Antioxidant properties of peel and pulp hydro extract in ten Persian pomegranate cultivars

The effect of concentrated pomegranate juice on biomarkers of inflammation, oxidative stress, and sex hormones in overweight and obese women with polycystic ovary syndrome: A randomized controlled trial

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disorder. Pomegranate juice (PJ) has been known to play anti-inflammatory and antioxidant roles. However, the effects of PJ on inflammation, oxidative stress, and sex hormones in PCOS patients are very little studied, and thus more studies are needed. This randomized controlled trial enrolled 44 women diagnosed with PCOS according to the Rotterdam criteria, body mass index (BMI) ≥ 25 kg/m² , and aged 18-40 years old. Participants were randomly assigned to take 45 ml/day of concentrated PJ or a control group without intervention. Some biomarkers of sex hormones, inflammation, and oxidative stress were quantified at baseline and after the 8-week intervention. Compared with the controls, serum testosterone levels were significantly decreased in overweight and obese women with PCOS who supplemented with concentrated PJ (-0.004 ± 0.013 vs. 0.039 ± 0.013, p = .039). However, we did not observe significant differences in luteinizing hormone (LH) and sex hormone-binding globulin (SHBG) levels and inflammation and oxidative stress factors between the two groups after adjustment for confounding variables. An 8-week supplementation with concentrated PJ could effectively improve testosterone levels in overweight and obese women with PCOS. This study was registered at www.irct.ir (IRCT20191109045383N1).

Fruit Juice Industry Wastes as a Source of Bioactives

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.

In-vitro antioxidant and antimicrobial studies of ethanolic plant extracts of P. granatum, O. stamineus, A. bilimbi, M. nigra, and E. longifolia

BACKGROUND

Acne is a serious skin problem that affects mostly adolescents. The topical and systematic therapies are effective but could lead to several side effects and the emergence of antibacterial resistance of the acne-causing bacteria. Plant resources have been used as traditional medicine for centuries and can be the alternative therapies for acne treatment. Antioxidants are compounds that can prevent or delay the oxidation of substrates when present in low concentrations. Antioxidants are usually involved in several mechanisms of action, including the inhibition of free radical generation, enhancement of the scavenging capacity against free radicals, and reducing power.

METHODS

In this study, three antioxidant assays, DPPH, ABTS, and FRAP were used to evaluate the antioxidant properties of the ethanolic extracts of five plant extracts (A. bilimbi, M. nigra, O. stamineus, P. granatum, and E. longifolia). Furthermore, the study aimed to identify the most potent plant extracts and their combination which could provide better antibacterial activities against acne-causing bacteria. Ethanolic extracts of A. bilimbi, O. stamineus, M. nigra, P. granatum, and E. longifolia were prepared by the Ultrasound-Assisted Extraction (UAE) technique. Their phytochemical contents were screened using several biochemical tests and GC-MS analysis.

RESULTS

The study found that only the extracts of P. granatum and O. stamineus exhibited good antioxidant activity using DPPH assay (82.37% and 81.72% μg/mL respectively) and in ABTS assay (87.25% and 88.85% μg/mL respectively); their observed FRAP values were 115.1667 ± 5.6182 and 41.3860 ± 2.4583 μg/mL, respectively. The preliminary antibacterial screening using the disc diffusion method showed that P. granatum and O. stamineus were the most potent extracts; hence, both extracts were combined at the ratios of 1:1, 1:2, and 2:1 to a total concentration of 400 mg/mL.

DISCUSSION

The antibacterial efficacy of the mixture was studied using the disc diffusion method and the MIC value was determined. Both S. aureus and S. epidermidis were sensitive to all the individual and combined extracts but C. acnes was resistant to all of them.

CONCLUSION

The antibacterial activity of the combined extracts against S. aureus showed a synergistic effect at the ratio of 2:1 with the inhibitory zone diameter of 18.00 ± 1.00 mm and MIC value of 12.5 mg/mL; however, antagonistic effects were observed against S. epidermidis while no effect was noted against C. acnes. Therefore, all the selected plant extracts exhibited antibacterial activities against certain bacteria and their effects may be enhanced by combining the plant extracts.

The effect of concentrated pomegranate juice consumption on risk factors of cardiovascular diseases in women with polycystic ovary syndrome: A randomized controlled trial

Polycystic ovary syndrome (PCOS) is associated with insulin resistance and dyslipidemia. Pomegranate juice is a rich source of polyphenols that may improve blood pressure, lipid profile, and other risk factors of cardiovascular diseases (CVDs). No study has examined the effects of pomegranate juice consumption on the clinical outcomes of PCOS. This study aimed to examine the effects of concentrated pomegranate juice (CPJ) consumption on risk factors of CVDs in women with PCOS. In this randomized clinical trial, 44 PCOS women with an age range of 18-40 years and body mass index (BMI) of ≥25 kg/m² were recruited. They were randomly allocated to the CPJ (n = 22) and control (n = 22) groups, and followed for 8 weeks. Anthropometric measures, blood pressure, and biochemical parameters were measured at baseline and at the end of the trial. Compared with the control group, CPJ consumption significantly reduced systolic (-9.77 ± 1.46 vs. -1.18 ± 1.46 mmHg, p < .001) and diastolic (-3.87 ± 1.36 vs. 0.30 ± 1.36 mmHg, p = .05) blood pressure, serum triglyceride (TG) levels (-7.82 ± 6.32 vs. 16.63 ± 6.32 mg/dl, p = .01), TG/high-density lipoprotein-cholesterol (HDL-C) ratio (-0.39 ± 0.24 vs. 0.66 ± 0.24, p = .007), and increased serum concentrations of low-density lipoprotein-cholesterol (LDL-C) (6.03 ± 2.47 vs. -1.98 ± 2.47 mg/dl, p = .04) and HDL-C (1.93 ± 1.10 vs. -1.78 ± 1.10 mg/dl, p = .03). These findings were obtained after taking baseline measurements and potential confounders into account. No adverse event or complication was reported due to CPJ consumption throughout the study. We found that CPJ consumption has a beneficial effect on blood pressure, serum concentrations of TG and HDL-C, and TG/HDL-C ratio in women with PCOS. However, this juice could increase serum LDL-C levels in these patients. This trial was registered at www.irct.ir as IRCT20191109045383N1.

Effects of pomegranate juice consumption on blood pressure and lipid profile in patients with type 2 diabetes: A single-blind randomized clinical trial

Pomegranate juice (PJ) has abundant anti-oxidative polyphenolic compounds which are assumed to have cardioprotective effects such as hypotensive properties. This study aimed to investigate the effects of PJ consumption on blood pressure and lipid profile F variables in patients with type 2 diabetes. Sixty subjects (30 in intervention group and 30 in control group) were recruited in this single-blind placebo-controlled randomized clinical trial. The volunteers were randomly assigned to one of two groups. Treatment group consumed 200 ml/day PJ for 6 weeks, while control group received no intervention. Systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) concentrations were measured following 12-14 h of fasting at baseline and at the end of the study. After 6 weeks of intervention, SBP (13.5 ± 1.5 mmHg vs. 12.3 ± 2.5, P < 0.001) and DBP (7.7 ± 1.6 vs. 7.2 ± 1.6 mmHg, P < 0.05) significantly decreased in the intervention group. Similarly, SBP and DBP in the intervention group were significantly lower than the control group after intervention (P < 0.02 and P < 0.03, respectively). At the end of the intervention, TC, TG, LDL-C and HDL-C did not significantly differ between the intervention group and the control group however, TC and LDL-C decreased significantly compared to pre-trial values within the intervention group. It is concluded that PJ consumption could decrease systolic and diastolic blood pressure in patients with diabetes while having no effect on lipid profile. A more definitive result will be obtained if future studies could conducted in hyperlipidemic individuals who might be more prone to respond to the lipid-lowering effects.

Pomegranate juice prevents development of non-alcoholic fatty liver disease in rats by attenuating oxidative stress and inflammation

BACKGROUND

The effects of pomegranate juice (PJ) on the risk factors of non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) have been reported previously; however, the effects on NAFLD and its prevention have not yet been clarified. The present study aimed to evaluate the effects of PJ consumption with respect to the prevention of NAFLD/NASH development. Sprague-Dawley rats were fed either a high-fat, high sugar diet (model group); a high-fat, high sugar diet plus PJ (model+PJ); or a chow diet ad libitum for 7 weeks. Serum levels of fasting glucose, triglyceride, cholesterol, liver enzymes, insulin and hepatic tumor necrosis factor-α and tissue growth factor-β gene expression were determined. Hepatic histology was examined by hemotoxylin and eosin staining.

RESULTS

The model+PJ group had significantly lower hepatic steatosis, ballooning, lobular inflammation and portal inflammation (P < 0.001); lower hepatic pro-inflammatory and pro-fibrotic gene expression (P < 0.001); and lower plasma levels of alanine aminotransferase (P = 0.026), aspartate aminotransferase (P = 0.041), insulin (P < 0.001), triglycerides (P = 0.041) and glucose (P = 0.009) compared to the model group; however, weight gain, food intake and plasma high-density lipoprotein levels were not significantly different between these two groups.

CONCLUSION

The data obtained in the present study indicate that the regular consumption of PJ can prevent NAFLD even in the presence of the other risk factors such as obesity, hypercholesterolemia, and high energy, fat and sugar intakes. © 2016 Society of Chemical Industry.

Effects of pomegranate juice consumption on oxidative stress in patients with type 2 diabetes: a single-blind, randomized clinical trial

Increased free radicals production due to hyperglycemia produces oxidative stress in patients with diabetes. Pomegranate juice (PJ) has antioxidant properties. This study was conducted to determine the effects of PJ consumption in oxidative stress in type 2 diabetic patients. This study was a randomized clinical trial performed on 60, 40-65 years old diabetic patients. The patients were randomly allocated either to PJ consumption group or control. Patients in PJ group consumed 200 ml of PJ daily for six weeks. Sex distribution and the mean age were not different between two groups. After six weeks intervention, oxidized LDL and anti-oxidized LDL antibodies decreased and total serum antioxidant capacity and arylesterase activity of paraoxonase increased significantly in the PJ-treated group compared to the control group. Our data have shown that six weeks supplementation of PJ could have favorable effects on oxidative stress in patients with type 2 diabetes (T2D).

Antifungal, antiradical and cytotoxic activities of extractives obtained from Tagetes patula L. (Asteraceae), a potential acaricide plant species

Tagetes patula L. shows a complex chemical composition, ranging from glycosylated flavonoids and thiophenes in extracts until terpenoids in the essential oil. In the present study, due to this rich flavonoidic constitution, its antioxidant potential was determined, having shown values of antiradical percentage superior to reference compounds, mainly the extracts prepared with flowers. Previous studies performed emphasized the acaricide potential of T. patula and thus, the present study aimed to verify the action of extractives obtained from aerial parts on growth of entomopathogenic fungi related to biological control of brown dog tick Rhipicephalus sanguineus and the action against pathogenic fungi closely associated with pets. None of the samples inhibited the growth of strains of Beauveria bassiana or Metarhizium anisopliae, enabling feasible future studies of synergism on acaricide activity of formulations containing fungi and extracts. The antimicrobial activity of ethanolic extract of flowers (FlEtOH70%) against Microsporum canis and Trichophyton rubrum was significant (193.3 μg/mL and 253.9 μg/mL, respectively), as well as ethanolic extract from aerial parts (APEtOH70%) against T. rubrum (312.5 μg/mL). In order to ensure the safety of a topical formulation containing the extractives of T. patula, the cytotoxic potential of these samples were tested in murine macrophages cells. At higher concentrations all extracts were quite lethal, with IC50 ranging from 210.96 μg/mL to 468.75 μg/mL for APEtOH70% and FlEtOH70%, respectively. These results suggest that the application of a product containing T. patula extractives in the control of ticks could be used, at principle, only on the environment.

A "White" Anthocyanin-less Pomegranate (Punica granatum L.) Caused by an Insertion in the Coding Region of the Leucoanthocyanidin Dioxygenase (LDOX; ANS) Gene

Color is an important determinant of pomegranate fruit quality and commercial value. To understand the genetic factors controlling color in pomegranate, chemical, molecular and genetic characterization of a "white" pomegranate was performed. This unique accession is lacking the typical pomegranate color rendered by anthocyanins in all tissues of the plant, including flowers, fruit (skin and arils) and leaves. Steady-state gene-expression analysis indicated that none of the analyzed "white" pomegranate tissues are able to synthesize mRNA corresponding to the PgLDOX gene (leucoanthocyanidin dioxygenase, also called ANS, anthocyanidin synthase), which is one of the central structural genes in the anthocyanin-biosynthesis pathway. HPLC analysis revealed that none of the "white" pomegranate tissues accumulate anthocyanins, whereas other flavonoids, corresponding to biochemical reactions upstream of LDOX, were present. Molecular analysis of the "white" pomegranate revealed the presence of an insertion and an SNP within the coding region of PgLDOX. It was found that the SNP does not change amino acid sequence and is not fully linked with the "white" phenotype in all pomegranate accessions from the collection. On the other hand, genotyping of pomegranate accessions from the collection and segregating populations for the "white" phenotype demonstrated its complete linkage with the insertion, inherited as a recessive single-gene trait. Taken together, the results indicate that the insertion in PgLDOX is responsible for the "white" anthocyanin-less phenotype. These data provide the first direct molecular, genetic and chemical evidence for the effect of a natural modification in the LDOX gene on color accumulation in a fruit-bearing woody perennial deciduous tree. This modification can be further utilized to elucidate the physiological role of anthocyanins in protecting the tree organs from harmful environmental conditions, such as temperature and UV radiation.

Pomegranate (Punicagranatum) juice decreases lipid peroxidation, but has no effect on plasma advanced glycated end-products in adults with type 2 diabetes: a randomized double-blind clinical trial

Introduction

Diabetes mellitus characterized by hyperglycemia could increase oxidative stress and formation of advanced glycated end-products (AGEs), which contribute to diabetic complications. The purpose of this study was to assess the effect of pomegranate juice (PJ) containing natural antioxidant on lipid peroxidation and plasma AGEs in patients with type 2 diabetes (T2D).

Materials and methods

In a randomized, double-blind, placebo-controlled trial, 44 patients (age range 56±6.8 years), T2D were randomly assigned to one of two groups: group A (PJ, n=22) and group B (Placebo, n=22). At the baseline and the end of 12-week intervention, biochemical markers including fasting plasma glucose, insulin, oxidative stress, and AGE markers including carboxy methyl lysine (CML) and pentosidine were assayed.

Results

At baseline, there were no significant differences in plasma total antioxidant capacity (TAC) levels between the two groups, but malondialdehyde (MDA) decreased levels were significantly different (P<0.001). After 12 weeks of intervention, TAC increased (P<0.05) and MDA decreased (P<0.01) in the PJ group when compared with the placebo group. However, no significant differences were observed in plasma concentration of CML and pentosidine between the two groups.

Conclusions

The study showed that PJ decreases lipid peroxidation. Therefore, PJ consumption may delay onset of T2D complications related to oxidative stress.

Carvacrol and pomegranate extract in treating methotrexate-induced lung oxidative injury in rats

Background

This study was designed to evaluate the effects of carvacrol (CRV) and pomegranate extract (PE) on methotrexate (MTX)-induced lung injury in rats.

Material/Methods

A total of 32 male rats were subdivided into 4 groups: control (group I), MTX treated (group II), MTX+CRV treated (group III), and MTX+PE treated (group IV). A single dose of 73 mg/kg CRV was administered intraperitoneally to rats in group III on Day 1 of the investigation. To group IV, a dose of 225 mg/kg of PE was administered via orogastric gavage once daily over 7 days. A single dose of 20 mg/kg of MTX was given intraperitoneally to groups II, III, and IV on Day 2. The total duration of experiment was 8 days. Malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), and oxidative stress index (OSI) were measured from rat lung tissues and cardiac blood samples.

Results

Serum and lung specimen analyses demonstrated that MDA, TOS, and OSI levels were significantly greater in group II relative to controls. Conversely, the TAC level was significantly reduced in group II when compared to the control group. Pre-administering either CRV or PE was associated with decreased MDA, TOS, and OSI levels and increased TAC levels compared to rats treated with MTX alone. Histopathological examination revealed that lung injury was less severe in group III and IV relative to group II.

Conclusions

MTX treatment results in rat lung oxidative damage that is partially counteracted by pretreatment with either CRV or PE.

Protein glycation inhibitory activity and antioxidant capacity of clove extract

Syzygium aromaticum (L.) (clove) is one of the most widely cultivated spices in many tropical countries. The aim of this study was to determine the phytochemical content, the antioxidant properties and the antiglycation properties of aqueous extract of clove against fructose-mediated protein glycation and oxidation. The result showed that the content of total phenolics and flavonoids in clove extract was 239.58 ± 0.70 mg gallic acid equivalents/g dried extract and 65.67 ± 0.01 mg catechin equivalents/g dried extract, respectively. In addition, clove exhibited antioxidant properties including DPPH radical scavenging activity (IC50 = 0.29 ± 0.01 mg/ml), Trolox equivalent antioxidant capacity (4.69 ± 0.03 μmol Trolox equivalents/mg dried extract), ferric reducing antioxidant power (20.55 ± 0.11 μmol ascorbic acid equivalents/mg dried extract), Oxygen radical absorbance capacity (31.12 ± 0.21 μmol Trolox equivalents/mg dried extract), hydroxyl radical scavenging activity (0.15 ± 0.04 mg Trolox equivalents/mg dried extract), and superoxide radical scavenging activity (18.82 ± 0.50 mg Trolox equivalents/mg dried extract). The aqueous extract of clove (0.25-1.00 mg/ml) significantly inhibited the formation of fluorescent advanced glycation end products (AGEs) and non-fluorescent AGEs (N(ɛ)-(carboxymethyl) lysine (CML)) in glycated BSA during 4 weeks of incubation. The extract also markedly prevented oxidation-induced protein damage by decreasing protein carbonyl formation and protecting against the loss of protein thiol group. These results clearly demonstrated that a polyphenol enriched clove extract, owing to its antioxidant, was capable to inhibit the formation of AGEs and protein glycation. The findings might lead to the possibility of using the clove extract for targeting diabetic complications.

Hyperoside and anthocyanin content of ten different pomegranate cultivars

Pomegranate (Punica granatum L.) is native to the Mediterranean region and has been used extensively as a medicine in many counties. Hyperoside is known as an important flavonoid with antioxidant activity and anti hypertension effect. Anthocyanins are the active component in several herbal medicines, thus accurate measurement of hyperoside and anthocyanins, along with their degradation indices, is very useful to food technologists and horticulturists. The aim of the current study was to determine the antioxidant capacity as hyperoside and anthocyanin content of ten different Iranian pomegranate cultivars. Spectroscopic analyses of the pomegranate showed Black peel cultivar had the highest hyperoside content (25.93 +/- 2.87, 620.41 +/- 30.32 mg/100 g) in its pulp and peel, respectively. Based on this study, the amounts of anthocyanin in pulp ranged between 1.56 +/- 0.05 and 3.89 +/- 0.07 mg g(-1) which related to Sweet white peel and Sweet alac cultivars, respectively. More over the highest and also the lowest peel anthocyanin contents related to these cultivars. The results revealed that the hyperoside and also anthocyanin peel content of each variety is higher than its pulp content. In addition the potency of black peel (Medicinal pomegranate) and Sweet alac cultivars for prevention of coronary heart disease and hypertension were presented.

HPLC Evaluation of Phenolic Profile, Nutritive Content, and Antioxidant Capacity of Extracts Obtained from Punica granatum Fruit Peel

This study revealed polyphenolic content, nutritive content, antioxidant activity, and phenolic profile of methanol and aqueous extracts of Punica granatum peel extract. For this, extracts were screened for possible antioxidant activities by free radical scavenging activity (DPPH), hydrogen peroxide scavenging activity and ferric-reducing antioxidant power (FRAP) assays. The total phenolics and flavonoid recovered by methanolic (MPE) and the water extract (AQPE) were ranged from 185 ± 12.45 to 298.00 ± 24.86 mg GAE (gallic acid equivalents)/gm and 23.05 ± 1.54 to 49.8 ± 2.14 quercetin (QE) mg/g, respectively. The EC50 of herbal extracts ranged from 100 µg/ml (0.38 quercetin equivalents), for AQPE, 168 µg/ml (0.80 quercetin equivalents), for MPE. The phenolic profile in the methanolic extracts was investigated by chromatographic (HPLC) method. About 5 different flavonoids, phenolic acids, and their derivatives including quercetin (1), rutin (2), gallic acid (3), ellagic acid (4), and punicalagin as a major ellagitannin (5) have been identified. Among both extracts, methanolic extract was the most effective. This report may be the first to show nutritive content and correlation analysis to suggest that phenols and flavonoids might contribute the high antioxidant activity of this fruit peel and establish it as a valuable natural antioxidant source applicable in the health food industry.

A Review on Antihyperglycemic and Antihepatoprotective Activity of Eco-Friendly Punica granatum Peel Waste

Over the past decade, pomegranate (Punica granatum) is entitled as a wonder fruit because of its voluminous pharmacological properties. In 1830, P. granatum fruit was first recognized in United States Pharmacopeia; the Philadelphia edition introduced the rind of the fruit, the New York edition the bark of the root and further 1890 edition the stem bark was introduced. There are significant efforts and progress made in establishing the pharmacological mechanisms of peel (pericarp or rind) and the individual constituents responsible for them. This review provides an insight on the phytochemical components that contribute too antihyperglycemic, hepatoprotective, antihyperlipidemic effect, and numerous other effects of wonderful, economic, and eco-friendly pomegranate peel extract (PP).

Antibacterial, antioxidant and tyrosinase-inhibition activities of pomegranate fruit peel methanolic extract

BACKGROUND

This study evaluated, using in vitro assays, the antibacterial, antioxidant, and tyrosinase-inhibition activities of methanolic extracts from peels of seven commercially grown pomegranate cultivars.

METHODS

Antibacterial activity was tested on Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia) using a microdilution method. Several potential antioxidant activities, including radical-scavenging ability (RSA), ferrous ion chelating (FIC) and ferric ion reducing antioxidant power (FRAP), were evaluated. Tyrosinase enzyme inhibition was investigated against monophenolase (tyrosine) and diphenolase (DOPA), with arbutin and kojic acid as positive controls. Furthermore, phenolic contents including total flavonoid content (TFC), gallotannin content (GTC) and total anthocyanin content (TAC) were determined using colourimetric methods. HPLC-ESI/MSn analysis of phenolic composition of methanolic extracts was also performed.

RESULTS

Methanolic peel extracts showed strong broad-spectrum activity against Gram-positive and Gram-negative bacteria, with the minimum inhibitory concentrations (MIC) ranging from 0.2 to 0.78 mg/ml. At the highest concentration tested (1000 μg/ml), radical scavenging activities were significantly higher in Arakta (83.54%), Ganesh (83.56%), and Ruby (83.34%) cultivars (P< 0.05). Dose dependent FIC and FRAP activities were exhibited by all the peel extracts. All extracts also exhibited high inhibition (>50%) against monophenolase and diphenolase activities at the highest screening concentration. The most active peel extract was the Bhagwa cultivar against monophenolase and the Arakta cultivar against diphenolase with IC50 values of 3.66 μg/ml and 15.88 μg/ml, respectively. High amounts of phenolic compounds were found in peel extracts with the highest and lowest total phenolic contents of 295.5 (Ganesh) and 179.3 mg/g dry extract (Molla de Elche), respectively. Catechin, epicatechin, ellagic acid and gallic acid were found in all cultivars, of which ellagic acid was the most abundant comprising of more than 50% of total phenolic compounds detected in each cultivar.

CONCLUSIONS

The present study showed that the tested pomegranate peels exhibited strong antibacterial, antioxidant and tyrosinase-inhibition activities. These results suggest that pomegranate fruit peel could be exploited as a potential source of natural antimicrobial and antioxidant agents as well as tyrosinase inhibitors.

Revealing the power of the natural red pigment lycopene

By-products derived from food processing are attractive source for their valuable bioactive components and color pigments. These by-products are useful for development as functional foods, nutraceuticals, food ingredients, additives, and also as cosmetic products. Lycopene is a bioactive red colored pigment naturally occurring in plants. Industrial by-products obtained from the plants are the good sources of lycopene. Interest in lycopene is increasing due to increasing evidence proving its preventive properties toward numerous diseases. In vitro, in vivo and ex vivo studies have demonstrated that lycopene-rich foods are inversely associated to diseases such as cancers, cardiovascular diseases, diabetes, and others. This paper also reviews the properties, absorption, transportation, and distribution of lycopene and its by-products in human body. The mechanism of action and interaction of lycopene with other bioactive compounds are also discussed, because these are the crucial features for beneficial role of lycopene. However, information on the effect of food processing on lycopene stability and availability was discussed for better understanding of its characteristics.