Quantitative determination of major polyphenol constituents in pomegranate products

Unlocking the Bioactive Potential of Pomegranate Peels: A Green Extraction Approach

Pomegranate (Punica granatum L.) is well known for its high content of bioactives, including polyphenols, flavonoids, and tannins, which have been shown to exhibit a wide range of biological activities, such as antioxidant, antimicrobial, and anticancer effects. It is worth noting that the majority of these molecules are found in the peels, which are usually disposed of after processing, causing a significant amount of waste, amounting to more than 3.6 million t/y. This work investigates microwave-assisted extraction (MAE) in water for the recovery of antioxidants from pomegranate peels (PP), including the optimisation of temperature and extraction times. The total phenolic, anthocyanin, flavonoid, and tannin contents of the recovered extracts were determined, as well as their antioxidant activities, which were found to be 356.35 mgGAE/gExtr, 303.97 µgCy3G/gExtr, 37.28 mgQE/gExtr, 56.48 mgGAE/gExtr, and 5.72 mmolTE/gExtr, respectively (according to the adopted reference). All results were compared with those obtained using a conventional protocol. In addition, the potential for water recycling by means of downstream nanofiltration in optimised MAE was investigated, leading to overall water reuse of approx. 75%. Power consumption (20.92 W/mgGAE) and common green metrics, Reaction Mass Efficiency (RME), E-Factor, and the Process Mass Intensiti/efficiency (PMI, PME), were considered in evaluating the proposed PP valorisation strategy. Finally, the biological activities of the main products were assessed. The antimicrobial properties of the PP extracts against three Gram-positive and three Gram-negative bacteria and their antiproliferative activity towards human cancer cells were tested. S. aureus bacteria was the most susceptible to the PP extracts. All tested products displayed antiproliferative activity against HeLa cells when higher concentrations were tested, with D-PP/NF (obtained from dried PP and sequential nanofiltration) being the most effective. This result was also confirmed via clonogenic analysis, which generally indicated the possible anti-cancer activity of pomegranate peel extracts obtained using this green approach.

Potential of phenolic compounds from pomegranate (Punica granatum L.) by-product with significant antioxidant and therapeutic effects: A narrative review

The wealth of epidemiological evidence in the scientific world underscores the possibility that a plant-based diet can reduce the prevalence of common diseases such as diabetes, cardiovascular disease, cancer, and stroke. The therapeutic effects of plant sources are partly explained by phenolic secondary metabolites or polyphenolic compounds. Therefore, polyphenolic compounds, which are widely distributed in plants, are of great interest for the development of effective specific drugs with antioxidant and anti-inflammatory effects. Moreover, polyphenol compounds have no harmful effects due to their natural biocompatibility and safety. Numerous studies have highlighted the potential of some industrial food wastes from plant material processing, including apple peels and mashed potatoes, grape skins, tomato and carrot peels, pomegranate peels and seeds, and many others. These byproducts are considered low-cost sources of natural biological compounds, including antioxidants, which have beneficial effects on human health. The polyphenol complex of pomegranate peel (Punica granatum L.), which makes up half of the pomegranate fruit, has more pronounced antioxidant and anti-inflammatory properties than other parts. And the most important active components of pomegranate peel, which are found only in this plant, are punicalagin, followed by ellagic acid and gallic acid. It is known that these polyphenolic compounds of pomegranate peel have the most pronounced therapeutic effect. Several studies have shown the protective effect of ellagic acid, punicalagin, against oxidative stress damage caused by free radicals. The potential of pomegranate peel as an antioxidant and therapeutic component in various biological systems is high, according to scientific sources. However, despite extensive research in recent years, a review of sources has shown that there is insufficient evidence to support the therapeutic effects of polyphenolic compounds from pomegranate peels. The role of pomegranate peel polyphenolic compounds, including flavonoids, as antioxidants in various biological systems also requires further research. Of particular importance are the mechanisms by which antioxidants influence the cellular response against oxidative stress. The purpose of this review was to report our current knowledge of plant polyphenolic compounds and their classification, and to evaluate the potential of phenolic compounds from pomegranate peels with significant antioxidant and therapeutic effects.

Pomegranate peel polyphenols prophylaxis against SARS-CoV-2 main protease by in-silico docking and molecular dynamics study

Pomegranate peel, the waste product generated from pomegranate fruit, has prophylactic properties, such as antimicrobial, anti-malarial, and controls respiratory infections and influenza. Based on the previous literature and need of the hour, molecular docking was performed to evaluate the inhibitory effects of major pomegranate peel polyphenols against COVID-19. Among the 44 studied compounds, 37 polyphenols show interaction with the catalytic dyad of the M^pro protease and 18 polyphenols have a higher binding affinity than that of the M^pro protease inhibitor (N3), indicating their high probability of binding at ACE2: SARS-CoV-2 interface. Furthermore, several polyphenols studied in this work are found to have higher binding affinity as compared to those of hydroxychloroquine, lopinavir, nelfinavir, and curcumin, some of which have been earlier tested against COVID-19. Further, molecular dynamics simulations (200 ns) for M^pro-polyphenols including pelargonidin3-glucoside, quercetin3-O-rhamnoside, cyanidin3-glucoside and punicalin revealed highly stable complexes with less conformational fluctuations and similar degree of compactness. Estimation of total number of intermolecular hydrogen bonds and binding free energy confirmed the stability of these M^pro-polyphenol complexes over M^pro-curcumin complex. Based on the greater binding affinity of polyphenols of pomegranate peel towards M^pro as compared to that of curcumin, pomegranate peel may be considered in any herbal medicinal formulation or may be incorporated into daily diets for prevention of COVID-19.Communicated by Ramaswamy H. Sarma.

Physical Characteristics, Mineral Content, and Antioxidant and Antibacterial Activities of Punica granatum or Citrus sinensis Peel Extracts and Their Applications to Improve Cake Quality

One-third of all food produced for human use is discarded as waste, resulting in environmental pollution and impaired food security. Fruit peels have bioactive compounds that may be used as antimicrobials and antioxidants, and the use of fruit peels is considered an alternative way to reduce environmental problems and agro-industrial waste. The aim of this study was to evaluate the phytochemical, mineral, extraction yield, total phenolic, total flavonoids, antioxidant, and antibacterial activity of several peel fruits, including Citrus sinensis (orange) and Punica granatum (pomegranate). The results revealed that pomegranate peel powder contains the highest amounts of ash, fiber, total carbohydrates, Ca, Fe, Mg, and Cu, while orange peel contains the highest amounts of moisture, protein, crude fat, P, and K. Furthermore, the aqueous and methanolic pomegranate peel extracts yielded higher total phenolic and total flavonoids than the orange peel extract. The identification and quantification of polyphenol compounds belonging to different classes, such as tannins, phenolic acids, and flavonoids in pomegranate peel and flavonoid compounds in orange peel were performed using UPLC-MS/MS. In addition, GC-MS analysis of orange peel essential oil discovered that the predominant compound is D-Limonene (95.7%). The aqueous and methanolic extracts of pomegranate peel were proven to be efficient against both gram-positive and gram-negative bacteria linked to human infections. Sponge cake substituting wheat flour with 3% pomegranate peel and 10% orange peel powder had the highest total phenolic, flavonoid compounds, and antioxidant activity as compared to the control cake. Our results concluded that pomegranate and orange peel flour can be used in cake preparation and natural food preservers.

Effects of drying methods and solvent extraction on quantification of major bioactive compounds in pomegranate peel waste using HPLC

Bioactive compound characterization is an essential step for utilizing pomegranate peel waste as food and nutraceuticals ingredients. In the present investigation, the effects of different drying methods (freeze, tray-oven, and sun) and extraction solvents such as methanol, ethanol, water, acetone, and hexane were investigated on the extraction and recovery of major bioactive compounds (ellagic acid, gallic acid, quercetin, and punicalagin) of pomegranate peel for two pomegranate varieties (i.e., Bhagwa and Ganesh) using high-performance liquid chromatography (HPLC). The results indicated that the freeze dried pomegranate peel powder of both pomegranate varities potential to extraction higher amount of bioactive compounds with methanol as extraction solvent as compared to other drying methods and solvents. Freeze-dried peel powder of Bhagwa pomegranate showed a higher amount of gallic acid (32.2 mg/g), ellagic acid (13.6 mg/g), punicalagin (15.2 mg/g), and quercetin (2.5 mg/g) with methanol solvent as compared to the other extract of Bhagwa and Ganesh varieties. The basis on the results of the current study, it can be concluded that the freeze-drying method of drying pomegranate peel powder and methanol as an extraction solvent are effective to recover higher amounts of bioactive compounds that can be utilized in food and pharmaceutical sectors at commercial scale.

Pomegranate trees quality under drought conditions using potassium silicate, nanosilver, and selenium spray with valorization of peels as fungicide extracts

The current study was performed on 8 years old "Succary" pomegranate cultivar (Punica granatum L.) during the 2019 and 2020 seasons. One hundred pomegranate trees were chosen and sprayed three times at the beginning of flowering, full bloom, and 1 month later with the following treatments: water as control, 0.025, 0.05 and 0.1 mg/L Se; 5 mL/L, 7.5 and 10 mL/L Ag NPs, and 0.5, 1 and 2 mg/L K₂Si₂O₅. The results showed that spraying of SE, Ag NPs, and K₂Si₂O₅ ameliorated the shoot length, diameter, leaf chlorophyll content, set of fruiting percentage, and fruit yield per tree and hectare compared to control through studying seasons. Moreover, they improved the fruit weight, length, and diameter, as well as total soluble solids, total, reduced, and non-reduced sugars percent, while they lessened the juice acidity percentage compared to control. The most obvious results were noticed with Se at 0.1 mg/L, Ag NPs at 10 mL/L, and K₂Si₂O₅ at 2 mg/L in both experimental seasons over the other applied treatments. By HPLC analysis, peel extracts showed the presence of several bioactive compounds of catechol, syringic acid, p-coumaric acid, benzoic acid, caffeic acid, pyrogallol, gallic acid, ferulic acid, salicylic acid, cinnamic acid, and ellagic acid. The extracts applied to Melia azedarach wood showed promising antifungal activity against Rhizoctonia solani and were considered wood-biofingicides.

Application of Citrus By-Products in the Production of Active Food Packaging

Some citrus by-products such as orange peel contains valuable compounds that could be recovered and restored into the food chain. In this study, an efficient valorization of orange peel has been investigated using green extraction, fractionation, and impregnation techniques. The first step included its extraction using CO2 and ethanol under different pressure (200–400 bar) and temperature (35–55 °C) conditions. The extracts obtained at 300 bar and 45 °C showed strong antioxidant with moderate antimicrobial activity. Then, the extract was subjected to a sequential fractionation process. The fraction obtained at 300 bar, 45 °C, and using 32% ethanol showed the strongest antioxidant and antimicrobial activity with a high extraction yield. Finally, the potential of the two best extracts (obtained at 400 bar and 45 °C before any fractionation and the fractions obtained at 300 bar, 45 °C using 32% ethanol) was determined by conducting an impregnation process to obtain an antioxidant food-grade rigid plastic that would preserve fresh food. The percentage of cosolvent (1 and 2% ethanol), the impregnation time (1 and 3 h), the pressure (200 and 400 bar), and the temperature (35 and 55 °C) were evaluated as variables of this process. The impregnated plastic showed good antioxidant and antimicrobial activities.

Phenolic Compounds Recovery from Pomegranate (Punica granatum L.) By-Products of Pressurized Liquid Extraction

This study aimed to valorize pomegranate by-products (peel and carpelar membranes—PPCM) through their high biological potential for phenolic compounds recovery. The influence of lower temperatures (40 and 60 °C) and pressures (20, 40, 60, 80, and 100 bar) than those generally used in pressurized liquid extraction (PLE) was evaluated through global extraction yield (X₀), and qualitative and quantitative composition of the phenolic compounds. Chromatographic techniques were used to analyze the two treatments with the highest X₀. Temperature, pressure, and their interaction had a significant influence on X₀. The best phenolic compounds extraction conditions were using pressurized ethanol at 60 °C and 40 bar (extract 1—E1, 37% on d.b.) and 60 °C and 80 bar (extract 2—E2, 45% on d.b.). Nevertheless, E1 presented a significantly higher content of α, β punicalagin, and ellagic acid (48 ± 2, 146 ± 11, and 25.6 ± 0.3 mg/100 g, respectively) than E2 (40 ± 2, 126 ± 4, and 22.7 ± 0.3 mg/100 g). Therefore, this study could validate the use of low pressures and temperatures in PLE to recover phenolic compounds from pomegranate residues, making this process more competitive and sustainable for the pomegranate industry.

Enhanced Bioactivity of Pomegranate Peel Extract following Controlled Release from CaCO3 Nanocrystals

Pomegranate peel extract is rich of interesting bioactive chemicals, principally phenolic compounds, which have shown antimicrobial, anticancer, and antioxidative properties. The aim of this work was to improve extract’ bioactivity through the adsorption on calcium carbonate nanocrystals. Nanocrystals revealed as efficient tools for extract adsorption reaching 50% of loading efficiency. Controlled release of the contained metabolites under acidic pH has been found, as it was confirmed by quantitative assay and qualitative study through NMR analysis. Specific functionality of inorganic nanocarriers could be also tuned by biopolymeric coating. The resulting coated nanoformulations showed a great antimicrobial activity against B. cinerea fungus preventing strawberries disease better than a commercial fungicide. Furthermore, nanoformulations demonstrated a good antiproliferative activity in neuroblastoma and breast cancer cells carrying out a higher cytotoxic effect respect to free extract, confirming a crucial role of nanocarriers. Finally, pomegranate peel extract showed a very high radical scavenging ability, equal to ascorbic acid. Antioxidant activity, measured also in intracellular environment, highlighted a protective action of extract-adsorbed nanocrystals twice than free extract, providing a possible application for new nutraceutical formulations.

Treatment and high value utilization of glutamic acid wastewater

Glutamate wastewater has a high yield in the world and is difficult to be treated due to its high acidity, high COD (chemical oxygen demand, reflecting the pollution degree of reduced substances in the water) and high ammonia nitrogen characteristics. In this study, Bacillus licheniformis M 2020051 was used to treat organic wastewater to ferment polyglutamic acid, which reduced the pollution of industrial wastewater and produced polyglutamic acid at a low cost. Firstly, a strain with high salt tolerance and high polyglutamic acid production was isolated from saline soil, and the mechanism of salt tolerance and polyglutamic acid production were also analyzed. Then Single-factor experiment and Response surface methodology (RSM) were used to determine the appropriate fermentation conditions to achieve maximum γ-polyglutamic acid production. After optimization, the yield of polyglutamic acid was increased to 6.91 g·L^-1 by shaking fermentation, an increase of 7.13%. Finally, the agronomic experiments were carried out, and the results showed that γ-polyglutamic acid could significantly increase the germination rate of corn seeds and the growth of rapeseed. These studies will lay the foundation for reducing industrial wastewater pollution and exploring the production model of γ-polyglutamic acid.

Fresh pomegranate juices from cultivars and local ecotypes grown in southeastern Italy: comparison of physicochemical properties, antioxidant activity and bioactive compounds

BACKGROUND

Pomegranate juice has gained attention for its health properties, becoming consequently a highly demanded product. The revival of the pomegranate in Italy, as in other Mediterranean countries, starts with the planting of new intensive orchards characterized by both the new cultivation technique and new varieties. As a result of growing demand and high productivity, pomegranate could become an interesting crop to diversify farm income. This study seeks to determine the aril juice quality attributes and bioactive compounds of six pomegranate cultivars ('Mollar', 'Dente di cavallo', 'Acco', 'Jolly red', 'Wonderful' and 'Wonderful Super') and two local ecotypes ('Eco BA' and 'Eco FG') grown in Apulia region, southern Italy.

RESULTS

The aril juices were evaluated for their main physicochemical properties (yield, color, pH, total soluble solids content, titratable acidity, sugar-acid ratio), chemical and bioactive compounds (vitamin C, phenolics, anthocyanins and antioxidant activities). 'Eco BA', 'Mollar' and 'Jolly red' genotypes were characterized by the highest maturity index, and then could be considered to be sweet-sour in taste. Total phenols and antioxidant activity were higher in 'Dente di cavallo' and 'Eco FG' genotypes. 'Eco FG' was also the richest in vitamin C, punicalagin and ellagic acids, while 'Dente di cavallo', 'Acco' and 'Wonderful' showed the highest content of the detected anthocyanin compounds.

CONCLUSION

These results contribute to current knowledge about chemical composition, phenolic contents, anthocyanin profiles and antioxidant activity of pomegranate juice from different genotypes, showing in most cases an appreciable juice quality and bioactive profile, although significant differences among them were detected. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Corrosion Inhibition of Carob Pod Pulp (Ceratonia siliqua L.) on Carbon Steel Surface C38 in Hydrochloric Acid

The effect of C. siliqua pulp corrosion inhibition on carbon steel has been studied by gravimetric testing and electrochemical methods. In this study, two raw extracts were prepared from the pod pulp of C. siliqua: the first is methanolic and the second is aqueous. The UHPLC/DAD analysis indicated gallic acid's presence in the extracts (methanolic and aqueous) of C. siliqua as a major compound. The inhibition results achieved revealed that the aqueous extract with gallic acid had a good anticorrosion activity with an inhibition rate of 91.32% at 3 g/l for a temperature of 323 K. Potentiodynamic polarization was performed in 1 M HCl without and with different concentrations of C. siliqua extracts clearly proves that inhibitor extracts behave as mixed type. Adsorption of this inhibitor for different extracts studied on the surface of the carbon steel obeys Langmuir adsorption with negative values of Δ G ads ∘ , suggesting a stable and spontaneous inhibition process.

Comparison of the Efficiency of Lepidium sativum, Ficus carica, and Punica granatum Methanolic Extracts in Relieving Hyperglycemia and Hyperlipidemia of Streptozotocin-Induced Diabetic Rats

BACKGROUND

Diabetes mellitus (DM) is a metabolic disorder characterized by high blood glucose levels that occurs either due to insufficient insulin production or mounting resistance to its action. The purpose of this study was to investigate if methanolic extracts of Lepidium sativum seeds, Ficus carica, and Punica granatum leaves had any effect on blood sugar levels in normal and streptozotocin (STZ) diabetic rats, as well as to explore the most effective extract.

METHOD

Healthy male albino rats weighing 185-266 g were divided into nine groups of eight rats each: normal control, diabetic control, diabetic rats with dietary supplements of L. sativum, F. carica, and P. granatum methanolic extracts, and diabetics treated with insulin. All of the rats were fed on ordinary diet with nutritional pellets and were given water ad libitum. To induce diabetes, all animals were administered with STZ intraperitoneal injection at a dose of 60 mg/kg body weight. For five weeks, the crude plant extracts were given orally to various groups of rats at doses of one hundred and two hundred mg/kg body weight. After that, animal groups were sacrificed and blood samples were taken.

RESULTS

Phytochemical analysis revealed that the highest amounts of polyphenolic compounds were present in L. sativum seeds and P. granatum leaves, while leaves of F. carica showed the highest amounts of alkaloid and flavonoid content compared to other extracts. Oral administration of F. carica and L. sativum extracts at the dosage of 100 and 200 mg/kg significantly reduced glucose, lipid profile, kidney, and liver enzyme levels. A significant increase in HbAlc levels was also observed with L. sativum extract at a dose of 200 mg/kg compared to diabetic controls. Mellitus rats supplemented with 100 and 200 mg/kg methanolic extracts of P. granatum had higher serum triglycerides and lower serum low-density lipoprotein cholesterol (LDL-C) than normal control rats. F. carica extract is more effective than L. sativum and P. granatum extracts in the prevention and control of type 2 diabetes mellitus (T2DM) and its consequences.

Physiological and Immune Functions of Punicalagin

The aim of this publication is to compile a summary of the findings regarding punicalagin in various tissues described thus far in the literature, with an emphasis on the effect of this substance on immune reactions. Punicalagin (PUN) is an ellagitannin found in the peel of pomegranate (Punica granatum). It is a polyphenol with proven antioxidant, hepatoprotective, anti-atherosclerotic and chemopreventive activities, antiproliferative activity against tumor cells; it inhibits inflammatory pathways and the action of toxic substances, and is highly tolerated. This work describes the source, metabolism, functions and effects of punicalagin, its derivatives and metabolites. Furthermore, its anti-inflammatory and antioxidant effects are described.

Alzheimer's Disease and Functional Foods: An Insight on Neuroprotective Effect of its Combination

Alzheimer's disease (AD) is a progressive neurodegenerative disease which impairs memory and cognitive function. Currently, AD has no cure and treatments are focused on relieving its symptoms. Several functional plants and foods, such as pomegranate, date fruits, honey, black seeds and figs, possess nutritious properties which alleviate AD. In vitro and in vivo studies reported that these functional foods exert neuroprotective effects through their antioxidant and anti-inflammatory properties. This review are going to discusses the bioactive components and neuroprotective activities of the functional foods such as pomegranate, dates, honey, black seeds and figs and the potential of functional foods combinations to alleviate AD. Functional food combinations have potential to be consumed for health benefit for the prevention and treatment of AD. This review summarises the functional foods which can be useful for the prevention, treatment and management of AD via oxidative and inflammatory mechanisms. Besides, it provides a new insight on the potential of functional food combinations for the prevention and treatment of AD.

Serum Metabolomics Profiling of Commercially Mixed Functional Foods—Effects in Beta-Amyloid Induced Rats Measured Using 1H NMR Spectroscopy

Functional foods such as pomegranate, dates and honey were shown by various previous studies to individually have a neuroprotective effect, especially in neurodegenerative disease such as Alzheimer’s disease (AD). In this novel and original study, an ¹H NMR spectroscopy tool was used to identify the metabolic neuroprotective mechanism of commercially mixed functional foods (MFF) consisting of pomegranate, dates and honey, in rats injected with amyloid-beta 1-42 (Aβ-42). Forty-five male albino Wistar rats were randomly divided into five groups: NC (0.9% normal saline treatment + phosphate buffer solution (PBS) solution injection), Abeta (0.9% normal saline treatment + 0.2 µg/µL Aβ-42 injection), MFF (4 mL/kg MFF treatment + PBS solution injection), Abeta–MFF (4 mL/kg MFF treatment + 0.2 µg/µL Aβ-42 injection) and Abeta–NAC (150 mg/kg N-acetylcysteine + 0.2 µg/µL Aβ-42 injection). Based on the results, the MFF and NAC treatment improved the spatial memory and learning using Y-maze. In the metabolic analysis, a total of 12 metabolites were identified, for which levels changed significantly among the treatment groups. Systematic metabolic pathway analysis found that the MFF and NAC treatments provided a neuroprotective effect in Aβ-42 injected rats by improving the acid amino and energy metabolisms. Overall, this finding showed that MFF might serve as a potential neuroprotective functional food for the prevention of AD.

Microencapsulated pomegranate peel extract induces mitochondrial complex IV activity and prevents mitochondrial cristae alteration in brown adipose tissue in mice fed on a high-fat diet

Pomegranate peel is an agro-industrial residue obtained after fruit processing with high total polyphenol (TP) content, making it an attractive by-product for its reuse. Pomegranate peel extract (PPE) and its bioactive compounds have shown positive effects on obesity models. Effects on favouring mitochondrial biogenesis and function have also been described. However, once phenolic compounds are extracted, their stability can be affected by diverse factors. Microencapsulation could improve PPE stability, allowing its incorporation into functional foods. Nevertheless, studies on the potential biological effects of PPE microparticles (MPPE) in obesity models are lacking. This study aims to evaluate the effect of MPPE on brown adipose tissue (BAT) mitochondrial structure and function and metabolic alterations related to obesity in mice fed a high-fat diet (HFD). PPE was microencapsulated by spray drying using inulin (IN) as a wall material and physically–chemically characterised. Eight-week-old male C57BL/6J mice (n 40) were randomly distributed into five groups: control diet (CD), HFD, HFD + IN, HFD + PPE (50 mg/kg per d TP) and HFD + MPPE (50 mg/kg per d TP), for 14 weeks. A glucose tolerance test and indirect calorimetry were conducted. Blood and adipose tissue samples were obtained. MPPE supplementation prevented HFD-induced body weight gain (P < 0·001), fasting glycaemia (P = 0·007) and total cholesterol rise (P = 0·001). MPPE resulted in higher BAT mitochondrial complex IV activity (P = 0·03) and prevented HFD-induced mitochondrial cristae alteration (P = 0·02). In conclusion, MPPE prevented HFD-induced excessive body weight gain and associated metabolic disturbances, potentially by activating complex IV activity and preserving mitochondrial cristae structure in BAT in mice fed with a HFD.

Effects of grape and pomegranate waste extracts on poultry carcasses microbial, chemical, and sensory attributes in slaughterhouse

Contamination of poultry carcasses is considered as a critical point in the evaluation of poultry meat safety. The present study aimed at determining the decontamination effects of natural antimicrobial derived from grape waste extract and pomegranate waste extract (GWE and PWE) on poultry carcasses in a slaughterhouse. Poultry carcasses were treated in chiller with concentrations of 0, 2, 4 and 6% of pomegranate and grape waste extracts. Pomegranate and grape waste extracts contained 432.20 and 328.43 mg GAE/g total phenolic compounds. These extracts showed significant antimicrobial effect on the main poultry bacteria in vitro. On the first day of cold storage, significant reduction in total bacterial counts (p < .05) was observed in treated carcasses. After 3 days of storage time, total bacteria, Staphylococcus aureus, and Escherichia coli reduced significantly (p < .05) compared to untreated samples. At sixth and ninth days of storage time, significant reduction in total volatile nitrogen (TVN), total bacteria counts, Staphylococcus aureus, coliforms, and Escherichia coli were observed. Sensory attributes in treated carcasses with PWE and GWE have been enhanced significantly compared to untreated during acceptable shelf time (p < .05). Based on the results, pomegranate and grape waste extracts can be used to preserve and improve the shelf life of the poultry carcasses close to the standard range until the ninth day of storage. Application of pomegranate and grape waste extracts in slaughterhouse could be considered as an environmentally, natural and safe decontamination intervention in integral food safety system.

Pomegranate as a source of bioactive constituents: a review on their characterization, properties and applications

Increasing awareness about the use of compounds obtained from natural sources exerting health-beneficial properties, including antimicrobial and antioxidant effects, led to increased number of research papers focusing on the study of functional properties of target compounds to be used as functional foods or in preventive medicine. Pomegranate has shown positive health properties due to the presence of bioactive constituents such as polyphenols, tannins, and anthocyanins. Punicalagin is the major antioxidant, abundantly found in pomegranate's peel. Research has shown that pomegranate polyphenols not only have a strong antioxidant capacity but they also inhibit the growth of pathogenic bacteria like V. cholera, P. aeruginosa and S. aureus, B. cereus, E. coli, and S. virulence factor, and inhibits fungi such as A. Ochraceus, and P. citrinum. Compounds of natural origin inhibit the growth of various pathogens by extending the shelf life of foodstuffs and assuring their safety. Therefore, the need to find compounds to be used in combination with antibiotics or as new antimicrobial sources, such as plant extracts. On the basis of the above discussion, this review focuses on the health benefits of pomegranate, by summarizing the current body of research focusing on pomegranate bioactive constituents and their therapeutic potential against some pathogenic microbes.

Characterization and Application of Pomegranate Epicarp Extracts as Functional Ingredients in a Typical Brazilian Pastry Product

Currently, there is a clear tendency to incorporate natural ingredients into food and pharmaceutical formulations. Besides being well-accepted by consumers, these ingredients have less adverse side effects than their artificial counterparts. The pomegranate processing industry produces large quantities of by-products that are discarded as bio-residues, despite containing bioactive compounds. Accordingly, the epicarp of two pomegranate varieties (Mollar de Elche and Purple Queen) was tested as a potential source of bioactive compounds with food application. The phenolic profile was identified by HPLC–DAD–ESI/MS, revealing fourteen phenolic compounds in both varieties (Purple Queen showed also three anthocyanins), with punicalagin isomers as the major compounds. Nonetheless, Mollar de Elche presented greater antioxidant and antibacterial activities. Despite this result, Purple Queen was selected to be tested as a new natural colouring and functionalizing ingredient in a Brazilian pastry product. The incorporation of the selected extract maintained the nutritional profile and provided a higher antioxidant activity compared to the traditional product. In this way, this work confirmed the possible use of pomegranate epicarp as a natural ingredient in the food industry, conferring dyeing and functionalizing effects, and anticipating a possible valorisation of this bio-residue.

The Chemical Composition, Antioxidant and Anti-Tyrosinase Activities, and Irritation Properties of Sripanya Punica granatum Peel Extract

This is the first study to investigate the effect of ethanol concentrations on the phenolic content and biological activities of Sripanya Punica granatum peel extract. Various concentrations of ethanol, (20 to 80% v/v), were used in the maceration process. Extracts were investigated for total phenolic content by the Folin–Ciocalteu method, antioxidant activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and anti-tyrosinase activity by a spectrophotometric method. The chemical composition was investigated using high-performance liquid chromatography. The irritation of the extracts was determined by Hen’s egg test–chorioallantoic membrane assay. The results demonstrated that E60, which was extracted using 60% v/v ethanol, had the highest yield (66.23 ± 0.38% w/w), the highest total phenolic content (490.42 ± 7.20 μg GAE/g), and the highest antioxidant and anti-tyrosinase activities. IC50 values on DPPH• and ABTS•+ inhibition were 10.97 ± 0.97 and 6.48 ± 0.06 µg/mL, respectively. The 60% v/v ethanol extract (E60) possessed strong tyrosinase inhibition with an IC50 value of 0.10 ± 0.13 µg/mL, which is more potent than kojic acid. The major constituents were punicalagin (4.05 ± 0.26% w/w) and ellagic acid (0.63 ± 0.04% w/w). E60 was safe for topical application since it did not induce irritation. Therefore, we suggest that E60 is a promising agent for further product development.

Ellagic Acid Recovery by Solid State Fermentation of Pomegranate Wastes by Aspergillus niger and Saccharomyces cerevisiae: A Comparison

Fermentation in solid state culture (SSC) has been the focus of increasing interest because of its potential for industrial applications. In previous studies SSC of pomegranate wastes by Aspergillus niger has been extensively developed and optimized for the recovery of ellagic acid (EA), a high value bioactive. In this study we comparatively investigated the SSC of powdered pomegranate husks by A. niger and Saccharomyces cerevisiae and evaluated the recovery yields of EA by an ultrasound and microwave-assisted 7:3 water/ethanol extraction. Surprisingly enough, the yields obtained by S. cerevisiae fermentation (4% w/w) were found 5-fold higher than those of the A. niger fermented material, with a 10-fold increase with respect to the unfermented material. The EA origin was traced by HPLC analysis that showed a significant decrease in the levels of punicalagin isomers and granatin B and formation of punicalin following fermentation. Other extraction conditions that could warrant a complete solubilization of EA were evaluated. Using a 1:100 solid to solvent ratio and DMSO as the solvent, EA was obtained in 4% yields from S. cerevisiae fermented husks at a high purity degree. Hydrolytic treatment of S. cerevisiae fermented pomegranate husks afforded a material freed of the polysaccharides components that gave recovery yields of EA up to 12% w/w.

Punicalagin, a Pomegranate-Derived Ellagitannin, Suppresses Obesity and Obesity-Induced Inflammatory Responses Via the Nrf2/Keap1 Signaling Pathway

SCOPE

Punicalagin (PCG) is one of the most abundant phytochemicals found in pomegranates. The effects and mechanistic action of PCG on obesity and obesity-induced inflammatory and oxidant responses are investigated in vitro and in vivo.

METHODS AND RESULTS

The effect of PCG on adipogenesis is examined using Oil red O staining. The effects and mechanism of action of PCG on inflammatory responses are determined in adipocyte-conditioned medium (ACM)-cultured macrophages, a cell-to-cell contact system, and a transwell system. The effects of PCG on obesity and obesity-induced inflammatory/oxidant responses are examined in high-fat diet (HFD)-fed mice. PCG effectively suppresses lipid accumulation in adipocytes and adipocyte-induced inflammatory responses in adipocyte-macrophage co-culture systems. Small interfering RNA (siRNA) transfection indicates that the PCG-mediated anti-inflammatory effect is exerted via the nuclear factor erythroid 2-related factor 2/Kelch-like ECH-associated protein 1(Nrf2/Keap1) pathway. PCG administration results in a significant reduction in body and white adipose tissue (WAT) weights. PCG favorably regulates pro- and anti-inflammatory cytokines, downregulating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Immunohistochemical (IHC) analysis demonstrates that PCG differentially modulates the distribution of complement component 3 receptor 4 subunit (CD11c) and cluster of differentiation 206 (CD206). PCG regulates the level of antioxidant and oxidant molecules by activating Nrf2/Keap1 signaling.

CONCLUSIONS

PCG ameliorates obesity and obesity-induced inflammatory responses via activation of Nrf2/Keap1 signaling, suggesting that PCG has potential as an oral agent to control obesity-mediated diseases.

Beneficial Effects of Pomegranate Peel Extract and Probiotics on Pre-adipocyte Differentiation

The beneficial effects of pomegranate are due to the ellagitannins and anthocyanins content, which are protective toward a wide variety of diseases including inflammatory diseases. Many investigators have reported that pomegranate waste (peel and seeds) extracts, made from waste product of industrial processing, show free radical scavenger and a potent antioxidant capacity. Pomegranate extracts (PEs) were also reported to possess noteworty antibacterial, antiviral, hypolipidemic, and anti-inflammatory bioactivities thanks to the polyphenolic compounds content, which includes punicalagins, gallic acid, and ellagic acid derivatives. The focus of the present manuscript was to study the prebiotic potentiality of a PE, soluble in water, and characterized through HPLC-PDA-ESI/MS ⁿ for its phenolic content. Moreover, since it has been reported that pomegranate extracts decreased the level of lipids in the blood and that a number of probiotic strains have been shown to affect adipogenesis in cell culture, this study was also performed to test the in vitro effects of PE and probiotic L. rhamnosus GG ATCC 53103 strain (LGG) on 3T3-L1 cell line. PE and probiotics substantially reduced the triglyceride content and intracellular lipid increase, compared to the control group. However, the combination treatment of PE and LGG filtered spent broth (SB) was the most effective in reducing triglyceride content and intracellular lipid accumulation. The mRNA expression levels of the main transcriptional factors implicated in adipocyte differentiation were substantially lower in 3T3-L1 cells treated with PE and LGG filtered SB. These results evidenced that a synergistic effect of probiotics and polyphenols contained in PE may affect in vitro adipogenesis and may contribute in development of new nutraceutical/probiotic-based remedies to prevent and to treat obesity.

A Critical Overview of Labeling Information of Pomegranate Juice-Based Drinks: Phytochemicals Content and Health Claims

Punicalagin is responsible for over 50% of the antioxidant activity of pomegranate, but ellagic acid (EA) and total polyphenol content (TPC) are also key parameters regarding pomegranate bioactivity. Many juices and other drinks based on pomegranate take advantage from the widespread healthy image of this fruit, whereas their real content of bioactive phytochemicals is low. For that reason, the objective of this study was to compare the labelling information with the real phytochemical contents (TPC, punicalagin [Pn] [isomers α, β], and EA). Titratable acidity (TA), color density (CD), polymeric color (PC), and sensory profiles (trained panel) were assessed. The experimental ranges of TPC and Pn contents were 2.75 to 70.9 mg/g and traces to 3.18 mg/g, respectively. The percentage of pomegranate juice was highly correlated with the intensity of the pomegranate ID attribute (R = 0.85; p < 0.001), Pn content (R = 0.71; p < 0.001), and EA content (R = 0.36; p < 0.001). The experimental results showed a high variability in the content of bioactive compounds and the need to urge food companies to optimize processes and storage conditions. Although no health claim for pomegranate has been authorized so far at the European Union, significant mismatches among labelling and bioactive compounds content are misleading consumers. PRACTICAL APPLICATION: Pomegranate juice and nectar producers need to evaluate the real content of bioactive Pn, EA, and TPC in their products to optimize formulation, heat treatment, packaging and storage conditions to guarantee high levels of bioactive compounds during shelf life. Producers' organizations may benefit from harmonizing Pom products labelling, so they may fulfill consumer expectations and may be ready if health claims are finally authorized for these products. The development of a new sensory quality marker will be an interesting option.

Detection and Quantitation of Frauds in the Authentication of Cranberry-Based Extracts by UHPLC-HRMS (Orbitrap) Polyphenolic Profiling and Multivariate Calibration Methods

UHPLC-HRMS (Orbitrap) polyphenolic profiling was applied to the characterization, classification, and authentication of cranberry-based natural and pharmaceutical products. Fifty three polyphenolic standards were characterized to build a user-accurate mass database which was then proposed to obtain UHPLC-HRMS polyphenolic profiles by means of ExactFinder software. Principal component analysis results showed a good sample discrimination according to the fruit employed. Regarding cranberry-based pharmaceuticals, discrimination according to the presentation format (syrup, sachets, capsules, etc.) was also observed due to the enhancement of some polyphenols by purification and preconcentration procedures. Procyanidin A2 and homogentisic, sinapic, veratric, cryptochlorogenic, and caffeic acids showed to be important polyphenols to achieve cranberry-based products discrimination against the other studied fruits. Partial least-squares regression allowed the determination of adulterant percentages in cranberry-fruit samples. Very satisfactory results with adulteration quantification errors lower than 6.0% were obtained even at low adulteration levels.

Phenolic profiling and antioxidant capacity in flowers, leaves and peels of Tunisian cultivars of Punica granatum L

The comprehensive phenolic fingerprints of flowers, peels and leaves of two Tunisian Punica granatum L. cultivars, namely Nabli and Gabsi, were investigated. The highest phenolic content was recorded in the Nabli flowers, followed by Gabsi peels extracts (152.6 and 125.8 mg gallic acid equivalent 100 g^-1, respectively) while flavonoids and flavonols were highest in Gabsi peels (19.2 and 26.0 mg Rutin equivalent per 100 g^-1). Besides, the antioxidant capacity was the highest in Gabsi peels (144.4 mg gallic acid equivalent 100 g^-1) and in Nabli flowers (161.6 mg gallic acid equivalent per 100 g^-1. Methanol extracts of all three plant portions of both cultivars were screened by ultra-high-performance liquid chromatography coupled to quadruple time of flight mass spectrometry, and the identified phenolics were further quantified. Nabli cultivar showed higher contents of flavonoids (in flowers and leaves), while phenolic acids were abundant in Gabsi leaves. Multivariate statistics highlighted differences in phenolic profile among organs and cultivars. These results showed that the pomegranate portions investigated are a valuable source of bioactive compounds with health-promoting properties, mainly belonging to the phenolic class of flavonoids.

Phenolic compounds as beneficial phytochemicals in pomegranate (Punica granatum L.) peel: A review

Pomegranate peel (PoP), a juice byproduct often considered as a waste, comprises nearly around 30-40% portion of the fruit. Phenolic compounds (one class of bioactive phytochemicals) are primarily concentrated in the peel portion of pomegranate fruit. In PoP, the main phenolic compounds reported in the literature include flavonoids (anthocyanins such as pelargonidin, delphinidin, cyanidin along with their derivatives and anthoxanthins such as catechin, epicatechin and quercetin), tannins (ellagitannins and ellagic acid derivatives such as punicalagin, punicalin and pedunculagin) and phenolic acids (such as chlorogenic, caffeic, syringic, sinapic, p-coumaric, ferulic, ellagic, gallic and cinnamic acid). It is generally accepted that phenolic compounds can be more efficiently recovered from PoP by improving the extraction efficiency. The curative relevance of these compounds has been mainly assessed by in vitro experimentation. Therefore, conclusive clinical trials of the phenolic compounds present in PoP are essential for correct validation of their health benefits.

Fermented pomegranate wastes as sustainable source of ellagic acid: Antioxidant properties, anti-inflammatory action, and controlled release under simulated digestion conditions

Wastes deriving from production of wines by yeast fermentation of Punica granatum (fermented pomegranate wastes, FPW) showed a marked antioxidant activity in a series of conventional chemical tests. HPLC/MS analysis of the methanol extract showed the presence of ellagic acid (EA) as the main phenolic component at levels up to 40% on a w/w basis. Experiments using murine macrophages showed that FPW extract is able to reduce the LPS-induced expression of pro-inflammatory genes IL-1β, TNF-α and iNOS. A remarkable increase in the antioxidant properties and extractable EA content was observed following acid hydrolytic treatment of FPW. Under simulated gastrointestinal conditions, EA was slowly released from FPW up to 80% of the overall content over 2 h incubation at the slightly alkaline pHs simulating the small intestine environment, suggesting a potential of the material in nutraceuticals and other applications.

Effects of anti-lipid peroxidation of Punica granatum fruit extract in endothelial cells induced by plasma of severe pre-eclamptic patients

Preeclampsia is a pregnancy disorder characterized by hypertension and proteinuria. This disorder involves oxidative stress and changes in endothelial homeostasis. This study was aimed to seek whether an ethanolic extract of Punica granatum fruit inhibits 8-iso-PGFα formation and modulates nitric oxide (NO) in endothelial cells induced by plasma from pre-eclamptic patients. Endothelial cells were cultured from human umbilical vein endothelial cells. At confluence, endothelial cells were divided into five groups, which included endothelial cells exposed to 2% plasma from normal pregnancy (NP), endothelial cells exposed to 2% plasma from pre-eclamptic patients (PP), endothelial cells exposed to PP in the presence of ethanolic extract of P. granatum (PP + PG) at the following three doses: 14; 28; and 56 ppm. Analysis of 8-iso-PGFα was done by immunoassay technique. Analysis of NO level was done by colorimetric technique. Plasma from PP significantly increased 8-iso-PGFα level compared to cells treated by normal pregnancy plasma. This increase in 8-iso-PGFα was significantly (p < 0.05) attenuated by all doses treatments of P. granatum extract. The level of NO was insignificant (p > 0.05) between groups. P. granatum fruit extract protects endothelial cells from oxidative stress induced by plasma from pre-eclamptic patients.

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Endothelial cells induce by preeclamptic plasma.

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8-iso-PGFα level significantly increased.

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NO level insignificantly changed.

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All doses of Theobroma cacao attenuated this 8-iso-PGFα increase.