Search Results (458)

In the sustainability framework, valorization of organic by-products as reservoirs of phytochemicals useful for human health represents a hot topic. Therefore, this study evaluated Norway spruce bark and twigs (NSB, NST), chestnut tree wood (CTW), and pomegranate fruit waste/pomace (PFW) as sources of bioactive compounds by employing green technologies. Microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE), applied individually or sequentially, were optimized by modulating solvent composition, temperature, time, microwave power, and ultrasound amplitude. Hydroalcoholic extraction (50% ethanol) combined with MAE yielded the highest phenolic recovery and antioxidant activity across all matrices. PFW exhibited the highest antioxidant activity assessed through FRAP, ORAC, and DPPH assays. Phytochemical profiling by HPLC-DAD identified stilbenes in spruce extracts, ellagic acid in chestnut wood, and ellagic acid and punicalagins in pomegranate waste as major bioactive constituents. Additionally, NSB and PFW exhibited α-amylase inhibitory activity. Antimicrobial testing demonstrated dose-dependent activity against Gram-positive (Staphylococcus epidermidis and Bacillus subtilis) and Gram-negative (Pseudomonas stutzeri) strains, with PFW exhibiting the strongest inhibition and NSB displaying broad-spectrum effects. Total phenolic content changed moderately after 21 days of storage. These results demonstrate that sustainable extraction enables efficient recovery of bioactive compounds from plant by-products, supporting their further functional, dietary, and medicinal applications. Full article

Efficient recovery of phenolic compounds from citrus processing by-products requires optimized solvent systems and reliable frameworks for comparing emerging extraction technologies. In this study, a solvent system was first optimized to maximize phenolic recovery from lemon (Citrus limon (L.) Burm. f.) processing by-products, enabling a standardized comparison of ultrasound-assisted extraction (UAE) and hydrodynamic cavitation (HC). A preliminary solid–liquid extraction screening using different water:ethanol ratios (v/v) identified a 50:50 hydroalcoholic mixture as the optimal solvent system for recovering phenolic compounds. HPLC analysis confirmed the presence of major flavanones (eriocitrin and hesperidin) and hydroxycinnamic acids (caffeic, p-coumaric, sinapic, and ferulic acids). Antioxidant capacity was assessed using complementary assays (Folin–Ciocalteu, DPPH, and ORAC) to provide a comprehensive evaluation of antioxidant activity. Under optimized solvent conditions, UAE significantly improved the recovery of total flavanones (+25.9%), hydroxycinnamic acids (+10.3%), total polyphenols (+20.5%), DPPH activity (+6.0%), and ORAC values (+9.6%) compared with conventional extraction. HC further enhanced extraction performance, increasing flavanone recovery by 12.0%, hydroxycinnamic acids by 7.2%, total polyphenols by 5.2%, and antioxidant activity (DPPH and ORAC) by 11.4% and 2.0%, respectively, relative to UAE. Following ethanol removal and concentration, HC-derived extracts showed the highest phenolic content and antioxidant capacity. These results demonstrate that solvent optimization, combined with a standardized comparison of extraction technologies, enhances phenolic recovery from lemon processing by-products. The findings indicate that HC is a promising, scalable approach for the sustainable recovery of bioactive compounds from citrus side-streams. The novelty of this work lies in the integration of solvent optimization with a systematic and standardized comparison of UAE and HC, providing a reproducible framework for evaluating emerging extraction technologies and highlighting the enhanced performance and scalability potential of HC for phenolic recovery from citrus processing by-products. Full article

This study presents an integrated approach for producing antioxidant-rich polar fractions from Inula salicina L. via pressurised ethanol/water extraction (PLE-EtOH/H₂O), optimised by coupling a central composite design and response surface methodology (CCD-RSM) with Aspen Plus^® simulation. The effects of PLE temperature, extraction time, and EtOH/H₂O ratio for yield, total phenolic (TPC) and flavonoid (TFC) content, and Trolox equivalent antioxidant capacity (TEAC) measured in ABTS^•+-scavenging, cupric ion reducing antioxidant (CUPRAC) and oxygen radical absorbance (ORAC) assays were assessed via a multi-response optimisation approach. Optimal conditions were set at 82 °C, 27 min, and 60% EtOH (v/v), yielding ~29 g extract per 100 g plant material, characterised by high TPC (227 mg GAE/g), TFC (34 mg QE/g), and TEAC values in the CUPRAC (1473 mg TE/g), ABTS (869 mg TE/g), and ORAC assays (1165 mg TE/g). The TPC and TEAC values of the post-extraction residue were >92% lower than those of unextracted I. salicina, confirming efficient recovery of the major portion of antioxidant-active constituents by PLE-EtOH/H₂O. The high in vitro radical scavenging capacity, reducing power, and photoprotective potential (sun protection factor ~50 at 0.5 mg/mL) of the I. salicina extract are consistent with its phenolic-rich composition, with chlorogenic acid (~97 mg/g extract) and its derivatives being the major constituents. The validated Aspen Plus^® model closely aligned with the CCD-RSM predictions, supporting process scale-up and energy feasibility and demonstrating an industry-relevant, green-solvent PLE process for producing higher value-added I. salicina fractions with potential applications in the food, pharmaceutical, nutraceutical, and cosmetic sectors. Full article

Phenolic compounds are plant-derived antioxidants crucial for human health and food preservation. Their bioactive potential including anti-inflammatory, antimicrobial, and anti-carcinogenic properties makes them a vital focus in nutritional, pharmaceutical, and agricultural research. This review critically evaluates the methodologies for their extraction, detection, and quantification to accurately assess antioxidant activity. Oxidative stress in biological systems and food matrices necessitates accurate analytical methodologies for assessing antioxidant behavior, which include both in vitro, in vivo and ex vivo approaches. Sample pretreatment and extraction techniques are critical for reliable analysis and vary depending on the matrix, compound polarity, and target phenolic subclass. We compare conventional extraction techniques (Soxhlet, maceration) with advanced methods like ultrasound-assisted, microwave-assisted, and supercritical fluid extraction. Detection methods reviewed include spectrophotometric assays (e.g., DPPH, FRAP, ORAC), electrochemical sensors, and chromatographic techniques (e.g., HPLC, HPLC−MS). While each method has distinct advantages, a lack of standardization remains the primary challenge, driven by variations in protocols and the vast chemical diversity of phenolics. This review underscores the critical need for integrated, standardized approaches to ensure the accurate and comparable evaluation of antioxidant activity in research and industry. Full article

Moringa oleifera leaves are recognized as a nutrient-dense plant material of compositional and nutritional interest. This study aimed to characterize the nutritional and physicochemical properties of M. oleifera dried leaves through nutritional assessment and spectroscopic fingerprinting. Amino acid profiling, antioxidant activity assessment using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays, chromatographic analysis of organic acids and sugars, color measurement, techno-functional characterization, and vibrational spectroscopy including Fourier Transform infrared with attenuated total reflectance (FT-IR/ATR) and Raman were employed. The crude protein content was 16.13 ± 0.43%. Moringa leaves contained all essential amino acids, with notably high tryptophan content (amino acid score, AAS = 200.00%). The amino acids limiting the nutritional value of the protein were primarily sulfur-containing amino acids (AAS = 49.57%) and lysine (AAS = 49.79%). Histidine, leucine, and valine also showed levels below the reference protein. Antioxidant activity exhibited solvent-dependent patterns: the 80% ethanolic extract demonstrated significantly higher FRAP activity (27.05 ± 1.05 mg Trolox Equivalent (TxE)/g dry matter (DM)) and ORAC values (107.24 ± 6.80 mg TxE/g DM), while no statistically significant differences between extracts were observed for DPPH, ABTS, or total phenolic content. Chromatographic profiling identified fructose and glucose as the predominant sugars, alongside citric, succinic, lactic, and acetic acids. The leaves exhibited favorable techno-functional properties, including high water holding capacity and water solubility index. Spectroscopic analysis revealed bands consistent with proteins, lipids, carbohydrates, and glycoside-related structures, while the preserved green-yellow coloration (hue angle 101.68°) indicated retention of pigment-related features during processing. These findings provide compositional and physicochemical characteristics of Moringa leaves relevant to their evaluation as a plant-derived food material. Full article

Hop (Humulus lupulus L.) cones are increasingly recognized as sources of phenolic compounds relevant to antioxidant-oriented applications beyond their traditional brewing role; however, genotype-dependent chemical diversity remains poorly characterized under South American cultivation. This study evaluated phenolic composition and antioxidant-related chemical signatures in 22 hop accessions, including commercial varieties and Chilean local ecotypes, cultivated under homogeneous conditions in southern Chile. Total phenolic content (TPC), total flavonoid content (TFC), and condensed tannins were determined using spectrophotometric assays, while phenolic acids, catechin, and prenylated flavonoids were quantified by HPLC. Antioxidant capacity was evaluated using the ORAC assay, and principal component analysis (PCA) was applied to integrate chemical variables. TPC ranged from 4051 to 8124 mg gallic acid equivalents/100 g dry weight, TFC from 655 to 3011 mg quercetin equivalents/100 g, and condensed tannins from 11.0 to 60.1 mg catechin equivalents/g. ORAC values ranged from 96,405 to 161,815 µmol Trolox equivalents/100 g dry weight, indicating substantial genotype-dependent variation. PCA explained 69.5% of total variance and revealed distinct phenolic composition patterns among genotypes. Pearson correlation analysis showed that antioxidant capacity was strongly associated with condensed tannins and total phenolic content, whereas total flavonoids were not significantly related to ORAC values. Prenylated flavonoids were negatively associated with antioxidant capacity, suggesting a limited contribution to peroxyl radical scavenging activity. These findings highlight the importance of phenolic subclass composition, particularly condensed tannins, in determining antioxidant capacity and support the selection of hop genotypes based on specific phenolic profiles for functional applications. Full article

This present study provides a comprehensive and novel assessment of Nannochloropsis sp. extracts as multifunctional ingredients for food applications, combining lipid profiling, nutritional quality indices, and antimicrobial activity. The extracts were obtained by ultrasound-assisted hydroethanolic extraction (90% EtOH solution; 20 kHz pulses of 30 s during 10 min). Nannochloropsis sp. biomass exhibited a high lipid content (36.6%), and GC-FID analysis of its extract revealed high concentrations of palmitic acid, palmitoleic acid, and eicosapentaenoic acid (EPA). Nutritional quality indices—including the index of atherogenicity (AI), the index of thrombogenicity (TI), and the hypocholesterolemic/hypercholesterolemic ratio (HH)—were favorable, and the health-promoting index (HPI) was high. Although the extract exhibited low antioxidant activity in ABTS, DPPH, and ORAC assays, it demonstrated inhibitory activity against Gram-negative (Yersinia enterocolitica, Escherichia coli, Salmonella enterica Serovar Enteritidis) and Gram-positive (Staphylococcus aureus, and Listeria monocytogenes) foodborne pathogens, with a minimal inhibitory concentration of 6.3–12.5 mg/mL. These findings highlight the novelty of positioning Nannochloropsis sp. extracts as multifunctional ingredients that couple favorable lipid nutrition with antimicrobial functionality, rather than as single-purpose bioactives. The results support their potential for application in healthy food formulations and shelf-life extension strategies. Full article

Propolis is a chemically complex natural product with recognized antioxidant potential, but its compositional heterogeneity and poor aqueous solubility complicate formulation and interpretation of in vitro release behavior. In this study, a nanostructured lipid carrier (NLC) based on Gelucire^® 44/14 was developed as a physicochemical platform to modulate the accessibility of a selected Chilean ethanolic propolis extract. Propolis extracts from different origins were first screened using complementary antioxidant assays (DPPH, ABTS, ORAC, FRAP), leading to the selection of the Peñaflor extract, which exhibited the highest phenolic content (~41 mg GAE/g) and antioxidant capacity. The selected extract was incorporated into NLCs with encapsulation efficiencies above 90%, a narrow size distribution (~200 nm), and high stability over 90 days. Under simple aqueous conditions, propolis release remained limited (<15% over 6 h), consistent with diffusion- and partition-controlled transport. In simulated gastrointestinal media containing bile components, pronounced pH- and composition-dependent effects were observed. While fed-state intestinal conditions induced extensive morphological remodeling without increasing the analytically accessible fraction (<3% at 4 h), fasted-state intestinal media promoted a higher accessible fraction (~14% within 1 h) without complete carrier disruption, as confirmed by transmission electron microscopy. Preliminary cytocompatibility studies in HepG2 cells showed acceptable viability at 10–40 µg/mL and concentration-dependent effects at higher doses. Overall, this work demonstrates that bile components modulate propolis accessibility through dynamic partitioning and colloidal reorganization rather than simple carrier breakdown, providing a physicochemical framework for future digestion and absorption studies. Full article

The objective of this study was to obtain and characterize bioactive peptides derived from common bean (Phaseolus vulgaris) landraces and to evaluate their antioxidant potential using multiple in vitro assays. Protein isolates were obtained by isoelectric precipitation followed by enzymatic hydrolysis using Alcalase. Peptides were separated by ultrafiltration into fractions < 3 kDa and 3–10 kDa, yielding a total of forty samples. Antioxidant activity was evaluated using DPPH, FRAP, and ORAC assays. Antioxidant responses ranged from 13.06 to 50.8% inhibition in DPPH, 52.2 to 1750 µmol TE/100 g in FRAP, and 305 to 5246 µmol TE/100 g in ORAC. Resistance against oxidation ranged from 10.6 to 68.8%. Peptides < 3 kDa generally exhibited higher antioxidant activity in the functional assays, particularly in the Apolo, Magnum, Boloto, and Hallado landraces, although some 3–10 kDa fractions also showed relevant activity. Peptide extraction yields ranged from 3.73 to 10.39% and from 1.33 to 4.74%, while soluble protein contents ranged from 23.1 to 460 and from 9.9 to 288 mg BSA/100 g beans for <3 kDa and 3–10 kDa fractions, respectively. Overall, the results support the potential of common bean-derived peptides as functional food ingredients with antioxidant activity mediated through multiple mechanisms. Full article

Background/Objectives: The consumption of olive oil and olives has been steadily increasing, leading to growing interest in the sustainable management of by-products such as olive stones. This work aimed to contribute to the development of valorization strategies by studying the chemical composition and biological potential of olive stone extracts, using both conventional and eco-friendly extraction methods with various solvents. Methods: Several extracts were prepared and chemically characterized regarding their fatty acid and phenolic profiles by GC-FID and HPLC-DAD-MS/MS, respectively. Their antioxidant, cytotoxic and antiproliferative activities were also evaluated. Results: n-Hexane Soxhlet extract yielded higher concentrations and a broader range of fatty acids when compared to the chloroform-methanol Folch extract. Oleic, palmitic, and linoleic acids were the predominant fatty acids in the extracts. A large variety of phenolic compounds were identified in extracts obtained by microwave-assisted extraction (MAE), including several flavonoids, small phenolic compounds, secoiridoids (nuezhenide and oleuropein), and hydroxytyrosol. MAE hydroalcoholic extracts showed high total phenolic content (TPC), antioxidant activity by the oxygen radical absorption capacity (ORAC) and hydroxyl radical scavenging capacity (HOSC) assays. Moreover, the aqueous ethanol (50%) and aqueous methanol (80%) extracts displayed low cytotoxicity toward the non-malignant Caco-2 cell line (IC₅₀ values of 1.29 and 1.40 mg/mL, respectively), while both induced complete loss of viability in the HT-29 human colon adenocarcinoma cell line at 0.63 mg/mL. Conclusions: These findings highlight the potential of olive stone as a valuable source of bioactive compounds with antioxidant and selective antiproliferative properties. The results support their further exploration in the development of sustainable valorization strategies for olive industry by-products. Full article

Tortillas are an essential food staple in the Mexican diet due to their nutritional value. Blue corn tortillas have been reported as a source of bioactive compounds, such as phenolic compounds and flavonoids. Likewise, the blue corn tortillas have been studied to enhance the nutritional and nutraceutical composition. In this sense, Quelites are a large family of plants with macronutrient and micronutrient content, as well as a source of phenolic compounds, flavonoids, and carotenoids. Among these, Amaranthus hybridus L. could fortify the blue corn tortilla composition. Therefore, this study aims to fortify blue corn tortillas with different concentrations of Quelites flours. The total flavonoid and phenolic compounds content, as well as the antioxidant capacity and identification of phenolic compounds, were evaluated on tortillas fortified with Quelites. The addition of Quelites to blue corn tortillas reduced the lipid and protein content, carbohydrate, and flavonoid content, and enhance the antioxidant capacity of tortillas as measured by FRAP, ORAC, and TEAC assays. Also, caffeic acid, chlorogenic acid, ferulic acid, and sinapic acid were identified on blue corn tortillas fortified with Quelites. These results support the use of A. hybridus L. as an ingredient to improve the nutrient and nutraceutical composition of foods. Full article

This study investigated the biochemical composition and antioxidant potential of flours from pigment-deficient Chlorella vulgaris variants (honey and white) and wild-type (green) and the impact of lactic acid bacteria–yeast co-culture fermentation. The three variants were characterized for composition, total polyphenol (TPC) and flavonoid (TFC) contents, antioxidant capacity (DPPH, FRAP, and ORAC assays), and reactive oxygen species production in HT-29 intestinal cells. All extracts were noncytotoxic up to 100 µg/mL. Among all variants, the green showed the highest native TPC, TFC, and overall antioxidant activity. TPC and TFC were similar between honey and white, while FRAP was higher in honey and ORAC was higher in white. Biomasses were subsequently fermented for 24 h using Lactiplantibacillus plantarum CR L1 or Levilactobacillus brevis L204 with either Saccharomyces cerevisiae TRE Y100 or Kluyveromyces marxianus MK Y55. Fermentation resulted in significant pH reduction and increases in titratable acidity and lactic acid production, particularly in co-cultures involving K. marxianus. However, the effects on antioxidant properties were strongly matrix-dependent, with significant increases in TPC and antioxidant activity observed only in the white variant. Overall, pigmentation and microbial pairing emerged as key determinants of metabolic outcomes. These findings highlight the potential of co-culture fermentation to enhance the bioactive profile of pigment-deficient C. vulgaris, supporting their application in functional foods. Full article

Traditionally, Lasiocephalus ovatus Schltdl. (Asteraceae) has been used as an aromatic medicinal plant, particularly in the treatment of kidney-related ailments. However, scientific evidence validating its chemical composition and bioactivity remains limited. According to our literature search, there are no previous studies on the in vitro antibacterial, antioxidant, or anti-inflammatory activities of the essential oil from the aerial parts of Lasiocephalus ovatus; therefore, this study provides the first experimental evidence of these biological activities for this species. An essential oil (EO) was steam-distilled from the aerial parts of L. ovatus, grown at 4410 m above sea level in the paramos of Chimborazo Province (Ecuador), and subsequently analyzed. The distillation yield was 0.21% (w/w) based on dry plant material. Gas chromatography was employed for qualitative (GC-MS) and quantitative (GC-FID) analyses, using two different capillary columns, coated with 5% phenyl methyl polysiloxane (non-polar) and polyethylene glycol (polar) stationary phases. Dual stationary phases were required to provide complementary selectivity, which reinforced the identification and quantification of compounds. The major components of the EO were silphinene (3.4–3.5%), δ-selinene (3.6–3.1%), β-cyclogermacrene (18.7–18.1%), kessane (4.5–4.2%), spathulenol (13.3–13.3%), viridiflorol (3.1–3.0%) and neophytadiene (4.8–4.4%), values referred to the non-polar and polar phase respectively. The enantioselective analysis revealed that (1S,5S)-(−)-α-pinene, (1S,5S)-(+)-β-pinene and (R)-(−)-α-phellandrene were enantiomerically pure, whereas germacrene D was present as a scalemic mixture. The essential oil of L. ovatus exhibited a minimum inhibitory concentration (MIC) of 250 µg/mL against Staphylococcus aureus and 500 µg/mL against Escherichia coli. Its antibacterial activity is likely associated with the presence of bioactive sesquiterpenes such as silphinene, δ-selinene, and spathulenol, which are known for their membrane-disruptive properties. Regarding its antioxidant potential, the observed moderate radical scavenging activity (SC₅₀ = of 375.7 µg/mL) can be attributed to its complex mixture, particularly to oxygenated terpenoids like viridiflorol and spathulenol, which are recognized for their radical-neutralizing capacity. In the anti-inflammatory assay, the EO’s moderate potency (IC₅₀ = 165.29 ± 4.75 μg/mL) is also consistent with the anti-inflammatory profile reported for several of its major constituents, including spathulenol and viridiflorol. While significantly lower than that of aspirin (28.85 ± 7.66 μg/mL), this bioactivity is considerable within the context of a plant extract. Overall, the antibacterial, antioxidant, and anti-inflammatory effects are consistent with the EO’s terpene-rich composition, particularly oxygenated sesquiterpenes, while the enantiomeric distribution of chiral monoterpenes may further modulate bioactivity; consequently, future studies should include enantioselective quantification, broader antioxidant assays (e.g., ABTS, FRAP, ORAC, CUPRAC), cytotoxicity at active concentrations, and mechanistic and in vivo validation. Full article

Background: Although the definition of dietary fibre is complex and constantly evolving, today we can identify it as “carbohydrate polymers with at least 10 monomeric units, which are not hydrolysed in the small intestine of humans”. In addition to the numerous and well-known benefits of dietary fibre for human health, our attention is drawn to its antioxidant properties, achieved through polyphenolic compounds linked to polysaccharide complexes. This study investigated the antioxidant effects of an extract from the fruit of Punica granatum (PUN), particularly rich in polyphenols, fibre, flavonoids, vitamins, organic acids, minerals, amino acids, and alkaloids. Furthermore, these effects were evaluated in two human nervous system cell lines under oxidative stress induced by hydrogen peroxide. Methodology: After examining the fibre composition, some polyphenols present in the extract were identified and quantified by HPLC. Furthermore, the antioxidant power of PUN was measured using the DPPH method, the chelating activity assay, the reducing power test, the ORAC method, the measurement of reactive oxygen species accumulation, the quantification of lipid peroxidation, and the detection of mitochondrial superoxide in cell cultures. Results: The results were consistent, and PUN demonstrated a strong antioxidant potential, justified not only by the high content of easily extractable polyphenols (EPPs) but also by a further addition of these more difficult to identify compounds (NEPPs), indicated as “hidden polyphenols”; therefore, the total polyphenol content in the extract resulted from the sum of EPPs + NEPPs (71 ± 7.9 + 55 ± 6.4 mg = 126 ± 14.3 mg gallic acid equivalent (GAE)/g dry weight). The fraction of hidden polyphenols could therefore explain a mechanism by which the fibre exerts an antioxidant effect. Another important result was achieved by the cell lines used, both of which were significantly protected by PUN following oxidative damage generated by a pro-oxidant treatment. However, astrocytes were found to be more responsive and sensitive than were human neurons. At the same time, PUN mitigated the effects of oxidative damage, and it could be hypothesised that this extract could be used to extinguish the A1 phenotype. Conclusions: We can conclude that the fibrous component of pomegranate is related to the antioxidant property exerted, and the neurodegeneration caused by oxidative stress could be slowed following the intake of Punica granatum. It is possible to identify the pomegranate as a “superfood” or “functional food”, with excellent nutritional characteristics and chemical composition. Full article

Understanding interactions between antioxidants is crucial since in biological and food matrices, we are dealing with complex multi-component antioxidant systems. This study aimed to quantitatively characterize interactions of antioxidants in anthocyanin-rich aqueous red cabbage extract with several natural (ascorbic acid, gallic acid, and glutathione) and synthetic (Trolox and TEMPOL) antioxidants and to determine their synergistic or antagonistic nature in the ORAC assay. Four parameters derivable from the ORAC assay (extent of fluorescence protection, lag time, fluorescence half-life t_1/2, and maximum rate of fluorescence decay) were analyzed in terms of the integrated interaction coefficient (IIC), reflecting the dependence of the analyzed values on the concentration of antioxidants and the sample interaction coefficient (SIC) derived from interaction at a single set of concentrations. IIC analysis revealed synergistic interactions of Trolox with the red cabbage extract on the basis of fluorescence protection, lag time, and t_1/2. Interactions of TEMPOL with the extract were antagonistic as assessed based on all parameters but the lag time. A correlation between the anodic peak and the lag time and t_1/2 values was observed for the antioxidants studied. The interactions between antioxidants in complex mixtures are important as they affect the measured total antioxidant activity, which, depending on the nature of the interactions, may be lower or higher than the sum of activities of individual components. Full article