Search Results (47)

Chili peppers (Capsicum spp.), cacao (Theobroma cacao L.), and coffee (Coffea spp.) are important crops worldwide. Nearly 35%, 80%, and 45% of the respective fruits are underutilized or discarded, representing a considerable economic loss. This work reviews and analyzes the environmental factors that influence the concentration of the main alkaloids in these crops, including capsaicin, theobromine, and caffeine. Their reported anti-inflammatory, cardioprotective, neuroprotective, and cytotoxic properties are also reviewed. This work explores strategies for the revalorization of these crops, comparing alkaloid extraction methods that use non-conventional techniques, including supercritical fluid extraction (SFE), ultrasound-assisted extraction (UAE), high-pressure and -temperature extraction (HPTE), pressurized liquid extraction (PLE), pressurized hot water extraction (PHWE), enzyme-assisted extraction (EAE), and pulsed electric field-assisted extraction (PEFAE), and their combination to enhance the recovery of capsaicin, theobromine, and caffeine, leading to sustainable and innovative uses of these crops’ byproducts. Capsaicin, theobromine, and caffeine alkaloids are promising ingredients for the development of functional foods, cosmeceuticals, and pharmaceuticals. Full article

Rosa damascena and Rosa rugosa, which are the two most commercial species in the Rosa genus, are used to make rose oil, cosmetics, and functional foods. The majority of polysaccharide constituents of both species is structurally diverse and demonstrates promising biological activities, such as moisturizing, immunomodulation, and antioxidant activity. The extraction technique has a significant impact on the yield, purity, and bioactivity of polysaccharides. Traditional extraction methods (hot water, ethanol) are simple and economical, yet they typically produce low yields and degrade sensitive compounds. Novel extraction methods (pressurized liquid extraction, enzyme-assisted extraction, ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction) offer higher efficiency, selectivity, and sustainability, while better preserving polysaccharide structure and bioactivity. This review serves as a comparative summary of conventional versus novel extraction methodologies of polysaccharides from R. damascena and R. rugosa, with particular consideration towards the yield, polysaccharide structural integrity, sustainability, and industrial conduct of each methodology. In addition, it summarizes the distribution and functional role of selected polysaccharides in the various organs of the plants, while also providing an overview of their antioxidant mechanisms and potential bioactive applications in health. Challenges and critical factors that surround specific species, standards for processes, and extraction methods, and that therefore appeal to time and economic considerations, are identified. In efforts to optimize the extraction methodology, the high economic and functional potential of the Rosa species can be maximized in the interest of healthy, functional consumables for the pharmaceutical, nutraceutical, and cosmetic industries. Full article

A simple Lagrangian travelling slice model has been successfully used to predict the relations between the process parameters and the strand temperatures in the continuous casting of steel. The present paper aims to include a simple macrosegregation, grain structure and mechanical stress and deformation model on top of the thermal slice framework. The basis of all the mentioned models is the slice heat-conduction model that considers the complex heat extraction mechanisms in the mould, with the sprays, rolls, and through radiation. Its main advantage is the fast calculation time, which is suitable for the online control of the caster. The macroscopic thermal and species transfer models are based on the continuum mixture theory. The macrosegregation model is based on the lever rule microsegregation model. The thermal conductivity and species diffusivity of the liquid phase are artificially enhanced to consider the convection of the melt. The grain structure model is based on cellular automata and phase-field concepts. The calculated thermal field is used to estimate the thermal contraction of the solid shell, which, in combination with the metallostatic pressure, drives the elastic-viscoplastic solid-mechanics models. The solution procedure of all the models is based on the meshless radial basis function generated finite difference method on the macroscopic scale and the meshless point automata concept on the grain structure scale. Simulation results point out the areas susceptible to hot tearing. Full article

This review highlights the recent advancements in extraction techniques for bioactive compounds from natural sources, focusing on methodologies that enhance both efficiency and sustainability. Techniques such as pressurized hot water extraction (PHWE), solid-state fermentation (SSF), ionic liquids (ILs), and electrohydrodynamic (EHD) methods have shown significant potential in improving extraction yields while preserving the bioactivity of target compounds. These innovative approaches offer significant advantages over traditional methods, including reduced energy consumption, minimal environmental impact, and the ability to extract thermosensitive compounds. PHWE and EHD are particularly effective for extracting antioxidants and thermosensitive compounds, whereas SSF provides an environmentally friendly alternative by valorizing agro-industrial waste. Ionic liquids, although promising for extracting complex phytochemicals, face challenges related to scalability and economic feasibility. The adoption of these advanced techniques represents a shift toward more sustainable and cost-effective extraction processes, promoting the discovery and utilization of high-value compounds. These methods also contribute to the development of eco-friendly, cost-effective strategies that align with green chemistry principles and regulatory standards. However, further research and technological advancements are required to address existing limitations and ensure the widespread application of these methods in industrial and pharmaceutical sectors. Full article

Geothermal energy can be obtained from hot dry rock (HDR). The target temperatures for heat extraction from HDR range from 100 to 400 °C. Artificial fracturing is employed to stimulate HDR and create a network of fractures for geothermal resource extraction. Liquid nitrogen (LN₂) is environmentally friendly and shows better performance in reservoir stimulation than does conventional fracturing. In this study, triaxial compression experiments and acoustic emission location techniques were used to evaluate the impacts of temperatures and confining pressures on the mechanical property deterioration caused by LN₂ cooling. The numerical simulation of LN₂ fracturing was performed, and the results were compared with those for water and nitrogen fracturing. The results demonstrate that the confining pressure mitigated the deterioration effect of LN₂ on the crack initiation stress, crack damage stress, and peak stress. From 20 to 60 MPa, LN₂-induced reductions in these three stress parameters ranged between 7.73–18.51%, 3.46–12.15%, and 2.51–8.50%, respectively. Cryogenic LN₂ increased the number and complexity of cracks generated during rock failure, further enhancing the fracture performance. Compared with those for water and nitrogen fracturing, the initiation pressures of LN₂ fracturing decreased by 61.54% and 68.75%, and the instability pressures of LN₂ fracturing decreased by 20.00% and 29.41%, respectively. These results contribute to the theoretical foundation for LN₂ fracturing in HDR. Full article

Cooling small components is becoming an attractive topic for researchers. In this paper, an attempt is made to use an ethylene glycol/water mixture as a cooling liquid. This liquid is a helpful application for when the fluid is in a harsh environment and should not freeze. The experiment uses an ethylene glycol/water mixture circulating through a triply periodic minimal surface structure (TPMS) made of aluminum and silver. A constant heat flux equal to 38,000 W/m² is applied, and three different flow rates, 11.8 cm³/s, 15.5 cm³/s, and 19.6 cm³/s, are studied. The experimental setup is complemented with numerical modelling by solving the Navier–Stokes equation and the energy equation using the finite element technique. The flow is Newtonian, and a laminar regime is implemented. Results reveal that the performance of the ethylene glycol/water mixture did not enhance heat removal when compared to water. The average Nusselt number is similar regardless of the concentration of ethylene glycol in the mixture. This average Nusselt number, Nu_average, in the presence of aluminum TPMS ranges between 60 and 80 (60 < Nu_average < 80) and between 65 and 85 (65 < Nu_average < 85) using silver TPMS. The increase in the mixture’s viscosity due to ethylene glycol increased the pressure drop. The performance evaluation criteria reach the maximum value of 90 when the mixture is composed of 5%vol ethylene glycol in water with aluminum TPMS. In the presence of silver TPMS, the maximum performance evaluation criterion is around 95 with a 5% ethylene glycol/water mixture. Finally, it is proven experimentally and confirmed numerically that the TPMS structure secures uniform heat extraction from the hot surface. Full article

Enhanced Geothermal Systems (EGS) represent a promising direction for sustainable energy development, yet their efficiency and feasibility often suffer due to suboptimal heat extraction methods and interface instability in U-shaped wells. This study introduces an innovative volume encapsulation technology that aims to address these challenges. The proposed technology employs a combination of hydraulic fracturing and acidification to prepare the rock interface, followed by encapsulation using high-temperature liquid metal. Low-melting-point alloys are utilized as a heat exchange medium between the horizontal sections of the wells. This study meticulously analyzes the impact of formation stress, thermal shock stress, and liquid metal properties on rock interface stability. Advanced simulation tools and experimental setups were used to test the encapsulation process under various conditions. The application of liquid metal encapsulation demonstrated significant improvements in energy conversion efficiency and rock interface stability. In conditions simulating a dry and hot rock reservoir at depths up to 3000 m and temperature gradients reaching 2200 °C/m, the adjusted depth of horizontal sections and increased pumping pressure contributed to maintaining interface stability. The established failure criteria provide a robust theoretical foundation for the encapsulation process. Volume encapsulation technology using liquid metal not only enhances the operational efficiency of EGS but also stabilizes the rock interface, thereby increasing the feasibility of continuous geothermal energy extraction. This study offers valuable theoretical insights and practical guidance for future research and applications in geothermal energy technologies, creating new pathways for the efficient exploitation of geothermal resources. Full article

Ugni candollei, commonly known as white murta, is a native Chilean berry with a polyphenol composition that has been underexplored. This study aimed to establish a comprehensive profile of white murta polyphenols using ultra-performance liquid chromatography electrospray ionization Orbitrap mass spectrometry (UPLC-ESI-ORBITRAP MS). Additionally, it compared the efficacy of conventional extraction methods with emerging techniques such as deep eutectic solvent (DES) extraction and hot pressurized water extraction (HPWE). The analysis tentatively identified 107 phenolic compounds (84 of them reported for the first time for this cultivar), including 25 phenolic acids, 37 anthocyanins, and 45 flavonoids. Among the prominent and previously unreported polyphenols are ellagic acid acetyl-xyloside, 3-p-coumaroylquinic acid, cyanidin 3-O-(6′-caffeoyl-glucoside, and phloretin 2′-O-xylosyl-glucoside. The study found HPWE to be a promising alternative to traditional extraction of hydroxybenzoic acids, while DES extraction was less effective across all categories. The findings reveal that white murta possesses diverse phenolic compounds, potentially linked to various biological activities. Full article

This study evaluated the effects of different drying techniques on the physicochemical properties of Pleurotus citrinopileatus Singer (P. citrinopileatus), focusing on the ergothioneine (EGT) contents. The P. citrinopileatus was subjected to natural ventilation drying (ND), freeze-drying (FD), and hot-air drying (HD). EGT was extracted using high-hydrostatic-pressure extraction (HHPE), and response surface methodology (RSM) was employed with four variables to optimize the extraction parameters. The crude EGT extract was purified by ultrafiltration and anion resin purification, and its antioxidant activity was investigated. The results showed that the ND method effectively disrupted mushroom tissues, promoting amino acid anabolism, thereby increasing the EGT content of mushrooms. Based on RSM, the optimum extracting conditions were pressure of 250 MPa, extraction time of 52 min, distilled water (dH₂O) as the extraction solvent, and a 1:10 liquid–solid ratio, which yielded the highest EGT content of 4.03 ± 0.01 mg/g d.w. UPLC-Q-TOF-MSE was performed to assess the purity of the samples (purity: 86.34 ± 3.52%), and MS² information of the main peak showed primary ions (m/z 230.1) and secondary cations (m/z 186.1050, m/z 127.0323) consistent with standard products. In addition, compared with ascorbic acid (VC), EGT showed strong free radical scavenging ability, especially for hydroxyl and ATBS radicals, at more than 5 mmol/L. These findings indicate that the extraction and purification methods used were optimal and suggest a possible synthetic path of EGT in P. citrinopileatus, which will help better explore the application of EGT. Full article

The present research study aims to appraise the potential of polyphenol-rich extracts from two Brassica rapa varieties on antioxidant, anti-inflammatory and analgesic activities using carrageenan-induced paw edema model in rats. Methanol extracts of peels and pulps of Brassica rapa yellow root (BRYR) and Brassica rapa white root (BRWR) were prepared using the soxhlet extraction technique. All four extracts were analyzed by reversed-phase high-pressure liquid chromatography (RP-HPLC) for the polyphenols, and results showed that 10 phenolic acids and 4 flavonoids were detected. Gallic acid was the major phenolic acid (174.6–642.3 mg/100 g of dry plant material) while catechin was the major (34.45–358.5 mg/100 g of dry plant material) flavonoid detected in the extracts. The total phenolic contents (TPC) of BRYR peel, BRWR peel, BRYR pulp and BRWR pulp extracts were in the range of 1.21–5.01 mg/g of dry plant material, measured as GAE, whereas the total flavonoid contents (TFC) were found in the range of 0.90–3.95 mg/g of dry plant material, measured as QE. BRYR peel extract exhibited the best DPPH radical scavenging activity (IC₅₀, 3.85 µg/mL) and reducing potential as compared with other extracts. The in vivo anti-inflammatory potential was assessed by carrageenan-induced rat paw edema, and the analgesic potential was investigated by a hot plate test. Suppression of biochemical inflammatory biomarkers including C-reactive protein (CRP), rheumatoid factor (RF) and tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) concentration were also determined. Results showed that BRYR peel extracts reduced paw edema and suppressed the production of TNF-α, IL-6, CRP and RF most significantly, followed by BRWR peel, BRYR pulp and BRWR pulp extracts. In addition, histopathology observation also supports the anti-inflammatory effect of peel extracts as being greater than that of root pulp extracts. Moreover, it was observed that the analgesic effect of the root-peel extracts was also more pronounced as compared with root-pulp extracts. It can be concluded that BRYR peel extract has higher phenolic contents and showed higher suppression of TNF-α, IL-6, CRP and RF, with strong antioxidant, anti-inflammatory and analgesic effects. Full article

The mangosteen (Garcinia mangostana L.) pericarp is known to be rich in potent bioactive phytochemical compounds such as xanthones, which possess pharmacologically important antioxidant activity and beneficial cardiometabolic properties. Mangosteen pericarp is typically classified as unavoidable food waste and discarded, despite being rich in bioactive phytochemical compounds that therefore present an exciting opportunity for valorization. Thus, this study aims to extract phytochemical compounds from mangosteen pericarp using pressurized hot water extraction (PHWE) and determine its biological effects in endothelial cells using RNA sequencing. Liquid chromatography with MS/MS (LC/MSMS) and UV detection (LC/UV) was subsequently used to identify three key phytochemical compounds extracted from the mangosteen pericarp: α-Mangostin, γ-Mangostin, and Gartanin. Within the tested range of extraction temperatures by PHWE, our results demonstrated that an extraction temperature of 120 °C yielded the highest concentrations of α-Mangostin, γ-Mangostin, and Gartanin with a concomitant improvement in antioxidant capacity compared to other extraction temperatures. Using global transcriptomic profiling and bioinformatic analysis, the treatment of endothelial cells with mangosteen pericarp extracts (120 °C PHWE) for 48 h caused 408 genes to be differentially expressed. Furthermore, our results demonstrated that key biological processes related to “steroid biosynthesis and metabolism”, likely involving the activation of the AMPK signaling pathway, were upregulated by mangosteen pericarp extract treatment. In conclusion, our study suggests a green extraction method to valorize phytochemical compounds from mangosteen pericarp as a natural product with potential beneficial effects on cardiometabolic health. Full article

The formulation of polymeric microparticles to encapsulate bioactive compounds from two hop varieties (Nugget and Perle) using sequential green extraction processes was performed. The technologies used were ultrasound-assisted extraction (UAE) and pressurized hot water (PHW) extraction. Liquid phases were analyzed for total phenolic content (~2%), antioxidant activity (IC_50, DPPH: 3.68 (Nugget); 4.46 (Perle) g/L, TEAC (~4–5%), FRAP (~2–3%), and reducing power (~4%)), protein content (~1%), oligosaccharide content (~45%), and for structural features. The fractions obtained from UAE were selected to continue with the drying process, achieving the maximum yield at 120 °C (Perle) and 130 °C (Nugget) (~77%). Based on these results, the formulation of polymeric microparticles using mannitol as the carrier was performed with these fractions. The production yield (~65%), particle size distribution (Perle: 250–750 µm and Nugget: ~100 µm), and rheological features (30–70 mPa s at 0.1 s⁻¹) were the parameters evaluated. The UAE extracts from hop samples processed using a sustainable aqueous treatment allowed the formulation of microparticles with a suitable yield, and morphological and viscosity properties adequate for potential food and non-food applications. Full article

The use of water–ethanol mixtures in hot pressurized liquid extraction (HPLE) to recover phenolic compounds from agro-industrial waste has been successfully investigated. However, the unresolved challenge of reducing solvent costs associated with the process hinders the scaling of this eco-friendly technology. This study evaluated the use of isopropanol as an alternative, lower-cost solvent for recovering polyphenols from discarded blueberries through the HPLE process. HPLE was carried out using water–isopropanol mixtures (0, 15 and 30%) at 70, 100, and 130 °C. The total polyphenol content (TPC), antioxidant capacity (DPPH and ORAC), glucose and fructose contents, and polyphenol profile of the extracts were determined. HPLE extracts obtained using high isopropanol concentrations (30%) and high temperatures (130 °C) presented the highest TPC (13.57 mg GAE/gdw) and antioxidant capacity (IC50: 9.97 mg/mL, ORAC: 246.47 µmol ET/gdw). Moreover, the use of 30% water–isopropanol resulted in higher yields of polyphenols and removal of reducing sugars compared to atmospheric extraction with water–acetone (60%). The polyphenolic profiles of the extracts showed that flavanols and phenolic acids were more soluble at high concentrations of isopropanol (30%). Contrarily, flavonols and stilbenes were better recovered with 15% isopropanol and pure water. Therefore, isopropanol could be a promising solvent for the selective recovery of different bioactive compounds from discarded blueberries and other agro-industrial residues. Full article

The use of high-pressure technologies is a hot topic in food science because of the potential for a gentle process in which spoilage and pathogenic microorganisms can be eliminated; these technologies also have effects on the extraction, preservation, and modification of some constituents. Whole grapes or bunches can be processed by High Hydrostatic Pressure (HHP), which causes poration of the skin cell walls and rapid diffusion of the anthocyanins into the pulp and seeds in a short treatment time (2–10 min), improving maceration. Grape juice with colloidal skin particles of less than 500 µm processed by Ultra-High Pressure Homogenization (UHPH) is nano-fragmented with high anthocyanin release. Anthocyanins can be rapidly extracted from skins using HHP and cell fragments using UHPH, releasing them and facilitating their diffusion into the liquid quickly. HHP and UHPH techniques are gentle and protective of sensitive molecules such as phenols, terpenes, and vitamins. Both techniques are non-thermal technologies with mild temperatures and residence times. Moreover, UHPH produces an intense inactivation of oxidative enzymes (PPOs), thus preserving the antioxidant activity of grape juices. Both technologies can be applied to juices or concentrates; in addition, HHP can be applied to grapes or bunches. This review provides detailed information on the main features of these novel techniques, their current status in anthocyanin extraction, and their effects on stability and process sustainability. Full article

Seaweeds, notably cochayuyo (Durvillaea incurvata), are recognized for their rich macro- and micronutrient content, along with their inhibitory effects on the α-glucosidase enzyme. The present study aims to evaluate the effectiveness of this inhibition in actual starchy food products under in vitro gastrointestinal conditions. This study utilized freeze-dried cochayuyo, extracted using hot pressurized liquid extraction with 50% ethanol at 120 °C and 1500 psi. The inhibition mechanism of α-glucosidase was determined, and the polyphenol composition of the extract was analyzed using Ultra-High-Performance Liquid Chromatography. This study further evaluated the extract’s impact on starch digestibility, total phenolic content, and antioxidant capacity in pasta (noodles) as representative starchy food under gastrointestinal conditions. The results indicate that the α-glucosidase inhibition mechanism is of mixed type. Phenolic compounds, primarily tetraphloroethol, could contribute to this anti-enzymatic activity. The extract was observed to decrease starch digestibility, indicated by a lower rate constant (0.0158 vs. 0.0261 min⁻¹) and digested starch at an infinite time (77.4 vs. 80.5 g/100 g). A significant increase (~1200 vs. ~390 µmol TROLOX/100 g) in antioxidant activity was also noted during digestion when the extract was used. Thus, this study suggests that the cochayuyo extract can reduce starch digestion and enhance antioxidant capacity under gastrointestinal conditions. Full article