IN VITRO ANTIOXIDANT PROPERTIES OF POMEGRANATE (PUNICA GRANATUM ) PEEL POWDER EXTRACT OBTAINED AS COPRODUCT IN THE JUICE EXTRACTION PROCESS

Improving oxidative stability of cream powder using pomegranate concentrate and peel extract

In this study, the influence of pomegranate peel extract (PPE) and pomegranate concentrate (PC) on improving the oxidative stability of cream powder in comparison with synthetic antioxidant (Butylated hydroxytoluene (BHT)) during the storage period at 20°C (8 weeks) and 45°C (4 weeks) was evaluated. The finding exhibited that peroxide, p-anisidine, and total oxidation (TOTOX) values increased during the storage period. Samples containing PPE and PC showed suitable performance in controlling the cream powder oxidation. Also, PPE showed the highest antioxidant activity and can be proposed as a suitable replacement for a synthetic antioxidant (BHT). L* and b* values increased, while a* value decreased during the storage period. Also, the pH of the powders decreased significantly throughout the storage (reached nearly 6). Microbial counts of cream powders did not change during the storage period. The control sample showed the highest overall acceptability. Antioxidants of pomegranate can be proposed to control the oxidative stability of fat-rich food products.

Development of fiber-enriched muffins using pomegranate peel powder and its effect on physico-chemical properties and shelf life of the muffins

BACKGROUND

Pomegranate peel is a by-product from the pomegranate processing industries and is a rich source of dietary fibers and bioactive compounds. It has good antioxidant and antimicrobial properties. In the present study, the effects of substitution of refined wheat flour with pomegranate peel powder (PPP) at a rate of 2%, 4%, 6%, 8% and 10% on the physico-chemical and sensorial properties as well as on the oxidative and microbial stability of muffins were investigated.

RESULTS

A significant reduction in specific volume (1.99 to 1.57 cm3  g-1 ), weight loss (11.73 to 10.14 g 100 g-1 ) and an increase in crumb hardness (633.06 to 2311.5 g) of muffins were observed on addition of PPP. Moreover, the nutritional value was improved by a significant increase in the fiber content (4.39 to 10.66%), total phenols (0.443 to 48.53 mg GAE 100 g-1 ), antioxidant activity (75.94% to 99.36%), calcium (200.33 to 294.33 mg 100 g-1 ), potassium (227.33 to 425.33 mg 100 g-1 ) and magnesium (96.33 to 288.33 mg 100 g-1 ). The pasting and rheological properties of muffin batter showed a significant decrease in the final and peak viscosity, as well as increase in storage, loss and complex modulus. The muffin samples were organoleptically acceptable up to a level of 8% PPP. Free fatty acid content, peroxide value and microbial count of the muffin with 8% PPP were significantly lower compared to the control sample and more oxidatively and microbially stable for a storage period of 21 and 28 days at ambient and refrigerated temperatures, respectively.

CONCLUSION

The present study provides the opportunity to use PPP as functional ingredients and natural preservative in the preparation of muffins. © 2023 Society of Chemical Industry.

Combination of Chemically Characterized Pomegranate Extract and Hydrophilic Vitamins against Prolonged Fatigue: A Monocentric, Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Prolonged fatigue is associated with non-pathological causes and lacks an established therapeutic approach. The current study is aimed at assessing the efficacy of a new food supplement (Improve™) based on a chemically characterized pomegranate extract and hydro-soluble vitamins (B complex and C). UHPLC-HRMS analysis of pomegranate extract showed the presence of 59 compounds, with gallotannins and ellagitannins being the most abundant phytochemicals. For the clinical study, 58 subjects were randomized into two groups, 1 and 2 (n = 29, each), which received either the food supplement or placebo. The effects of the food supplement against fatigue were assessed via validated questionnaires, recorded at time intervals t0 (at baseline), t1 (after 28 days), t2 (56 days), and t3 (after follow-up) in combination with the analysis of biochemical markers at t0 and t2. Fatigue severity scale (FSS) questionnaire scores were significantly decreased at the t2 and t3 time intervals in subjects treated with the food supplements, while the effect of the food supplement on a 12-Item Short Form Survey (SF-12) was not considerable. Moreover, the food supplement did not significantly affect biochemical parameters associated with fatigue and stress conditions. This study shows that the food supplement tested reduces prolonged fatigue following two months of supplementation in healthy subjects with mild prolonged fatigue.

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.

From Pomegranate Byproducts Waste to Worth: A Review of Extraction Techniques and Potential Applications for Their Revalorization

The food industry is quite interested in the use of (techno)-functional bioactive compounds from byproducts to develop ‘clean label’ foods in a circular economy. The aim of this review is to evaluate the state of the knowledge and scientific evidence on the use of green extraction technologies (ultrasound-, microwave-, and enzymatic-assisted) of bioactive compounds from pomegranate peel byproducts, and their potential application via the supplementation/fortification of vegetal matrixes to improve their quality, functional properties, and safety. Most studies are mainly focused on ultrasound extraction, which has been widely developed compared to microwave or enzymatic extractions, which should be studied in depth, including their combinations. After extraction, pomegranate peel byproducts (in the form of powders, liquid extracts, and/or encapsulated, among others) have been incorporated into several food matrixes, as a good tool to preserve ‘clean label’ foods without altering their composition and improving their functional properties. Future studies must clearly evaluate the energy efficiency/consumption, the cost, and the environmental impact leading to the sustainable extraction of the key bio-compounds. Moreover, predictive models are needed to optimize the phytochemical extraction and to help in decision-making along the supply chain.

Natural Polyphenols for the Preservation of Meat and Dairy Products

Food spoilage makes foods undesirable and unacceptable for human use. The preservation of food is essential for human survival, and different techniques were initially used to limit the growth of spoiling microbes, e.g., drying, heating, salting, or fermentation. Water activity, temperature, redox potential, preservatives, and competitive microorganisms are the most important approaches used in the preservation of food products. Preservative agents are generally classified into antimicrobial, antioxidant, and anti-browning agents. On the other hand, artificial preservatives (sorbate, sulfite, or nitrite) may cause serious health hazards such as hypersensitivity, asthma, neurological damage, hyperactivity, and cancer. Thus, consumers prefer natural food preservatives to synthetic ones, as they are considered safer. Polyphenols have potential uses as biopreservatives in the food industry, because their antimicrobial and antioxidant activities can increase the storage life of food products. The antioxidant capacity of polyphenols is mainly due to the inhibition of free radical formation. Moreover, the antimicrobial activity of plants and herbs is mainly attributed to the presence of phenolic compounds. Thus, incorporation of botanical extracts rich in polyphenols in perishable foods can be considered since no pure polyphenolic compounds are authorized as food preservatives. However, individual polyphenols can be screened in this regard. In conclusion, this review highlights the use of phenolic compounds or botanical extracts rich in polyphenols as preservative agents with special reference to meat and dairy products.

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.

Gelatin-Based Antimicrobial Films Incorporating Pomegranate (Punica granatum L.) Seed Juice by-Product

Pomegranate (Punica granatum L.) seed juice by-product (PSP) was added as reinforcing and antimicrobial agent to fish gelatin (FG) films as a promising eco-friendly active material for food packaging applications. A complete linkage analysis of polysaccharides in PSP showed xylan and cellulose as main components. This residue showed also high total phenolic content and antioxidant activity. Three formulations were processed by adding PSP to FG (0, 10, 30 wt. %) by the casting technique, showing films with 10 wt. % of PSP the best performance. The addition of PSP decreased elongation at break and increased stiffness in the FG films, particularly for 30 wt. % loading. A good compatibility between FG and PSP was observed by SEM. No significant (p < 0.05) differences were obtained for barrier properties to oxygen and water vapour permeability compared to the control with the incorporation of PSP, whereas water resistance considerably increased and transparency values decreased (p < 0.05). High thermal stability of films and inhibition against S. aureus were observed. The addition of PSP at 10 wt. % into FG was shown as a potential strategy to maintain the integrity of the material and protect food against lipid oxidation, reducing huge amounts of pomegranate and fish wastes.

Finding solutions for agricultural wastes: antioxidant and antitumor properties of pomegranate Akko peel extracts and β-glucan recovery

Pomegranate peels are the major by-products of the processing of pomegranate juice. Scientific research studies have shown that pomegranate peels are an extraordinary source of bioactive compounds, most of which can be converted into value added products. From this point of view, the present study was carried out with the aim of providing a solid basis for the use of whole pomegranate peels (Akko variety) as a source of nutraceutical compounds, such as β-glucans. Moreover, acetone (S1) and methanolic (S2) extracts, obtained in the preliminary stage of the β-glucan isolation procedure, have been tested for their antioxidant and antitumor activities. The total phenolic content and phenolic profile of S1 and S2 were determined. S1 and S2 exhibited a significant DPPH scavenging activity, with an IC50 value for S1 1.5-fold lower than that for the standard Trolox. Both S1 and S2 extracts possess in vitro ROS scavenging activity toward 3T3-L1 murine fibroblasts and Hek-293 human embryonic kidney epithelial cells and antiproliferative activity towards human breast MCF-7 and uterine HeLa cancer cells.

Effect of particle size on phytochemical composition and antioxidant properties of two persimmon flours from Diospyros kaki Thunb. vars. 'Rojo Brillante' and 'Triumph' co-products

BACKGROUND

This contribution studies the influence of the particle size of persimmon flours (from two cultivars, 'Rojo Brillante' and 'Triumph') on their primary (sugars and organic acids) and secondary (polyphenols, flavonoids and carotenoids) metabolite content, and also on their antioxidant activity, to assess whether these flours could find applications in the food industry as a potential functional ingredient.

RESULTS

The main sugars were fructose and glucose and the principal organic acid was malic acid. The highest content of total phenols, flavonoids and carotenoids was found in flour fractions from cv. 'Rojo Brillante'. The phenol profile determined by HPLC identified six phenolic compounds in both persimmon flours, the most abundant being gallic acid. The greatest ABTS and DPPH radical scavenging capacity and ferric reducing power were found in flour fractions from cv. 'Rojo Brillante'. Although the influence of particle size on all these properties was not always evident, in general, the higher bioactive compound content and antioxidant capacity were in the finest particles.

CONCLUSION

Co-products from cvs. 'Rojo Brillante' and 'Triumph' persimmon juice extraction can be processed to obtain flours rich in sugars, organic acids and bioactive compounds, suggesting their possible use as a functional ingredient (with antioxidant properties) in different food products. © 2017 Society of Chemical Industry.

Effects of pomegranate peel polyphenols on lipid accumulation and cholesterol metabolic transformation in L-02 human hepatic cells via the PPARγ-ABCA1/CYP7A1 pathway

PPPs, PC and PEA in different concentrations were found to decrease the total cholesterol (TC) content and increase the total bile acid (TBA) content of a human hepatic cell model, and so possess a lipid-lowering effect.

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.

Pomegranate peel and fruit extracts: a review of potential anti-inflammatory and anti-infective effects

ETHNOPHARMACOLOGICAL RELEVANCE

Punica granatum L. (Punicaceae) has been used for centuries in many cultures for the prevention and treatment of a wide number of health disorders such as inflammation, diabetes, diarrhea, dysentery, dental plaque and to combat intestinal infections and malarial parasites.

AIM OF THE REVIEW

This review aims at providing an up-to-date overview of the chemical constituents, traditional uses, phytochemistry, pharmacology and toxicology of Punica granatum L. Moreover, the focus of this review is the possible exploitation of this species to treat different diseases and to suggest future investigations.

MATERIALS AND METHODS

An extensive and systematic review of the extant literature was carried out, and the data under various sections were identified by using a computerized bibliographic search via PubMed, Web of Science and Google Scholar. All abstracts and full-text articles were examined. The most relevant articles were selected for screening and inclusion in this review.

KEY FINDINGS

A variety of pomegranate ethnomedical uses have been recorded. Additionally, over the last decade, there has been a dramatic increase of interest in pomegranate as a medicinal and nutritional product due to its n1ewly identified potential health effects, which include treatment and prevention of cancer and cardiovascular diseases. From the toxicological perspective, pomegranate fruit juice, extracts and preparations have been proven to be safe.

CONCLUSIONS

The ethnopharmacological relevance of pomegranate is fully justified by the most recent findings indicating the fruit is a medicinal and nutritional agent useful for treating a wide range of human disorders and maladies. Further investigations are needed to fully understand the mode of action of the active constituents and to fully exploit pomegranate's preventive and therapeutic potential.