The research team, led by Aljawharah Alqathama of Umm Al-Qura University in Makkah and Rizwan Ahmad of Imam Abdulrahman Bin Faisal University in Dammam, Saudi Arabia, purchased eleven commercially available chia seed batches coded C1 through C11, representing origins that included Saudi Arabia, Ecuador, Bahrain, India, Argentina, Mexico, Peru (both yellow and brown varieties), Bolivia, the United States, and Spain. Rather than relying on harsh organic solvents, the team embraced green chemistry. They tested twelve solvent systems in an ultrasonic dismembrator probe, which uses cavitation bubbles to rupture plant cell walls and release their chemical cargo. The winning combination was acetone and water in a 70:30 ratio, which extracted roughly 168.4 parts per million of cumulative phenolics—about three times more than a 50:50 acetone-water mix and well above any ethanol-water blend.

The intermediate polarity of the acetone-water system proved ideal for simultaneously dissolving both moderately polar phenolic acids and more polar flavonoids, while ultrasonic cavitation enhanced mass transfer through the seed matrix. Using a fully validated UPLC-DAD method built on a C18 reverse-phase column with a formic acid mobile phase gradient, the researchers quantified five target phenolics: chlorogenic acid, rosmarinic acid, ferulic acid, quercetin, and kaempferol. Rosmarinic acid dominated at 385.77 ppm, followed by chlorogenic acid at 86.33 ppm and ferulic acid at 40.51 ppm, with kaempferol and quercetin present only in trace amounts. Geographical origin mattered enormously: seeds from the United States accumulated the highest total phenolics at 78.7 ppm, followed by Saudi Arabia at 69.2 ppm and Ecuador at 52.5 ppm.

With the chemistry mapped, the team turned to biology, screening every extract against five enzymes selected for their therapeutic relevance. Alpha-amylase, the carbohydrate-digesting enzyme targeted by the diabetes drug acarbose, was inhibited by 38 to 71 percent across origins in initial screening. The Indian origin sample, C4, proved the standout, achieving the lowest IC50 value of 104.4 micrograms per milliliter—remarkably close to acarbose’s own 78.82 micrograms per milliliter. Intriguingly, C4 did not have the highest total phenolic content. Instead, it carried elevated levels of ferulic acid and chlorogenic acid, both known competitive inhibitors of carbohydrate-digesting enzymes, suggesting that the composition of a seed’s phenolic cocktail matters more than its sheer quantity.

The cholinesterase results may be the most clinically provocative. Acetylcholinesterase inhibition ranged from 36 to 63 percent, with Mexican and American samples leading the field and posting IC50 values of 99.02 and 97.52 micrograms per milliliter respectively—both below the 100 micrograms per milliliter threshold the authors describe as having considerable therapeutic relevance. Butyrylcholinesterase inhibition was even more consistent, spanning 53 to 73 percent across all origins. The American sample C10 delivered the single strongest result of the entire study, an IC50 of 79.41 micrograms per milliliter against BChE. Because butyrylcholinesterase activity rises in the later stages of Alzheimer’s disease, dual cholinesterase inhibition is considered superior to targeting acetylcholinesterase alone, placing chia seeds in the same pharmacological neighborhood as rosemary and sage extracts rich in rosmarinic acid.

The American sample’s dominance extended to lipid metabolism. Pancreatic lipase, the enzyme targeted by the anti-obesity drug orlistat, was inhibited by 37 to 69 percent in preliminary screening, with C10 again posting the lowest IC50 at 90.82 micrograms per milliliter. Mexico and Spain followed closely. The authors attribute this activity to chlorogenic acid, rosmarinic acid, and quercetin, which are thought to block the catalytic serine residue of lipase and obstruct access to its hydrophobic binding pocket. The potency rivals previously reported values for green tea catechins and grape seed proanthocyanidins, positioning chia extracts as candidates for anti-obesity functional beverages and metabolic health supplements.

Tyrosinase, the copper-containing enzyme behind skin pigmentation and enzymatic browning in foods, told a different story. Here the Ecuadorian and yellow Peruvian samples shone, with inhibition of 67 and 66 percent and IC50 values of 88.81 and 95.41 micrograms per milliliter. The Ecuadorian sample’s high rosmarinic acid content of 42.70 ppm fits the known mechanism: phenolic acids chelate the copper ions at tyrosinase’s binuclear active site and compete with the L-DOPA substrate. Strikingly, the American sample that dominated every other assay failed to yield a measurable tyrosinase IC50, an inverse relationship the authors interpret as evidence that specific phenolic profiles confer selectivity toward particular enzymes rather than blanket inhibition.

To untangle these patterns, the team deployed a statistical arsenal of k-means clustering, one-way ANOVA with Tukey post-hoc tests, and principal component analysis. The clustering separated the eleven origins into distinct groups, with chlorogenic acid and quercetin emerging as powerful discriminators. ANOVA revealed that ferulic acid significantly influenced both alpha-amylase and tyrosinase inhibition, while chlorogenic acid showed a pronounced effect against acetylcholinesterase. Principal component analysis, interpreted cautiously as exploratory given the small dataset and low Kaiser-Meyer-Olkin value of 0.14, explained a cumulative 82 percent of variance across four components, with quercetin and rosmarinic acid loading strongly on the first component alongside a notable negative loading for acetylcholinesterase inhibition.

Why should geography shape a seed’s pharmacy so profoundly? The answer lies in plant secondary metabolism. Environmental variables such as soil composition, pH, irrigation, temperature, radiation, and altitude all feed into the phenylpropanoid pathway that manufactures phenolic compounds. Abiotic stresses, including water scarcity and elevated ultraviolet exposure, can stimulate this pathway as part of the plant’s defense arsenal, boosting phenolic accumulation. Post-harvest handling, particularly drying methods, can further degrade or preserve these fragile molecules. The result is that two genetically similar chia seeds, grown on different continents, can carry measurably different chemical fingerprints and, by extension, different biological activities.

The study’s implications ripple outward in several directions. For the functional food and nutraceutical industries, it suggests that origin-specific sourcing could become a quality control strategy: American chia for neuroprotective and anti-obesity formulations, Indian chia for glycemic control, Ecuadorian chia for cosmeceutical applications. The authors caution, however, that the chemometric trends are preliminary and that the multivariate modeling was constrained by the small sample size and incomplete IC50 coverage. They call for broader geographic sampling, molecular docking and enzyme kinetics studies to confirm binding specificity, investigation of the seed’s lipid fraction, and ultimately in vivo studies and clinical trials to translate these in vitro signals into therapeutic reality. Until then, the findings add a compelling new dimension to the chia story: the seed’s celebrated health benefits may be written not just in its genes, but in the soil, sun, and stress of the places where it grows.

Subject of Research: Origin-dependent phenolic profiling and multi-target enzyme inhibition of chia seed extracts

Article Title: Antidiabetic, antihyperlipidemic, and anticholinesterase enzymes inhibitory potential of green-extracted and UPLC-DAD-quantified chia (Salvia hispanica, Lamiaceae) seed phenolic compounds

Article References: Alqathama, A., & Ahmad, R. (2026). Antidiabetic, antihyperlipidemic, and anticholinesterase enzymes inhibitory potential of green-extracted and UPLC-DAD-quantified chia (Salvia hispanica, Lamiaceae) seed phenolic compounds. Plant Biosystems, 160(5), Article 251. https://doi.org/10.1007/s44473-026-00260-z

Image Credits: AI Generated

DOI: 10.1007/s44473-026-00260-z

Keywords: chia seeds, phenolic compounds, enzyme inhibition, alpha-amylase, cholinesterase, lipase, tyrosinase, UPLC-DAD, green extraction, chemometrics, functional foods, Alzheimer's disease

The team focused on three widely distributed brown seaweeds: Sargassum polycystum, Turbinaria ornata, and Rosenvingea intricata. These species are abundant along Indian shorelines, yet they remain largely underexploited as raw materials for nutraceuticals, functional foods, and pharmaceuticals. Brown seaweeds in general are known to be reservoirs of valuable molecules, including phenolic compounds, flavonoids, sulfated polysaccharides such as fucoidan, and the carotenoid fucoxanthin, all of which have attracted intense scientific interest for their antioxidant, anti-inflammatory, and potential anticancer properties. The challenge has always been extraction: how to pull these compounds out of a tough, gelatinous algal matrix efficiently, cheaply, and without resorting to toxic chemicals that compromise the safety and sustainability of the final product.

Hot water extraction offers an elegant answer. Water is non-toxic, inexpensive, non-flammable, and universally available, making it arguably the greenest solvent that exists. The technique sits conceptually close to subcritical water extraction, a method in which heated liquid water becomes an increasingly capable solvent as its dielectric constant drops with rising temperature, allowing it to dissolve compounds that would normally require organic solvents. In this study, the researchers compared extraction performance at three temperatures: 28.5 degrees Celsius, representing ambient conditions, 70 degrees Celsius, and 90 degrees Celsius. The differences they observed were striking and statistically significant, underscoring how profoundly temperature shapes both the quantity and the quality of what can be recovered from seaweed biomass.

The yield data tell the first part of the story. At 90 degrees Celsius, extraction yielded 9.18 percent for Sargassum polycystum, 10.14 percent for Turbinaria ornata, and 8.78 percent for Rosenvingea intricata, each figure significantly higher than what was obtained at the lower temperatures. In practical terms, roughly a tenth of the dried seaweed biomass was converted into soluble extract simply by treating it with hot water. For an industry built on margins, that recovery rate matters. It means that a coastal biorefinery could valorize seaweed harvests with minimal solvent costs, minimal hazardous waste streams, and straightforward equipment, since the process requires nothing more technically demanding than controlled heating and filtration.

Yield alone, however, says nothing about biological activity, and this is where the study delivers its most compelling evidence. Across all three species, extracts obtained at 90 degrees Celsius showed significantly higher antioxidant properties than extracts prepared at lower temperatures, as measured by total phenolic content, total flavonoid content, and ferric reducing antioxidant power assays. The researchers attribute this to the thermal disruption of the seaweed matrix at higher temperatures. Heat softens and breaks down cell walls and liberates bound phenolic compounds that remain locked inside the algal tissue under ambient conditions. In effect, boiling water does mechanically and chemically what harsher solvents do, but without the environmental baggage.

The antioxidant story was reinforced by two free radical assays. Extracts from the 90 degree Celsius treatments showed significantly greater scavenging activity against 2,2-diphenyl-1-picrylhydrazyl, the stable free radical commonly known as DPPH that serves as a standard benchmark for antioxidant capacity. They also performed significantly better in the deoxyribose assay, a test that evaluates both site-specific and non-site-specific radical scavenging by measuring the protection of deoxyribose sugar from degradation by hydroxyl radicals. Because hydroxyl radicals are among the most reactive and damaging species generated in living tissues, strong performance in this assay hints at genuine protective potential in biological systems rather than mere laboratory chemistry.

Perhaps the most visually dramatic evidence came from the DNA nicking assay. In this experiment, plasmid DNA is exposed to Fenton’s reagent, a mixture that generates hydroxyl radicals and converts the intact supercoiled DNA into fragmented, nicked forms that migrate differently on a gel. When the seaweed extracts were added, they shielded the DNA from this oxidative damage, preserving its structural integrity. The result demonstrates that the compounds recovered by hot water extraction are not just chemically active in solution but capable of protecting a biologically central molecule, DNA, from radical-induced breakage. That protective effect strengthens the case for these extracts as candidates for dietary supplements, nutraceuticals, and functional food ingredients aimed at reducing oxidative stress.

The implications extend well beyond human nutrition. The authors point to the potential of these seaweed extracts as immune boosters and growth enhancers for animals, fish, and shellfish, a direction that could matter enormously for India’s vast aquaculture sector. Natural antioxidant additives derived from marine algae could reduce reliance on synthetic antioxidants in feed, improve animal health, and add value to seaweed harvests that currently command low prices. Given that global interest in seaweed farming is rising rapidly, both as a food source and as a tool for climate mitigation, methods that convert raw biomass into high-value products are exactly the kind of technology that could accelerate the so-called blue economy.

There are, of course, caveats and next steps. The study reports crude extracts rather than purified single compounds, so further work will be needed to identify precisely which molecules drive the observed antioxidant and DNA-protective effects, and to confirm that the activity survives digestion, storage, and processing at industrial scale. Temperature optimization will also need balancing against the thermal sensitivity of individual compounds, since prolonged high heat can degrade some bioactives even as it releases others. Nevertheless, the central message stands: for three abundant Indian brown seaweeds, ordinary hot water outperformed milder conditions on every measure of yield and antioxidant potency tested, all with a solvent that costs essentially nothing and harms nothing. In a field often enamored with exotic solvents and high-tech equipment, the humble kettle may turn out to be the biorefinery’s most underrated tool.

Subject of Research: Hot water extraction of antioxidant bioactive compounds from Indian brown seaweeds

Article Title: Optimization of Hot Water Extraction as a Green Approach to Valorise Bioactive Compounds from Indian Brown Seaweeds: A Comparative Study of Sargassum polycystum, Turbinaria ornata, and Rosenvingea intricata

Article References: Optimization of Hot Water Extraction as a Green Approach to Valorise Bioactive Compounds from Indian Brown Seaweeds: A Comparative Study of Sargassum polycystum, Turbinaria ornata, and Rosenvingea intricata. (n.d.). https://doi.org/10.1007/s12649-026-03789-4

Image Credits: AI Generated

DOI: 10.1007/s12649-026-03789-4

Keywords: brown seaweeds, hot water extraction, green extraction, antioxidant activity, bioactive compounds, Sargassum polycystum, Turbinaria ornata, Rosenvingea intricata, DNA protection, nutraceuticals, phenolic compounds, waste valorization

Sea buckthorn, Hippophae rhamnoides L., is a deciduous shrub native to the Xinjiang region of China and now widely distributed across Asia, Europe and Canada. Its berries are loaded with carbohydrates, polysaccharides, polyphenols, vitamins and amino acids, and have been linked to antioxidant, anticarcinogenic, anti-inflammatory, antimicrobial and hepatoprotective effects. Proanthocyanidins, or PAs, are oligomeric and polymeric flavonoid polyphenols that accumulate in the fruit peel, seeds and stems. They are prized for potent antioxidant activity, cardiovascular protection, anti-obesity potential through pancreatic lipase inhibition, and enhancement of microvascular integrity. Yet most research has focused on PAs from the pulp, while the seed, leaf and peel fractions, which are routinely discarded during processing, have been largely ignored.

Extracting PAs from plant matrices is technically difficult because plant cell walls resist penetration and polyphenols degrade easily. Conventional approaches such as high-pressure extraction, supercritical carbon dioxide and ultrasonic-assisted extraction all suffer from high equipment costs, heavy organic solvent consumption, large energy inputs and secondary pollution risks. The Chinese team turned instead to deep eutectic solvents, or DESs, a class of designer solvents formed when a hydrogen bond donor and a hydrogen bond acceptor combine into a eutectic mixture. Typically built from cheap, biodegradable and environmentally benign components, DESs can dissolve polyphenols through hydrogen-bonding networks that are stronger than the interactions between water and the solutes themselves, loosening the binding forces that hold phenolic compounds inside the plant matrix.

The researchers tested five choline chloride-based solvent systems in which choline chloride served as the hydrogen bond acceptor, paired with five different donors: 1,4-butanediol, citric acid, lactic acid, urea and malonic acid. Water content proved critical, producing a characteristic bell-shaped yield curve. At low water levels the solvent is too viscous to penetrate the seed matrix efficiently; moderate water addition disrupts inter-solvent hydrogen bonds and lowers viscosity, boosting diffusivity. But beyond an optimum, added water competes with the PAs for hydrogen-bonding sites and hydrates the solvent components, weakening the DES-PA interactions that drive extraction. All five solvent systems significantly outperformed 75 percent ethanol, and the champion, choline chloride with 1,4-butanediol at 50 percent water, reached an absorbance of 0.255, a full 201.2 percent higher than the ethanol control.

With the solvent chosen, the team optimized the process using single-factor experiments followed by a three-factor, three-level Box-Behnken response surface design. The solid-to-liquid ratio exerted the strongest influence, followed by temperature and time, and the interaction between solvent ratio and temperature was highly significant because heating thins the solvent and speeds mass transfer only when enough solvent is present, while excessive heat destroys the thermolabile PAs. The model predicted a maximum yield of 48.025 milligrams per gram at a 41:1 milligram-per-milliliter ratio, 61.11 degrees Celsius and 3.29 hours. Validation runs at practical adjusted conditions delivered 47.591 milligrams per gram, a relative error of just 0.90 percent, with a regression fit of R squared 0.9964. Purification on D101 macroporous adsorption resin lifted the extract to 69.17 percent total proanthocyanidins.

Liquid chromatography-tandem mass spectrometry then revealed exactly what the green solvent had pulled from the seeds. Monomeric catechin and epicatechin appeared at mass-to-charge ratios of 291.08 and 292.08, while the dimeric proanthocyanidins B1 through B4 showed characteristic signals at m/z 579.15 to 581.15. Notably, no trimer or tetramer peaks were detected, indicating that sea buckthorn seed PAs consist almost entirely of monomers and dimers. Antioxidant testing across three independent assays showed the extract scavenging DPPH radicals at 4.61, ABTS cation radicals at 5.53 and reducing ferric iron at 6.24 micromoles of Trolox equivalents per milligram, respectable values that trailed only slightly behind pure ascorbic acid and confirmed the extract retained strong reducing and radical-scavenging capacity.

The second half of the study tackled the compounds’ Achilles heel: poor water solubility, instability under heat, pH swings and gastrointestinal conditions, and rapid metabolism in the body. Using ionic gelation, the team encapsulated the purified PAs within a composite wall of sodium alginate and carboxymethyl cellulose, extruding the mixture into a calcium chloride bath to form microcapsules with an encapsulation efficiency of 89.015 percent. Scanning electron microscopy showed intact, roughly elliptical particles without tears or holes, their surface folds a by-product of freeze-drying that increases surface area and may aid retention.

Spectroscopic and thermal analyses confirmed that the capsule walls protect without chemically altering the payload. Fourier transform infrared spectra showed hydrogen-bond interactions between the phenolic hydroxyl groups of the PAs and the polysaccharide wall, but no new peaks and no shift in the aromatic ring vibrations, proving a non-covalent, structure-preserving association. Thermogravimetric analysis was even more dramatic: free PAs lost mass sharply between 100 and 150 degrees Celsius and left only about 8 percent residual char at 600 degrees, whereas loaded microcapsules degraded gradually like the blank wall material, retaining roughly 26 percent residue and shielding the core from direct heat exposure, a critical advantage for foods and pharmaceuticals that undergo thermal processing.

Simulated digestion told a similar story. In gastric fluid at pH 2.0, free PAs flooded out, releasing 29.58 percent within the first 30 minutes and 53.64 percent by 180 minutes, while microencapsulated PAs released only 2.86 percent early on and 21.99 percent at 180 minutes, a delay of more than 31 percentage points. The team attributes this to the pH sensitivity of alginate, whose carboxyl groups protonate in acid, shrinking the matrix and blocking penetration. In neutral intestinal fluid the balance reversed: microcapsules reached a cumulative release of 45.65 percent at 180 minutes, surpassing the free PAs at 39.57 percent and still climbing, exactly the controlled, intestine-targeted release profile desired for maximizing absorption and bioactivity.

The authors are candid about the hurdles separating bench from factory. The choline chloride-1,4-butanediol solvent is relatively viscous, complicating continuous large-scale extraction, and freeze-drying inflates production costs. They propose screening lower-viscosity ternary solvent systems, coupling extraction with ultrasound or microwaves, blending in cheaper agricultural waste-derived polysaccharides such as corn fiber or rice bran cellulose, and ultimately running in vivo trials of bioavailability, tissue distribution and long-term safety. If those steps succeed, the implications extend well beyond sea buckthorn. The integrated solvent-and-encapsulation strategy offers a reusable blueprint for converting fruit-processing residues of every kind into stabilized, deliverable nutraceutical ingredients, turning industrial garbage into functional-food gold with nothing more exotic than biodegradable chemistry.

Subject of Research: Green extraction and microencapsulation of sea buckthorn seed proanthocyanidins using deep eutectic solvents

Article Title: Extraction and purification and microcapsulation of sea buckthorn seed proanthocyanidins using deep eutectic solvent-assisted extraction

Article References: Sun, Y., Sun, D., Ahmad, M., Li, X., Huang, M., Bi, X., Han, L., & Hao, G. (2026). Extraction and purification and microcapsulation of sea buckthorn seed proanthocyanidins using deep eutectic solvent-assisted extraction. Food Chemistry: X, 39, Article 104394. https://doi.org/10.1016/j.fochx.2026.104394

Image Credits: AI Generated

DOI: Not provided

Keywords: sea buckthorn, proanthocyanidins, deep eutectic solvents, microencapsulation, antioxidants, green extraction, sodium alginate, carboxymethyl cellulose, response surface methodology, in vitro digestion, food by-products, functional foods

Pea pod peel is a lignocellulosic treasure chest. On a fresh-weight basis it accounts for nearly 30 percent of the total pod, and its composition is approximately 69 percent cellulose, 22 percent hemicellulose, 5 percent carbohydrates and 4 percent lignin. That makeup makes it a natural candidate for dietary fiber recovery, a field dominated until now by better-studied agricultural by-products such as citrus peel, apple pomace, wheat bran and sugar beet pulp. Pea pod peel, despite its abundance, has been investigated to a far lesser extent for fiber recovery, and because the chemical composition of lignocellulosic biomass varies with plant origin, results from other wastes cannot be directly transferred to it. A systematic study of this specific material was therefore needed.

Dietary fibers are the non-digestible carbohydrate polymers that resist enzymatic breakdown in the human gastrointestinal tract, and they fall into two physiologically distinct families. Insoluble dietary fiber, built from structural polysaccharides such as cellulose, lignin and portions of hemicellulose, adds fecal bulk and improves intestinal motility, while soluble dietary fiber, which includes functional polysaccharides such as pectins, β-glucans, inulin and galactomannans, helps regulate blood glucose, lowers cholesterol and increases gut viscosity, supporting cardiometabolic health. Because market demand for both fractions keeps climbing in the functional food and nutraceutical sectors, food scientists are hunting for cheap, sustainable raw materials, and pea pod peel fits the bill.

The researchers compared three extraction routes: conventional alkaline extraction, microwave-assisted alkaline extraction and ultrasound-assisted alkaline extraction. In the conventional method, ten grams of pea pod peel powder were treated with about 400 milliliters of 1.2 mol/L sodium hydroxide at 40 °C for two hours in a water bath with continuous mixing, then centrifuged for 15 minutes at 5000 g to separate the insoluble residue from the soluble supernatant. The microwave approach used the same alkaline chemistry but replaced the long water-bath treatment with a brief exposure to 450 W of microwave energy, varying the solid-to-solvent ratio from 0.025 to 0.1 g/mL and the treatment time from 3 to 6 minutes. The ultrasound route swept the ultrasonic power from 150 to 300 W, used the same range of solid-to-solvent ratios, and varied times from 3 to 12 minutes. All experiments were performed in triplicate, and the design space for each technique was first mapped by single-factor screening experiments.

To squeeze the maximum fiber recovery out of each technology, the team turned to response surface methodology. For microwave extraction, 13 experimental runs optimized two variables at fixed power; for ultrasound, 20 runs optimized power, solid-to-solvent ratio and time simultaneously. Quadratic regression models captured how each factor and their interactions shaped total, soluble and insoluble fiber yields. The models were statistically significant, with R² values as high as 0.9983 for the ultrasound responses, and non-significant lack-of-fit tests confirmed their adequacy. Validation runs showed prediction errors as small as 0.01 to 0.34 percent between predicted and measured yields, a remarkable agreement demonstrating how reliably the models describe extraction behavior across the studied parameter space.

The results delivered a clear winner. Conventional alkaline extraction, optimized at a solid-to-solvent ratio of 0.033 g/mL, recovered 84.40 percent total dietary fiber, comprising 23.35 percent soluble and 61.07 percent insoluble fiber. Microwave-assisted extraction at 0.0625 g/mL and 4.5 minutes raised the total to 88.90 percent, with 26.67 percent soluble and 62.23 percent insoluble fiber. But ultrasound-assisted extraction dominated, achieving 95.69 percent total dietary fiber, 28.71 percent soluble fiber and 66.98 percent insoluble fiber at 225 W, 0.0625 g/mL and 7.5 minutes. The mechanism behind this superiority is cavitation: collapsing ultrasonic bubbles generate shock waves and microjets that tear open cell walls, boost solvent penetration and accelerate mass transfer. Pushing the power beyond 225 W or extending sonication past 7.5 minutes actually reduced yields, because excessive cavitation fragments fiber molecules into pieces too small to recover, a reminder that in extraction, more energy is not always better.

The solid-to-solvent ratio told a similar story of a sweet spot. Yields climbed as the ratio rose from 0.025 to 0.0625 g/mL, then fell at 0.1 g/mL, because thicker slurries impede both microwave energy transmission and ultrasonic wave propagation. Microwave time peaked at 4.5 minutes, after which thermal degradation of polysaccharide chains set in. The authors note that these energy-assisted methods work by fundamentally different mechanisms: microwaves heat the material volumetrically and build internal pressure that ruptures cells, while ultrasound applies mechanical shear that disintegrates the fiber matrix. Both improve mass transfer, but ultrasound does so with fewer thermal side effects, which appears to protect the fiber’s molecular integrity while opening up its structure. Each method also carries known limitations: conventional alkaline treatment demands long times and large chemical inputs and can break down fiber structure under harsh alkaline conditions, microwaves can cause non-uniform heating and localized overheating, and overly intense sonication can depolymerize fibers and alter their functionality.

Characterization revealed how deeply extraction technology rewrites fiber architecture. Particle size analysis showed that ultrasound produced the finest powders, with mean diameters of 136.28 μm for soluble fiber and 233.18 μm for insoluble fiber, the smallest among all treatments. Scanning electron microscopy made the difference visible. Alkaline-treated fibers displayed compact, smooth, low-porosity surfaces, whereas ultrasound-treated fibers were rough, cracked, porous and fibrillated, a consequence of cavitation-driven erosion. Microwave-treated fibers showed a looser, sponge-like honeycomb texture produced by internal superheating. X-ray diffraction found the same crystal phases in all samples, confirming that no new chemical phases formed, but the degree of crystallinity dropped significantly after assisted extraction, with ultrasound-extracted soluble and insoluble fibers showing the lowest values at 15.24 and 22.27 percent. A more amorphous structure means more accessible binding sites for water and oil, which is precisely what the functional tests confirmed.

Those functional gains are the study’s most commercially significant finding. Ultrasound-extracted insoluble fiber held 4.8 g of water per gram, 2.7 g of oil per gram and swelled to 7.0 mL/g, while the soluble fraction held 3.2 g of water, 1.5 g of oil and swelled to 4.0 mL/g, all the highest values among the three methods. Fourier transform infrared spectroscopy confirmed that despite this structural remodeling, the chemistry survived intact: characteristic O-H, C-H and C-O stretching bands, including lignin-associated aromatic signals, were all preserved, indicating that the polysaccharide backbones of cellulose, hemicellulose and pectic components remained undamaged. Thermogravimetric analysis added another advantage: ultrasound-extracted fibers were the most thermally robust, with the highest thermal resistance at 270 °C, meaning these ingredients could withstand baking and other high-temperature food processes without collapsing.

Together, the data sketch a coherent structure-function story. Ultrasound cavitation reduces particle size, roughens surfaces, loosens crystalline order and exposes hydrophilic and hydrophobic binding sites, all of which translate into superior hydration, oil binding and swelling, the very properties food technologists prize when formulating high-fiber breads, beverages and meat alternatives. The technique also cuts extraction time from two hours to 7.5 minutes, a dramatic process intensification that could reduce energy and solvent costs at scale. The authors caution that the work remains at laboratory scale: energy consumption, economic feasibility, pilot-scale performance and real-food application, including effects on texture, shelf life and consumer acceptance, still need to be demonstrated. Future studies should also probe health-relevant functions such as glucose adsorption, bile acid binding, fermentability and prebiotic potential.

Even so, the message is striking. A waste stream generated at a scale of millions of tons a year, currently treated as a disposal problem, can be converted into a dietary fiber ingredient that outperforms conventionally processed material on nearly every functional metric, using nothing more exotic than sound waves and dilute alkali. As food manufacturers race to meet consumer demand for fiber-enriched products and regulators push for greener processing, ultrasound-assisted extraction of pea pod peel offers a rare win-win: less waste in the landfill, more functionality on the plate, and a sustainable, cost-effective route to value-added ingredients grown from one of the world’s most widely cultivated and freeze-tolerant legume crops.

Subject of Research: Green extraction of dietary fiber from pea pod peel waste using ultrasound and microwave assisted alkaline methods

Article Title: Optimization and characterization of microwave and ultrasound assisted alkaline extracted pea pod peel dietary fiber

Article References: Sharma, P., & Kumar, P. (2026). Optimization and characterization of microwave and ultrasound assisted alkaline extracted pea pod peel dietary fiber. Discover Industrial Chemistry and Materials, 1(1), Article 19. https://doi.org/10.1007/s44508-026-00020-z

Image Credits: AI Generated

DOI: 10.1007/s44508-026-00020-z

Keywords: pea pod peel, dietary fiber, ultrasound-assisted extraction, microwave-assisted extraction, response surface methodology, soluble dietary fiber, insoluble dietary fiber, food waste valorization, green extraction, functional properties, agro-industrial byproducts, thermal stability

Cassia absus belongs to the Fabaceae family and grows in tropical and subtropical regions of Asia. Its seeds have a history of medicinal use and contain reported bioactive constituents including chaksine and isochaksine. That traditional and phytochemical background made the plant a candidate for a more systematic investigation of its extractable compounds. The researchers were not testing a finished medicine or demonstrating a treatment for disease; they were developing and optimizing a laboratory extraction process. The distinction matters because measurements such as antioxidant activity in a test tube do not establish clinical benefit. They do, however, help characterize extracts and identify whether a plant material may warrant further chemical, toxicological and pharmaceutical study.

The process began with seeds purchased from a local market in Lahore, Pakistan. The seeds were washed, dried, ground and passed through an 80-mesh sieve to produce a relatively uniform powder. The material was defatted by soaking it in n-hexane for three days, then dried at 40 degrees Celsius. For the greener extraction stage, the researchers prepared the deep eutectic solvent by combining choline chloride and glycerol in a 1:3 molar ratio. The mixture was heated at 80 degrees Celsius for two hours under vacuum until it formed a clear, colourless liquid. For extraction, the solvent was mixed with water in equal proportions. This water-containing system was then brought into contact with one gram of the prepared seed powder.

Ultrasound supplied the physical force intended to open the plant matrix. When a probe emits high-intensity sound into a liquid, microscopic bubbles can form, grow and collapse in a phenomenon known as acoustic cavitation. These rapid events can disturb cell walls, improve wetting and solvent penetration, and increase movement of dissolved molecules from the solid material into the surrounding liquid. The technique can therefore accelerate mass transfer compared with passive soaking. But more energy or more time is not automatically better. Excessive sonication can increase heating, alter fragile compounds or reduce the energy delivered efficiently through the liquid. The researchers monitored temperature and avoided excessive heat build-up while varying ultrasound amplitude, extraction time and solvent-to-feed ratio across a Box–Behnken experimental design.

The study evaluated four responses: total phenolic content, total flavonoid content, DPPH radical-scavenging activity and iron-chelating activity. Total phenolic content was expressed as milligrams of gallic acid equivalents per gram, while flavonoid content was reported using a rutin-equivalent calibration. DPPH testing measures how effectively an extract reduces a stable laboratory radical, producing an estimate of radical-scavenging capacity. The iron-chelation assay examined the ability of the extract to interfere with the reaction between ferrous ions and ferrozine, with lower colour formation corresponding to greater apparent chelation. These are widely used screening measurements, but they represent chemical behaviour under defined assay conditions rather than proof that the extract will neutralize radicals or regulate iron in a human body.

Seventeen experimental runs, including five centre points, were used to map how the three process variables affected the four responses. The results showed that no single run maximized every measurement. One run produced the highest total phenolic content at 44.18 milligrams of gallic acid equivalents per gram, another produced the highest flavonoid content at 29.26 milligrams of rutin equivalents per gram, a third reached 89.53 percent DPPH radical-scavenging activity, and a fourth recorded 90.31 percent iron-chelating activity. This divergence reflects the chemical complexity of extraction. Phenolics, flavonoids and other active constituents differ in polarity, solubility and stability, so conditions that release one group efficiently may not recover another group or preserve its activity. Maximizing one result could consequently produce an extract that performs poorly across the broader set of desired properties.

Response surface methodology was used first to fit second-order polynomial models describing linear, quadratic and interaction effects. The models were statistically significant for all four responses, with p-values below 0.0001 for phenolic and flavonoid content, 0.0011 for DPPH activity and 0.0024 for iron-chelating activity. Model R-squared values ranged from 0.9299 to 0.9933, indicating that the equations accounted for much of the variation within the tested design space. The solvent-to-feed ratio emerged as the strongest influence on phenolic and flavonoid recovery. Increasing solvent availability likely improved penetration and maintained a concentration gradient that favoured diffusion, but the negative quadratic terms showed that the benefit eventually levelled off or declined. Too much solvent could dilute the extract or reduce ultrasonic energy density.

The antioxidant response was more complicated. Extraction time had a significant negative effect on DPPH activity, suggesting that prolonged sonication may have degraded or structurally modified sensitive radical-scavenging compounds. Ultrasound amplitude and solvent-to-feed ratio also interacted, meaning their effects could not be interpreted independently. Iron-chelating activity was governed mainly by quadratic effects rather than simple increases or decreases in individual variables. The researchers then trained a feedforward artificial neural network using 70 percent of the experimental data for training, with 15 percent each reserved for validation and testing. The selected network used two hidden layers containing 20 and 10 neurons, with logsig and tansig activation functions. Its overall correlation values ranged from 0.97256 for iron-chelating activity to 0.99469 for total phenolic content, although the small dataset means these strong figures apply only within the investigated range and require confirmation with additional experiments.

TOPSIS provided the final decision framework by treating every experimental run as an alternative and all four responses as beneficial criteria. The data were normalized, given equal weights and compared with an ideal solution representing the best combined performance. Run 12 achieved the highest closeness coefficient, 0.7153, at 60 percent amplitude, six minutes and 20 millilitres per gram. Its measured results were 33.51 milligrams of gallic acid equivalents per gram of total phenolics, 27.99 milligrams of rutin equivalents per gram of flavonoids, 74.70 percent DPPH activity and 82.33 percent iron-chelating activity. It did not lead every individual category, but it offered the strongest overall balance. Compared with the lowest-ranked run, it had approximately 2.7 times more total phenolics, 27 percent higher flavonoid content and 59 percent higher DPPH activity, despite slightly lower iron-chelating activity.

The modelling comparison gave the neural network a modest advantage over response surface methodology. At the selected condition, the artificial neural network showed prediction errors of 1.15 percent for flavonoid content and 2.18 percent for DPPH activity, while TOPSIS was closest for total phenolic content with a 1.03 percent error. All models predicted iron-chelating activity with errors below 1 percent. Across the dataset, the neural network generally produced lower average absolute deviations and mean absolute percentage errors, particularly for the nonlinear antioxidant and chelation responses. The researchers also assessed the method with the ComplexMoGAPI green analytical metric, which gave an overall score of 81. The favourable score reflected the use of a choline chloride–glycerol and water system, room-temperature extraction, short sonication and avoidance of more hazardous conventional solvents. However, the reported E-factor was 60, and extraction yield remained below 70 percent, showing that waste and solvent efficiency still need improvement.

The findings position the method as a promising laboratory framework rather than an industrially validated product. Natural deep eutectic solvents can be tuned by changing their components and proportions, and their low volatility and biodegradability are attractive for natural-product processing. Yet solvent recovery, viscosity, long-term stability, compound identification and scale-up must be addressed before commercial adoption. The researchers recommend compound-level characterization, stability testing, toxicity evaluation and pilot-scale validation. Future work could also examine whether the solvent can be reused, whether lower solvent volumes can maintain performance and which specific molecules account for the measured activities. For now, the study demonstrates how acoustic cavitation and data-driven optimization can turn a traditional plant resource into a more systematically studied extraction target, while also showing that a greener label does not eliminate the need to measure waste, validate predictions and test biological claims carefully.

An important consideration is that the reported response values are operational measurements tied to the extraction and assay protocols. Total phenolic and flavonoid results depend on the calibration standards used, while DPPH and iron-chelation values summarize reactions in controlled chemical systems. They can therefore be useful for comparing extraction conditions without identifying which individual seed constituents produced the response. Chemical profiling would be needed to connect the optimized process with specific molecules such as the reported Cassia absus alkaloids or other extract components.

The optimization also illustrates why process conditions should be treated as a defined operating window rather than a universal recipe. The selected settings were derived from a Box–Behnken design covering particular amplitude, time and solvent-to-feed ranges, with a 50:50 NaDES–water extraction mixture and pretreated seed powder. Performance outside those conditions cannot be inferred from the model alone. Changes in particle characteristics, solvent composition, equipment geometry or temperature control could alter cavitation and mass transfer. Independent confirmation using new batches of seeds, expanded chemical characterization and scale-relevant equipment would help establish how reproducible the balance identified by TOPSIS is.

Subject of Research: AI-guided ultrasound extraction of Cassia absus seed phytochemicals using a natural deep eutectic solvent

Article Title: Artificial neural network and TOPSIS guided ultrasound extraction of Cassia absus L. seed phytochemicals using a natural deep eutectic solvent

Article References: Khalid, N. U. A., Iftikhar, H., Ahmed, D., & Mushtaq, M. (2026). Artificial neural network and TOPSIS guided ultrasound extraction of Cassia absus L. seed phytochemicals using a natural deep eutectic solvent. Discover Green Chemistry, 1(1), Article 26. https://doi.org/10.1007/s44509-026-00031-1

Image Credits: AI Generated

DOI: 10.1007/s44509-026-00031-1

Keywords: Cassia absus, green extraction, natural deep eutectic solvents, ultrasound extraction, artificial neural networks, TOPSIS, antioxidants, phytochemicals, Artificial, neural, network, guided