Characterization of the Antiproliferative Activity of Sargassum muticum Low and High Molecular Weight Polysaccharide Fractions.

The extract obtained by pressurized hot water extraction from Sargassum muticum, to recover the bioactive compound known as fucoidan, was fractionated using membranes of 100, 50, 30, 10, and 5 kDa, obtaining five retentates and the final permeate. These fractions were characterized for phloroglucinol content, protein content, sulfate content, and trolox equivalent antioxidant capacity (TEAC); apart from oligosaccharides, FTIR and molar mass distribution were also evaluated. Retentates of 100 and 50 kDa showed higher values for phloroglucinol, TEAC, and sulfate content. The rheology of the alginate fraction was also evaluated. Regarding the potential antitumoral activity, all fractions were assessed in MCF-7 cells using a metabolic activity assay based on the reduction of a tetrazolium compound, the most efficient being R100 and R50. Based on the results, these fractions were compared with commercial fucoidans at the same concentrations, and similar results were found. In addition, synergistic cytotoxic effects using two drugs commonly used in breast cancer, cis-Platinum (cis-Pt) and 5-fluorouracil (5-FU), were tested in combination with R100 and R50. Promising results were obtained when the retentate and the drugs were mixed, showing an improvement in the cytotoxicity induced by the chemotherapy.

Extraction and characterization of polysaccharide-enriched fractions from Phoma dimorpha mycelial biomass.

Ultrasound-assisted extraction (UAE) and pressurized hot water extraction (PHWE) were tested as advanced clean methods to obtain polysaccharides from Phoma dimorpha mycelial biomass. These methods were compared to conventional extraction (hot water extraction, HWE) in terms of polysaccharides-enriched fractions (PEF) yield. A central composite rotational design was performed for each extraction method to investigate the influence of independent variables on the yield and to help the selection of the condition with the highest yield using water as an extraction solvent. The best extraction condition of PEF yielded 12.02 wt% and was achieved when using UAE with direct sonication for 30 min under the intensity of 75.11 W/cm2 and pulse factor of 0.57. In the kinetic profiles, the highest yield (15.28 wt%) was obtained at 50 °C under an ultrasound intensity of 75.11 W/cm2 and a pulse factor of 0.93. Structural analysis of extracted polysaccharide was performed using Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and thermal property. The water solubility index, water holding capacity, and emulsification index of PEF were 31.3 ± 1.5%, 138.1 ± 3.2%, and 62.9 ± 2.3%, respectively. The submerged fermentation demonstrates the huge potential of Phoma dimorpha to produce polysaccharides with bioemulsifying properties as a biotechnologically cleaner alternative if compared to commercial petroleum-derived compounds. Furthermore, UAE and PHWE are green technologies, which can be operated at an industrial scale for PEF extraction.

Selective pressurized hot water extraction of nutritious macro-nutrients vs. micro-nutrients in Moringa oleifera leaves-a chemometric approach.

Moringa oleifera leaves are widely used in traditional medicine as a food supplement because they are high in essential and nutritious content. Pressurized hot water extraction (PHWE), which is a green approach, was used for the recovery of the macro-nutrient and micro-nutrient elements from dried leaf powder of Moringa oleifera. In this study, response surface methodology was applied to assess the influence of temperature (50-200 °C) and time (5-60 min) on the extractability pattern of macro-nutrient and micro-nutrient elements from the leaves of Moringa oleifera when processed by PHWE. The quantification of macro-nutrient elements such as Ca, K and Mg and micro-nutrient elements like Al, Co, Cr, Cu, Fe, Ni and Zn from the leaves was determined using inductively coupled plasma optical emission spectroscopy (ICP-OES). Obtained results revealed that the extraction of macro-nutrient elements from the Moringa oleifera leaves was enhanced by increasing the extraction time more than the extraction temperature. On the contrary, the amounts of extractable micro-nutrient elements were increased by increasing the extraction temperature. Hence, the recovery for macro-nutrient elements ranged from 88 to 98% while for micro-nutrients it ranged from 21 to 46%. This implies that macro-nutrient elements are extracted with relatively high selectivity in relation to micro-nutrient elements in Moringa dried leaf powder using the PHWE technique.

Selective Extraction of Cannabinoid Compounds from Cannabis Seed Using Pressurized Hot Water Extraction.

Phytochemicals of Cannabis sativa mainly for the use in the different industries are that of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Pressurized hot water extraction (PHWE) is seen as an efficient, fast, green extraction technique for the removal of polar and semi-polar compounds from plant materials. The PHWE technique was applied to extract cannabinoid compounds from Cannabis sativa seed. Response surface methodology was used to investigate the influence of extraction time (5-60 min), extraction temperature (50-200 °C) and collector vessel temperature (25-200 °C) on the recovery of delta-9-tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD), cannabichromene (CBG) and cannabigerol (CBC) from Cannabis sativa seed by PHWE. The identification and semi quantification of cannabinoid compounds were determined using GCXGC-TOFMS. The results obtained from different extractions show that the amount of THC and CBN was drastically decreasing in the liquid extract when the temperature rose from 140 to 160 °C in the extraction cell and the collector's vessel. The optimal conditions to extract more CBD, CBC, and CBG than THC and CBN were set at 150 °C, 160 °C and 45 min as extraction temperature, the temperature at collector vessel, and the extraction time, respectively. At this condition, the predicted and experimental ratio of THCt (THC + CBN)/CBDt (CBD + CBC+ CBG) was found to be 0.17 and 0.18, respectively. Therefore, PHWE can be seen as an alternative to the classic extraction approach as the efficiency is higher and it is environmentally friendly.

Characteristics of pressurized hot water extract from abalone muscle and the antioxidant ability during simulated digestion in vitro.

The physicochemical properties of pressurized hot-water extract (PHE) from abalone muscle and the antioxidant activities of its digestive products were investigated in this study. The PHE contained protein of 49.58% and carbohydrate of 41.95%. After ethanol graded precipitation, most of carbohydrate and protein in PHE were successively remained in 40% ethanol precipitate (EP40) and 80% ethanol precipitate (EP80), respectively. High proportions of Glu and Gly were found in the PHE, EP40 and EP80, but the proportion of Ala in ethanol soluble extract (ESE) reached up to 46.00%. Both PHE and EP40 were rich in glucose, while galactose and glucose were main monosaccharides in the EP80 and ESE. Based on the results of SDS-PAGE and HPLC, high molecular weight components from PHE were precipitated in the EP40, but oligopeptides and free amino acids were fractionated in EP80 and ESE. Among the PHE and the digestive products, the highest antioxidant ability was found to be EP80 hydrolysate, the IC50 values of which for scavenging activity on hydroxyl radical, DMPD radical and ABTS radical were 1.05 mg/mL, 1.40 mg/mL and 0.56 mg/mL, respectively. It is concluded that carbohydrate of abalone muscle was dissolved more easily into hot water than protein, and protein hydrolysate of PHE might play an important role in antioxidant activity of gastrointestinal digestion.

Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives.

In this work we have analyzed the pine and spruce softwood lignin fraction recovered from a novel pressurized hot water extraction pilot process. The lignin structure was characterized using multiple NMR techniques and the thermal properties were analyzed using thermal gravimetric analysis. Acetylated and selectively methylated derivatives were prepared, and their structure and properties were analyzed and compared to the unmodified lignin. The lignin had relatively high molar weight and low PDI values and even less polydisperse fractions could be obtained by fractionation based on solubility in i-PrOH. Condensation, especially at the 5-position, was detected in this sulphur-free technical lignin, which had been enriched with carbon compared to the milled wood lignin (MWL) sample of the same wood chips. An increase in phenolic and carboxylic groups was also detected, which makes the lignin accessible to chemical modification. The lignin was determined to be thermally stable up to (273⁻302 °C) based on its Tdst 95% value. Due to the thermal stability, low polydispersity, and possibility to tailor its chemical properties by modification of its hydroxyl groups, possible application areas for the lignin could be in polymeric blends, composites or in resins.

Pressurized Hot Water Extraction and Capillary Electrophoresis for Green and Fast Analysis of Useful Metabolites in Plants.

The search for useful compounds from plants is an important research area. Traditional screening that involves isolation and identification/quantitation is tedious, time consuming, and generates a significant amount of chemical waste. Here, we present a simple, fast, and green strategy to assess ≥0.1% wt/wt quantities of useful compounds in plants/spices using pressurized hot water extraction using a household espresso machine followed by chemical analysis using capillary electrophoresis. Three demonstrations with polygodial, cinnamaldehyde, coumarin, and shikimic acid as target metabolites are shown. Direct analysis of extracts was by the developed micellar electrokinetic chromatography and capillary zone electrophoresis methods. The approach, which can be implemented in less developed countries, can process many samples within a day, much faster than traditional techniques that would normally take at least a day. Finally, 0.8-1.1% wt/wt levels of shikimic acid were found in Tasmanian-pepperberry and Tasmanian-fuschia leaves via the approach.

Simultaneous extraction of phenolics and essential oil from peppermint by pressurized hot water extraction.

Phenolics and essential oil of peppermint were obtained by pressurized hot water extraction (PHWE). The best extraction conditions were found to be 130 °C for temperature, 10 min for extraction time, and 3 cycles for extraction number. There were no statistically significant differences between 130 and 160 °C in terms of essential oil content. Total phenolic contents (TPC) of the extracts were higher at 160 °C than that of 130 °C. However, further HPLC analysis of the extracts revealed that hydrolysis and/or decomposition of phenolics were observed in the extracts obtained at 160 °C. The main phenolic of peppermint was determined as eriocitrin by HPLC-DAD, while menthol was the dominant component in essential oil fraction of peppermint by GC-FID. The present study demonstrated that PHWE was a suitable technique for simultaneous extraction of phenolics and essential oil from peppermint. The technique might be used as an analytical extraction tool for determination of phenolics and essential oil. Moreover, the extracts of PHWE could directly be evaluated for the enrichment of liquid food formulations or be transformed into solid form by suitable techniques such as spray drying for easy storage and subsequent enrichment of food products.

Pressurized hot water extraction of bioactive compounds from artichoke by-products.

Artichoke by-products are a suitable source of health-promoting ingredients for the production of dietary supplements and food additives. A pressurized hot water extraction (PHWE) was developed to recover caffeoylquinic acids (CQAs) and flavone glycosides (FLs) from agro-industrial artichoke by-products. The main factors influencing PHWE efficiency and CQA isomerization (temperature, numbers of cycles, modifier, and extraction time) were carefully studied and optimized by response surface design. The proposed PHWE procedure provides an exhaustive extraction of CQAs and FLs (recoveries: 93-105% and 90-105%) from artichoke external bracts and leaves of different cultivars (p > 0.05), without significant formation of artefacts generated by high temperatures. PHWE extracts showed CQA and FL levels (14-37 mg/g and 3-19 mg/g, respectively) comparable to commercial products and marked antioxidative effects (EC50 11-83 µg/mL) by cellular antioxidant activity assay in human hepatocarcinoma HepG2 cells. These results proved that PHWE is an excellent green technique to recover bioactive compounds from artichoke agro-industrial residues.

Green Extraction Methods for Polyphenols from Plant Matrices and Their Byproducts: A Review.

Polyphenols as phytochemicals have gained significant importance owing to several associated health benefits with regard to lifestyle diseases and oxidative stress. To date, the development of a single standard method for efficient and rapid extraction of polyphenols from plant matrices has remained a challenge due to the inherent limitations of various conventional extraction methods. The exploitation of polyphenols as bioactive compounds at various commercial levels has motivated scientists to explore more eco-friendly, efficient, and cost-effective extraction techniques, based on a green extraction approach. The current review aims to provide updated technical information about extraction mechanisms, their advantages and disadvantages, and factors affecting efficiencies, and also presents a comparative overview of applications of the following modern green extraction techniques-supercritical fluid extraction, ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction, and pressurized hot water extraction-as alternatives to conventional extraction methods for polyphenol extraction. These techniques are proving to be promising for the extraction of thermolabile phenolic compounds due to their advantages over conventional, time-consuming, and laborious extraction techniques, such as reduced solvent use and time and energy consumption and higher recovery rates with lower operational costs. The growing interest in plant-derived polyphenols prompts continual search for green and economically feasible modern extraction techniques. Modern green extraction techniques represent promising approaches by virtue of overcoming current limitations to the exploitation of polyphenols as bioactive compounds to explore their wide-reaching applications on an industrial scale and in emerging global markets. Future research is needed in order to remove the technical barriers to scale-up the processes for industrial needs by increasing our understanding and improving the design of modern extraction operations.

Design and development of solar parabolic concentrator, closed-loop pressurized hot water for a household baking system - For the case of injera baking in Ethiopia.

A laboratory setup with two axis of manual sun-tracking was designed and built. To get the predicted values for a solar injera stove, a 20-min heating time to prepare it for baking, 3.1 kWh power in the first hour, and 5.8 kWh (with only an 87 percent increase) in the second hour were acquired to bake 9 and 28 injera using electric injera stove, respectively. The temperature distribution on the clay surface was the range of 180 °C-220 °C. Solar injera baking stove was designed and built using the average energy required to bake one injera from an electrical injera stove. The laboratory setup was put to the test, temperatures at the receiver's surface ranging from 315 to 318 °C and an average solar radiation of 1000 W/m2 was obtained on the first test. The injera stove inlet reached a maximum temperature of 180.92 °C with a pressure of 14.5 bars during a pressurized hot water production and circulation test (load test). The surface temperature of the solar injera stove clay plate reached a maximum of 62.69 °C. Temperature of more than 60 °C was maintained on the surface of the solar injera stove plate for nearly 2 h.

Green Extraction of Antioxidant Fractions from Humulus lupulus Varieties and Microparticle Production via Spray-Drying.

The formulation of polymeric microparticles to encapsulate bioactive compounds from two hop varieties (Nugget and Perle) using sequential green extraction processes was performed. The technologies used were ultrasound-assisted extraction (UAE) and pressurized hot water (PHW) extraction. Liquid phases were analyzed for total phenolic content (~2%), antioxidant activity (IC50, DPPH: 3.68 (Nugget); 4.46 (Perle) g/L, TEAC (~4-5%), FRAP (~2-3%), and reducing power (~4%)), protein content (~1%), oligosaccharide content (~45%), and for structural features. The fractions obtained from UAE were selected to continue with the drying process, achieving the maximum yield at 120 °C (Perle) and 130 °C (Nugget) (~77%). Based on these results, the formulation of polymeric microparticles using mannitol as the carrier was performed with these fractions. The production yield (~65%), particle size distribution (Perle: 250-750 µm and Nugget: ~100 µm), and rheological features (30-70 mPa s at 0.1 s-1) were the parameters evaluated. The UAE extracts from hop samples processed using a sustainable aqueous treatment allowed the formulation of microparticles with a suitable yield, and morphological and viscosity properties adequate for potential food and non-food applications.

Formulation of Polymeric Microparticles Using Eco-Friendly Extracted Crude Fucoidans from Edible Brown Seaweed Undaria pinnatifida.

Several bioactive compounds that hold a potential interest in the food industry as phenolic compounds, polysaccharides, proteins and vitamins, among others, are present in seaweeds. Green extraction technologies are the preferred way to obtain these compounds. Pressurized hot water extraction, from 160 to 220 °C, was tested to achieve high yields of these components from the edible brown seaweed, Undaria pinnatifida. The maximum fucoidan content was recovered at 160 °C, while the phloroglucinol content and antioxidant activity were maximum at 220 °C. The possibility of encapsulating these bioactive fractions using mannitol was assessed. The highest production yield of the polymeric particles was found using the 220 °C fraction (close to 75%). In order to formulate microparticles with bioactive potential, several ratios of liquid phases were assessed, 3:1, 1:1 and 1:3 (w:w), using the liquid fractions obtained at 160 °C and 220 °C. The yield production was always above 67%, being in the 1:3 ratio (160 °C:220 °C) and close to 75%. The rheological results indicated that the presence of microparticles enhanced the apparent viscosity of the aqueous dispersions with non-Newtonian profiles, achieving the highest viscosity for those formulated with microparticles from 160 °C:200 °C (3:1).

High-Yield Recovery of Antioxidant Compounds from Bambusa chungii Culms Using Pressurized Hot Water Extraction.

A large amount of waste from Bambusa chungii culms is generated from the bamboo pulping industry, causing disposal problems. Nevertheless, bamboo culms are a suitable source of functional ingredients, such as antioxidant compounds. However, because of the high compactness and tightness in their material structure, obtaining phytochemicals from bamboo culms using conventional organic solvent extraction methods can be inefficient. In this research, we developed a pressurized hot water extraction (PHWE) method to recover 19 target phenolic compounds from Bambusa chungii culms. The extracted compounds were determined by ultra-high performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-QTOF-MS). The antioxidant potential of the extracts was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. We investigated the effects of temperature, extraction time, and the material-to-liquid ratio on PHWE, and these parameters were optimized with a Box-Behnken design experiment and response surface tool. The optimal extraction condition was found at 170 °C, with a 1:30 g/mL material-to-liquid ratio and a 14 min extraction time. Following these optimal parameters, the total yield of target phenolic compounds (TYPC) reached 3.85 mg/g of raw material, and the half-maximal inhibitory concentrations (IC50) for the DPPH and ABTS tests were 94.7 mg/L and 21.88 mg/L, respectively. The FRAP value was 1.23 µmol FSE/mg of dried extract. A strong correlation between TYPC and the antioxidant activity of the extract was confirmed. The TYPC and antioxidant capacity of the optimal PHWE extract of the Bambusa chungii culms were both considerably higher than those of extracts obtained from conventional solvent extractions. These results indicated that PHWE is an excellent green technique for recovering phenolic compounds from bamboo culms, and the PHWE extracts of Bambusa chungii culms may be a good source of natural antioxidants.

Screening for α-Glucosidase-Inhibiting Saponins from Pressurized Hot Water Extracts of Quinoa Husks.

The present study extracted total saponins from quinoa husks with pressurized hot water extraction and optimized the extraction conditions. The response surface methodology (RSM) with a Box-Behnken design (BBD) was employed to investigate the effects of extraction flow rate, extraction temperature and extraction time on the extraction yield of total saponins. A maximal yield of 23.06 mg/g was obtained at conditions of 2 mL/min, 210 °C and 50 min. The constituents of the extracts were analyzed by liquid chromatography-mass spectrometry (LC-MS). A total of twenty-three compounds were identified, including five flavonoids, seventeen triterpenoid saponins and a phenolic acid. Moreover, we performed an in vitro assay for the α-glucosidase activity and found a stronger inhibitory effect of the quinoa husk extracts than acarbose, suggesting its potential to be developed into functional products with hypoglycemic effect. Finally, our molecular docking analyses indicated triterpenoid saponins as the main bioactive components.

Pressurized hot water extraction, structural properties, biological effects, and in vitro microbial fermentation characteristics of sweet tea polysaccharide.

Although sweet tea is rich in bioactive polysaccharides, the knowledge regarding their structures, bioactivities, and gut microbial metabolism is still limited. Therefore, in order to promote the application of sweet tea polysaccharide (STP) in the food industry, the pressurized hot water extraction (PHWE) of STP was optimized, and its structural properties and biological effects as well as microbial fermentation characteristics were investigated. The maximum extraction yield (4.64 % ± 0.03 %) of STP extracted by PHWE was obtained under the optimal conditions. Both homogalacturonan and arabinogalactan might exist as major polysaccharide fragments in STP. Additionally, STP exerted obviously in vitro antioxidant, anti-diabetic, and immunostimulatory effects, which might be related to its chemical properties, such as uronic acids, conjugated polyphenolics, and esterification degree. Furthermore, STP could be consumed by intestinal microbiota, and its fermentability was about 54 % at the end stage of fecal fermentation. Indeed, STP could modulate the microbial composition via improving the growth of several beneficial microbes, causing the release of beneficial short-chain fatty acids. Collectively, the findings indicate that the PHWE is an efficient method for extracting bioactive polysaccharides from sweet tea, and results can also provide a scientific basis for developing STP into functional foods or functional ingredients.

Adjustable Gel Texture of Recovered Crude Agar Induced by Pressurized Hot Water Treatment of Gelidium sesquipedale Industry Waste Stream: An RSM Analysis.

A significant amount of bioactive compound-rich solid waste is released during the industrial phycocolloid-centric extraction of Gelidium sesquipedale. The impact of mild pressurized hot water extraction on repurposing this waste for the recovery of agar with an adjustable gel texture is investigated. A two-factor interaction response surface model assessed the influences of the operating temperatures (80 to 130 °C), times (45 and 150 min), pressures (1 to 70 bar), and algae concentrations (3 to 10% (w:v)). At a temperature of 100 °C, a pressure of 10.13 bar, a recovery time of 45 min, and a 10% algae concentration, the working parameters were considered ideal (w:v). Agar with a hardness of 431.6 g, an adhesiveness of -13.14 g.s-1, a springiness of 0.94, a cohesiveness of 0.63, and a gumminess of 274.46 g was produced under these conditions. A combined desirability of 0.78 was obtained for the exposed technology that retrieved gels with a minimum agar yield of 10% and thermal hysteresis between 39 ± 1 and 52 ± 0.5 °C. The fitted design can provide a high techno-commercial value to the agri-food industrial waste stream.

Pressurized Hot Water Extraction of Okra Seeds Reveals Antioxidant, Antidiabetic and Vasoprotective Activities.

Abelmoschus esculentus L. Moench (okra) is a commonly consumed vegetable that consists of the seeds and peel component which are rich in polyphenolic compounds. The aim of this study is to utilize pressurized hot water extraction (PHWE) for the extraction of bioactive phytochemicals from different parts of okra. A single step PHWE was performed at various temperatures (60 °C, 80 °C, 100 °C and 120 °C) to determine which extraction temperature exhibits the optimum phytochemical profile, antioxidant and antidiabetic activities. The optimum temperature for PHWE extraction was determined at 80 °C and the biological activities of the different parts of okra (Inner Skin, Outer Skin and Seeds) were characterized using antioxidant (DPPH and ABTS), α-glucosidase and vasoprotective assays. Using PHWE, the different parts of okra displayed distinct phytochemical profiles, which consist of primarily polyphenolic compounds. The okra Seeds were shown to have the most antioxidant capacity and antidiabetic effects compared to other okra parts, likely to be attributed to their higher levels of polyphenolic compounds. Similarly, okra Seeds also reduced vascular inflammation by downregulating TNFα-stimulated VCAM-1 and SELE expression. Furthermore, metabolite profiling by LC/MS also provided evidence of the cytoprotective effect of okra Seeds in endothelial cells. Therefore, the use of PHWE may be an alternative approach for the environmentally friendly extraction and evaluation of plant extracts for functional food applications.

Macromolecular Model of the Pectic Polysaccharides Isolated from the Bark of Norway Spruce (Picea abies).

The bark of Norway spruce (Picea abies) contains up to 13% pectins that can be extracted by pressurized hot water, which constitute a valuable renewable resource in second-generation lignocellulosic biorefineries. This article proposes, for the first time, structural molecular models for the pectins present in spruce bark. Pectin fractions of tailored molar masses were obtained by fractionation of the pressurized hot water extract of the inner bark using preparative size-exclusion chromatography. The monosaccharide composition, average molar mass distribution, and the glycosidic linkage patterns were analyzed for each fraction. The pectin fraction with high molecular weight (Mw of 59,000 Da) contained a highly branched RG-I domain, which accounted for 80% of the fraction and was mainly substituted with arabinan and arabinogalactan (type I and II) side chains. On the other hand, the fractions with lower molar masses (Mw = 15,000 and 9000 Da) were enriched with linear homogalacturonan domains, and also branched arabinan populations. The integration of the analytical information from the macromolecular size distributions, domain composition, and branch lengths of each pectin fraction, results in a comprehensive understanding of the macromolecular architecture of the pectins extracted from the bark of Norway spruce. This paves the way for the valorization of spruce bark pectic polymers in targeted applications based on their distinct polymeric structures and properties.

The Antidiabetic Effect of Grape Pomace Polysaccharide-Polyphenol Complexes.

Type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic metabolic diseases of the 21st century. Nevertheless, its prevalence might be attenuated by taking advantage of bioactive compounds commonly found in fruits and vegetables. This work is focused on the recovery of polyphenols and polysaccharide-polyphenol conjugates from grape pomace for T2DM management and prevention. Bioactives were extracted by solid-liquid extraction and by pressurized hot water extraction (PHWE). Polyphenolic fraction recovered by PHWE showed the highest value for total phenolic content (427 µg GAE.mg-1), mainly anthocyanins and proanthocyanidins, and higher antioxidant activity compared to the fraction recovered by solid-liquid extraction. Polysaccharide-polyphenol conjugates comprehended pectic polysaccharides to which approximately 108 µg GAE of phenolic compounds (per mg fraction) were estimated to be bound. Polyphenols and polysaccharide-polyphenol conjugates exhibited distinct antidiabetic effects, depending on the extraction methodologies employed. Extracts were particularly relevant in the inhibition of a-glucosidase activity, with free polyphenols showing an IC50 of 0.47 µg.mL-1 while conjugates showed an IC50 of 2.7, 4.0 and 5.2 µg.mL-1 (solid-liquid extraction, PHWE at 95 and 120 °C, respectively). Antiglycation effect was more pronounced for free polyphenols recovered by PHWE, while the attenuation of glucose uptake by Caco-2 monolayers was more efficient for conjugates obtained by PHWE. The antidiabetic effect of grape pomace bioactives opens new opportunities for the exploitation of these agri-food wastes in food nutrition, the next step towards reaching a circular economy in grape products.