Browsing by Subject "Phenolic compounds"

Now showing 1 - 4 of 4

Bioactive compounds and antioxidant activity in the fruit of rosehip (Rosa canina L. and Rosa rubiginosa L.)
(2023) Peña, Fabiola; Valencia, Sebastián; Tereucán, Gonzalo; Nahuelcura, Javiera; Jiménez-Aspee, Felipe; Cornejo, Pablo; Ruiz, Antonieta
Rosehips (Rosa spp., Rosaceae) are wild rose bushes with more than 100 species. Its fruits vary in colour and size, depending on the species, and are recognised for their nutritional characteristics. Ten samples of Rosa canina L. and Rosa rubiginosa L. fruits were collected at different geographical points from Southern Chile. Nutrients such as crude protein and minerals and functional properties such as phenolic compounds, ascorbic acid, and also antioxidant activities were evaluated by HPLC-DAD-ESI-MS/MS. The results revealed a high content of bioactive compounds, primarily ascorbic acid (6.0 to 8.2 mg g−1 fresh weight (FW)), flavonols (427.9 ± 0.4 μg g−1 FW) and antioxidant activity. We established a relationship between the antioxidant activity using Trolox equivalent antioxidant capacity (TEAC), cupric reducing antioxidant capacity (CUPRAC) and 2,2-diphenyl radical (DPPH) methods and the concentration of uncoloured compounds, such as flavonols and catechin. This antioxidant activity was primarily associated with the samples from Gorbea, Lonquimay, Loncoche, and Villarrica localities, and all of them were of the species Rosa rubiginosa L. The results here obtained represent novel information of rosehip fruits. In this sense, the reported information about compounds and antioxidant activities in rosehip fruits allowed us to continue new lines of research in relation to the potential formulation of new functional foods and also in the treatment and/or prevention of some diseases.
Effect of thermal treatment on the extraction and antioxidant and antiglycation activities of (poly)phenols from Ribes magellanicum
(2025) Ávila, Felipe; Martinez, Natalia; Mora, Nicolás; Márquez, Katherine; Jiménez-Aspee, Felipe; Rupasinghe, H. P. Vasantha
Phenolic compounds have antiglycation activity, but the changes occurring during thermal treatment (TT) in these activities are not completely understood. The effects of the extraction conditions of (poly)phenols from Ribes magellanicum fruits, before and after TT, on their antioxidant and antiglycation effects were assessed. (Poly)phenol-enriched extracts (PEEs) from raw and TT (90 °C, 1 h) Ribes magellanicum were extracted using three solvent mixtures (ethanol/water/acetic acid) with increasing water content (0, 24, and 49%) and three solvent-to-solid ratios (5, 10, and 20 mL/g). PEEs of raw samples showed increased values of total (poly)phenols (TPC), TEAC, and FRAP and decreased IC50 values of fluorescent advanced glycation end products (AGEs) with increasing water content. An increase in TPC and FRAP values was observed for TT samples, but an increase in the IC50 values of fluorescent AGEs for PEEs with increasing water content was observed. Antiglycation activity (IC50 raw/IC50 TT) depended on the solvent-to-solid ratio and the extracting solvent. HPLC-DAD-MS analysis of raw and TT samples showed degradation of anthocyanins, flavonoid fragmentation, and oxidation as the main changes in the phenolic composition of TT samples. We show that TT affects the (poly)phenolic composition of R. magellanicum, producing a decrease in the antiglycation activity when extractions are performed with increasing water content, despite increasing TPC and FRAP activity.
Mitigating phytotoxicity of hydrothermal liquefaction hydrochar toward potential agricultural applications
(2026) Batista, Gabriel F.; Kruse, Andrea; Becker, Gero C.
Valorizing hydrothermal liquefaction (HTL) by-products is essential to improve process sustainability and support its industrial-scale implementation. However, the direct agricultural application of HTL-derived hydrochar remains limited due to reported phytotoxic effects. By studying and mitigating phytotoxicity, this work evaluates the potential suitability for agricultural use of hydrochar, the solid by-product from continuous HTL of a 50/50 wt. % cattle manure and wheat straw mixture at 325 °C, separated with an in-line filter. Phytotoxicity was assessed using seed germination assays with Barley (Hordeum vulgare) and Cress (Lepidium sativum) seeds. Two hydrochar post-treatments, washing (hydrochloric acid and water) and pyrolysis (300 °C and 500 °C), were examined to mitigate hydrochar phytotoxicity. Raw HTL-hydrochar significantly hindered plant growth, reducing the root lengths of barley and cress by 37 % and 70 %, respectively, compared to the control. Water-washed post-treatment eliminated hydrochar phytotoxicity and enhanced Barley root growth by 42 % compared to control at a 15 ton ha⁻¹ application rate, indicating a possible growth-stimulating effect. Pyrolysis also mitigated hydrochar phytotoxic effects, with cress root lengths statistically similar to the control. No uptake of heavy metals by the plants were observed in the germination assays. These results suggest that phytotoxicity originates from water-soluble organic compounds, likely phenols, short-chain organic acids and aldehydes, produced during HTL process and adsorbed in the hydrochar surface. The novelty of this work lies in demonstrating the complete removal of phytotoxicity from HTL hydrochar using technologically mature and scalable post-treatments. Therefore, a barrier to hydrochar valorization is removed, enabling further investigations into agronomic applications. This work contributes to a circular biomass valorization strategy.
Stability of bioactive compounds and antioxidant activity in rosehip juice (Rosa spp.)
(2024) Peña, Fabiola; González, Felipe; Jiménez-Aspee, Felipe; Bustamante, Luis; Ruiz, Antonieta
Rosehip fruits, characterized by their high concentrations of bioactive compounds and antioxidant activity (AA), have been traditionally used to make jams, infusions, and juices. Thus, the objective of this research was to evaluate the stability of rosehip juice by determining the concentrations of bioactive compounds and total phenols and the AA using chromatographic and spectroscopic methods. The stability of the juice was evaluated with three treatments and different storage conditions, namely, unpasteurized–refrigerated, pasteurized–room temperature, and pasteurized–refrigerated, and measurements were taken for eight months. Individual and total phenolic compounds, evaluated by chromatographic methods, reported differences until the end of this study. The total phenolic compounds by Folin–Ciocalteu method presented an average decrease of 57% in the three treatments in relation to the initial conditions. On the other hand, the ascorbic acid content decreased considerably, disappearing at week six. Furthermore, for the unpasteurized–refrigerated and pasteurized–refrigerated samples, a correlation was found between flavonols, total phenols, ascorbic acid, and antioxidant activity determined by the TEAC method. For the pasteurized–room temperature samples, correlations were found between the levels of several flavonols, hydroxycinnamic acid, total phenols, and ascorbic acid and the antioxidant activity determined by the CUPRAC method. The stability of the compounds was mainly correlated with the storage conditions of the juice and not with pasteurization. The highest stability was observed for the unpasteurized–refrigerated and pasteurized–refrigerated samples. Although the concentrations of the compounds evaluated decreased during this study, significant levels of AA persisted, providing beneficial characteristics for consumer health.