Vassilia J. Sinanoglou

Antiradical–antimicrobial activity and phenolic profile of pomegranate (Punica granatum L.) juices from different cultivars: a comparative study

Pomegranate juice (PJ) constituents have shown to exhibit anticarcinogenic, antimicrobial, antioxidant and antiviral activities. In the present study, the concentration of phenolic compounds and the antiradical activity of PJs from the fruits of the two relatively new Greek cultivars “Persephone” and “Porphiroyeneti” were determined in comparison to the “Wonderful” cultivar. Total phenolic content and antiradical activity of the examined juices were found to vary in the same decreasing manner as follows: “Porphiroyeneti” > “Wonderful” > “Persephone”. The antimicrobial activity of PJs was also determined, showing equal or higher effect than commercial antimicrobial agents (streptomycin, ampicillin, bifonazole and ketoconazole). All tested extracts demonstrated noteworthy antibacterial activity with minimal inhibitory concentration ranging from 0.05 to 0.20 mg mL−1 and minimal bactericidal concentration ranging from 0.10 to 0.40 mg mL−1. Moreover, PJ extracts showed satisfactory fungistatic (0.05–0.2 mg mL−1) and fungicidal (0.1–0.3 mg mL−1) activity against all fungi tested. Among the cultivars tested, “Porphiroyeneti” showed slightly better antiradical and antimicrobial activity. In addition, a GC-MS methodology was developed for the determination of the phenolic profile of the extracts of PJ after different types of chemical hydrolysis. Finally, an HPLC-PDA-ESI-MSn analysis was conducted for the identification of the phenolic compounds in the extracts of PJ. In total, more than 30 non-anthocyanidinic and more than 20 anthocyanidinic compounds were identified. Our results confirm the functionality of pomegranate juices and the potential applications of PJ extracts towards novel products as food additives or preservatives.

Carotenoids from Foods of Plant, Animal and Marine Origin: An Efficient HPLC-DAD Separation Method

Carotenoids are important antioxidant compounds, present in many foods of plant, animal and marine origin. The aim of the present study was to describe the carotenoid composition of tomato waste, prawn muscle and cephalothorax and avian (duck and goose) egg yolks through the use of a modified gradient elution HPLC method with a C30 reversed-phase column for the efficient separation and analysis of carotenoids and their cis-isomers. Elution time was reduced from 60 to 45 min without affecting the separation efficiency. All-trans lycopene predominated in tomato waste, followed by all-trans-β-carotene, 13-cis-lutein and all-trans lutein, while minor amounts of 9-cis-lutein, 13-cis-β-carotene and 9-cis-β-carotene were also detected. Considering the above findings, tomato waste is confirmed to be an excellent source of recovering carotenoids, especially all-trans lycopene, for commercial use. Xanthophylls were the major carotenoids of avian egg yolks, all-trans lutein and all-trans zeaxanthin in duck and goose egg yolk, respectively. In the Penaeus kerathurus prawn, several carotenoids (zeaxanthin, all-trans-lutein, canthaxanthin, cryptoxanthin, optical and geometrical astaxanthin isomers) were identified in considerable amounts by the same method. A major advantage of this HPLC method was the efficient separation of carotenoids and their cis-isomers, originating from a wide range of matrices.

EPA, DHA, cholesterol and phospholipid content in Pagrus pagrus (cultured and wild), Trachinus draco and Trigla lyra from Mediterranean Sea

EPA, DHA, cholesterol and phospholipid content were determined in the Trachinus draco, Trigla lyra and (wild and cultured) Pagrus pagrus muscles. The EPA and DHA levels - as determined by GC-GC/MS - in the cultured P. pagrus muscles (233.20 +/- 16.3 and 399.39 +/- 31.1 mg/100g of the wet tissue respectively) were found to be significantly higher compared to the ones in the wild P. pagrus, T. draco and T. lyra (26.31 +/- 2.26, 158.24 +/- 10.92 mg/100 g, 28.65 +/- 1.68, 155.97 +/- 2.63 mg/100 g 35.66 +/- 0.66 and 102.52 +/- 1.71 mg/100 g of the wet muscles respectively). The amounts of cholesterol (determined by GC on a capillary column) and phospholipids in the cultured P. pagrus muscles were significantly higher (149.3 mg/100 g and 0.80 g/100 g of the wet tissue respectively) compared to the ones in the wild P. pagrus (8.73 mg/100 g and 0.40 g/100 g), T. draco (41.72 mg/100 g and 0.59 g/100 g) and T. lyra muscles (38.63 mg/100 g and 0.40 g/100 g of the wet tissue respectively). The highest DHA/EPA and omega-3/omega-6 ratios were 6.00 and 5.93 in wild P. pagrus and T. draco muscles respectively, while the lowest in cultured P. pagrus (1.71 and 1.48 respectively).

On the Combined Application of Iatroscan TLC-FID and GC-FID to Identify Total, Neutral, and Polar Lipids and Their Fatty Acids Extracted from Foods

An efficient separation and quantification of the individual neutral and polar lipid classes and their constituent fatty acids was achieved by the combination of two different detection techniques: Iatroscan TLC-FID and GC-FID. The solvent composition and ratio of development system, the sample size, the fidelity, and precision were tested in order to estimate the effectiveness of separation of individual neutral and polar lipid classes and the quantitative reproducibility of the Iatroscan TLC-FID technique. GC-FID method, with a high-quality capillary column, allowed sensitive and reproducible fatty acid qualitative and quantitative analyses, separation of fatty acid structural isomers (e.g., n-C16:0, iso-C16:0 and anteiso-C16:0), positional isomers (e.g., C18:1ω-9 and C18:1ω-7), geometrical isomers (cis-trans), and homologues (e.g., C16:0, C17:0, C18:0, etc.) in standards and complex lipid samples. Seventeen (17) lipid classes and fifty-two (52) saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were identified and quantified, respectively, in samples of standard lipid and fatty acid mixtures, simulating the composition of natural lipids and their fatty acid methyl esters in common foods. The wide number of applications establishes this combination of Iatroscan TLC-FID and GC-FID methods as a powerful tool for lipid class and fatty acid analysis of any fat origin.

Isolation and identification of phospholipid molecular species in α wild marine shrimp Penaeus kerathurus muscle and cephalothorax

The concentration of TL in Penaeus kerathurus muscle and cephalothorax was 1.03+/-0.04 (75.9+/-0.8% of which was PhL) and 2.36+/-0.07% (45.5+/-0.8% of which was PhL) of the wet tissue, respectively. The phosphatidylethanolamine represented 26.4+/-0.6% (85.6% diacyl- and 14.4% alkyl-acyl- or alkenyl-acyl-analogues) of muscle and 24.7+/-0.2% (90.7% diacyl- and 9.3% alkyl-acyl- or 1-alkenyl-acyl-analogues) of cephalothorax phospholipids while the phosphatidylcholine represented 57.1+/-0.6% (86.9% diacyl- and 13.1% alkyl-acyl- or alkenyl-acyl-analogues) of muscle and 47.2+/-0.4% (89.1% diacyl- and 10.9% alkyl-acyl- or 1-alkenyl-acyl-analogues) of cephalothorax phospholipids, respectively. The main fatty acids of phosphatidylethanolamine were C16:0, C18:0, C18:1 omega-9, C20:4 omega-6, C20:5 omega-3, C22:6 omega-3 and of phosphatidylcholine were C16:0, C18:0, C18:1 omega-9, C20:4 omega-6, C20:5 omega-3. Low percentages of 2-OH C14:0 and cyclo-17:0 fatty acids were also determined. Phosphatidylethanolamine were found to contain a significantly (P<0.05) higher percentage of polyunsaturated fatty acids compared to phosphatidylcholine. The omega-3/omega-6 ratio in muscle phosphatidylethanolamine and phosphatidylcholine was significantly (P<0.05) higher to the ones of cephalothorax.

Response surface methodology toward the optimization of high-energy carotenoid extraction from Aristeus antennatus shrimp.

High-energy assisted extraction techniques, like ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), are widely applied over the last years for the recovery of bioactive compounds such as carotenoids, antioxidants and phenols from foods, animals and herbal natural sources. Especially for the case of xanthophylls, the main carotenoid group of crustaceans, they can be extracted in a rapid and quantitative way with the use of UAE and MAE. Response surface methodology (RSM) is used for the optimization of extraction methodologies, also being applied to optimize high energy techniques. Three independent variables, namely extraction time, ultrasound or microwave power and solvent/material ratio, were investigated for both methods by employing a 16-run three-level Box-Behnken design (BBD). Considering the extraction efficiency for carotenoids from Aristeus antennatus shrimp, the selected conditions for UAE were 5 min, 600 W and 10:1 mL g(-1). Acetone was the solvent of choice for the extraction procedure. For MAE, the best experimental values were 7 min, 30 W and 20:1 mL g(-1) using n-hexane:acetone:ethanol 2:1:1 (v/v/v) as extraction solvent. The determination of total carotenoid yield was carried out using the spectophotometric calibration curve (A=0.1646(±0.0061)C-0.005(±0.022), R(2)=0.996, n=3) of a standard mix solution of canthaxanthin, zeaxanthin and lutein at 452.1 nm. Under the selected conditions, the yield of total carotenoids for UAE was 23.4(±2.3) and 6.73(±0.56) mg of carotenoids per 100 g dry sample for the head and the body of shrimp, while for MAE was 23.92(±0.63) and 13.3(±1.1) mg of carotenoids per 100g dry sample, respectively. The recovery of both methods was calculated between 60 and 105%. The results indicate that high-energy extraction techniques are faster, less laborious, more repeatable and reproducible methods than the conventional approaches for the quantitative recovery of sensitive bioactive compounds. Moreover, the recovery of a high-added value group of bioactive molecules from natural sources, such as carotenoids, can constitute a profitable and valuable commercial alternative, as these compounds can be used as dietary supplements, food color enhancers and additives in animal feeds, functional foods, preservatives, pharmaceuticals and cosmetics.

Total phenolic content, antioxidant capacity and phytochemical profiling of grape and pomegranate wines

The object of this study was to determine the phenolic profile, the total phenolic content and antioxidant capacity of pomegranate wine and compare to multi-varietal red wine using different spectrophotometric and spectrometric techniques. Total phenolic content was determined by the Folin–Ciocalteu assay. The antioxidant capacity was measured by the DPPH and the ABTS radical scavenging assays. The radical-scavenging capacity was higher for pomegranate wine (statistically significant difference was observed for the DPPH assay) in agreement with its higher total phenolic content (383.19 ± 18.22 and 296.57 ± 25.23 mg gallic acid equivalents/100 mL for pomegranate and grape wine respectively). Customized HPLC-PDA-ESI-MSn and GC-MS methods were applied for the identification and chemical characterization of the phenolic compounds for both wines. Identification using LC-MS was based on their λmax (nm) and the characteristic fragments which derived from the sequential fragmentation in MS while GC-MS was based on commercial libraries and mass spectra of authentic standards. Eighty one different phenolic compounds were characterised by LC-MS and one hundred eight compounds by GC-MS after different chemical hydrolysis regimes. The study signifies the prior treatment with alkaline hydrolysis which had a considerable effect on the detection of phenolic compounds. The results showed that the combination of LC-MS and GC-MS methods allowed the detection of different compounds while results from both techniques are complementary and may confirm each other. Phytochemicals with proven biological activities including antimicrobial, antiviral and chemoprotective, have been identified mainly in pomegranate wines. Furthermore, a significant diversity between pomegranate and grape wines was observed, in terms of their phenolic content and antioxidant profiles indicating the-nutritive and health-promoting effects of pomegranate wine.

Lipid and fatty acid profile of the edible fungus Laetiporus sulphurous. Antifungal and antibacterial properties

Laetiporus sulphureus is a saprophyte belonging to a specific group of wood-decomposing Basidiomycetes growing on deciduous trees. This fungus has been characterized as a herbal medicine and is also known for its antimicrobial properties. In the present study, high energy extraction techniques using different solvents were compared to obtain maximum yield of the edible fungus Laetiporus sulphureus total lipids. The lipid classes and fatty acid composition of the fruiting bodies’ total lipids has been studied using GC-FID and Iatroscan TLC-FID analysis. Among the lipids, the neutral lipids predominated followed by phospholipids and glycolipids. Triglycerides were the most abundant in the neutral lipid fraction, whereas phosphatidylcholine in phospholipids. The existence of relatively high amount of sterols may be correlated to fungus pharmaceutical properties. Total lipids were found to contain high unsaturated degree fatty acids (UFA/SFA>3.4) and dominated of C18:2ω-6, C18:1ω-9 and C16:0 fatty acids. Antibacterial and antifungal properties of mushrooms’ lipid extracts from two different solvents were also examined. Results indicated that hexane extracts possessed better antifungal and slightly better antibacterial activity compared to chloroform extracts though both were less active than the commercial antimicrobial agents.

Comparison of the Antioxidant and Antiradical Activity of Pomegranate (Punica Granatum L.) by Ultrasound-Assisted and Classical Extraction

ABSTRACT The antiradical and antioxidant properties of pomegranate (Punica granatum L.) extracts from the arils, juice, and seeds were examined and compared for classical and ultrasound-assisted extraction. The total phenolic concentration, 2,2-diphenyl-1-picryl-hydrazyl, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, and ferric reducing antioxidant power assays were compared. High correlations were found between total phenolic concentration and antiradical activities. Juice extracts exhibited the highest total phenolic concentrations and antiradical activity compared to seed and aril extracts. However, juice extracts provided the lowest antioxidant capacities because phenolics present in juice may scavenge free radicals rather than reduce Fe(III). Arils were similar due to their high juice content. Only seed extracts exhibited statistically significant higher scavenging and antioxidant activities with the use of ultrasound-assisted extraction that may be attributed to the antioxidant character of the phenolics to scavenge free radicals. The total phenolic concentrations in aril and juice extracts by ultrasound-assisted extraction were similar to results obtained by classical extraction. The results show that pomegranate juice and seeds have high nutritional value.

Factors affecting human colostrum fatty acid profile: A case study.

The role of maternal colostrum to infant development has been extensively studied and presented. Among the main factors which contribute to breast milk composition are maternal diet, age and body mass index, parity, duration of pregnancy and stage of lactation. This study aims to investigate the potential impact of several factors including demographic (i.e. maternal age and nationality) on the colostrum fatty acid profile. Colostrum was collected the third day postpartum in a Greek maternity hospital. Certain lipid quality indices and fatty acid ratios were estimated and results were statistically processed. The main identified fatty acids were palmitic (C16:0), oleic (C18:1ω-9), and linoleic (C18:2ω-6) acids. Among fatty acids, saturated fatty acids predominated (47.61%), followed by monounsaturated fatty acids (39.26%), while polyunsaturated fatty acids had the lowest proportion (13.13%). Values of lipid quality indices were within the reported in the literature ranges. Maternal body mass index, nationality, age, mode of delivery, gender and fetal weight percentile were studied in respect to their potential influence on the fatty acid profile of colostrum fat. Results suggest that colostrum fatty acid profile was mainly dependent on maternal nationality and age rather than mode of delivery and maternal BMI. Regarding the effect of maternal nationality, significant differences were found for saturated and monounsaturated fatty acids. Of the most interesting findings is that colostrum fat from older (≥35 years) mothers had less saturated fat and more appropriate LQIs values. Finally, a reversed correlation was observed between the customized centile of the infants and the colostrum fat content.