Artemisia arborescens and Artemisia inculta from Crete; Secondary Metabolites, Trace Metals and In Vitro Antioxidant Activities.

BACKGROUND: Currently, the use of medicinal plants has increased. Artemisia species have been used in several applications, including medicinal use and uses in cosmetics, foods and beverages. Artemisia arborescens L. and Artemisia inculta are part of the Mediterranean diet in the form of aqueous infusions. Herein, we aimed to compare the secondary metabolites of the decoctions and two different extracts (methanolic and aqueous-glycerolic) of these two species, as well as their antioxidant capacity and trace metal levels. METHODS: Total phenolic, total flavonoid, total terpenes, total hydroxycinnamate, total flavonol, total anthocyanin contents and antioxidant/antiradical activity were determined, and GC/MS analysis was applied to identify and quantify phenolics and terpenoids. Trace metals were quantified with ICP-MS. RESULTS: Aqueous-glycerolic extracts demonstrated higher levels of total secondary metabolites, greater antioxidant potential and higher terpenoid levels than decoctions and methanolic extracts. Subsequently, the aqueous-glycerolic extract of a particularly high phenolic content was further analyzed applying targeted LC-MS/MS as the most appropriate analytic tool for the determination of the phenolic profile. Overall, twenty-two metabolites were identified. The potential contribution of infusions consumption to metal intake was additionally evaluated, and did not exceed the recommended daily intake. CONCLUSIONS: Our results support the use of these two species in several food, cosmetic or pharmaceutical applications.

Copper Complexing Capacity and Trace Metal Content in Common and Balsamic Vinegars: Impact of Organic Matter.

Complex formation is among the mechanisms affecting metal bioaccessibility. Hence, the quantification of organic metal complexation in food items is of interest. Organic ligands in solutions of environmental and/or food origin function as buffering agents against small changes in dissolved metal concentrations, being able to maintain free metal ion concentrations below the toxicity threshold. Organic matter in vinegars consists of bioactive compounds, such as polyphenols, Maillard reaction endproducts, etc., capable of complexing metal ions. Furthermore, transition metal ions are considered as micronutrients essential for living organisms exerting a crucial role in metabolic processes. In this study, differential pulse anodic stripping voltammetry (DPASV), a sensitive electrochemical technique considered to be a powerful tool for the study of metal speciation, was applied for the first time in vinegar samples. The concentrations of Cu complexing ligands (LT) in 43 vinegars retailed in Greece varied between 0.05 and 52 µM, with the highest median concentration determined in balsamic vinegars (14 µM), compared to that of common vinegars (0.86 µM). In 21% of the vinegar samples examined, LT values were exceeded by the corresponding total Cu concentrations, indicating the presence of free Cu ion and/or bound within labile inorganic/organic complexes. Red grape balsamic vinegars exhibited the highest density of Cu ligands per mass unit of organic matter compared to other foodstuffs such as herbal infusions, coffee brews, and beers. Among the 16 metals determined in vinegars, Pb is of particular importance from a toxicological point of view, whereas further investigation is required regarding potential Rb biomagnification.

Plasma free amino acid profile in quiescent Inflammatory Bowel Disease patients orally administered with Mastiha (Pistacia lentiscus); a randomised clinical trial.

BACKGROUND: Natural products have been studied regarding their effectiveness on Inflammatory Bowel Disease (IBD). HYPOTHESIS/PURPOSE: To examine the effects of Mastiha (Pistacia lentiscus var. Chia) on clinical course and amino acid (AA) profile of patients in remission. STUDY DESIGN: This is a randomised, double-blind, placebo-controlled clinical trial. METHODS: Patients (n = 68) were randomly allocated to Mastiha (2.8  g/day) or placebo adjunct to stable medication. Free AAs were identified applying Gas Chromatography-Mass Spectrometry in plasma. Medical-dietary history, Inflammatory Bowel Disease Questionnaire, Harvey-Bradshaw Index, Partial Mayo Score, biochemical, faecal and blood inflammatory markers were assessed. Primary endpoint was the clinical relapse rate at 6 months. Secondary endpoints included variations in free AAs, inflammatory biomarkers and quality of life. Statistical significance was set at 0.05. RESULTS: Concerning AAs and biochemical data, alanine (p = 0.006), valine (p = 0.047), proline (p = 0.022), glutamine (p < 0.001) and tyrosine (p = 0.043) along with total cholesterol (p = 0.032) and LDL cholesterol (p = 0.045) increased only in placebo group compared with baseline and the change between the study groups was significantly different. Inflammatory markers had not a significantly different change between the two groups, even serum IL-6, faecal calprotectin and faecal lactoferrin increased only in the placebo group. Although Mastiha was not proven superior to placebo in remission rate (17.6% vs. 23.5%, p = 0.549), attenuation in increase of free AAs levels in verum group is reported. CONCLUSION: Mastiha inhibited an increase in plasma free AAs seen in patients with quiescent IBD. Since change of AAs is considered an early prognostic marker of disease activity, this indicates a potential role of Mastiha in remission maintenance.

Antioxidative Efficacy of a Pistacia Lentiscus Supplement and Its Effect on the Plasma Amino Acid Profile in Inflammatory Bowel Disease: A Randomised, Double-Blind, Placebo-Controlled Trial.

Oxidative stress is present in patients with Inflammatory Bowel Disease (IBD), and natural supplements with antioxidant properties have been investigated as a non-pharmacological approach. The objective of the present study was to assess the effects of a natural Pistacia lentiscus (PL) supplement on oxidative stress biomarkers and to characterise the plasma-free amino acid (AA) profiles of patients with active IBD (Crohn's disease (CD) N = 40, ulcerative colitis (UC) N = 20). The activity was determined according to 5 ≤ Harvey Bradshaw Index ≤ 16 or 2 ≤ Partial Mayo Score ≤ 6. This is a randomised, double-blind, placebo-controlled clinical trial. IBD patients (N = 60) were randomly allocated to PL (2.8 g/day) or to placebo for 3 months being under no treatment (N = 21) or under stable medical treatment (mesalamine N = 24, azathioprine N = 14, and corticosteroids N = 23) that was either single medication (N = 22) or combined medication (N = 17). Plasma oxidised, low-density lipoprotein (oxLDL), total serum oxidisability, and serum uric acid were evaluated at baseline and follow-up. OxLDL/LDL and oxLDL/High-Density Lipoprotein (HDL) ratios were calculated. The plasma-free AA profile was determined by applying a gas chromatography/mass spectrometry analysis. oxLDL (p = 0.031), oxLDL/HDL (p = 0.020), and oxLDL/LDL (p = 0.005) decreased significantly in the intervention group. The mean change differed significantly in CD between groups for oxLDL/LDL (p = 0.01), and, in the total sample, both oxLDL/LDL (p = 0.015) and oxLDL/HDL (p = 0.044) differed significantly. Several changes were reported in AA levels. PL ameliorated a decrease in plasma-free AAs seen in patients with UC taking placebo. In conclusion, this intervention resulted in favourable changes in oxidative stress biomarkers in active IBD.

Bioactive compounds and antioxidant activity exhibit high intraspecific variability in Pleurotus ostreatus mushrooms and correlate well with cultivation performance parameters.

Experimental data related with oyster mushroom production and nutritional properties usually derive from the examination of only one strain, and hence their representativeness/usefulness is questionable. This work aims at assessing intraspecific variability in Pleurotus ostreatus by studying 16 strains, under the same conditions, in respect to essential cultivation and mushroom quality aspects, and by defining the impact of intrinsic/genetic factors on such parameters. Hence, mushroom yield, earliness, crop length, biological efficiency, productivity, and their content in selected macro and microconstituents (e.g. fatty acids, sterols, individual phenolic compounds, terpenic acids, glucans) as well as their antioxidant properties (i.e., antiradical activity, ferric reducing potential, inhibition of serum oxidation) were assayed. The effect of intrinsic/genetic factors was evident, especially as regards earliness, yield of each production flush and mushroom weight, whereas biological efficiency was not particularly influenced by the cultivated strain. Moreover, phenolics, ergosterol and antiradical activity demonstrated significant variability among strains in contrast to what was observed for fatty acids, ß-glucans and ferric reducing potential. The observed heterogeneity reveals the limitations of using a low number of strains for evaluating mushroom production and/or their content in bioactive compounds, and as evidenced, it is valuable for breeding and commercial purposes.

Amelioration of oxidative and inflammatory status in hearts of cholesterol-fed rats supplemented with oils or oil-products with extra virgin olive oil components.

PURPOSE: The contribution of extra virgin olive oil (EVOO) macro- and micro-constituents in heart oxidative and inflammatory status in a hypercholesterolemic rat model was evaluated. Fatty acid profile as well as α-tocopherol, sterol, and squalene content was identified directly in rat hearts to distinguish the effect of individual components or to enlighten the potential synergisms. METHODS: Oils and oil-products with discernible lipid and polar phenolic content were used. Wistar rats were fed a high-cholesterol diet solely, or supplemented with one of the following oils, i.e., EVOO, sunflower oil (SO), and high-oleic sunflower oil (HOSO) or oil-products, i.e., phenolics-deprived EVOO [EVOO(-)], SO enriched with the EVOO phenolics [SO(+)], and HOSO enriched with the EVOO phenolics [HOSO(+)]. Dietary treatment lasted 9 weeks; at the end of the intervention blood and heart samples were collected. RESULTS: High-cholesterol-diet-induced dyslipidemia was shown by increase in serum total cholesterol, low-density lipoprotein cholesterol, and triacylglycerols. Dyslipidemia resulted in increased malondialdehyde (MDA) and tumor necrosis factor-α (TNF-α) levels, while glutathione and interleukin 6 levels remained unaffected in all intervention groups. Augmentation observed in MDA and TNF-α was attenuated in EVOO, SO(+), and HOSO(+) groups. Heart squalene and cholesterol content remained unaffected among all groups studied. Heart α-tocopherol was determined by oil α-tocopherol content. Variations were observed for heart ß-sitosterol, while heterogeneity was reported with respect to heart fatty acid profile in all intervention groups. CONCLUSIONS: Overall, we suggest that the EVOO-polar phenolic compounds decreased MDA and TNF-α in hearts of cholesterol-fed rats.

Parenteral MCT/ω-3 Polyunsaturated Fatty Acid-Enriched Intravenous Fat Emulsion Is Associated With Cytokine and Fatty Acid Profiles Consistent With Attenuated Inflammatory Response in Preterm Neonates: A Randomized, Double-Blind Clinical Trial.

BACKGROUND: Soybean oil-based intravenous fat emulsion (IVFE) administered to preterm neonates can induce oxidative stress and inflammatory response, which are associated with severe complications of prematurity. This study aimed to test the hypothesis that administration of medium-chain triglyceride (MCT)/ω-3 polyunsaturated fatty acid (PUFA)-enriched IVFE in preterm neonates is associated with a cytokine and fatty acid (FA) profile consistent with attenuated inflammatory response. PATIENTS/METHODS: In a double-blind randomized study, 60 preterm neonates (gestational age 26-32 weeks) were randomized to receive either MCT/ω-3 PUFA-enriched IVFE (intervention group) or soybean oil-based IVFE (control group). Serum biochemistry, tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, α-tocopherol, and FAs were assessed at baseline, on day of life 15, and day of life 30 or at the end of intervention. RESULTS: All cytokine levels changed significantly across the 3 time points, whereas the type of IVFE had a significant effect on final IL-6 and IL-8 levels, which were lower in the intervention group. The difference in final IL-6 and IL-8 levels remained significant after controlling for bronchopulmonary dysplasia and/or infection. α-Tocopherol and FA values changed significantly over time. MCT/ω-3 PUFA-enriched IVFE administration was associated with significantly higher α-tocopherol, eicosapentaenoic acid, docosahexaenoic acid, and ω-3 PUFAs and lower linolenic acid, total PUFA, and ω-6/ω-3 PUFA values compared with soybean oil-based IVFE. Both IVFEs were well tolerated. CONCLUSION: Compared with the soybean oil-based IVFE, the MCT/ω-3 PUFA-enriched IVFE is associated with a more favorable cytokine and FA profile consistent with attenuated inflammatory response in preterm neonates.

Serum lipid profile and inflammatory markers in the aorta of cholesterol-fed rats supplemented with extra virgin olive oil, sunflower oils and oil-products.

Extra virgin olive oil (EVOO) major and minor component anti-inflammatory effect on aorta was evaluated; Wistar rats were fed (9 weeks) on either a high-cholesterol diet (HCD) or a HCD supplemented with oils, i.e. EVOO, sunflower oil (SO), high-oleic sunflower oil (HOSO), or oil-products modified to their phenolic content, i.e. phenolics deprived-EVOO [EVOO(-)], SO enriched with the EVOO phenolics [SO(+)], HOSO enriched with the EVOO phenolics [HOSO(+)]. HCD induced dyslipidemia and resulted in higher aorta adhesion molecules levels at euthanasia. Groups receiving EVOO, EVOO(-), HOSO, HOSO(+) presented higher serum TC and LDL-c levels compared to cholesterol-fed rats; attenuation of aorta E-selectin levels was also observed. In EVOO/EVOO(-) groups, aorta vascular endothelial adhesion molecule-1 (VCAM-1) was lower compared to HCD animals. SO/SO(+) diets had no effect on endothelial dysfunction amelioration. Overall, our results suggest that major and/or minor EVOO constituents improve aorta E-selectin and VCAM-1, while serum lipids do not benefit.

Copper complexing properties and physico-chemical characterisation of the organic matter in Greek herbal infusions.

Complex formation is among the mechanisms affecting metals' bioaccessibility. Evaluating the extent of interactions between trace elements and several constituents of food items is of great interest. This paper examines the release of copper-complexing ligands in herbal infusions of 13 aromatic plants commonly used in Greece. The concentration of ligands (LT) and the copper-binding strength (logKapp) of herbal infusions were determined with Differential Pulse Anodic Stripping Voltammetry (DPASV). All herbal infusions were found to release Cu complexing ligands, at concentrations ranging from 8.8 to 112.5 µM in rosemary and marjoram, respectively. In all infusions the total copper concentrations were lower than the corresponding LT values, indicating that Cu is fully complexed. Aiming to partially characterise the physico-chemical properties of the released organic material, the surface active substances (SAS), reduced sulphur species (RS) and catalytically active compounds (CAC) were measured, for the first time, in herbal infusions by sensitive electrochemical techniques.

Phenolic profiles and antioxidant and anticarcinogenic activities of Greek herbal infusions; balancing delight and chemoprevention?

Total phenolic content, antioxidant activity and phenolic profiles of six herbal infusions - namely rosemary, Cretan dittany, St. John's Wort, sage, marjoram and thyme were assayed. Additionally, the infusion anticarcinogenic effect as to their ability to (a) scavenge free radicals, (b) inhibit cell growth, (c) decrease IL-8 levels and (d) regulate p65 subunit in epithelial colon cancer (HT29) and prostate (PC3) cancer cells was investigated. LC-DAD-MS and GC-MS analyses showed major qualitative and quantitative differences in phenolic profiles of the infusions. All herbal infusions exhibited antiradical activity which correlated strongly with their total phenolic content. Infusions exhibited the potential to inhibit cell growth and to reduce IL-8 levels in HT29 colon and PC3 prostate cancer cells. The regulation reported in p65 subunit in HT29 treated with St John's Wort and in PC3 treated with thyme might point to the NF-κB as the molecular target underlying the effect of these infusions.

The impact of fruit maturation on bioactive microconstituents, inhibition of serum oxidation and inflammatory markers in stimulated PBMCs and sensory characteristics of Koroneiki virgin olive oils from Messenia, Greece.

Olive fruits from the Koroneiki cultivar (Olea europaea L.) grown in Messenia, Greece, were hand-picked from the same trees in progressive maturity stages, covering three months, and processed identically with a commercial olive mill and a three-phase decanter. Data on quality parameters, and antioxidant activity of the obtained oils were collected by employing the conventional analytical methods set by European Union Commission Regulation no. 61/2011. Additionally, the potential of oils' polar extract to inhibit total serum lipid oxidation and inflammatory markers in stimulated human mononuclear cells was assayed. The results showed that ripening caused an increase in monounsaturated and decrease in polyunsaturated fatty acids, as well as an increase in phenolic compounds - mainly hydroxytyrosol - and in squalene. The extracts' ferric reducing power was in line with the increase of phenolic compounds. In later stages of maturation, lipoprotein oxidation was less potent and the decrease of inflammatory markers in stimulated human mononuclear cells was more powerful. Sensory evaluation detected differences in oils' "bitter" attributes, while the analysis of oils' volatiles revealed quantitative differences.

Herbal infusions; their phenolic profile, antioxidant and anti-inflammatory effects in HT29 and PC3 cells.

In this survey, we analyzed the phenolic profile of six herbal infusions namely Cretan marjoram, pink savory, oregano, mountain tea, pennyroyal and chamomile by LCDAD-MS and by GC-MS. Further, we investigated their anticarcinogenic effect as to their ability to (a) scavenge free radicals (b) inhibit proliferation (c) decrease IL-8 levels and (d) regulate nuclear factor-kappa B in epithelial colon cancer (HT29) and prostate (PC3) cancer cells. All herbal infusions exhibited antiradical activity correlated positevely with total phenolic content. Further, infusions exhibited the potential to inhibit cell proliferation and to reduce IL-8 levels in HT29 colon and PC3 prostate cancer cells. The molecular target for chamomile in HT29 seemed to be the NF-κB, while for the other herbal infusions needs to be identified. This study is the first to show the potential chemopreventive activity of infusions prepared from the examined herbs.

Nutritional evaluation and health promoting activities of nuts and seeds cultivated in Greece.

Available data suggest that genetic as well as environmental factors may influence nuts and seeds nutrients content. In this context nuts and seeds cultivated in Greece were studied. Macronutrients content was in agreement with that from other areas. Total phenolics content was in the range of 43.0 ± 2.1-1512.7 ± 60.7 mg GAE/100 g for chestnut and walnut, respectively. Thirteen to 22 individual phenolics were identified in the studied species. Oleanolic acid was in the range of 0.10-9.03 mg/100 g. Pumpkin seeds contained the higher squalene content (71.6 mg/100 g). ß-Sitosterol predominated in all samples except pumpkin seeds. Tocopherols ranged from 8.9 mg/100 g (chestnut) to 29.3 mg/100 g (almond). Nuts and seeds hydrophilic extracts at quantities corresponding to the estimated daily consumption by the Greeks succeeded in inhibiting LDL oxidation in vitro by increasing lag time 1.1-14.1 times. One serving of nuts or seeds may cover a significant fraction of health promoting microconstituents daily intake.

Flaxseed oil does not affect inflammatory markers and lipid profile compared to olive oil, in young, healthy, normal weight adults.

OBJECTIVE: Olive oil (OO) is a rich source of monounsaturated fat and bioactive components that exert strong anti-oxidant and anti-inflammatory properties. Flaxseed oil (FO) is rich in α-linolenic n-3 fatty acid (ALA), which also exhibits anti-inflammatory effects. This randomized, cross-over study aimed at exploring whether diet's enrichment with FO could beneficially alter inflammatory markers and lipid profile, compared to OO, in a sample of normal weight, apparently healthy young adults. MATERIALS AND METHODS: Participants were supplied with 15 mL/day of either FO or OO. Each intervention and the wash-out period lasted 6 weeks. Dietary, anthropometric and physical activity variables were recorded at the beginning and the end of each intervention. Serum biochemical and inflammatory markers were measured. Compliance to the intervention was evaluated by fatty acid analysis in erythrocytes. Repeated Measures ANOVA was used to assess the effect of the treatment. RESULTS: Thirty seven participants completed the study. No difference between the two interventions was observed in adiponectin, TNF-α, high sensitivity-CRP or glucose levels and lipid profile. At the end of the FO period, participants exhibited significant reductions in total (-5.0%) and LDL-cholesterol (-6.7%) levels (all P<0.01). During the FO and the OO period serum adiponectin changes were significantly correlated with changes in erythrocyte %ALA (rs=0.34, P=0.007) and in erythrocyte %EPA (r(s)=0.47, P=0.01), respectively. CONCLUSIONS: Daily consumption of FO did not confer any benefit in inflammatory or biochemical markers in normal weight young adults, who traditionally use olive oil as the main edible oil.

Unsaturated fatty acids are inversely associated and n-6/n-3 ratios are positively related to inflammation and coagulation markers in plasma of apparently healthy adults.

BACKGROUND: Blood lipids and inflammatory markers levels have been associated with the development and progression of atherosclerosis. As the association of inflammatory markers with plasma fatty acids has not been extensively evaluated and understood, we sought to investigate the associations between dietary and plasma fatty acids with various inflammation and coagulation markers. METHODS: High sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), fibrinogen, and homocysteine were measured in serum of 374 free-living, healthy men and women, randomly selected from the ATTICA's study database. Total plasma fatty acids were determined by gas chromatography. Dietary fatty acids were assessed through a semi-quantitative FFQ. RESULTS: Multi-adjusted regression analyses revealed that plasma n-3 fatty acids were inversely associated with CRP, IL-6 and TNF-alpha; plasma n-6 fatty acids were inversely associated with CRP, IL-6 and fibrinogen; monounsaturated fatty acids were inversely associated with CRP and IL-6 (all p-values<0.05). Interestingly, the n-6/n-3 ratios exhibited the strongest positive correlations with all the markers studied. No associations were observed between dietary fatty acids and the investigated markers. CONCLUSIONS: Measurements of total plasma fatty acids could provide insights into the relationships between diet and atherosclerotic disease. Moreover, the n-6/n-3 ratio may constitute a predictor of low-grade inflammation and coagulation.

Deployment of response surface methodology to optimise recovery of grape (Vitis vinifera) stem polyphenols.

A 2(3)-full factorial design and response surface methodology were deployed to assess some basic factors (time, % ethanol and pH) affecting profoundly the extractability of polyphenolic phytochemicals from grape (Vitis vinifera) stems. In an effort to obtain a thorough insight into the applicability of the models established, stem extracts from three different varieties were tested, by determining several indices of the polyphenolic composition, such as total polyphenol (TP), total flavanol (TFl), total flavone (TFn) and proanthocyanidin (PC) concentration. It was shown that the models generated can adequately predict the recovery levels for each polyphenol group, but the optimal conditions predicted for TP, TFl, TFn and PC recovery varied significantly. Notable differences were also seen among the different varieties. Correlation of the polyphenol indices with the antiradical activity and reducing power of the extracts indicated that the PC fraction might exert strong effects, while the influence of other groups was not apparent. Examination of the optimally obtained extracts using liquid chromatography-mass spectrometry revealed that the most prominent compounds were caftaric acid, flavanols and derivatives thereof, as well as dehydroflavonols and flavonols.

Validation of the MedDietScore via the determination of plasma fatty acids.

BACKGROUND: The purpose of the present work was to validate the MedDietScore by means of plasma fatty acid levels. METHODS: The study sample consisted of 189 men (44+/-13 years old) and 185 women (40+/-15 years old), randomly selected from the ATTICA study database. All participants completed a food frequency questionnaire (the EPIC-Greek FFQ), and a modified version of the MedDietScore (using weights) was then calculated to evaluate the level of adherence to the Mediterranean diet. Plasma and dietary fatty acids were measured. RESULTS: Correlation analysis revealed a strong positive relationship between the MedDietScore, monounsaturated fatty acids (P <0.001), monounsaturated fatty acids to saturated fatty acids (P <0.001), docosahexaenoic acid (22:6 n-3) (P <0.05) and n-3 fatty acids (P <0.001), and inverse correlations between the diet score and polyunsaturated fatty acids (comprised of the sum of n-3 and n-6 fatty acids) (P <0.001), saturated fatty acids (P <0.01), and total n-6 fatty acids (P <0.001). The effect size of the relationships between the weighted-MedDietScore and fatty acids was better than the relationships with the initial version of the diet score. CONCLUSIONS: Our findings suggest that the modified MedDietScore is a valid measure of various plasma fatty acids, and may prove a useful tool in assessing diet quality of adults.

Thermal stability of anthocyanin extract of Hibiscus sabdariffa L. in the presence of beta-cyclodextrin.

The thermal stability of anthocyanin extract isolated from the dry calyces of Hibiscus sabdariffa L. was studied over the temperature range 60-90 degrees C in aqueous solutions in the presence or absence of beta-cyclodextrin (beta-CD). The results indicated that the thermal degradation of anthocyanins followed first-order reaction kinetics. The temperature-dependent degradation was adequately modeled by the Arrhenius equation, and the activation energy for the degradation of H. sabdariffa L. anthocyanins during heating was found to be approximately 54 kJ/mol. In the presence of beta-CD, anthocyanins degraded at a decreased rate, evidently due to their complexation with beta-CD, having the same activation energy. The formation of complexes in solution was confirmed by nuclear magnetic resonance studies of beta-CD solutions in the presence of the extract. Moreover, differential scanning calorimetry revealed that the inclusion complex of H. sabdariffa L. extract with beta-CD in the solid state was more stable against oxidation as compared to the free extract, as the complex remained intact at temperatures 100-250 degrees C where the free extract was oxidized. The results obtained clearly indicated that the presence of beta-CD improved the thermal stability of nutraceutical antioxidants present in H. sabdariffa L. extract, both in solution and in solid state.

Squalene in oils and fats from domestic and commercial fryings of potatoes.

Squalene was determined in commercial frying oils and fats (sunflower oil, cottonseed oil, corn oil, soybean oil, palm kernel oil, palm oil, vegetable shortening oil, and cooking fats) sampled during deep-frying of potatoes from 21 restaurants in Athens, Greece, and in domestic frying oils [virgin olive oil (VOO), vegetable shortening and sunflower oil] used during the domestic pan-frying and deep-frying of potatoes. The analyses were carried out after cold saponification of the oils followed by gas chromatography-mass spectrometry of the hexane extract. Quantification was carried out by reference curve, using standard squalene solutions. Fresh vegetable oils and fats were found to contain small amounts of squalene (10.2-49.3 mg/100 g oil or fat), with the exception of fresh VOO, which contained 454 mg/100 g. The squalene content of the frying oils was reduced during frying, its lower concentration found in cooked fats (5.9 mg/100 g fat) and its higher in fried VOO (428 mg/100 g oil) after the first frying session. Squalene appeared to be rather stable during frying. Its retention in used restaurant seed oils and fats remained over 50% even after 30 h of frying while a high recovery of 84-96% was observed during the domestic deep-frying of potatoes in VOO. It seems that by using VOO as frying medium a considerable amount of squalene is absorbed by the fried potatoes, thus becoming part of our diet.

Deterioration of natural antioxidant species of vegetable edible oils during the domestic deep-frying and pan-frying of potatoes.

In the present work, virgin olive oil, sunflower oil and a vegetable shortening were used as cooking oils for the deep-frying and pan-frying of potatoes, for eight successive sessions, under the usual domestic practice. Several chemical and physicochemical parameters (acidic value, peroxide value, total polar artefacts, total phenol content and triglyceride fatty acyl moiety composition) were assayed during frying operations in order to evaluate the status of the frying oils, which were found within expected ranges similar to those previously reported. The oil fatty acids were effectively protected from oxidation by the natural antioxidants. The frying oil absorption by the potatoes was quantitated within 6.1-12.8%, depending on the oil type and the frying process. The retention of alpha- and (beta + gamma)-tocopherols during the eight fryings ranged from 85-90% (first frying) to 15-40% (eighth frying), except for the (beta + gamma)-tocopherols of sunflower oil, which almost disappeared after the sixth frying. The deterioration during the successive frying of several phenolic species present in virgin olive oil is reported for the first time. The retention of total phenolics ranged from 70-80% (first frying) to 20-30% (eighth frying). Tannic acid, oleuropein and hydroxytyrosol-elenolic acid dialdeydic form showed remarkable resistance in all frying sessions in both frying methods, while hydroxytyrosol and hydroxytyrosol-elenolic acid were the faster eliminated. The deterioration of the other phenolic species account for 40-50% and 20-30% for deep-frying and pan-frying, respectively, after three to four frying sessions, which are the most usual in the household kitchen. Deep-frying resulted in better recoveries of all the parameters examined. The correlation of the deterioration rate of the phenolic compounds and tocopherols during frying is discussed and the nutritional aspects of the natural antioxidant intake, through the oil absorbed by the potatoes, are evaluated.