Antioxidant and antimicrobial activity of pomegranate peel extract improves the shelf life of chicken products

Phenolic profiles, antihyperglycemic, antihyperlipidemic, and antioxidant properties of pomegranate (Punica granatum) peel extract

This work is aimed to evaluate phenolics composition, and in vitro antioxidant activities of hydro-methanol pomegranate (Punica granatum L.) peel extract (MPE). In addition, the antihyperglycemic, hypolipidemic, and hepatoprotective effect of MPE in Wister albino rats was compared with standard drugs (glibenclamide and atorvastatin). Total phenolic content and total flavonoid contents in MPE (mg g^-1 ) accounted for 188.9 as GAE and 13.95 as QE, respectively. Phenolic and flavonoids compounds in MPE analyzed by HPLC and revealed the presence of 23 phenolic compounds and 20 flavonoid compounds. For in vivo experiment, 56 rats were distributed into 8 groups. Group 1 was the normal control, while group 2 contained rats orally administrated with 200 mg kg^-1 MPE daily. Group 3 contained diabetic rats (induced with a single dose of 100 mg/kg b.w. alloxan). Group 4 contained diabetic rats administered daily with 200 mg/kg MPE. Group 5 contained diabetic rats administered orally with a glibenclamide (standard drug for diabetic) at 10 mg/kg daily. Group 6 fed with high fat diet (HFD). Group 7 contained HFD-rats administered orally with 200 mg/kg MPE daily. Group 8 contained HFD-rats administered orally with atorvastatin (used to lower LDL-cholesterol (LDL-C) and fats and to raise HDL-cholesterol (HDL-C) in the blood) at 10 mg/kg daily. The study lasted for 56 days. Administration with MPE 200 mg/kg to both diabetic and hyperlipidemic rats significantly decreased blood glucose, HbA_1c , total lipid, total cholesterol, LDL-C, and very low density lipoprotein cholesterol levels, while increased high density lipoprotein cholesterol levels, as well as improved liver and kidney functions, compared with glibenclamide and atorvastatin effects. PRACTICAL APPLICATIONS: Pomegranate peel, constituted about 50% of fruit fresh weight, is rich in bioactive compounds with potent health-promoting activities. The results of the current study stated that MPE is rich in phenolics and flavonoids with powerful antioxidant potential. In addition, MPE showed antihyperglycemic and antihyperlipidemic activities due to the strong antiradical action via its antioxidant compounds. MPE enhanced liver and kidney functions when compared to standard drugs in diabetic and hyperlipidemic rats. MPC could be used as a natural material to develop diabetic and hyperlipidemic drugs.

Critical pharmacokinetic and pharmacodynamic drug-herb interactions in rats between warfarin and pomegranate peel or guava leaves extracts

BACKGROUND

In-depth information of potential drug-herb interactions between warfarin and herbal compounds with suspected anticoagulant blood thinning effects is needed to raise caution of concomitant administration. The current study aimed to investigate the impact of co-administration of pomegranate peel and guava leaves extracts, including their quality markers namely; ellagic acid and quercetin, respectively, on warfarin's in vivo dynamic activity and pharmacokinetic actions, in addition to potential in vitro cytochrome P450 enzymes (CYP) inhibition.

METHODS

Influence of mentioned extracts and their key constituents on warfarin pharmacodynamic and kinetic actions and CYP activity were evaluated. The pharmacodynamic interactions were studied in Sprague Dawley rats through prothrombin time (PT) and International Normalized Ratio (INR) measurements, while pharmacokinetic interactions were detected in vivo using a validated HPLC method. Furthermore, potential involvement in CYP inhibition was also investigated in vitro on isolated primary rat hepatocytes.

RESULTS

Preparations of pomegranate peel guava leaf extract, ellagic acid and quercetin in combination with warfarin were found to exert further significant increase on PT and INR values (p < 0.01) than when used alone (p < 0.05). Pomegranate peel extract showed insignificant effects on warfarin pharmacokinetics (p > 0.05), however, its constituent, namely, ellagic acid significantly increased warfarin Cmax (p < 0.05). Guava leaves extract and quercetin resulted in significant increase in warfarin Cmax when compared to control (p < 0.01). Furthermore, guava leaves extract showed a significant effect on changing the AUC, CL and Vz. Significant reduction in CYP2C8, 2C9, and 3A4 was seen upon concomitant use of warfarin with ellagic acid, guava leaves and quercetin, unlike pomegranate that insignificantly affected CYP activities.

CONCLUSION

All combinations enhanced the anticoagulant activity of warfarin as the results of in vivo and in vitro studies were consistent. The current investigation confirmed serious drug herb interactions between warfarin and pomegranate peel or guava leaf extracts. Such results might conclude a high risk of bleeding from the co-administration of the investigated herbal drugs with warfarin therapy. In addition, the results raise attention to the blood-thinning effects of pomegranate peel and guava leaves when used alone.

Effect of supplementing moringa (Moringa oleifera) leaf meal and pomegranate (Punica granatum) peel meal on performance, carcass attributes, immune and antioxidant responses in broiler chickens

An experiment was conducted to study the benefits of dietary supplementation of moringa (Moringa oleifera) leaf meal (MLM) and pomegranate (Punica granatum) peel meal (PPM) on the performance, carcass attributes, immune and antioxidant responses in commercial broiler chickens during 1–42 days of age. In total, 450 Cobb-400 broiler male chicks raised in wire-floor stainless-steel battery brooder pens in an open-side poultry house were divided into five experimental groups with 18 replicates of five chicks each and fed a standard control diet (CD) and the test diets supplemented with MLM (500 and 1000 mg/kg) or PPM (250 and 500 mg/kg), each at two different concentrations. Bodyweight gain, feed conversion efficiency and carcass attributes were not affected (P &gt; 0.05). The cell-mediated immune response to phytohaemagglutinin phosphate was not influenced (P &gt; 0.05), but the antibody titre against Newcastle disease (ND) vaccine was significantly (P &lt; 0.05) improved by supplementation of MLM or PPM in broiler diet at 42 days of age. However, at 21 days of age, the ND titre was similar in broilers fed CD and 500 mg/kg PPM fed group. Activities of glutathione reductase and super oxide dismutase in liver were not influenced (P &gt; 0.05), while lipid peroxidation (LP) reduced significantly (P &lt; 0.05) with the herbal additives. The LP in the PPM group was significantly (P &lt; 0.05) lower than that in groups fed MLM. The activity of glutathione peroxidase (GSHPx) was significantly (P &lt; 0.05) improved in the PPM group. Activities of antioxidant enzymes (super oxide dismutase, glutathione reductase, GSHPx) in spleen were not influenced (P &gt; 0.05). The degree of LP in the 500 mg/kg PPM group was significantly (P &lt; 0.05) lower than that in groups fed the CD. It is concluded that supplementation of MLM (500 and 1000 mg/kg) or PPM (250 and 500 mg/kg) in diets improved humoral immune response (against ND vaccine) at 42 days of age and reduced LP in liver in commercial broilers, without showing any negative effects on performance and carcass attributes. Supplementation of PPM (250 and 500 mg/kg) significantly improved the activity of GSHPx in the liver of broiler chickens.

Carcass yields, muscle amino acid and fatty acid profiles, and antioxidant indices of broilers supplemented with synbiotic and/or organic acids

The objective of the current research was to explore the possible impacts of dietary supplementation with synbiotic and/or organic acids (OA) on the performance traits, carcass yields and muscle amino acid and fatty acid (FA) profiles of broilers. Randomly, a total of 160 day-old chicks (Ross 308) were assigned into four equal groups (40 birds each), with each group subdivided into eight replicates (five birds/pen). The control group (CON) fed the basal diet with no supplements, while diets of the treated groups were supplemented with OA (Sodium butyrate 40%; 1 g/kg), synbiotic (comprised Bacillus subtilis, Saccharomyces cerivisiae, Streptococcus faecium, Mannan-Oligosaccharides and β-Glucan; 1 g/kg) and equal mix of OA and synbiotic (2 g/kg). Broilers fed the diets supplemented with synbiotic or synbiotic plus OA produced a significantly higher feed utilization efficiency (p = 0.021) and carcass yields (p = 0.038) than the CON and OA-supplemented groups. The group fed the diet supplemented with the synbiotic showed lowered serum cholesterol (p = 0.049), triglycerides (p = 0.001) and very low density lipoprotein (p = 0.032) when compared with the CON group. Regarding the polyunsaturated FA (PUFA) of breast muscles, synbiotic-supplemented birds had significantly lower n-6:n-3 ratio (p = 0.047), however, a greater hypocholesterolaemic to hypercholesterolaemic FA (H/H) ratio was reported when compared with the CON group (p = 0.002). Among the essential amino acids, the contents of leucine and methionine in the breast (p = 0.032 and 0.007 respectively) and thigh (p = 0.023 and 0.003 respectively) muscles were greater in the synbiotic-supplemented birds compared with the CON group. In conclusion, the synbiotic-supplemented diet improved the PUFA:SFA, n-6:n-3 and H/H ratios by altering the FA composition of broiler muscles, which are important with regards to human health.

Evaluation of microfiltration and heat treatment on the microbiological characteristics, phenolic composition and volatile compound profile of pomegranate (Punica granatum L.) juice

BACKGROUND

Since processing technology and storage may influence the sensory and nutritional value as well as the shelf life of pomegranate juice (PJ), mild technologies based on microfiltration may be a promising alternative to heat treatments for fruit juice preservation. In this study, physicochemical and microbiological properties of raw (RPJ), microfiltered (MPJ) and cloudy pasteurized (PPJ) PJ were compared over a period of 4 weeks.

RESULTS

Data demonstrated that microfiltration was comparable to pasteurization in guaranteeing microbiological stability of the juice, avoiding spoilage of the final product. After treatment, PPJ showed the highest amounts of gallic acid (GA) and ellagic acid derivatives (EAs). During storage, the amount of ellagitannins, EAs and GA similarly decreased in all types of juice. Trends towards variations of monomeric anthocyanins in MPJ and variations of polymeric and copigmented anthocyanins in both MPJ and PPJ were found over storage.

CONCLUSION

The optimization of pretreatments and filtration parameters can lead to the industrial scale-up of microfiltration technology for the development of high-quality non-heat-treated PJ. © 2017 Society of Chemical Industry.

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.

Effects of natural antioxidants on the stability of omega-3 fatty acids in dog food

Introduction

The efficiency of five natural antioxidants (curcumin, cranberry, pomegranate, grape seed extract (GSE), and açai berry) in reducing lipid oxidation in dog food was compared to that of the synthetic antioxidant butylated hydroxyanisole (BHA).

Material and Methods

In two different experiments content parameters were measured after 12 days of storage at 55°C. In experiment one, the natural antioxidants were added at 0.2% and BHA at 0.02% of the food (DM basis), and samples were analysed for thiobarbituric acid-reactive substances (TBARS). In experiment two, the effects of GSE and curcumin at two admixture proportions (0.1% and 0.2% of food DM) on omega-3 fatty acid (FA) content were evaluated.

Results

TBARS values were lower than the control (P < 0.01) for curcumin, cranberry, pomegranate, and GSE but not for the açai berry (P > 0.05). By day 12, although there were no significant differences (P > 0.05) between the two curcumin treatments, they preserved higher concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (P < 0.05) than the BHA and control treatments. The addition of GSE or BHA to dog food held (P < 0.05) the concentrations of EPA higher than the control. The concentrations of EPA and DHA for the 0.2% GSE treatment were greater (P < 0.05) than the 0.1% GSE treatment. Grape seed extract at 0.2% lost less (P < 0.05) EPA concentration than BHA.

Conclusion

The present results showed that, except for açai berry, the tested natural antioxidants could be used as a substitute for BHA in dog food.

In vitro bioaccessibility and functional properties of polyphenols from pomegranate peels and pomegranate peels-enriched cookies

Obesity is an urgent social problem and new functional foods providing polyphenols and dietary fibers (DF) may be promising tools to modulate oxidative stress, inflammation and energy homeostasis. Pomegranate peels (PPe) are an agro-industrial by-product containing polyphenols such as ellagitannins (ETs), gallic acid (GA), ellagic acid (EA) and its derivatives (EAs), as well as DF. In this study, PPe enriched cookies (PPeC) were developed, and the bioaccessibility as well as the ability of their polyphenols to exert antioxidant activity along the Gastro-intestinal Tract (GiT) and to modulate digestive enzymes were evaluated in vitro. Data showed that the potential bioaccessibility of ETs was 40% lower from PPeC than PPe whereas EAs' and GA bioaccessibility increased by 93% and 52% for PPeC compared to PPe. The concentration of the polyphenols at each digestion step was associated with the total antioxidant capacity of the potentially bioaccessible material. Moreover the polyphenols released in the simulated duodenal phase upon PPeC digestion exhibited inhibitory activity towards α-glucosidase, α-amylase and lipase, being α-glucosidase > α-amylase > lipase. In conclusion, the data demonstrated that the inclusion of PPe at 7.5% in a bakery product potentially led to a high bioaccessibility of ETs' degradation products (mainly EA and EAs) in the duodenum, with a consequent antioxidant protection along the GiT and modulation of glucose metabolism. Further human studies are warranted to evaluate whether these effects also occur in vivo.

Antimicrobial efficacy of Syzygium antisepticum plant extract against Staphylococcus aureus and methicillin-resistant S. aureus and its application potential with cooked chicken

For the past decades, there has been a growing demand for natural antimicrobials in the food industry. Plant extracts have attracted strong research interests due to their wide-spectrum antimicrobial activities, but only a limited number have been investigated thoroughly. The present study aimed at identifying a novel anti-staphylococcal plant extract, to validate its activity in a food model, and to investigate on its composition and antimicrobial mechanism. Four plant extracts were evaluated against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in vitro, with Syzygium antisepticum leaf extract showing the strongest antimicrobial activity (MIC = 0.125 mg/mL). Relatively high total phenolic content (276.3 mg GAE/g extract) and antioxidant activities (90.2-138.0 mg TE/g extract) were measured in S. antisepticum extract. Food validation study revealed that higher extract concentration (32 mg/mL) was able to inhibit or reduce staphylococcal growth in cooked chicken, but caused color change on meat surface. By GC-MS, β-caryophyllene (12.76 area%) was identified as the dominant volatile compound in extract. Both crude extract and pure β-caryophyllene induced membrane damages in S. aureus. These results suggested good anti-staphylococcal properties of S. antisepticum plant extract, identified its major volatile composition and its membrane-damaging antimicrobial mechanism.

Natural antimicrobial/antioxidant agents in meat and poultry products as well as fruits and vegetables: A review

Synthetic preservatives are widely used by the food industry to control the growth of spoilage and pathogenic microorganisms and to inhibit the process of lipid oxidation extending the shelf-life, quality and safety of food products. However, consumer's preference for natural food additives and concern regarding the safety of synthetic preservatives prompted the food industry to look for natural alternatives. Natural antimicrobials, including plant extracts and their essential oils, enzymes, peptides, bacteriocins, bacteriophages, and fermented ingredients have all been shown to have the potential for use as alternatives to chemical antimicrobials. Some spices, herbs and other plant extracts were also reported to be strong antioxidants. The antimicrobial/antioxidant activities of some plant extracts and/or their essential oils are mainly due to the presence of some major bioactive compounds, including phenolic acids, terpenes, aldehydes, and flavonoids. The proposed mechanisms of action of these natural preservatives are reported. An overview of the research done on the direct incorporation of natural preservatives agents into meat and poultry products as well as fruit and vegetables to extend their shelf-life is presented. The development of edible packaging materials containing natural preservatives is growing and their applications in selected food products are also presented in this review.

Evaluation of antioxidant capacity and flavor profile change of pomegranate wine during fermentation and aging process

Antioxidant properties and flavor characteristic profile of pomegranate wine during winemaking were investigated. The total phenol content and radical scavenging activity exhibited a slightly decrease in the end edge. Punicalagins and gallic acid were revealed to be the most abundant phenolic compounds, followed by ellagic acid and vanillic acid. These constituents were mainly responsible for the effective antioxidant capacity of pomegranate wine. The major changes of flavor qualities occurred in the initial stage, particularly 0-4day of fermentation. Fermentation significantly reduced the relative content of aldehydes, ketones, heterocyclic and aromatic compounds, but promoted the generation of esters and alcohols. This is the first time of using E-nose and E-tongue to monitor odour and taste changes in the brewing process of pomegranate wine. The study may provide a promising instruction for improving functional features and quality control of the pomegranate wine.

Antioxidant activity of pomegranate peel extract on lipid and protein oxidation in beef meatballs during frozen storage

Antioxidant effect of pomegranate peel extract (PE) to retard lipid and protein oxidation in beef meatballs was investigated during frozen storage at -18±1°C. Concentrated and freeze dried aqueous extract of pomegranate peel was incorporated into freshly prepared meatball mix at 0.5% and 1.0% concentrations, and compared with 0.01% butylated hydroxytoluene (BHT) and control (without any antioxidant). In PE treated samples, particularly in high PE concentration, peroxide, malondialdehyde and carbonyl formation, loss of total protein solubility and sulfhydryl groups were significantly lower than control after 6months of storage. A diminution of both myofibrillar (MP) and sarcoplasmic (SP) proteins of high molecular weight was detected after 6months of the storage according to gel electrophoresis patterns. The 1.0% PE led to maintain colour intensity (C) and hue (h°) value. The results from sensory analyses revealed that PE addition to meatballs was effective on preventing rancid odour formation. Addition of both 0.5 and 1% PE in meatballs reduced lipid and protein oxidation and improved sensory scores. These results indicated that PE was effective on retarding lipid and protein oxidations.

Effects of Methanolic Pomegranate Peel Extract on the Chemical, Sensory, Textural, and Microbiological Properties of Gutted Rainbow Trout ( Oncorhynchus mykiss ) during Frozen Storage

The effects of methanolic pomegranate peel extract (MPPE) on the quality of gutted rainbow trout ( Oncorhynchus mykiss ) were examined periodically during 6 months of storage at -18°C. Fresh samples were dipped (ratio of fish to liquid, 1:2 [wt/vol]) in sterile water or in sterile water containing 1, 2, or 4% (wt/vol) MPPE and packed in low-density polyethylene pouches. The control and treated samples were analyzed monthly for microbiological, chemical, sensory, and textural characteristics. Microbial growth in samples was significantly reduced by MPPE treatment (P < 0.05). Smaller increases in the values for total volatile base nitrogen, peroxide, and thiobarbituric acid-reactive substances and better oxidative stability were also obtained. Moreover, higher organoleptic scores were recorded. However, regarding the general acceptability, the highest score was achieved in the 1% MPPE group. Greater hardness and chewiness were obtained with 4% MPPE (P < 0.05). Therefore, dipping fish in MPPE can be considered an effective method to extend the shelf life and the overall quality of the product.

ω-3 in meat products: benefits and effects on lipid oxidative stability

Although ω-3 intake has been associated with numerous health benefits, its addition to certain food matrices, and in particular meat products, may involve various technological barriers influencing the final quality of the products. Lipid oxidation must be highlighted due to the modification of both the sensory characteristics and the shelf-life of meat products. In order to reduce the impact of chemical changes and promote oxidative stability, the use of natural antioxidants has gained ground owing to the health and safety advantages linked to its effectiveness at reducing lipid oxidation. Many natural compounds have also been successfully tested in animal feed, in order to protect the raw meat materials and reduce the risk of lipid oxidation in processed products. This review aims to address the challenges and advantages of the incorporation of ω-3 fatty acids in raw meat materials and processed meat products, and to describe the use of different compounds to enhance lipid oxidative stability. © 2015 Society of Chemical Industry.

Effect of pomegranate peel extract on lipid and protein oxidation in beef meatballs during refrigerated storage

Antioxidant effect of pomegranate peel extract (PE) to retard lipid and protein oxidation was investigated in meatballs during refrigerated storage at 4±1°C. Concentrated lyophilised water extract of pomegranate peel was incorporated into freshly minced beef meat at 0.5% and 1% concentrations and compared with 0.01% butylated hydroxytoluene (BHT) as a reference and control (without any antioxidant). PE showed high phenolic content and antioxidant activity. In PE added samples, thiobarbituric acid reactive substances (TBARS) value, peroxide formation, loss of sulfhydryl groups and formation of protein carbonyls were lower than control (P<0.01) after 8 days of storage. Sensory evaluation with respect to colour and rancid odour revealed that PE incorporation in meatballs prolonged the refrigerated storage up to 8 days. Addition of both 0.5 and 1% PE in meatballs reduced lipid and protein oxidation and improved sensory scores. These results indicated that PE was effective on retarding lipid and protein oxidation.

Identification of anti-cancer targets of eco-friendly waste Punica granatum peel by dual reverse virtual screening and binding analysis

BACKGROUND

Punica granatum (family: Lythraceae) is mainly found in Iran, which is considered to be its primary centre of origin. Studies on pomegranate peel have revealed antioxidant, anti-inflammatory, anti- angiogenesis activities, with prevention of premature aging and reducing inflammation. In addition to this it is also useful in treating various diseases like diabetes, maintaining blood pressure and treatment of neoplasms such as prostate and breast cancer.

OBJECTIVES

In this study we identified anti-cancer targets of active compounds like corilagin (tannins), quercetin (flavonoids) and pseudopelletierine (alkaloids) present in pomegranate peel by employing dual reverse screening and binding analysis.

MATERIALS AND METHODS

The potent targets of the pomegranate peel were annotated by the PharmMapper and ReverseScreen 3D, then compared with targets identified from different Bioassay databases (NPACT and HIT's). Docking was then further employed using AutoDock pyrx and validated through discovery studio for studying molecular interactions.

RESULTS

A number of potent anti-cancerous targets were attained from the PharmMapper server according to their fit score and from ReverseScreen 3D server according to decreasing 3D scores.

CONCLUSION

The identified targets now need to be further validated through in vitro and in vivo studies.

Physical Properties, Antioxidant and Antimicrobial Activity of Chitosan Films Containing Carvacrol and Pomegranate Peel Extract

Chitosan-based active films were developed by incorporation of carvacrol (10 g/L), pomegranate peel extract (PPE, 10 g/L) and carvacrol + PPE (10 g/L of each) and their physical, antioxidant and antimicrobial properties were investigated. Incorporation of carvacrol and carvacrol + PPE into the films significantly decreased the water vapor permeability, tensile strength and percentage of elongation at break. Incorporation of carvacrol, PPE and carvacrol + PPE into the films decreased the transparency, but significantly increased the total phenol content and antioxidant activity. All the films, with the exception of PPE-incorporated film, exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. In addition, the antibacterial activity against Staphylococcus aureus of the film incorporated with carvacrol + PPE was moderately higher than that incorporated with carvacrol or PPE alone, suggesting a synergistic action between carvacrol and PPE.

Pomegranate peel and peel extracts: chemistry and food features

The present review focuses on the nutritional, functional and anti-infective properties of pomegranate (Punica granatum L.) peel (PoP) and peel extract (PoPx) and on their applications as food additives, functional food ingredients or biologically active components in nutraceutical preparations. Due to their well-known ethnomedical relevance and chemical features, the biomolecules available in PoP and PoPx have been proposed, for instance, as substitutes of synthetic food additives, as nutraceuticals and chemopreventive agents. However, because of their astringency and anti-nutritional properties, PoP and PoPx are not yet considered as ingredients of choice in food systems. Indeed, considering the prospects related to both their health promoting activity and chemical features, the nutritional and nutraceutical potential of PoP and PoPx seems to be still underestimated. The present review meticulously covers the wide range of actual and possible applications (food preservatives, stabilizers, supplements, prebiotics and quality enhancers) of PoP and PoPx components in various food products. Given the overall properties of PoP and PoPx, further investigations in toxicological and sensory aspects of PoP and PoPx should be encouraged to fully exploit the health promoting and technical/economic potential of these waste materials as food supplements.