Search Results (88)

Alpinia officinarum Hance exhibits various bioactivities, with polysaccharides being one of its key bioactive components. However, the relationship between the structural characteristics of these polysaccharides and their bioactivities remains unclear and underexplored. In this study, to optimize the extraction process, a Response Surface Methodology-based design combined with single-factor experiments was applied to determine the optimal conditions for the ultrasonic-microwave-assisted extraction of polysaccharides from A. officinarum. The primary structural characteristics and antioxidant activities of two polysaccharide fractions, PAOR-1 extracted by ultrasonic-microwave-assisted extraction and PAOR-2 extracted by hot reflux extraction (HRE), were systematically compared. The optimal extraction conditions, including a liquid–solid ratio of 1:50, extraction time of 19 mins, and ultrasonic power of 410 W, yielded a maximum polysaccharide extraction rate of 18.28% ± 2.23%. The extracted polysaccharides were characterized as acidic polysaccharides with a three-dimensional structure. PAOR-1 and PAOR-2 have different monosaccharide compositions, surface morphologies, and thermal stabilities. The antioxidant activity in vitro studies suggest that PAOR-1 may have higher antioxidant activity than PAOR-2 due to its higher content of uronic acids, lower relative molecular mass, and a more closely packed spatial configuration. These findings provide a theoretical basis for the development and utilization of AOR. Full article

This study employed high-pressure ultrasonic-microwave-assisted extraction (HP-UMAE) to extract gingerols from ginger. The extraction yield and total polyphenol content of the extracts were determined. Their antioxidant activity was assessed by DPPH and ABTS radical scavenging assays, and compared with extracts obtained by leaching extraction, reflux extraction, ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), and ultrasonic-microwave-assisted extraction (UMAE). The results demonstrated that HP-UMAE achieved the highest extraction yield and the strongest ABTS radical scavenging activity among the evaluated methods. Furthermore, HP-UMAE extracts exhibited the highest concentrations of key gingerol constituents: 6-gingerol (14.29 mg/L), 8-gingerol (0.38 mg/L), 10-gingerol (1.95 mg/L), and 6-shogaol (4.32 mg/L). This enhanced efficacy is attributed to the synergistic combination of ultrasonic cavitation and microwave-induced thermal effects under elevated pressure. This synergy creates conditions promoting cellular wall disruption, facilitating the release of intracellular components, while concurrently enhancing solvent penetration and gingerol solubility. Scanning electron microscopy (SEM) analysis confirmed the significant structural damage inflicted on ginger cell walls following HP-UMAE treatment. The process parameters for HP-UMAE were optimized using single-factor experiments. The optimal extraction conditions were determined as follows: microwave power 800 W, ultrasonic power 1000 W, liquid-to-solid ratio 55:1, and temperature 100 °C (corresponding pressure 2 MPa). Under these optimized parameters, the extraction yield and ABTS radical scavenging rate reached their peak performance, yielding values of 4.52% and 43.23%, respectively. Full article

Cacao is a food of global interest. Currently, the industry primarily utilizes the seed, which represents between 21% and 23% of the total fruit weight. In 2023, global production reached 5.6 million tons of fermented dry cacao beans, while approximately 25.45 million tons corresponded to cacao residues. The objective of this review was to compile and analyze alternatives for the utilization of cacao by-products. The methodology involved technological surveillance conducted in specialized databases between 2015 and 2025. Metadata were analyzed using VOSviewer software version 1.6.20. Priority was given to the most recent publications in high-impact indexed journals. Additionally, 284 patent documents were identified, from which 15 were selected for in-depth analysis. The reviewed articles and patents revealed a wide range of industrial applications for cacao by-products. Technologies including ultrasonic and microwave-assisted extraction, phenolic microencapsulation, cellulose nanocrystal isolation and targeted microbial fermentations maximize the recovery of polyphenols and antioxidants, optimize the production of high-value bioproducts such as citric acid and ethanol, and yield biodegradable precursors for packaging and bioplastics. The valorization of lignocellulosic by-products reduces pollutant discharge and waste management costs, enhances economic viability across the cacao value chain, and broadens functional applications in the food industry. Moreover, these integrated processes underpin circular economy frameworks by converting residues into feedstocks, thereby promoting sustainable development in producer communities and mitigating environmental impact. Collectively, they constitute a robust platform for the comprehensive utilization of cacao residues, fully aligned with bioeconomy objectives and responsible resource stewardship. Full article

Pine nut oil (PNO) is highly valued by consumers for its rich content of unsaturated fatty acids, which confer unique nutritional benefits. However, PNO is highly susceptible to lipid oxidation during storage and extraction. This chemical degradation compromises product quality and poses potential risks to food safety. To address this challenge, the food industry is developing antioxidant strategies, including optimizing pretreatment conditions to improve flavor and storage stability. Green extraction technologies such as microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) have been introduced to enhance extraction efficiency and promote environmental sustainability. Light-proof packaging, reduced oxygen environments, and temperature control have also been employed to significantly extend the shelf life of PNO. Furthermore, to maintain the nutritional integrity and safety of PNO while expanding its functional applications in the food industry, several innovative approaches have been employed. These include the incorporation of natural antioxidants, the development of Pickering emulsions, the use of microencapsulation, and the formulation of oleogels. Full article

As the focus on green chemistry intensifies, researchers are progressively looking to incorporate biodegradable and environmentally friendly solvents. Given the prevalent use of inorganic solvents in conventional methods for detecting selenium content, this study utilized a mixture design approach to create four deep eutectic solvents (DESs). The elements of the DESs consisted of six different compounds: guanidine hydrochloride, fructose, glycerol, citric acid, proline, and choline chloride. The synthesized deep eutectic solvents (DESs) exhibited a uniform and transparent appearance. The ideal ratios for each DES were established based on their density and viscosity measurements, leading to the formulations of DES1 (34% guanidine hydrochloride, 21% fructose, 45% water), DES2 (23% guanidine hydrochloride, 32% glycerol, 45% water), DES3 (27.5% citric acid, 27.5% proline, 45% water), and DES4 (30% choline chloride, 25% citric acid, 45% water). The characterization of the deep eutectic solvents (DESs) was performed using nuclear magnetic resonance (NMR) spectroscopy and infrared (IR) spectroscopy, which confirmed the molecular formation of each DES. Following this, the DESs were applied as extraction solvents in a process involving ultrasonic-assisted microextraction (UAE) combined with inductively coupled plasma mass spectrometry (ICP-MS) to assess the selenium levels in selenium-rich rice. The results were benchmarked against traditional microwave-assisted acid digestion (TM-AD), revealing selenium recovery rates ranging from 85.5% to 106.7%. These results indicate that UAE is an effective method for extracting selenium from selenium-rich rice, thereby establishing a solid data foundation for the environmentally friendly analysis of selenium content in rice. Full article

Eugenol is the key bioactive compound in clove oil, which has a variety of biological functions and is extensively employed in the medicinal and food industries. Nowadays, deep eutectic solvents (DESs) have received considerable attention as green solvents that enhance extraction efficiency. The present study investigated the effects of DESs on the eugenol composition in clove essential oils (CEOs) extracted from clove buds using ultrasonic- and microwave-assisted hydrodistillation techniques. The study revealed that both DES-based microwave-assisted hydrodistillation (DES-MHD) and ultrasonic-assisted DES pretreatment followed by microwave-assisted hydrodistillation (U-DES-MHD) significantly enhanced the eugenol purity in CEOs compared to the MHD method without the use of DESs. The great CEOs with a high amount of eugenol obtained via choline chloride–oxalic acid (ChCl-OA) at a 1:2 molar ratio were used as DESs. Their oils had a eugenol content of 82.90% and 83.34%, respectively, corresponding to the extraction by DES-MHD and U-DES-MHD methods, which were raised from the oil’s extraction without DES by MHD 7.42% and 8.36%, respectively. Corresponding to a strong antioxidant agent of eugenol, the oils extracted by ChCl-OA-based MHD and ultrasonic-assisted ChCl-OA-based MHD methods had significantly stronger DPPH radical scavenging activity with an IC₅₀ level of 2.16 ± 0.11 and 2.19 ± 0.05 μg/mL, respectively, than the oils extracted without DESs. Hence, these innovative processes offer a promising approach to improving the bioactivity of clove oils, while providing straightforward operation and environmentally friendly extraction methods. Additionally, these novel processes may find application in other edible essential oil extractions for the food and pharmaceutical industries. Full article

To investigate the structure–antioxidant activity relationship, Pleurotus ferulae polysaccharides were extracted using ultrasonic (U-PFPS) and microwave/ultrasonic-assisted methods (MU-PFPS). Compared to U-PFPS with a molecular weight of 1.566 × 10³ kDa, MU-PFPS exhibited a lower molecular weight of 89.26 kDa. In addition, unlike U-PFPS, which is primarily composed of glucose (Glu:Man:Gal = 91.1:3.5:5.4), MU-PFPS has a more balanced composition of Glu:Man:Gal in the ratio of 39.4:27.8:32.8 and contains more branched chains. Furthermore, antioxidant analysis revealed that high concentration (at concentrations above 600 μg/mL) MU-PFPS demonstrated stronger protective effects against oxidative damage in RAW264.7 cells than U-PFPS did. Collectively, these data suggest that lower molecular weight and higher branching degree of polysaccharides at appropriate concentrations may correlate with enhanced antioxidant enzyme activities. Our work provides a method for isolating polysaccharides with higher antioxidant activity and offers insights into the structure–activity relationship of polysaccharides, laying the foundation for future applications in polysaccharide modification and structural characterization. Full article

Flavonoids are the most abundant functional compounds distributed in higher plants, and are used as important dietary components for human health protection. The development of natural flavonoids, such as functional food or medicinal food, has received extensive attention in recent years. The extraction, separation, and quantitation of flavonoids are the key techniques in the utilization of flavonoid resources. The traditional methods for flavonoid extraction and separation always used toxic solvents, which produce toxic residues and pollute the environment. Based on an analysis of the literature on flavonoid resources, the utilization, separation, quantitation, and green separation techniques of flavonoids were summarized. First, extraction by hot water or hot ethanol, assisted by pressurization and microwave-ultrasonication, then concentration and precipitation of flavonoids by cool water or cool ethanol or ethanol/water in specific ratios. This method could obtain over 85% purity in the first cycle and over 95% purity after three precipitation cycles in the separation of the most commonly used flavonoids, such as dihydromyricetin, rutin, and quercetin. In conclusion, flavonoids showed great prospects in human health protection and disease treatment. Chemical structure-based separation using the water–ethanol methods and assisted with microwave-ultrasonication, pressurization, and temperature regulation proved to be efficient and environmentally friendly, showing great potential for the flavonoid industry. These “green” processing techniques and mechanisms deserve further research. Full article

Marine microalgae are emerging as promising sources of polyphenols, renowned for their health-promoting benefits. Recovering polyphenols from microalgae requires suitable treatment and extraction techniques to ensure their release from the biomass and analytical methodologies to assess their efficiency. This review provides a comprehensive comparison of traditional and cutting-edge extraction and analytical procedures applied for polyphenolic characterization in marine microalgae over the past 26 years, with a unique perspective on optimizing their recovery and identification. It addresses (I) cell disruption techniques, including bead milling, high-speed homogenization, pulsed electric field, ultrasonication, microwave, freeze-thawing, and enzymatic/chemical hydrolysis; (II) extraction techniques, such as solid–liquid extraction, ultrasound and microwave-assisted extraction, pressurized-liquid extraction, and supercritical CO₂; (III) analytical methods, including total phenolic and flavonoid content assays and advanced chromatographic techniques like GC-MS, HPLC-DAD, and HPLC-MS. Key findings showed bead milling and chemical hydrolysis as effective cell disruption techniques, pressurized-liquid extraction and microwave-assisted extraction as promising efficient extraction methods, and HPLC-MS as the finest alternative for precise phenolic characterization. Unlike previous reviews, this study uniquely integrates both extractive and analytical approaches in one work, focusing exclusively on marine microalgae, a relatively underexplored area compared to freshwater species, offering actionable insights to guide future research and industrial applications. Full article

This study represents the first investigation into the ultrasonic and microwave extraction of bioactive metabolites from Jania rubens (J. rubens) (red seaweed) and Sargassum. muticum (S. muticum) (brown seaweed), with a focus on their biological activities. The research compares ultrasound-assisted extraction (UAE) with microwave-assisted extraction (MAE) utilizing a hydromethanolic solvent to evaluate their effects on these seaweeds’ bioactive compounds and biological activities. The assessment included a series of antioxidant essays: DPPH, ABTS, phenanthroline, and total antioxidant capacity, followed by enzyme inhibition activities: alpha-amylase and urease. Results revealed significant proportions of phenolic compounds, ranging from 48.31 ± 0.32 to 74.42 ± 0.80 μg GAE/mg, depending on the extraction method. The extracts demonstrated a high antioxidant activity, with IC₅₀ values ranging from 26.58 ± 0.39 to 87.55 ± 0.69 μg/mL. Notably, the MAE extract of S. muticum showed a value of 48.11 ± 2.75 μg/mL for alpha-amylase inhibition, which is strictly superior to the reference acarbose with an IC₅₀ equal to 3431.01 μg/mL. UPLC-ESI-MS/MS analysis identified 14 bioactive compounds. The proportion of riboflavin with MAE was 70.58% and 59.11% for J. rubens and S. muticum fractions, respectively. These findings underscore the critical influence of extraction technique selection on bioactive compounds’ yield and efficiency, highlighting the potential of algal biomass as a sustainable alternative in various applications. Full article

Nowadays, eco-friendly extraction techniques are often used to develop natural plant extracts for commercial use. In the current investigation, Greek oregano (Origanum vulgare) phenolic extracts from different cultivated accessions were recovered employing ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), and accelerated solvent extraction (ASE). The phytochemical profile of the oregano extracts, as determined by spectrophotometric and chromatographic techniques, as well as antioxidant activity (ABTS, DPPH, and FRAP assays), was used to compare the three extraction approaches. The results showed that oregano phenolic extracts obtained by MAE held the highest total phenolic content, total flavonoid content, and also a higher content of the main phenolic compounds identified, rosmarinic acid, salvianolic acid B and carvacrol, as determined by LC-MS analysis, followed by those extracted by UAE and ASE. All of the tested extracts exhibited relatively high antioxidant activities, especially the MAE extracts. Oregano extracts produced by various extraction techniques were subjected to a multivariate data analysis to highlight differences in phytochemical profiles, and their correlation to antioxidant activity. According to our findings, it was evident that MAE offers more efficient and effective extraction of bioactive compounds in terms of obtaining phytochemical-rich oregano extracts, with applications in the food and pharmaceutical industries. Full article

Phycocyanin was extracted from Spirulina platensis using conventional extraction (CE), direct ultrasonic-assisted extraction (direct UAE), indirect ultrasonic-assisted extraction (indirect UAE), and microwave-assisted extraction (MAE) methods at different temperatures, extraction intervals, stirring rate, and power intensities while maintaining the same algae to solvent ratio (1:15 w/v). The optimization of the extraction parameters indicated that the direct UAE yielded the highest phycocyanin concentration (29.31 ± 0.33 mg/mL) and antioxidant activity (23.6 ± 0.56 mg TE/g algae), while MAE achieved the highest purity (Rp = 0.5 ± 0.002). Based on the R_P value, phycocyanin extract obtained by MAE (1:15 w/v algae to solvent ratio, 40 min, 40 °C, and 900 rpm) was selected as active compound in an alginate-based hydrogel formulation designed as potential wound dressings. Phycocyanin extracts and loaded hydrogels were characterized by FT-IR analysis. SEM analysis confirmed a porous structure for both blank and phycocyanin loaded hydrogels, while the mechanical properties remained approximately unchanged in the presence of phycocyanin. Phycocyanin release kinetics was investigated at two pH values using Zero-order, First-order, Higuchi, and Korsmeyer-Peppas kinetics models. The Higuchi model best fitted the experimental results. The R² value at higher pH was nearly 1, indicating a superior fit compared with lower pH values. Full article

As natural bioactive compounds, plant pigments play crucial roles not only in plant phenotype, growth, development, and adaptation to stress but also hold unique value in biotechnology, healthcare, and industrial applications. There is growing interest in the biosynthesis and acquisition of plant pigments. Thus, this paper explores emerging extraction methods of natural pigments and elucidates the biosynthesis pathways of four key plant pigments, chlorophylls, carotenoids, anthocyanins, and betalaine in vivo and in vitro. We comprehensively discuss the application of solvent, supercritical fluid [extraction], ultrasonic, and microwave-assisted extraction techniques, as well as introducing key enzymes, precursors, and synthetic pathways involved in pigment synthesis. δ-Aminolevulinic acid represents a pivotal initiating enzyme for chlorophyll synthesis, whereas isopentenylpyrophosphate, (IPP) and dimethylallyl pyrophosphate, (DMAPP) are closely associated with carotenoid biosynthesis. Phenylalanine and tyrosine are critical substances for anthocyanin and betalaine synthesis, respectively. Hence, crucial genes such as chlI, crtB, PGT8, CYP76AD1, and BvDODA can be employed for heterologous biosynthesis in vitro to meet the demand for increased plant pigment amount. As a pivotal determinant of plant coloration, an in-depth exploration into the high-quality acquisition of plant pigments can provide a basis for developing superior pigments and offer new insights into increasing pigment yield. Full article

Gracilaria lamaneiformis, a red seaweed, is an abundant source of bioactive polysaccharides with significant health-promoting properties. Nevertheless, the broad application of G. lamaneiformis in the nutraceutical and pharmaceutical sectors remains constrained due to the absence of comprehensive data. This review provides a detailed examination of the preparation methods, structural characteristics, and biological activities of G. lamaneiformis polysaccharides (GLPs). We explore both conventional and advanced extraction techniques, highlighting the efficiency and yield improvements achieved through methods such as microwave-, ultrasonic-, and enzyme-assisted extraction. The structural elucidation of GLPs using modern analytical techniques, including high-performance liquid chromatography, gas chromatography, and nuclear magnetic resonance spectroscopy, is discussed, providing comprehensive insights into their molecular composition and configuration. Furthermore, we critically evaluate the diverse biological activities of GLPs, including their antioxidant, anti-inflammatory, antitumor, and gut microbiota modulation properties. This review underscores the therapeutic potential of GLPs and suggests future research directions to fully harness their health benefits. Full article

The worrying and constant increase in the quantities of food and beverage industry by-products and wastes is one of the main factors contributing to global environmental pollution. Since this is a direct consequence of continuous population growth, it is imperative to reduce waste production and keep it under control. Re-purposing agro-industrial wastes, giving them new life and new directions of use, is a good first step in this direction, and, in global food production, vegetables and fruits account for a significant percentage. In this paper, brewery waste, cocoa bean shells, banana and citrus peels and pineapple wastes are examined. These are sources of bioactive molecules such as polyphenols, whose regular intake in the human diet is related to the prevention of various diseases linked to oxidative stress. In order to recover such bioactive compounds using more sustainable methods than conventional extraction, innovative solutions have been evaluated in the past decades. Of particular interest is the use of deep eutectic solvents (DESs) and compressed solvents, associated with green techniques such as microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), pressurized liquid extraction (PLE) and pulsed-electric-field-assisted extraction (PEF). These novel techniques are gaining importance because, in most cases, they allow for optimizing the extraction yield, quality, costs and time. Full article