Recent Advances in Microwave Assisted Extraction of Bioactive Compounds from Complex Herbal Samples: A Review

Current developments and trends in hybrid extraction techniques for green analytical applications in natural products

Natural product extraction has advanced significantly due to the growing need for environmentally friendly and sustainable analytical techniques. The medicinal benefits of natural products are gaining worldwide recognition. This shift emphasizes the need for sustainable extraction methods, as traditional organic solvents can negatively impact biodiversity. This review looks at new green extraction methods such as pressurized liquid extraction, ultrasound-assisted extraction, microwave-assisted extraction, and supercritical fluid extraction. The overview describes the main goals, workings, and extraction principles of these techniques, which are used to extract phytochemicals from various plant sources. Additionally covered is how green solvents, more especially bio-based and deep eutectic solvents, can enhance the sustainability of these techniques. This review examines the developments in synergistic extraction, emphasizing how these hybrid techniques can be used to isolate a variety of natural products, including polyphenols, alkaloids, essential oils, and more. It also emphasizes how crucial these techniques are to the development of high-performance, environmentally friendly analytical platforms for the use of natural products. The recent uses of these extraction techniques are covered in this review. Despite the positive results, standardization, selectivity, scalability, and economic viability issues must be recognized and addressed.

Therapeutic Prospects of Undaria pinnatifida Polysaccharides: Extraction, Purification, and Functional Activity

Undaria pinnatifida, an edible brown seaweed that is widely consumed in East Asia, has gained increasing recognition for its health benefits. Among its bioactive compounds, polysaccharides have attracted significant attention due to their diverse biological activity. This review provides a comprehensive overview of recent advancements in the extraction, purification, structural characterization, and bioactivity of U. pinnatifida polysaccharides. We discuss state-of-the-art extraction techniques, including ultrasound-assisted, microwave-assisted, and enzyme-assisted extraction, as well as purification strategies such as membrane separation and chromatographic methods. Furthermore, we highlight their potential biological activity, including antioxidant, immunomodulatory, anticancer, gut health-promoting, and anti-hyperglycemic effects, along with their underlying mechanisms of action. By summarizing the latest research, this review aims to provide valuable insights into the development and application of U. pinnatifida polysaccharides in functional foods and pharmaceuticals.

Improving Triterpenoid Extraction Efficiency from Inonotus hispidus Using Macroporous Adsorption Resin: An Aim for Functional Food Development

The triterpenoids from Inonotus hispidus exhibit several valuable bioactivities, including antioxidant, anti-inflammatory, and anticancer properties, making them highly sought-after for applications in functional foods. To obtain more I. hispidus triterpenoids with higher content for subsequent application in functional food, this study firstly screened a strain with a high triterpenoid yield for the cultivation of fruiting bodies. Afterwards, the static adsorption and desorption capacities of seven macroporous adsorption resins (MARs) for fruiting body triterpenoids were evaluated via static tests, and MAR HPD-600 showed the best performance. The static adsorption kinetics and isotherms of triterpenoids were analyzed further using MAR HPD-600, revealing that the adsorption process followed pseudo-second-order kinetics and the Freundlich model, indicating a spontaneous exothermic reaction. The dynamic adsorption-desorption parameters of MAR HPD-600 were subsequently evaluated to establish the optimal enrichment process. With the optimal strategy, the content of triterpenoids in the desorption solution of MAR HPD-600 increased from 26.72 to 129.28 mg/g, with a high yield of 75.48%. Conclusively, the application of MAR presents an efficient and cost-effective technique for extracting I. hispidus triterpenoids, making it well-suited for functional food production requirements.

Anti-inflammatory Effect of Microwave-Assisted Opuntia humifusa Extract (MA-OHE) against DSS-Induced Colitis

Ulcerative colitis (UC), including chronic colitis, is characterized by severe inflammation and oxidative stress in the colon. This study investigated the therapeutic potential of microwave-assisted Opuntia humifusa extract (MA-OHE), prepared using water (WE) and water-methanol (WME) solvents, in a chronic colitis model in mice induced by dextran sodium sulfate (DSS). Chemical profiling using UV-vis, FTIR, and HPLC analyses revealed that WME contains significantly higher concentrations of phenolic and flavonoid compounds than WE. These bioactive compounds enhance the antioxidant capacity of WME, as demonstrated by the superior radical scavenging activity in DPPH and ABTS assays and more pronounced suppression of nitric oxide (NO) synthesis in RAW 264.7 cells activated with LPS. In the DSS-induced chronic colitis model, treatment with WME notably enhanced colitis indicators, such as by restoring body weight, lowering the disease activity index (DAI) score, and maintaining colon length. Additionally, MA-OHE (WME) treatment decreased proinflammatory cytokine levels, such as TNF-α, IL-6, and IL-1β, in a dose-dependent manner, demonstrating strong anti-inflammatory effects. Histological examination additionally validated the recovery of colonic crypts and goblet cells and the reduction in inflammatory infiltration in groups treated with MA-OHE. These findings highlight the enhanced therapeutic potential of WME compared with that of WE, which is attributed to its richer composition of bioactive compounds. MA-OHE, particularly WME, demonstrated strong antioxidant, anti-inflammatory, and tissue-protective effects, indicating its potential as a natural treatment for chronic colitis management. Proinflammatory cytokine level modulation underscores its effectiveness in mitigating inflammation and supporting colonic tissue recovery.

Natural Products Targeting Tau Protein Phosphorylation: A Promising Therapeutic Avenue for Alzheimer's Disease

Alzheimer's disease is a progressive neurodegenerative disorder characterized by tau protein hyperphosphorylation and neurofibrillary tangle formation, which are central to its pathogenesis. This review focuses on the therapeutic potential of natural products in targeting tau phosphorylation, a key factor in Alzheimer's disease progression. It comprehensively summarizes current research on various natural compounds, including flavonoids, alkaloids, saponins, polysaccharides, phenols, phenylpropanoids, and terpenoids, highlighting their multitarget mechanisms, such as modulating kinases and phosphatases. The ability of these compounds to mitigate oxidative stress, inflammation, and tau pathology while enhancing cognitive function underscores their value as potential anti-Alzheimer's disease therapeutics. By integrating recent advances in extraction methods, pharmacological studies, and artificial intelligence-driven screening technologies, this review provides a valuable reference for future research and development of natural product-based interventions for Alzheimer's disease.

Comparative evaluation of ultrasound-assisted extraction with other green extraction methods for sustainable recycling and processing of date palm bioresources and by-products: A review of recent research

The global food waste crisis has significantly contributed to climate change, water pollution, and land degradation. Date palm waste, including seeds, fronds, and fruit pulp residues, represents a valuable source of bioactive compounds with potential applications in food, pharmaceutical, and cosmetic industries. This study presents a comparative evaluation of ultrasound-assisted extraction and other novel extraction techniques, such as pressure-based extraction, pulsed electric fields, microwaves, and natural deep eutectic solvents, for recovering bioactive compounds from date palm waste. These methods were assessed for their efficiency and sustainability in extracting antioxidants and phenolic compounds, and other bioactives while minimizing the use of harmful solvents and high temperatures. Critical factors, such as extraction time, solvent type, temperature, and pressure were crucial indicators to achieve higher extraction efficiencies with lower environmental impacts compared to traditional methods. Additionally, combining these techniques may further optimize the extraction process. This study contributes to the development of sustainable strategies for valorizing date palm byproducts and promoting a circular economy in the food industry. By developing sustainable extraction methods that minimize environmental impacts, this research directly supports the United Nations' Sustainable Development Goals, particularly SDG 12 (Responsible Consumption and Production) and SDG 13 (Climate Action).

Production, extraction, and authentication of natural and non-natural vanillin. A comprehensive review and economic future biotechnology perspectives

Vanillin is a chief flavoring agent owing to its immense popularity in food, beverage, and pharmaceutical industries. This study holistically dissects vanillin quality control approaches that include conventional, hyphenated, and sensory analyses. Markers to differentiate between authentic, synthetic, and adulterated vanilla are highlighted using hyphenated techniques. Carbon isotope ratio range appears of potential to identify vanillin originating from biosynthetic (C3 plant), synthetic (petroleum) sources, or vanilla pods. Novel extraction methods typically provide greater selectivity, higher purity, shorter extraction times, and ecofriendly attributes compared to conventional methods. Best methods include supercritical fluids (SCF) or natural deep eutectic solvents (NADES) that promoted higher yield of vanillin. The review also highlights the promising avenue of biotransformation, the safest technique for the production of vanilla flavor components, tackling current challenges and emphasizing its potential to meet the market needs for authenticated and high-quality yields of vanillin.

Anethum graveolens L. (dill) seed polyphenolic fractions: Assessment of high-voltage electrical discharges, subcritical water, and microwave-assisted extraction systems

Continuous exploration of innovative and sustainable solutions within green chemistry is imperative to tackle challenges inherent in traditional production processes. This study examined three novel methods for obtaining polyphenolic extracts from dill seeds: nonthermal high voltage electric discharge (HVED), subcritical water extraction (SWE), and microwave-assisted extraction (MAE). SWE was conducted at temperatures ranging from 100 to 200°C under 30 bar pressure, while MAE utilized a hydroethanolic solvent at temperatures from 40 to 120°C. HVED extraction was performed at varying frequencies (40-100 Hz) and durations (5-15 min) in water. The total phenolic and flavonoid content of the extracts was quantified, and antioxidant activity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Polyphenol content and DPPH radical scavenging capacity varied across techniques, with MAE at 40°C yielding the highest values. Increasing MAE temperature caused a steep decline in total phenol and flavonoid contents and a rise in DPPH IC50 values. Conversely, SWE significantly increased phenolic recovery at temperatures between 150-200°C. HVED extraction revealed frequency as the most critical parameter for phenolic recovery. Catechin (224.88 µg/mL), epicatechin (120.62 µg/mL), epigallocatechin (107.56 µg/mL), and procyanidin B1 (116.36 µg/mL) emerged as the primary phenolics. SWE demonstrated superior suitability for individual phenolic recovery compared with the other two techniques. Multivariate data analysis reveals relationships between extraction parameters and polyphenol recovery, underscoring the potential for eco-friendly and efficient extraction processes. This study highlights the transition toward sustainable extraction methods in modern industrial processing. PRACTICAL APPLICATION: This study provides insights into innovative extraction techniques for obtaining polyphenols from dill seeds, which could be applied in the food, cosmetic, and pharmaceutical industries. The findings suggest that these eco-friendly methods can improve the efficiency of extracting antioxidants, offering manufacturers a greener and more effective approach to producing health-promoting ingredients.

Extraction and Processing of Bioactive Phytoconstituents from Widely Used South African Medicinal Plants for the Preparation of Effective Traditional Herbal Medicine Products: A Narrative Review

Medicinal plants are sources of crude traditional herbal medicines that are utilized to reduce the risk of, treat, or manage diseases in most indigenous communities. This is due to their potent antioxidant and anti-inflammatory effects. It is estimated that about 80% of the population in developing countries rely on herbal traditional medicines for healthcare. This signifies the need for traditional herbal medicines, which are polyherbal formulations prepared by traditional health practitioners. This review examines preparatory steps to extract bioactive phytoconstituents and post-extraction processes to increase the potency of the extracted bioactive phytoconstituents. Achieving this will allow for the reduced use of plant materials and promote the sustainable use of the limited resource of medicinal plants, especially in our South African context. Electronic ethnobotanical books and online databases were used to find studies that focus on phytoconstituent extraction and post-extraction processing to enhance the potency of the extracted bioactive phytoconstituents. Modification of the extracted bioactive phytoconstituents to synthesize daughter compounds facilitates an enhancement in their potency and bioavailability. Based on the data collected through this review, the importance of understanding the properties of the targeted phytoconstituents is essential in selecting the required extraction method. This determines the quality and yield of extracted bioactive phytoconstituents.

Preparation of Rare Dehydrated Protopanaxadiol Ginsenosides from Panax notoginseng Leaves by Confined Microwave-Driven Transformation

Rare dehydrated ginsenosides barely exist in natural ginseng plants. Herein, the confined microwave technique was utilized to transform the main ginsenosides of Panax notoginseng leaves (PNL) into dehydrated ginsenosides. The main microwave-treated products of dried PNL are dehydrated ginsenoside Rk1, Rg5, notoginsenoside SFt3, and SFt4. Comparatively, the main microwave-treated products of water preimmersed PNL are dehydrated ginsenoside Rk2, Rh3, notoginsenoside SFt3, and SFt4. The impacts of solvent, solid-liquid ratio, microwave temperature and duration on the yield of dehydrated ginsenosides were explored. Based on theoretical calculation, primary ginsenosides in water preimmersed PNL are more prone to deglycosylation at the C-20 site and dehydration elimination reactions at the side chain during microwave treatment. Moreover, reference compounds were used to verify ginsenoside transformation pathway, and the dehydrated ginsenosides were individually purified and identified. In short, this study elucidates novel approach for preparing rare Δ20(21)- and Δ20(22)-dehydrated protopanoxadiol ginsenosides.

Physical field-assisted deep eutectic solvent processing: A green and water-saving extraction and separation technology

Extraction of organic and bioactive compounds from plant materials with the traditional organic solvents aided by water or oil bath heating is not sustainable, because it consumes a lot of energy, time, water/oil, solvents, and results in lower yield. This review discusses deep eutectic solvent (DES) as a green solvent, physical field technology (PFT) as a water-saving and green technology, and how the coupling of PFT (ultrasound [US], microwave [MW], infrared [IR]) to DES will improve the yield and quality of protein, polysaccharides, polyphenols, pectin, and terpenoids extracted from plant materials. Ultrasonication increases DES extraction efficiency via cavitation dislodgement and pores creation. IR coupling to DES enhances the extraction yield of polyphenols and the antioxidant and antiradical activity. MW improves DES extraction yield, reduces energy consumption, operational cost, and compound degradation, and is inferred to be the greenest technology.

Extraction and Analytical Methods for the Characterization of Polyphenols in Marine Microalgae: A Review

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.

Application of Microwave-Assisted Water Extraction (MAWE) to Fully Realize Various Physiological Activities of Melaleuca quinquenervia Leaf Extract

Melaleuca quinquenervia is widely grown in tropical areas worldwide. Studies have demonstrated that extracts of its buds, leaves, and branches obtained through hydrodistillation, steam distillation, or solvent extraction exhibit physiological activities, including anti-melanogenic, antibacterial, and antioxidant properties; nevertheless, such extracts are mostly not effectively collected or adequately utilized. Accordingly, this study applied a rapid, effective, and easy-to-operate microwave-assisted water extraction (MAWE) technique for the first time to prepare M. quinquenervia leaf extract (MLE) with improved physiological activities. The results indicated that the optimal irradiation time and liquid/solid ratio for the production of the MLE were 180 s and 20 mL/g, respectively. Under optimal conditions, the freeze-dried MLE achieved a high yield (6.28% ± 0.08%) and highly effective broad-spectrum physiological activities. The MLE exhibited strong antioxidant, antiaging, and anti-inflammatory activities and excellent antityrosinase and antimicrobial activities. Additionally, the MLE was noncytotoxic at concentrations of ≤300 mg/L, at which it exhibited pharmacological activity. The results also indicated that the MLE comprised a total of 24 chemical compounds and 17 phenolic compounds. Among these compounds, luteolin contributed to antityrosinase activity. The extract's antiaging activity was attributed to ellagic acid and quercetin, its anti-inflammatory activity resulted from ellagic acid and kaempferol, and its antimicrobial activity resulted from quercetin and 3-O-methylellagic acid. In conclusion, the MAWE-derived MLE may be useful as a functional ingredient in cosmetic products, health foods, and botanical drugs.

Innovation in cacti extraction: Evaluating green methods for bioactive compounds

The extraction of bioactive compounds from cacti using green methods holds promise as an area of research that remains relatively underexplored. This review aims to summarize findings and trends in this field, assessing the effectiveness of green techniques applied to these unique plants. Among the green methods, Ultrasound-Assisted Extraction (UAE) stands out as the most extensively studied, consistently yielding a higher extraction of compounds irrespective of the duration and solvents employed. Supercritical Fluid Extraction (SFE) emerges as the second most utilized technique, demonstrating efficacy in extracting a broad spectrum of bioactive compounds, particularly oils and various phenolics. Although Microwave-Assisted Extraction (MAE) has been the least used, preliminary studies indicate a potential that still needs to be explored. Notably, green methods offer reduced environmental impact by minimizing harmful solvents and optimizing energy consumption, aligning with the growing demand for sustainable and eco-friendly processes and the increasing preference for natural and healthier products. The cacti most commonly studied beyond Opuntia spp. and Hylocereus spp. include cladodes, shells, and seeds. Despite advancements, numerous cactus species remain underexplored, underscoring the necessity for ongoing research to fully harness the promising potential of these plants in developing practical applications for bioactive compounds.

Lower Energy-Demanding Extraction of Bioactive Triterpene Acids by Microwave as the First Step towards Biorefining Residual Olive Skin

In the olive oil industry, a pit fraction is collected from olive pomace and split into a clean pit fraction and a residual olive skin-rich fraction, which does not an industrial application. Therefore, in this work, microwave-assisted extraction (MAE) was applied to obtain high-value triterpene acids (maslinic acid and oleanolic acid) from this biomass using the renewable solvent ethanol. The response surface methodology was used to gain a deeper understanding of how the solvent (ethanol-water, 50-100% v/v), time (4-30 min), and temperature (50-120 °C) affect the extraction performance, as well as the energy required for the process. The effect of milling was also studied and the solid-to-liquid ratio was also evaluated, and overall, a good compromise was found at 10% (w/v) using the raw sample (unmilled biomass). The optimised conditions were applied to residual olive skin sourced from various industries, yielding up to 5.1 g/100 g and 2.2 g/100 g dry biomass for maslinic acid and oleanolic acid, respectively. In conclusion, the residual olive skin is a promising natural source of these triterpene acids, which can be extracted using MAE, releasing extracted solids rich in polymeric carbohydrates and lignin that can be valorised under a holistic biorefinery process.

Nutraceutical potential of Mediterranean agri-food waste and wild plants: Green extraction and bioactive characterization

The agricultural waste and wild plants of the Mediterranean region offer significant nutraceutical potential, rich in bioactive compounds such as phenolics, carotenoids, lipids and volatile organic compounds. These compounds exhibit health-promoting properties, including antioxidant, neuroprotective and anti-inflammatory effects. Advanced analytical techniques such as HPLC, GC-MS and NMR are essential for the accurate chemical characterization of these bioactives. Green extraction methods, including ultrasound-assisted, enzyme-assisted and cold plasma-assisted extractions, provide efficient and environmentally friendly alternatives to classical techniques for the isolation of bioactive compounds. The valorization of Mediterranean agricultural by-products, such as olive pomace, grape seeds, and citrus peels, exemplifies sustainable approaches to the utilization of these underutilized resources. This chapter explores the bioactive characterization and green extraction methods that contribute to unlocking the nutraceutical potential of Mediterranean plant waste and wild plants, highlighting their role in the development of functional foods and natural health products.

Polysaccharides from Hericium erinaceus and its immunomodulatory effects on RAW 264.7 macrophages

This study aimed to optimize the extraction of Hericium erinaceus polysaccharides (HEP) using ultrasound-assisted enzymatic extraction combined with Plackett-Burman design (PBD) and response surface methodology (RSM). The optimal extraction conditions were identified as: 33 min extraction time, 30:1 liquid to material ratio, 38 °C extraction temperature, 9 g/kg cellulase amount, pH 4, and 20 % ethanol concentration. Under these conditions, the extraction yield of HEP was 5.87 ± 0.16 %, consistent with the predicted results. Additionally, the potential immunomodulatory activity of HEP on RAW 264.7 macrophage was evaluated. The results revealed that HEP improved the immunostimulatory activity of RAW264.7 cells, evident from increased production of IL-6 and TNF-α. These findings suggest that HEP is capable of enhancing the immune activity of RAW 264.7 macrophage.

Development of the Pipette-Tip Micro-Solid-Phase Extraction for Extraction of Rutin From Moringa oleifera Lam. Using Activated Hollow Carbon Nanospheres as Sorbents

Herein, a micro-solid-phase extraction (μSPE) method was developed using a pipette tip for rutin extraction, employing activated hollow carbon nanospheres (HCNSs) as the sorbent. Characterization of the activated carbon nanospheres through TGA, FTIR, and SEM analysis confirmed the success of the activation process. The study demonstrated the efficacy of PT-μSPE in rutin extraction under pH 2 conditions with a standard concentration of 2 mg·L-1. The optimal mass of HCNSs was found to be 2 mg, and a loading volume of 500 μL resulted in the maximum recovery of rutin. Propan-2-ol was the best elution solvent with 15 aspirating/dispensing cycles. The correlation of determination (R 2) for the calibration curve was found to be 0.9991, and the LOD and LOQ values were 0.604 and 1.830 mg·L-1, respectively. The applicability of the method was demonstrated by extracting rutin from a complex Moringa oleifera leaf extract with the relative standard deviation (RSD) of 3.26%, thereby validating this method as feasible for the extraction of useful bioactive compounds from complex plant samples.

Extraction of Bioactive Compounds From Centella asiatica and Enlightenment of Its Utilization Into Food Packaging: A Review

Centella asiatica is a medicinal herb, well known for its phytochemical activities because of the presence of terpenoids and polyphenols, which contribute to the bioactivity of herb extract that can be effectively utilized in the packaging industry. Biopolymers infused with C. asiatica extract could be a promising solution in the food sector. The antibacterial and antioxidant qualities of C. asiatica can help preserve the quality and lengthen the freshness of food products, thereby preventing food loss. Selection of a suitable extraction method is essential to retain the yield and properties of the bioactive compounds of C. asiatica extract. Many research has been conducted on the separation of C. asiatica by using conventional and novel extraction techniques and its execution in packaging as a functional component. This review provides an overview of the extraction of phytochemicals from C. asiatica and its utilization in biopolymer film as an active component to modify the packaging film characteristics.

Quercetin, the Potential Powerful Flavonoid for Human and Food: A Review

Flavonoids occur naturally in different types of fruits and vegetables, including tea, cabbage, cauliflower, elderberries, cranberries, red apples, lettuce, pears, spinach, green hot peppers, white and red onions, kale, blueberries, and nuts. Among these flavonoids is quercetin, a potent natural antioxidant and cytotoxic substance with a number of therapeutic functions. Nowadays, quercetin is a common ingredient in many nutraceutical and cosmeceutical products due to its antioxidant properties. Its antibacterial effects and possible action mechanisms have been explored in many studies. From these, it has been established that quercetin stops the activity of numerous Gram-negative and -positive bacteria, fungi, and viruses. This review clarifies the plant sources and extraction methods of quercetin, as well as its medicinal applications as an antibacterial, antifungal, antiviral, and antioxidant agent, with a particular emphasis on the underlying mechanisms of its biological activity. The mechanism of its antimicrobial effect involves damaging the cell membrane-e.g., by changing its permeability, preventing biofilm formation, reducing the mitochondrial expression of virulence factors, and inhibiting protein and nucleic-acid synthesis. Moreover, quercetin has been shown to impede the activity of a variety of drug-resistant bacterial strains, pointing to the possibility of using it as a strong antimicrobial substance against such strains. In addition, it has occasionally been demonstrated that specific structural alterations to quercetin can increase its antibacterial action in comparison to the parent molecule. Overall, this review synthesizes our understanding of the mode of action of quercetin and its prospects for use as a therapeutic material.

Circular Bioeconomy in Action: Transforming Food Wastes into Renewable Food Resources

The growing challenge of food waste management presents a critical opportunity for advancing the circular bioeconomy, aiming to transform waste into valuable resources. This paper explores innovative strategies for converting food wastes into renewable food resources, emphasizing the integration of sustainable technologies and zero-waste principles. The main objective is to demonstrate how these approaches can contribute to a more sustainable food system by reducing environmental impacts and enhancing resource efficiency. Novel contributions of this study include the development of bioproducts from various food waste streams, highlighting the potential of underutilized resources like bread and jackfruit waste. Through case studies and experimental findings, the paper illustrates the successful application of green techniques, such as microbial fermentation and bioprocessing, in valorizing food wastes. The implications of this research extend to policy frameworks, encouraging the adoption of circular bioeconomy models that not only address waste management challenges but also foster economic growth and sustainability. These findings underscore the potential for food waste to serve as a cornerstone in the transition to a circular, regenerative economy.

Advances in Eucommia ulmoides polysaccharides: extraction, purification, structure, bioactivities and applications

Eucommia ulmoides (EU) is a precious tree species native to China originating during the ice age. This species has important economic value and comprehensive development potential, particularly in medicinal applications. The medicinal parts of EU are its bark (Eucommiae cortex) and leaves (Eucommiae folium) which have been successively used as a traditional Chinese medicine to treat diseases since the first century BC. During the last 2 decades, as natural polysaccharides have become of increasing interest in pharmacology, biomedicine, cosmetic and food applications, more and more scholars have begun to study polysaccharides derived from EU as well. EU polysaccharides have been found to have a variety of biological functions both in vivo and in vitro, including immunomodulatory, antioxidant, anti-inflammatory, anticomplementary, antifatigue, and hepatoprotective activities. This review aims to summarize these recent advances in extraction, purification, structural characteristics, pharmacological activities and applications in different fields of EU bark and leaf polysaccharides. It was found that both Eucommiae folium polysaccharides and Eucommiae cortex polysaccharides were suitable for medicinal use. Eucommiae folium may potentially be used to substitute for Eucommiae cortex in terms of immunomodulation and antioxidant activities. This study serves as a valuable reference for improving the comprehensive utilization of EU polysaccharides and further promoting the application of EU polysaccharides.

Natural Pigments Recovery from Food By-Products: Health Benefits towards the Food Industry

Given the health risks associated with synthetic colorants, natural pigments have emerged as a promising alternative. These renewable choices not only provide health benefits but also offer valuable technical and sensory properties to food systems. The effective application of natural colorants, however, requires the optimization of processing conditions, exploration of new sources, and development of novel formulations to ensure stability and maintain their inherent qualities. Several natural pigment sources have been explored to achieve the broad color range desired by consumers. The purpose of this review is to explore the current advances in the obtention and utilization of natural pigments derived from by-products, which possess health-enhancing properties and are extracted through environmentally friendly methods. Moreover, this review provides new insights into the extraction processes, applications, and bioactivities of different types of pigments.

A practical guide to the discovery of biomolecules with biostimulant activity

The growing demand for sustainable solutions in agriculture, which are critical for crop productivity and food quality in the face of climate change and the need to reduce agrochemical usage, has brought biostimulants into the spotlight as valuable tools for regenerative agriculture. With their diverse biological activities, biostimulants can contribute to crop growth, nutrient use efficiency, and abiotic stress resilience, as well as to the restoration of soil health. Biomolecules include humic substances, protein lysates, phenolics, and carbohydrates have undergone thorough investigation because of their demonstrated biostimulant activities. Here, we review the process of the discovery and development of extract-based biostimulants, and propose a practical step-by-step pipeline that starts with initial identification of biomolecules, followed by extraction and isolation, determination of bioactivity, identification of active compound(s), elucidation of mechanisms, formulation, and assessment of effectiveness. The different steps generate a roadmap that aims to expedite the transfer of interdisciplinary knowledge from laboratory-scale studies to pilot-scale production in practical scenarios that are aligned with the prevailing regulatory frameworks.

Characterizing date seed polysaccharides: A comprehensive study on extraction, biological activities, prebiotic potential, gut microbiota modulation, and rheology using microwave-assisted deep eutectic solvent

This study investigated the biological activities, prebiotic potentials, modulating gut microbiota, and rheological properties of polysaccharides derived from date seeds via microwave-assisted deep eutectic solvent systems. Averaged molecular weight (246.5 kDa) and a monosaccharide profile (galacturonic acid: glucose: mannose: fructose: galactose), classifying MPS as a heteropolysaccharide. MPS, at concentrations of 125-1000 µg/mL, demonstrates increasing free radical scavenging activities (DPPH, ABTS, MC, SOD, SORS, and LO), potent antioxidant potential (FRAP: 51.2-538.3 µg/mL; TAC: 28.3-683.4 µg/mL; RP: 18.5-171.2 µg/mL), and dose-dependent antimicrobial activity against common foodborne pathogens. Partially-purified MPS exhibits inhibition against α-glucosidase (79.6 %), α-amylase (85.1 %), and ACE (68.4 %), along with 80 % and 46 % inhibition against Caco-2 and MCF-7 cancer cells, respectively. Results indicate that MPS fosters the growth of beneficial fecal microbiota, including Proteobacteria, Firmicutes, and Actinobacteria, supporting microbes responsible for major SCFAs (acetic, propionic, and butyric acids) production, such as Ruminococcus and Blautia.

Chromatographic Methods and Sample Pretreatment Techniques for Aldehydes, Biogenic Amine, and Carboxylic Acids in Food Samples

This review paper critically examines the current state of research concerning the analysis and derivatization of aldehyde, aromatic hydrocarbons and carboxylic acids components in foods and drinks samples, with a specific focus on the application of Chromatographic techniques. These diverse components, as vital contributors to the sensory attributes of food, necessitate accurate and sensitive analytical methods for their identification and quantification, which is crucial for ensuring food safety and compliance with regulatory standards. In this paper, High-Performance Liquid Chromatography (HPLC) and Gas Chromatographic (GC) methods for the separation, identification, and quantification of aldehydes in complex food matrices were reviewed. In addition, the review explores derivatization strategies employed to enhance the detectability and stability of aldehydes during chromatographic analysis. Derivatization methods, when applied judiciously, improve separation efficiency and increase detection sensitivity, thereby ensuring a more accurate and reliable quantification of aldehyde aromatic hydrocarbons and carboxylic acids species in food samples. Furthermore, methodological aspects encompassing sample preparation, chromatographic separation, and derivatization techniques are discussed. Validation was carried out in term of limit of detections are highlighted as crucial elements in achieving accurate quantification of compounds content. The discussion presented by emphasizing the significance of the combined HPLC and GC chromatography methods, along with derivatization strategies, in advancing the analytical capabilities within the realm of food science.

Research Progress on Taxus Extraction and Formulation Preparation Technologies

Taxus, as a globally prevalent evergreen tree, contains a wealth of bioactive components that play a crucial role in the pharmaceutical field. Taxus extracts, defined as a collection of one or more bioactive compounds extracted from the genus Taxus spp., have become a significant focus of modern cancer treatment research. This review article aims to delve into the scientific background of Taxus extracts and their considerable value in pharmaceutical research. It meticulously sifts through and compares various advanced extraction techniques such as supercritical extraction, ultrasound extraction, microwave-assisted extraction, solid-phase extraction, high-pressure pulsed electric field extraction, and enzymatic extraction, assessing each technology's advantages and limitations across dimensions such as extraction efficiency, extraction purity, economic cost, operational time, and environmental impact, with comprehensive analysis results presented in table form. In the area of drug formulation design, this paper systematically discusses the development strategies for solid, liquid, and semi-solid dosage forms based on the unique physicochemical properties of Taxus extracts, their intended medical uses, and specific release characteristics, delving deeply into the selection of excipients and the critical technical issues in the drug preparation process. Moreover, the article looks forward to the potential directions of Taxus extracts in future research and medical applications, emphasizing the urgency and importance of continuously optimizing extraction methods and formulation design to enhance treatment efficacy, reduce production costs, and decrease environmental burdens. It provides a comprehensive set of preparation techniques and formulation optimization schemes for researchers in cancer treatment and other medical fields, promoting the application and development of Taxus extracts in pharmaceutical sciences.

Puerarin-A Promising Flavonoid: Biosynthesis, Extraction Methods, Analytical Techniques, and Biological Effects

Flavonoids, a variety of plant secondary metabolites, are known for their diverse biological activities. Isoflavones are a subgroup of flavonoids that have gained attention for their potential health benefits. Puerarin is one of the bioactive isoflavones found in the Kudzu root and Pueraria genus, which is widely used in alternative Chinese medicine, and has been found to be effective in treating chronic conditions like cardiovascular diseases, liver diseases, gastric diseases, respiratory diseases, diabetes, Alzheimer's disease, and cancer. Puerarin has been extensively researched and used in both scientific and clinical studies over the past few years. The purpose of this review is to provide an up-to-date exploration of puerarin biosynthesis, the most common extraction methods, analytical techniques, and biological effects, which have the potential to provide a new perspective for medical and pharmaceutical research and development.

Research progress and future development potential of Flammulina velutipes polysaccharides in the preparation process, structure analysis, biology, and pharmacology: A review

In recent years, Flammulina velutipes (F. velutipes) has attracted consequential attention in various research fields due to its rich composition of proteins, vitamins, amino acids, polysaccharides, and polyphenols. F. velutipes polysaccharides (FVPs) are considered as key bioactive components of F. velutipes, demonstrating multiple physiological activities, including immunomodulatory, anti-inflammatory, and antibacterial properties. Moreover, they offer health benefits such as antioxidant and anti-aging properties, which have exceptionally valuable clinical applications. Polysaccharides derived from different sources exhibit a wide range of biomedical functions and distinct biological activities. The varied biological functions of polysaccharides, coupled with their extensive application in functional foods and clinical applications, have prompted a heightened focus on polysaccharide research. Additionally, the extraction, deproteinization, and purification of FVPs are fundamental to investigate the structure and biological activities of polysaccharides. Therefore, this review provides a comprehensive and systematic overview of the extraction, deproteinization, purification, characterization, and structural elucidation of FVPs. Furthermore, the biological activities and mechanisms of FVPs have been further explored through in vivo and in vitro experiments. This review aims to provide a theoretical foundation and guide future research and development of FVPs.

Polysaccharides from fructus corni: Extraction, purification, structural features, and biological activities

Fructus Corni, derived from the dried fruit of Cornus officinalis Sieb. Et Zucc., is widely used as a food source and Chinese herb. Fructus Corni, as an indispensable ingredient in Liuwei Dihuang decoction, tonifies the liver and kidneys. As the main component of water decoctions, Fructus Corni polysaccharides demonstrate multifaceted effects, including hypoglycemic, hypolipidemic, antioxidant, anti-aging, sexual function regulation, and anti-epileptic, The ultrasound-assisted extraction method obtained the highest yields of Fructus Corni polysaccharides. However, it has notable shortcomings and lacks further innovation. The homogeneous polysaccharides obtained from Fructus Corni are mostly neutral polysaccharides with relatively limited structure, and the mechanism of their biological activity needs to be further elucidated. In addition, different extraction, isolation and purification methods may change the molecular weight, monosaccharide composition, and biological activity of polysaccharides. Therefore, this study systematically summarized the extraction, purification, structural features, and biological activities of Fructus Corni polysaccharides. This study aimed to provide support for the ongoing development and application of Fructus Corni polysaccharides.

Innovative Bioactive Products with Medicinal Value from Microalgae and Their Overall Process Optimization through the Implementation of Life Cycle Analysis-An Overview

Microalgae are being recognized as valuable sources of bioactive chemicals with important medical properties, attracting interest from multiple industries, such as food, feed, cosmetics, and medicines. This review study explores the extensive research on identifying important bioactive chemicals from microalgae, and choosing the best strains for nutraceutical manufacturing. It explores the most recent developments in recovery and formulation strategies for creating stable, high-purity, and quality end products for various industrial uses. This paper stresses the significance of using Life Cycle Analysis (LCA) as a strategic tool with which to improve the entire process. By incorporating LCA into decision-making processes, researchers and industry stakeholders can assess the environmental impact, cost-effectiveness, and sustainability of raw materials of several approaches. This comprehensive strategy will allow for the choosing of the most effective techniques, which in turn will promote sustainable practices for developing microalgae-based products. This review offers a detailed analysis of the bioactive compounds, strain selection methods, advanced processing techniques, and the incorporation of LCA. It will serve as a valuable resource for researchers and industry experts interested in utilizing microalgae for producing bioactive products with medicinal properties.

Cellulose nanocrystals from marine algae Cladophora glomerata by using microwave-assisted extraction

Algae of the order Cladophorales are the source of a unique nanocellulose with high crystallinity and a large aspect ratio, enabling broad surface modification. Cellulose nanocrystals (CNCs) are obtained via acid hydrolysis of nanocellulose, which is highly crystalline. However, the production of CNCs from Cladophorales algae is limited and still uses a conventional heating method. Thus, this study aimed to develop a microwave-assisted extraction (MAE) method for fast and efficient extraction of CNCs from Cladophora glomerata algae. Additionally, we replaced the use of hypochlorite with H2O2, which is more environmentally friendly, and compared the CNCs obtained from the conventional methods with our new method. The functional structure of CNCs was confirmed by Fourier-transform infrared spectroscopy. Single-step H2O2 bleaching with MAE yielded the smallest-sized CNCs. Our developed method resulted in the production of CNCs with a high crystallinity index, high thermal stability, and high purity of native cellulose. Additionally, none of the CNCs were toxic to primary normal human dermal fibroblasts. The properties of the isolated CNCs may make them useful materials in pharmaceutical and cosmetic formulations.

Plant-based proteins from agro-industrial waste and by-products: Towards a more circular economy

There is a pressing need for affordable, abundant, and sustainable sources of proteins to address the rising nutrient demands of a growing global population. The food and agriculture sectors produce significant quantities of waste and by-products during the growing, harvesting, storing, transporting, and processing of raw materials. These waste and by-products can sometimes be converted into valuable protein-rich ingredients with excellent functional and nutritional attributes, thereby contributing to a more circular economy. This review critically assesses the potential for agro-industrial wastes and by-products to contribute to global protein requirements. Initially, we discuss the origins and molecular characteristics of plant proteins derived from agro-industrial waste and by-products. We then discuss the techno-functional attributes, extraction methods, and modification techniques that are applied to these plant proteins. Finally, challenges linked to the safety, allergenicity, anti-nutritional factors, digestibility, and sensory attributes of plant proteins derived from these sources are highlighted. The utilization of agro-industrial by-products and wastes as an economical, abundant, and sustainable protein source could contribute towards achieving the Sustainable Development Agenda's 2030 goal of a "zero hunger world", as well as mitigating fluctuations in food availability and prices, which have detrimental impacts on global food security and nutrition.

Research progress in the preparation, structural characterization, and biological activities of polysaccharides from traditional Chinese medicine

Traditional Chinese medicines are tremendous sources of polysaccharides, which are of great interest in the human welfare system as natural medicines, food, and cosmetics. This review aims to highlight the recent trends in extraction (conventional and non-conventional), purification and analytic techniques of traditional Chinese medicine polysaccharides (TCMPs), and the chemical structure, biological activities (anti-tumor, hypoglycemic, antioxidant, intestinal flora regulation, immunomodulatory, anti-inflammatory, anti-aging, hypolipidemic, hepatoprotective, and other activities), and the underlying mechanisms of polysaccharides extracted from 76 diverse traditional Chinese medicines were compared and discussed. With this wide coverage, a total of 164 scientific articles were searched from the database including Google Scholar, PubMed, Web of Science, and China Knowledge Network. This comprehensive survey from previous reports indicates that TCMPs are non-toxic, highly biocompatible, and good biodegradability. Besides, this review highlights that TCMPs may be excellent functional factors and effective therapeutic drugs. Finally, the current problems and future research advances of TCMPs are also introduced. New valuable insights for the future researches regarding TCMPs are also proposed in the fields of therapeutic agents and functional foods.

Sustainable Green Extraction of Carotenoid Pigments: Innovative Technologies and Bio-Based Solvents

Carotenoids are ubiquitous and versatile isoprenoid compounds. The intake of foods rich in these pigments is often associated with health benefits, attributable to the provitamin A activity of some of them and different mechanisms. The importance of carotenoids and their derivatives for the production of foods and health-promotion through the diet is beyond doubt. In the new circular economy paradigm, the recovery of carotenoids in the biorefinery process is highly desirable, for which greener processes and solvents are being advocated for, considering the many studies being conducted at the laboratory scale. This review summarizes information on different extraction technologies (ultrasound, microwaves, pulsed electric fields, pressurized liquid extraction, sub- and supercritical fluid extraction, and enzyme-assisted extraction) and green solvents (ethyl lactate, 2-methyltetrahydrofuran, natural deep eutectic solvents, and ionic liquids), which are potential substitutes for more toxic and less environmentally friendly solvents. Additionally, it discusses the results of the latest studies on the sustainable green extraction of carotenoids. The conclusions drawn from the review indicate that while laboratory results are often promising, the scalability to real industrial scenarios poses a significant challenge. Furthermore, incorporating life cycle assessment analyses is crucial for a comprehensive evaluation of the sustainability of innovative extraction processes compared to industry-standard methods.

Review of isolation, purification, structural characteristics and bioactivities of polysaccharides from Portulaca oleracea L

Portulaca oleracea L., also known as purslane, affiliates to the Portulacaceae family. It is an herbaceous succulent annual plant distributed worldwide. P. oleracea L. is renowned for its nutritional value and medicinal value, which has been utilized for thousands of years as Traditional Chinese Medicine (TCM). The extract derived from P. oleracea L. has shown efficacy in treating various diseases, including intestinal dysfunction and inflammation. Polysaccharides from P. oleracea L. (POP) are the primary constituents of the crude extract which have been found to have various biological activities, including antioxidant, antitumor, immune-stimulating, and intestinal protective effects. While many publications have highlighted on the structural identification and bioactivity evaluation of POP, the underlying structure-activity relationship of POP still remains unclear. In view of this, this review aims to focus on the extraction, purification, structural features and bioactivities of POP. In addition, the potential structure-activity relationship and the developmental perspective for future research of POP were also explored and discussed. The current review would provide a valuable research foundation and the up-to-date information for the future development and application of POP in the field of the functional foods and medicine.

Metabolomics of natural samples: A tutorial review on the latest technologies

Metabolomics is the study of metabolites present in a living system. It is a rapidly growing field aimed at discovering novel compounds, studying biological processes, diagnosing diseases, and ensuring the quality of food products. Recently, the analysis of natural samples has become important to explore novel bioactive compounds and to study how environment and genetics affect living systems. Various metabolomics techniques, databases, and data analysis tools are available for natural sample metabolomics. However, choosing the right method can be a daunting exercise because natural samples are heterogeneous and require untargeted approaches. This tutorial review aims to compile the latest technologies to guide an early-career scientist on natural sample metabolomics. First, different extraction methods and their pros and cons are reviewed. Second, currently available metabolomics databases and data analysis tools are summarized. Next, recent research on metabolomics of milk, honey, and microbial samples is reviewed. Finally, after reviewing the latest trends in technologies, a checklist is presented to guide an early-career researcher on how to design a metabolomics project. In conclusion, this review is a comprehensive resource for a researcher planning to conduct their first metabolomics analysis. It is also useful for experienced researchers to update themselves on the latest trends in metabolomics.

Development of an ultrasound-assisted pre-treatment strategy for the extraction of D-Limonene toward the production of bioethanol from citrus peel waste (CPW)

Citrus is one of the world's most abundant fruits containing vitamins, pigments, and fragrances, making it vital for several industries. However, these fruits contain about 45-50% residues (peels), which often end up as waste and can be harmful to the environment if not properly treated. Bioethanol production from citrus peel waste offers a potential solution to this problem. Hence, this study explores the potential of using ultrasound-assisted pre-treatment method as a novel strategy to extract D-Limonene (essential oil in the residue), and further demonstrates bioethanol production. This was done by investigating ultrasonication's optimal effect on pre-treatment of the citrus residue, followed by bioethanol production. The results show that, optimum values for D-Limonene extraction were obtained at a temperature of 14.6 °C and an ultrasound intensity of 25.81 W/cm2 with a validation yield of 134 ± 4.24 mg/100 g dry CPW. With optimal ultrasonic parameters, the study went further to demonstrate the effect of the essential oil on bioethanol production which is hindered by the oils present. Key findings show better bioethanol yield once the essential oil was extracted (treated) from the citrus waste as opposed to it not extracted (untreated), with a 66 and a 29% increase when comparing simultaneous saccharification and fermentation (SSF) and sequential hydrolysis and fermentation (SHF) respectively. Based on this result, ultrasound-assisted extraction as a pretreatment method was found suitable for bioethanol production from citrus residue and could be utilized as a biorefinery pre-treatment approach to scale bioethanol production.

Rutin extraction from female Carica papaya Linn. using ultrasound and microwave-assisted extractive methods: Optimization and extraction efficiencies

Green extractive methods accompanied by resource conservation through process optimization are important in working towards sustainable processes. In the present paper, rutin was extracted from the leaf of female Carica papaya Linn using microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), sequential microwave ultrasound-assisted extraction (MUAE), and sequential ultrasound microwave-assisted extraction (UMAE) methods. Subsequently, the effect of extraction parameters on rutin yield were analyzed and compared. In addition, the extraction efficiency and energy consumption of the extraction processes were measured and discussed. In the present study, solid-liquid (S/L) ratio was determined to be the most significant extraction variable. Under optimized conditions, MUAE and UMAE were determined to yield the highest amount of rutin extracted at 18.46 ± 0.64 mg/g and 18.43 ± 0.81 mg/g, respectively. However, MUAE was determined to be the least resource efficient method as it consumed the highest amount of energy due to its relatively long extraction time. UAE was determined to be the most efficient in resource utilization as it required the least amount of energy for every mg/g of yield extracted, while the yield obtained was, nonetheless, comparatively high. The optimal condition obtained for UAE was 20 min of ultrasonic extraction time (TU), 20 % of ethanol mixture concentration (C), 710 μm of particle size (S), and 1:650 wt/wt of solid-liquid (S/L) ratio (R).

Microwave-assisted extraction in closed vessel in food analysis

Microwave-assisted extraction (MAE) is an important technique in analytical chemistry. It offers several advantages over traditional extraction methods, such as improved extraction efficiency, shorter extraction times, reduced solvent consumption, and enhanced analyte recovery. Using microwaves, heat is directly applied to the sample, leading to rapid and efficient extraction of target compounds by enhancing the solubility and diffusion of the target compounds, thus requiring lower solvent volume. Therefore, MAE can be considered a more environmentally friendly and cost-effective option facilitating the transition toward greener and more sustainable analytical chemistry workflows. This contribution systematically reviews the application of MAE to a selection of target compounds/compounds classes of relevance for food quality and safety assessment. As inclusion criteria, MAE active temperature control and molecularly-resolved characterization of the extracts were considered. Contents include a brief introduction of the principles of operation, available systems characteristics, and key parameters influencing extraction efficiency and selectivity. The application section covers functional food components (e.g., phenols, diterpenes, and carotenoids), lipids, contaminants (e.g., polycyclic aromatic hydrocarbons and mineral oil hydrocarbons), pesticides, veterinary drug residues, and a selection of process contaminants and xenobiotics of relevance for food safety.

Valorization of fruit and vegetable processing by-products/wastes

Fruit and vegetable processing by-products and wastes are of great importance due to their high production volumes and their composition containing different functional compounds. Particularly, apple, grape, citrus, and tomato pomaces, potato peel, olive mill wastewater, olive pomace and olive leaves are the main by-products that are produced during processing. Besides conventional techniques, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction (sub-critical water extraction), supercritical fluid extraction, enzyme-assisted extraction, and fermentation are emerging tools for the recovery of target compounds. On the other hand, in the view of valorization, it is possible to use them in active packaging applications, as a source of bioactive compound (oil, phenolics, carotenoids), as functional ingredients and as biofertilizer and biogas sources. This chapter explains the production of fruit and vegetable processing by-products/wastes. Moreover, the valorization of functional compounds recovered from the fruit and vegetable by-products and wastes is evaluated in detail by emphasizing the type of the by-products/wastes, functional compounds obtained from these by-products/wastes, their extraction conditions and application areas.

The Separation, Purification, Structure Identification, and Antioxidant Activity of Elaeagnus umbellata Polysaccharides

In order to investigate the antioxidant activity of Elaeagnus umbellata polysaccharides, the physicochemical characteristics of purified Elaeagnus umbellata polysaccharides (EUP, consisting of two fractions, EUP1 and EUP2) were investigated using UV spectrophotometry, high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), and Fourier transform infrared spectroscopy (FT-IR). This revealed that EUP1 and EUP2 were acidic polysaccharides with an average molecular weight (MW) of 63 and 38 kDa, respectively. EUP1 mainly consisted of L-rhamnose and D-galactose in a molar ratio of 2.05:1, and EUP2 consisted of D-mannose, L-rhamnose, D-galactose, and D-arabinose in a molar ratio of 2.06:1:2.78:1. Furthermore, EUP exhibited considerable antioxidant potential for scavenging hydroxyl, superoxide anion, DPPH, and ABTS radicals. Therefore, EUP can be developed as a potential antioxidant for the functional food or pharmaceutical field.

Research progress and application of ultrasonic- and microwave-assisted food processing technology

Microwaves are electromagnetic waves of specific frequencies (300 MHz-3000 GHz), whereas ultrasonic is mechanical waves of specific frequencies. Microwave and ultrasonic technology as a new processing method has been widely used in food processing fields. Combined ultrasonic and microwave technology is exploited by researchers as an improvement technique and has been successfully applied in food processing such as thawing, drying, frying, extraction, and sterilization. This paper overviews the principle and characteristics of ultrasonic- and microwave-assisted food processing techniques, particularly their combinations, design of equipment, and their applications in the processing of agricultural products such as thawing, drying, frying, extraction, and sterilization. The combination of ultrasonic and microwave is applied in food processing, where microwave enhances the heating rate, and ultrasonic improves the efficiency of heat and mass transfer. The synergy of the heating effect of microwave and the cavitation effect of ultrasonic improves processing efficiency and damages the cell structure of the material. The degradation of nutrient composition and energy consumption due to the short processing time of combined ultrasonic and microwave technology is decreased. Ultrasonic technology, as an auxiliary means of efficient microwave heating, is pollution-free, highly efficient, and has a wide range of applications in food processing.

Prunella vulgaris L.: An Updated Overview of Botany, Chemical Composition, Extraction Methods, and Biological Activities

Prunella vulgaris L. (PV) is a well-known renewable drug resource full of different groups of biologically active substances with a wide range of pharmacological actions and applications in medicine. In this review, we present an updated comprehensive overview of the botany, extracting methods, chemical composition, and pharmacological activity of different parts of PV extracts. As a result of this review, it was found that chemical composition of PV depends on various factors ranging from the part of the plant to the method of extraction. We also highlight extraction methods that have not been previously used for obtaining PV extracts and may have high scientific interest. With this review, we hope to guide present and future professionals and provide possible previously unexplored areas to find new solutions associated with PV plant.

Flavonoids: Overview of Biosynthesis, Biological Activity, and Current Extraction Techniques

Recently, increased attention has been paid to natural sources as raw materials for the development of new added-value products. Flavonoids are a large family of polyphenols which include several classes based on their basic structure: flavanones, flavones, isoflavones, flavonols, flavanols, and anthocyanins. They have a multitude of biological properties, such as anti-inflammatory, antioxidant, antiviral, antimicrobial, anticancer, cardioprotective, and neuroprotective effects. Current trends of research and development on flavonoids relate to identification, extraction, isolation, physico-chemical characterization, and their applications to health benefits. This review presents an up-to-date survey of the most recent developments in the natural flavonoid classes, the biological activity of representative flavonoids, current extraction techniques, and perspectives.

Solid-oil separation of coal tar residue to reduce polycyclic aromatic hydrocarbons via microwave-assisted extraction

Coal tar residue (CTR) is acknowledged as hazardous industrial waste with high contents of carbon and toxic polycyclic aromatic hydrocarbons (PAHs). Microwave-assisted extraction for separating tar and residue in CTR was investigated to reduce the content of PAHs. The key operating factors such as solvent type, solvent addition amount, radiation temperature, and radiation time in the extraction process were evaluated. Results showed that extreme extraction performance in the solvent with cyclic structure was attained, and an enhancement in extraction efficiency was achieved in elevated solvent addition amount, radiation temperature, or radiation time in a certain range. The optimized conditions were determined as benzene was chosen as extractant, solvent-solid ratio of 5:1 mL/g, radiation temperature of 75 °C, and radiation time of 10 min. Relative extraction efficiency of CTR and reduction efficiency of 16 priority control PAHs were 28.70% and 92.82%, respectively. According to the characterizations of extracted residue (MCTR) and tar (MCT) under optimum experimental conditions, it is possible to convert them into value-added products (carbon materials, solid fuels, or chemicals). Solid-oil separation via microwave-assisted extraction is a safe and high-valued utilization approach for CTR.

Oxidative stability, quality, and bioactive compounds of oils obtained by ultrasound and microwave-assisted oil extraction

Vegetable oils are extracted from oilseeds, fruits and other parts of plants. The method used in oil extraction is of great importance, as it affects both the quality of the final product and the environment. It is desirable that the extraction method be minimally costly, fast, environmentally friendly, and produce oil of high quality and quantity. Common oil extraction methods are mechanical pressing and solvent extraction, and these methods have advantages and disadvantages over each other. Mechanical extraction and solvent extraction are controversial due to poor product quality and high environmental impacts. This review presents applications where conventional oil extraction processes are assisted by microwave or ultrasound. It is necessary to evaluate the impact of ultrasound and microwave-assisted extraction on the quality of the extracted oil and also to compare the results with those of conventional extraction methods. For this purpose, this review discusses the effects of microwave and ultrasound-assisted extraction on the physicochemical, oxidation indices, bioactive compounds, and antioxidant properties of oil extracted from oil seeds and fruits. Furthermore, this review provides readers with in-depth information on the mechanisms involved, their use, and the impact of operating conditions. The yield and quality of the oil obtained by these processes can vary depending on parameters such as microwave power, ultrasound power, processing time, and temperature. Finally, the review also discusses the challenges and advantages of the industrial application of these technologies.

Third-Generation Snacks Manufactured from Andean Tubers and Tuberous Root Flours: Microwave Expansion Kinetics and Characterization

Andean tubers and tuberous roots have nutritional and medicinal properties transferred through ancestral generations. In this study, we aim to promote cultivation and consumption by developing a snack based on these crops. Corn grits were thoroughly mixed with sweet potato, mashua, and three varieties of oca flour (white, yellow, and red) in an 80:20 ratio, and a single-screw laboratory extruder was utilized to produce third-generation (3G) dried pellets. Microwave expansion was studied, and the dried 3G pellets and expanded snacks were characterized. The microwave expansion curves of the dried 3G pellets were adjusted to the Page, logarithmic, and Midilli-Kucuk models. During the characterization, the influence of the raw material composition was observed in sectional expansion, water content, water activity, water absorption, water solubility, swelling, optical and textural properties, and bioactive compounds. According to global color variation (mixture vs. expanded and dried vs. expanded) and bioactive compound analysis, the mashua suffered little chemical change or nutritional loss during the process. The extrusion process was shown to be an ideal method for manufacturing snacks from Andean tuber flours.

Black rice and its by-products: anthocyanin-rich extracts and their biological potential

Recently, growing demand for products enriched with natural compounds that support human health has been observed. Black rice, its by-products, and residues are known to have in their composition a large amount of these compounds with biological potential, mainly anthocyanins. These compounds have reported effects on anti-obesity, antidiabetic, antimicrobial, anticancer, neuroprotective, and cardiovascular disease. Therefore, the extract from black rice or its by-products have great potential for application as ingredients in functional foods, supplements, or pharmacological formulations. This overview summarizes the methods employed for the extraction of anthocyanins from both black rice and its by-products. In addition, trends in applications of these extracts are also evaluated regarding their biological potential. Commonly, the extraction methods used to recover anthocyanins are conventional (maceration) and some emerging technologies (Ultrasound-Assisted Extraction - UAE, and Microwave-Assisted Extraction - MAE). Anthocyanin-rich extracts from black rice have presented a biological potential for human health. In vitro and in vivo assays (in mice) showed these compounds mainly with anti-cancer properties. However, more clinical trials are still needed to prove these potential biological effects. Extracts from black rice and its by-products have great potential in applying functional products with beneficial characteristics to humans and reducing agro-industrial residues.