Free Ellagic Acid Research Articles

Unlocking the Therapeutic Potential of Ellagic Acid for Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis.

Obesity is in epidemic proportions in many parts of the world, contributing to increasing rates of non-alcoholic fatty liver disease (NAFLD). NAFLD represents a range of conditions from the initial stage of fatty liver to non-alcoholic steatohepatitis (NASH), which can progress to severe fibrosis, through to hepatocellular carcinoma. There currently exists no treatment for the long-term management of NAFLD/NASH, however, dietary interventions have been investigated for the treatment of NASH, including several polyphenolic compounds. Ellagic acid is one such polyphenolic compound. Nutraceutical food abundant in ellagic acid undergoes initial hydrolysis to free ellagic acid within the stomach and small intestine. The proposed mechanism of action of ellagic acid extends beyond its initial therapeutic potential, as it is further broken down by the gut microbiome into urolithin. Both ellagic acid and urolithin have been found to alleviate oxidative stress, inflammation, and fibrosis, which are associated with NAFLD/NASH. While progress has been made in understanding the pharmacological and biological activity of ellagic acid and its involvement in NAFLD/NASH, it has yet to be fully elucidated. Thus, the aim of this review is to summarise the currently available literature elucidating the therapeutic potential of ellagic acid and its microbial-derived metabolite urolithin in NAFLD/NASH.

Enhanced activity of Ellagic acid in lipid nanoparticles (EA-liposomes) against Acinetobacter baumannii in immunosuppressed mice

Acinetobacter baumannii infections have come to the surface in huge numbers in the recent decades. Furthermore, A. baumannii has adopted great ability to nullify the majority of currently available antibiotics. With the purpose of finding a nontoxic and efficient therapeutic agent, we analyzed the activity of Ellagic acid (EA) against the multidrug-resistant A. baumannii. EA not only demonstrated its activity against A. baumannii, but also inhibited the biofilm formation. Since EA shows poor solubility in an aqueous environment, a lipid nanoparticle-based (liposomal) formulation of EA (EA-liposomes) was prepared and its effectiveness was assessed to treat bacterial infection in the immunocompromised murine model. Therapy with EA-liposomes imparted greater protection to infected mice by increasing the survival and decreasing the bacterial load in the lungs. A. baumannii infected mice treated with EA-liposomes (100 mg/kg) showed 60% survival rate as compared to 20% of those treated with free EA at the same dose. The bacterial load was found to be 32778 ± 12232 in the lungs of EA-liposomes (100 mg/kg)-treated mice, which was significantly lower to 165667 ± 53048 in the lung tissues of free EA treated mice. Likewise, EA-liposomes also restored the liver function (AST and ALT) and kidney function parameters (BUN and creatinine). The broncho-alveolar fluid (BALF) from infected mice contained greater quantities of IL-6, IL-1β and TNF-α, which were significantly alleviated in EA-liposomes treated mice. These findings together support the possible implication of EA-liposomes to treat A. baumannii infection, especially in immunocompromised mice.

Morphological and phytochemical characterization of Rosa sweginzowii fruit from Poland

The morphological and chemical characterization of Rosa sweginzowii Koehne fruit, which belongs to the Rosa section (formerly Cinnamomeae), as a source of valuable bioactive compounds is presented. The chemical composition of rose hips was evaluated in terms of the total content of anthocyanins (TAC), phenolics (TPC), and flavonoids (TFC) by spectrophotometry, and ellagic acid concentration by spectrofluorimetry (as borax complex). Morphology of fruit in macro- and microscale (by Scanning Electron Microscopy) and the presence of selected elements by Energy Dispersive X-Ray Spectroscopy were examined. The free ellagic acid content was found at a high level (16.101–24.465 mg/100g dw), and the one of total ellagic acid, after hydrolysis, was in the range of 20.244–29.771 mg/100g dw. Estimated TAC, TPC and TFC were 0.43–7.40 mg CGE/100g, 18 559–27 404 mg GAE/100g, and 10 293–14 159 mg CE/100g, respectively. Regarding the presence of valuable natural antioxidants in R. sweginzowii fruit, this plant could be used as functional food.

Quantitative conversion of free, acid-hydrolyzable, and bound ellagic acid in walnut kernels during baking

Ellagitannins, the main components of walnut kernel polyphenols, are easily degraded by heating to produce ellagic acid, precursor in the production of urolithins that show multiple physiological functions. To analyze the conversion of ellagitannins to free ellagic acid in walnut kernels during baking, a quantitative method was developed to investigate the ellagic acid content (EAC) in free phenolic acid (FPA), acid-hydrolyzable phenolic acid (AHPA), and bound phenolic acid (BPA) fractions. The results showed that the EAC in FPA reached its maximum (5.17 ± 0.30 mg/g DW) after baking at 165 °C for 30 min, which increased by 99.52% compared with the control. Meanwhile, the content of ellagitannins (ETC) in AHPA and BPA dropped by 89.14% and 26.08%, respectively. It suggested that baking promoted the conversion of ellagitannins in AHPA and BPA to ellagic acid in FPA. Eight ellagitannins were regarded as the main precursors of ellagic acid in walnut kernels.

Cornus officinalis Sieb. et Zucc. Seeds as a Dietary Source of Ellagic Acid

Ellagic acid (EA), a natural food component, has been identified as a functional food because of its role in disease prevention. In our previous study on the chemical component of the seeds of Cornus officinalis Sieb. et Zucc., ellagitannins (ETs) were firstly isolated and identified; these compounds can yield EA by acidic hydrolysis. Therefore, to evaluate the seeds as a potential source of EA, the free and total EA contents of the seeds, sarcocarps, and barks were evaluated separately. The highest total EA content was found in seeds (14.51-21.58 mg/g), followed by the sarcocarp (1.97-4.51 mg/g) and bark (trace amounts). EA mainly existed as ET in both the seeds and sarcocarps, while a small portion existed in free form. The findings of this study prove that the seeds of C. officinalis are a rich source of EA. This study reports a unique EA profile of C. officinalis for the first time, which may assist in the selection of EA sources for use in research and for the food and pharmaceutical industries.

Phenolic composition of peels from different Jaboticaba species determined by HPLC-DAD-ESI/MSn and antiproliferative activity in tumor cell lines

Jaboticaba has been studied extensively, mainly in the context of its phenolic composition. Although there are several varieties, research has been concentrated on Sabará and Paulista due to their greater dispersion. This study aimed to characterize five jaboticaba varieties in terms of their anthocyanin and nonanthocyanin phenolic compositions and their antiproliferative action on tumor cells of breast and prostate cancer. The most abundant anthocyanins were cyanidin-3-glycoside and delphinidin-3-glycoside. Three myricitin derivatives, 14 quercetin derivatives (including free quercetin), 13 ellagic acid derivatives (including free ellagic acid) and 4 methylellagic acid derivatives were detected. The variety that showed the best antiproliferative action was Pintada (PFP), which was harvested in the 2015 crop. The phenolic compounds showed differences in different crop years however, samples from both years decreased cellular proliferation.

Encapsulation of Ellagic Acid in Di-Block Copolymeric Micelle for Non-Small Cell Lung Cancer Therapy

Ellagic acid (EA) is an anticancer agent as evidenced in numerous pre-clinical studies. The clinical application of EA is limited because of its poor aqueous solubility and bioavailability. The present study was designed to formulate polymeric micelles of the drug using poly(L-lactide-co-glycolide)-poly (ethylene glycol) (PLGA-PEG) di-block copolymer. The particle size and entrapment efficiency of EA by the polymeric micelle were found to be dependent on the concentration of polymer. Consequently, optimized micellar formulations with 82 ± 7.1 nm size and 45.32 ± 5.43% drug entrapment were further evaluated for cytotoxicity, cell cycle arrest, and apoptotic potential in the human lung adenocarcinoma cell line, A549. EA was toxic to A549 cells, and this cytotoxicity was significantly increased when EA was delivered using a micellar formulation. Flow cytometry analysis revealed a superior G1 phase arresting potential of the optimized EA-loaded PLGA-PEG micelles (PLGA-PEG-EA-F3), with a concomitant increased apoptotic potential. Further investigation of the mechanism of apoptosis showed a significant overexpression of caspase-3 in A549 cells when treated with PLGA-PEG-EA-F3 compared to free EA. Thus, it can be concluded that the PLGA-PEG polymeric micellar platform for EA could be a potential tool to treat lung cancer.

Traditional Decoction and PUAE Aqueous Extracts of Pomegranate Peels as Potential Low-Cost Anti-Tyrosinase Ingredients

The aim of the study is to evaluate the anti-tyrosinase activity of different aqueous extracts obtained from pomegranate juice processing by-products. External pomegranate peels of two certified cultivars (Akko and Wonderful), were extracted using only water as the extraction solvent. A traditional decoction and a pulsed ultrasound-assisted extraction (PUAE), both 10 min long, were performed and compared. All the aqueous extracts proved to be rich in bioactive compounds. In particular, the total phenolic content (TPC) ranged from 148 to 237 mg gallic acid equivalent (GAE)/g of dried peels (DW), the radical-scavenging ability (RSA) ranged from 307 to 472 mg ascorbic acid equivalent (AAE)/g DW, the free ellagic acid content (EA) ranged from 49 to 94 µg/mL, and the ellagitannins (ETs) ranged from 242 to 340 µg/mL. For both cultivars, PUAE extracts had higher ET content and a lower EC50, while the decoctions had slightly higher TPC, RSA, and free EA amounts. Principal component analysis (PCA) highlighted the direct correlation between the ET content and the tyrosinase enzyme inhibition (lower values of EC50). These findings suggest the potential use of both these natural extracts as low-cost lightening and/or anti-browning ingredients exploitable in several formulations (e.g., cosmetics) or extemporarily usable.

Layered Double Hydroxide Nanoparticles to Overcome the Hydrophobicity of Ellagic Acid: An Antioxidant Hybrid Material.

Ellagic acid (EA), a polyphenolic antioxidant of poor water solubility, was intercalated into biocompatible layered double hydroxide (LDH) nanoparticles by the coprecipitation method. Structural investigation of the composite revealed that the lactone bonds split under the synthetic experimental conditions, and EA was transformed to 4,4′,5,5′,6,6′-hexahydroxydiphenic acid during intercalation. To improve the surface properties of the EA-LDH composite, the samples were treated with different organic solvents. The antioxidant activity of the LDH hybrids was assessed in test reactions. Most of the obtained hybrids showed antioxidant activity comparable to the one of the free EA indicating that the spontaneous structural transformation upon immobilization did not change the efficiency in radical scavenging. Treatments with organic solvents influenced the activities of the materials remarkably. The main advantage of the immobilization procedure is that the products can be applied in aqueous samples in high concentrations overcoming the problem related to the low solubility of EA in water. The developed composites of high antioxidant content can be applied as efficient reactive oxygen species scavenging materials during biomedical treatments or industrial manufacturing processes.

A comparative study on schizophyllan and chitin nanoparticles for ellagic acid delivery in treating breast cancer

In this study, following encapsulation of ellagic acid (EA), an anti-cancer agent, loaded in schizophyllan (EA/SPG-NP) and chitin (EA/Ch-NP) nanoparticles, its release in 95% ethanol, and different mediums of digestive systems with pH ranging 1.5 to 7.4, were examined before investigating for treatment of breast cancer MCF-7cells. Following synthesis, the EA was characterized by FT-IR, SEM, XRD, DLS and zeta potential analysis. Loading capacity of schizophyllan and chitin were 30.08 and 79.52%, respectively, while SEM images indicated respective size distributions of 217.8 and 39.82 nm, with the corresponding zeta potentials being +27 and −9.14 mV. As EA was loaded in nanoparticles, antioxidant activity, examined by DPPH method, of the free EA was found to be higher than both EA/SPG-NP and EA/Ch-NP, but lower than the latter at 7.4 pH. Interestingly, scavenging activities for EA and EA/SPG-NP reduced for higher pH. The MTT cytotoxicity indicated that EA/SPG-NP and EA/Ch-NP inhibited effectively cell growth of breast cancer cell lines at IC50 of 60 and 115 μg/ml, respectively.

Nanoformulated ellagic acid ameliorates pentylenetetrazol-induced experimental epileptic seizures by modulating oxidative stress, inflammatory cytokines and apoptosis in the brains of male mice.

The present study evaluated the neuroprotective and antiepileptic efficacy of ellagic acid (EA) encapsulated in calcium-alginate nanoparticles (Ca2+-ALG NPs) in pentylenetetrazol (PTZ)-induced seizures in male mice. EA was encapsulated in ALG NPs using a nanospray drying method followed by ionotropic crosslinking with Ca2+. Characterization of the developed Ca2+-crosslinked EA-ALG NPs showed spherical, high stability NPs; successful loading of EA within crosslinked ALG NPs; and sustained release of EA. Male Swiss albino mice were divided into ten groups as follows; Group I- (control), Group II (50mg EA /kg) - (EA), Group III polyethylene glycol (PEG), Group IV EA NPs (50mg/kg) - (EA NP), Group (50mg/kg alginate) V void V NPs - (void NPs), Group VI: (37.5 PTZ mg/kg) -(PTZ), Group VII: PTZ and EA - (PTZ-EA). Group VIII: animals received PTZ and PEG concurrently (PTZ-PEG). Group IX; animals received PTZ and void NPs concurrently - (PTZ-void). Group X: animals received PTZ and EA NPs concurrently (PTZ-EA NPs). PTZ was used to induce experimental epilepsy. Ca2+-ALG NPs prevented seizures throughout the experimental period and had a more prominent effect than free EA did. Ca2+-ALG NPs prevented increased glutamate, decreased GABA concentrations and ameliorated increased amyloid-β and homocysteine levels in the serum and brain. Ca2+-EA-ALG NPs were superior to free EA in improving increased IL-6 and TNF-α. Ca2+-ALG NPs ameliorated PTZ-induced oxidative stress, as evidenced by decreased 4HNE levels and enhanced GSH, GR and GPx levels in the brain. These changes were accompanied by amelioration of apoptosis and its regulating proteins, including Cytochrome C, P53, Bax, Bcl2 and caspase-3 and caspase-9, and protected against DNA damage. Histological examination of the hippocampus confirmed that the neuroprotective effect of Ca2+-EA-ALG NPs was superior and more effective than that of free EA.

ELLAGIC ACID CONTENT IN SELECTED WILD SPECIES OF FRUIT ROSES

Ellagic acid (EA) is a natural antioxidant, belonging to the group of polyphenolic compounds. It displays a broad spectrum of pro-health effects, ranging from the prevention of cancer to antiviral properties. It is present in many fruit from the rose family (Rosaceae): strawberries, raspberries, blackberries and walnuts as well as cranberries and grapes. The available literature states that the fruit of roses, in addition to their aesthetic and functional applications, also show therapeutic properties, which, among other things, are associated with a high content of polyphenols, including ellagic acid derivatives. The aim of this research was to determine the differences in the content of free ellagic acid in the fruit of selected rose species. The test material consisted of freeze-dried sublimation and ground fruit from the following species of roses: R. canina, R. moyesii, R. pendulina. The fruit was separated into two fractions: flesh and seeds. Quantitative analysis of free ellagic acid was carried out by spectrofluorimetry. The free EA was present both in the flesh and in the seeds of the studied species of roses. Its content in the mentioned fractions varied depending on the species. The flesh of R. pendulina was characterised by the highest level of EA in free form (247.72 μg·g–1 of dry weight). The seeds of R. moyesii proved to be the most abundant in free EA (105.69 μg·g–1 of dry weight.

Traditional or hydro-diffusion and gravity microwave coupled with ultrasound as green technologies for the valorization of pomegranate external peels

To exploit the full potential of pomegranate marcs, this study explores different conditions of ‘green’ extraction of ellagitannins and other bio-active phenolic compounds from the ‘external by-product’ of pomegranate industrial processing. Significant recoveries of ellagitannins, free ellagic acid and radical scavenging compounds were obtained by coupling both the traditional (MH) or the hydro-diffusion gravity (MHG) microwave assisted drying to a direct ultrasound assisted extraction (UAE) using a food-grade solvent (EtOH/H2O). The amounts of the ellagitannins after microwave drying were always significantly higher than with the traditional oven drying. Moreover, microwaves reduced the drying times from several hours to few minutes reaching comparable residual moisture content. The microwave hydro-diffusion gravity system allowed the recovery of bio-active compounds in the condensed water too. The comparison of UAE with traditional maceration and decoction highlighted the higher efficiency of UAE in the quicker extraction of bio-active compounds, except for the total ellagitannins which were better recovered after the longer maceration.

Bioavailability and bioactivity of free ellagic acid compared to pomegranate juice

Pomegranates are an excellent source of ellagic acid (EA), ellagitannins (ETs), anthocyanins and other phytochemicals. The health benefits of pomegranate (Pom) have been mainly related to its EA and ET content. The objective of the present study was to determine EA bioavailability and bioactivity from different sources such as pure/free or natural form (PomJ). This was a cross-over study with healthy volunteers consuming one dose of EA dietary supplement (500 mg free EA) vs. one serving of PomJ (237 mL, ∼120 mg of EA) in a random order. Our data showed that there was no difference in plasma EA concentration between PomJ and EA intake; however, urinary dimethylellagic acid glucuronide (DMEAG), normalized to creatinine, was significantly higher after the consumption of PomJ compared to EA. Plasma insulin at 1 h increased after PomJ consumption compared to the baseline while decreased after EA consumption compared to the baseline. Plasma glucose decreased below the baseline 2 h after the consumption of PomJ but not EA. Plasma leptin was significantly decreased at 1 and 2 h after PomJ and EA consumption. Plasma MCP1 decreased only after PomJ but not after pure EA consumption. To conclude, one serving of PomJ provided the same level of EA in blood, while the increase in phase II metabolism of EA and an acute suppression of plasma MCP1 were only observed after PomJ consumption, suggesting that other constituents present in PomJ, in addition to EA, are bioactive and likely play a role in regulating EA phase II metabolism.

Enhanced anticancer activity and oral bioavailability of ellagic acid through encapsulation in biodegradable polymeric nanoparticles.

Despite the fact that various studies have investigated the clinical relevance of ellagic acid (EA) as a naturally existing bioactive substance in cancer therapy, little has been reported regarding the efficient strategy for improving its oral bioavailability. In this study, we report the formulation of EA-loaded nanoparticles (EA-NPs) to find a way to enhance its bioactivity as well as bioavailability after oral administration. Poly(ε-caprolactone) (PCL) was selected as the biodegradable polymer for the formulation of EA-NPs through the emulsion–diffusion–evaporation technique. The obtained NPs have been characterized by measuring particle size, zeta potential, Fourier transform infrared, differential scanning calorimetry, and X-ray diffraction. The entrapment efficiency and the release profile of EA was also determined. In vitro cellular uptake and cytotoxicity of the obtained NPs were evaluated using Caco-2 and HCT-116 cell lines, respectively. Moreover, in vivo study has been performed to measure the oral bioavailability of EA-NPs compared to free EA, using New Zealand white rabbits. NPs with distinct shape were obtained with high entrapment and loading efficiencies. Diffusion-driven release profile of EA from the prepared NPs was determined. EA-NP-treated HCT-116 cells showed relatively lower cell viability compared to free EA-treated cells. Fluorometric imaging revealed the cellular uptake and efficient localization of EA-NPs in the nuclear region of Caco-2 cells. In vivo testing revealed that the oral administration of EA-NPs produced a 3.6 times increase in the area under the curve compared to that of EA. From these results, it can be concluded that incorporation of EA into PCL as NPs enhances its oral bioavailability and activity.

English

A food grade compatible enzyme assisted extraction (EAE) technique for extracting bioactive compounds from freeze-dried Kakadu plum puree was evaluated. To optimise the extraction, a central composite rotatable design (CCRD) was conducted and effects of solvent concentration, enzyme concentration and time of reaction on extracted levels of free ellagic acid (fEA), ascorbic acid (AA) and total phenolic content (TPC) were determined. In the extracts, concentration of fEA ranged from 53.6 to 266.6 mg/100 g dry weight (DW) of Kakadu plum puree; AA 63.7 to 112.1 mg/100 g DW and TPC levels of 73.23 to 104.74 mg of gallic acid equivalent (GAE)/g. Extraction yield of fEA ranged from 10.3 to 51.3%. The model was found to be suitable for extraction of fEA - an important bioactive compound with documented antimicrobial properties from Kakadu plum fruit. A solvent (propylene glycol) concentration of 1.5% (w/w), enzyme (pectolytic enzymes) concentration of 300 mg/L and extraction time of 15 h was ascertained as optimum for the fEA extraction delivering a yield of 51.3%. The extraction method described here facilitates the provision of a simple, cost effective food-grade compatible extract that by-passes the need for organic solvents thereby obtaining an EA-rich aqueous extract with enhanced biological activities. This simple extraction method can also be applied to other EA rich plant material like pomegranate and peel of many common fruits which are generated as food processing by-products and can be easily adopted by numerous industries. Key words: Central composite rotatable design, ellagic acid, enzyme assisted extraction, Kakadu plum fruit, Terminalia ferdinandiana.

Antioxidant Compounds, Nutritional Quality and Colour of Two Strawberry Genotypes from Fragaria × Ananassa

In this study, average weight, colour, soluble solids content and titratable acidity were determined as quality parameters of strawberry fruits while ascorbic acid, total anthocyanins, total phenolics, total flavonoids, minerals and trace elements content as nutritional parameters. All these attributes along with the DPPH radical scavenging activity were screened in two strawberry genotypes grown on the same site at the ripe stage. Also, the phenolic profiles of the strawberry fruits were obtained by HPLC. Except colour, results showed no significant differences between cultivars in quality parameters. Ascorbic acid found for ‘Premial’ cv. (81.62 mg/100 g) was twice the amount found in ‘Magic’ cv. (42.15 mg/100 g), total phenolics varied from 207.95 (cv. ‘Premial’) to 249.98 (cv. ‘Magic’) mg GAE/100 g while total flavonoid content in fruits of ‘Magic’ cultivar (79.56 mg/100 g) was 2‑fold higher than the one of the ‘Premial’ cv. The quercetin content ranged from 2.72 to 4.66 mg/100 g, whereas free ellagic acid ranged from 6.79 to 9.03 mg/100 g. The pale shiny fruits of ‘Premial’ cv. (higher L*, ho and chroma index) had a lower total anthocyanin content (19.07 mg CG/100 g) than the bluish fruits of the ‘Magic’ cv. (23.96 mg CG/100 g). An inverse relationship between the levels of ascorbic acid and anthocyanin contents was also noticed in strawberry samples. Significant differences were found also in minerals and trace elements content of the two strawberry cultivars. The results revealed the importance of genetic background for the content of antioxidant compounds in strawberry fruits.

Measuring free ellagic acid: influence of extraction conditions on recovery by studying solubility and UV-Visible spectra

AbstractRecent investigations into plant tissues have indicated that the free form of the natural polyphenolic antioxidant, ellagic acid (EA), is much more plentiful than first envisaged; consequently a re-assessment of solvent systems for the extraction of this water-insoluble form is needed. As EA solubility and its UV-Vis spectrum, commonly used for detection and quantification, are both governed by pH, an understanding of this dependence is vital if accurate EA measurements are to be achieved. After evaluating the pH effects on the solubility and UV-Vis spectra of commercial EA, an extraction protocol was devised that promoted similar pH conditions for both standard solutions and plant tissue extracts. The extraction so devised followed by HPLC with photodiode-array detection (DAD) provided a simple, sensitive and validated methodology that determined free EA in a variety of plant extracts. The use of 100 % methanol or a triethanolamine-based mixture as the standard dissolving solvents were the best choices, while these higher pH-generating solvents were more efficient in extracting EA from the plants tested with the final choice allied to the plants’ natural acidity. Two of the native Australian plants anise myrtle (

Measuring the three forms of ellagic acid: suitability of extraction solvents

Accurate quantification of ellagic acid and its derivatives, ellagic acid glycosides and ellagitannins, present in plant-based foods is a vital prerequisite for any study of their health-promoting properties. This goal is impeded by the lack of commercially available standards and the fact that these three forms differ widely in solubility. This disparity necessitates careful attention being paid to the choice of extraction solvents to ensure that precise and reproducible content measurements are achieved. This work sought to devise an extraction protocol that is effective for all ellagic acid forms whilst keeping the water-insoluble free ellagic acid solubilised during all analysis stages. To overcome this unavailability of commercial standards, the designated “targeted” ellagic acid derivatives identified in the selected fruit were monitored during the course of extraction that employed a number of commonly used solvents. Large variations in the extraction yield of the solvents tested for the ellagic acid and its derivatives were identified, extending even to the different fruit samples for the same form. It is regarded as unlikely that any selected extraction solvent could be universally employed to effectively extract all the ellagic acid compounds; however, the use of the solvent 50 : 50 vol. methanol–dimethylformamide satisfied most requirements.

Raspberry marc extracts increase antioxidative potential, ellagic acid, ellagitannin and anthocyanin concentrations in fruit purees

Two types of fruit puree consisting of (1) pears/apples/yellow cherry plums and (2) apples/black currants were enriched with raspberry marc extract containing valuable antioxidants. The addition of 2% marc extract increased total phenolic content (TPC) from 108.8 to 345.8 and from 176.1 to 396.2 mg/100 g in the puree (1) and (2), respectively. The total anthocyanin content (TAC), ellagic acid and ellagitannin concentrations as well as antioxidant capacity of purees also increased with increasing concentration of marc extract additive. The increase of free ellagic acid (up to 44%) in the purees with extract additives after preparation was related to a partial hydrolysis of ellagitannins. Higher extract concentrations resulted in the increased bitterness and astringency of the products; therefore the concentration of raspberry marc additives in purees of up to 1.6% may be recommended.