlighting their ability to exploit plant cell totipotency for the controlled synthesis of bioactive compounds with pharmaceutical, nutraceutical, and cosmetic value. These systems enable scalable, reproducible, and environmentally responsible production, supported by innovations in elicitation, metabolic engineering, and omics technologies that enhance yield and stability. Despite challenges such as high establishment costs and species-specific requirements, in vitro approaches ensure continuous metabolite production independent of climatic or ecological factors. Moreover, these biotechnological strategies open new opportunities to explore and preserve global plant biodiversity—particularly in regions rich in endemic flora, such as Ecuador—while promoting equitable access to scientific and industrial applications. Ultimately, in vitro plant culture serves as both a platform for secondary metabolite discovery and a pathway toward sustainable, inclusive, and socially impactful biotechnological development.

Plant in vitro culture has emerged as a biotechnological approach for the sustainable production of high-value secondary metabolites. Despite advances in plant tissue culture and phytochemical research, converting biologically productive in vitro systems into reliable production platforms remains a major challenge because metabolite production alone does not necessarily reflect technological maturity. This review evaluates plant in vitro production platforms for secondary metabolites in tropical and subtropical plant species by distinguishing validated, partially validated, and emerging platforms according to their level of technological development. To support this assessment, we propose a technological validation framework based on complementary experimental evidence that distinguishes species-level scientific knowledge from platform-level technological validation. The analysis reveals substantial differences in platform development and identifies production reliability as the principal limitation preventing many systems from reaching more advanced stages of technological maturity. These findings indicate that technological maturity should be understood as a progressive process driven by the accumulation of complementary experimental evidence rather than isolated experimental achievements. Future advances in plant in vitro production will depend on integrating mechanistic understanding of secondary metabolite biosynthesis with process engineering approaches to develop robust, reproducible, and scalable production platforms, thereby facilitating the sustainable biotechnological exploitation of tropical and subtropical plant biodiversity.