Phenolic compounds and antioxidant activity of Spanish commercial grape juices

Evaluation of the antioxidant activity of components of the diet is important in order to establish healthy consumption patterns. Data are reported here on the antioxidant activity (FRAP and ABTS), of 20 commercial grape juices and 10 typical Spanish wines and on their content of total phenolic compounds, anthocyanins, flavonoids and 10 individual phenolic compounds (flavanols, benzoic acids and cinnamic acids, measured by HPLC-UV). Red grape juices had a significantly higher (p < 0.05) concentration of total phenols (1177 vs. 744 mg gallic acid/L), flavonoids (98 vs. 63 mg catechin/L) and a higher antioxidant activity (9.16 vs. 2.83 meq Trolox/L) in comparison to white grape juices. In comparison to the white wines, white grape juices contained more total phenols (744 vs. 286 mg gallic acid/L) and flavonoids (63 vs. 29 mg catechin/L) and evidenced higher antioxidant activity (p < 0.05). In comparison to the red wines, a lower content of total phenols (286 vs. 2358 mg gallic acid/L) and flavonoids (228 vs. 29 mg catechin/L) and an absence of anthocyanins were observed in the white wines, which are therefore less antioxidant. Although a two-fold higher concentration of antioxidant compounds was found in red wines than in red grape juices, the latter may be a good option for all age groups because of the absence of alcohol and the potentially beneficial health effects of their phenolic composition and elevated antioxidant activity.     

In vitro antioxidant activities of Stevia rebaudiana leaves and callus

Leaf extract of Stevia rebaudiana promotes effects on certain physiological systems such as the cardiovascular and renal and influences hypertension and hyperglycemia. Since these activities may be correlated with the presence of antioxidant compounds, leaf and callus extracts of Stevia rebaudiana were evaluated for their total phenols, flavonoids content and total antioxidant capacity. Total phenols and flavonoids were analyzed according to the Folin–Ciocalteu method and total antioxidant activity of water and methanolic extracts of stevia leaves and callus was assessed by ferric reducing/antioxidant power (FRAP) assay as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The total phenolic compounds were found to be 25.18 mg/g for stevia leaves and 35.86 mg/g for callus on dry weight basis. The flavonoids content was found to be 21.73 and 31.99 mg/g in the leaf and callus, respectively. The total antioxidant activity was expressed as mg equivalent of gallic acid, ascorbic acid, BHA and trolox per gram on dry weight basis. Total antioxidant activity found was ranged from 9.66 to 38.24 mg and 11.03 to 36.40 mg equivalent to different standards in water and methanolic extract of stevia leaves, respectively. In case of stevia callus, it was found to be 9.44 to 37.36 mg for water extract and 10.14 to 34.37 mg equivalent to standards for methanolic extract. The concentrations required for 50% inhibition (IC₅₀) of DPPH radicals were 11.04, 41.04 and 57.14 μg/mL for gallic acid, trolox and butylated hydroxyanisole (BHA), respectively. The percent inhibition of DPPH radical of various extracts of stevia leaves and callus found were ranged from 33.17% to 56.82%. The highest percent of inhibition was observed in methanolic extract of callus.     

Effect of solvents in extracting polyphenols and antioxidants of selected raw vegetables

Thirty-seven raw vegetables were extracted using four solvent systems: 70% acetone, 70% ethanol, 70% methanol, and distilled water. The extracts were tested for their total phenolic content, total flavonoid content and antioxidant activities (using diphenylpicryl-hydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The results revealed the effect of different extracting solvents in altering the quantitative analyses of all vegetables and 70% acetone was identified as the most efficient solvent for extracting polyphenolic antioxidants from the vegetables. The highest total phenolic content and total flavonoid content were obtained from 70% acetone extract of Portulaca oleracea (138.2 ± 2.1 mg GAE/g dw basis) and 70% methanol extract of Cosmos caudatus (27.7 ± 1.0 mg QE/g dw basis), respectively. The 70% acetone extract of Etlingera elatior with moderate amount of total phenolic content exhibited the highest antioxidant activity in both assays. The correlation analyses within 37 different extracts of each solvent extraction demonstrated weak to moderate relationships between all the studied parameters. The highest r value of 0.7139 (p < 0.001) was determined between total phenolic contents and FRAP values of the 70% methanol extracts. Meanwhile, a wide range of correlation coefficients was derived from correlation analyses within four different extracts of each vegetable, with the highest relationship between total phenolic contents and FRAP values for the extracts of Coriandrum sativum (r = 0.9998, p < 0.001).     

Effect of full-scale brewing process on polyphenols in Italian all-malt and maize adjunct lager beers

This paper analyses, in a full-scale industrial process, the flavonoids, non-flavonoids, tannins and non-tannins in all malt worts and in maize adjunct worts and their fate during the main brewing steps. The effect on wort phenols of two different wort separation technologies, a mash filter (Meura 2001) and a lauter tun (Steinecker FVAS 26), were also investigated. The results obtained showed that total phenols are lower in maize-adjunct, than in all-malt worts (542 mg/L and 730 mg/L, respectively), and that non-tannins are the main phenolic components: 91% of the total in all-malt and 82% in maize-adjunct worts, respectively. The overall brewing process reduces the initial content of total phenols by 50%, and the highest reduction is on tannins and flavonoids. After the brewing process, total phenols in beer were 336.5 mg/L in all-malt and 280 mg/L in maize adjunct. In moderate drinkers they contribute to 10–20% of the total phenolic daily intake accounting for around 4–8% of the total antioxidant capacity of the diet. As regards the influence of lauter tun and mash filter on phenols, our results showed their great depletion when using lauter tun, and suggested that the brewing process may be adapted in order to overcome the high impact of lauter tun on phenols.     

The effect of frying on anthocyanin stability and antioxidant activity of crisps from red- and purple-fleshed potatoes (Solanum tuberosum L.)

Red- and purple-fleshed potatoes (Solanum tuberosum L.) are a good source of polyphenols, mainly anthocyanins as one of the most important components. The chemical composition with reducing sugars and the total polyphenol contents were analyzed in four purple potato varieties (Salad Blue, Vitelotte, Valfi, Blue Congo) and three red-fleshed potato varieties (Rosalinde, Herbie 26, Highland Burgundy Red). The anthocyanin composition of raw potato and potato crisps was characterized by high-performance liquid chromatography tandem mass spectrometry (HPLC–MS/MS) method. Moreover, the antioxidant activity was measured with the radical scavenging assays using 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical as well as ferric reducing ability of plasma assay (FRAP). In addition, colour parameters in prepared potato crisps were evaluated. Both red and purple-fleshed potato varieties contained high levels of total polyphenols (227–845 mg 100 g⁻¹ dry weight) and anthocyanins (21–109 mg 100 g⁻¹ dry weight). The process of frying caused degradation of anthocyanin compounds (38–70%). The HPLC–MS/MS analysis showed that pelargonidin and malvidin derivates were more stable during frying than petunidin derivatives. Although frying process affected the anthocyanin and polyphenol levels, obtained potato crisps exhibited bright intensive colour and good antioxidant activity.     

Antioxidant components and antioxidant/antiradical activities of desert truffle (Tirmania nivea) from various Middle Eastern origins

Dried desert truffles from Bahraini, Iranian, Moroccan and Saudi origins were examined for their antioxidant and antiradical activities using four analytical methods: ferric reducing ability (FRAP), DPPH, deoxyribose, and nitric oxide (NO). Chemical constituents contributing towards these activities were also investigated. Generally, these truffles possessed varying concentration of antioxidant chemicals averaging 9.6 ± 0.15, 12.0 ± 8.34, 1860 ± 361, 1328 ± 167 and 293 ± 32 mg/100 g dw, for ascorbic, anthocyanins, total esterified phenolics, total free phenolics and total flavonoids, respectively; total carotenoids averaged 681 ± 245 g/100 g dw. Dried truffles also varied with regard to their antioxidant and antiradical activities. The FRAP value averaged 15.41 ± 3.51 mmol/100 g dw. Antiradical activity measured as percent inhibition of DPPH quenching averaged 30.6 ± 12.97% and EC₅₀ of 0.55 ± 0.38 mg. The average EC₅₀ of NO scavenging activity was 159.4 ± 69.3 μg, whereas the average percent inhibition of deoxyribose degradation was 55.9 ± 30.1%. The Iranian truffles yielded the highest in several variables, whereas the Moroccan truffles possessed the lowest values of many variables among the four tested samples. Significant correlation was established between total and free phenolics and FRAP values, and between flavonoids and percent radical inhibition using DPPH, NO and deoxyribose assays.     

Nutritive value,antioxidant activity and phenolic compounds profile of brewer’s spent yeast extract

Spent yeast is the second major by-product from brewing. Mechanical disruption of yeast cell wall can be used to obtain β-glucan rich ingredients and separate inner yeast content, both with potential applications as food and nutraceutical ingredients. In this work, the nutritional composition, including minerals and B-complex vitamins, together with the antioxidant activity and phenolic compounds profile of yeast extract, prepared by mechanic disruption of brewer’s spent yeast and removal of yeast cell wall, was investigated. The lyophilised yeast extract presented 64% of proteins with high proportion of essential amino acids and 4% of RNA; macrominerals (Na, K, Ca, Mg), trace elements such as Zn (11.9 mg/100 g dw), Fe (1.76 mg/100 g dw), and Mn (0.564 mg/100 g dw), and vitamins B3 (77.2 mg/100 mg dw), B6 (55.1 mg/100 g dw) and B9 (3.01 mg/100 g dw). Two phenolic compounds were quantified as free forms, gallic acid and (±) catechin, whereas other bounded phenolic compounds were also quantified. The nutrients content, antioxidant properties and phenolic composition of the lyophilised brewer’s spent yeast extract indicates that it can be an interesting food or nutraceutical ingredient. Thus, its recovery will be beneficial in terms of sustainability and environmental impact.     

Anthocyanin profile and antioxidant capacity of black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) from Cuevas Bajas,Spain

The present work deals with the study of the anthocyanin profile of two different black carrots (Daucus carota L. ssp. sativus var. atrorubens Alef.) cultivars, associated with Antonina and Purple Haze varieties, from Cuevas Bajas (Málaga, Spain) and some of their antioxidant features. The main anthocyanins detected by LC–MS were found to correspond to five cyanidin-based anthocyanins: cyanidin 3-xylosylglucosylgalactoside, cyanidin 3-xylosylgalactoside and the sinapic, ferulic and coumaric acids derivative of cyanidin 3-xylosylglucosylgalactoside. The anthocyanins present in the black carrots were essentially acylated and their levels were found to correspond to 25% and 50% of the total phenolic content for the Purple Haze and Antonina varieties, respectively. Moreover, the reducing capacity of the two black carrots extracts (86.4 ± 8.0 and 182.0 ± 27 μM TE/100 g fw) and the radical scavenging ability (17.6 ± 9.0 and 240.0 ± 54.0 μM TE/100 g fw) expressed in Trolox equivalents units were determined. The antioxidant features of the black carrot extracts were shown to be significantly higher than those of orange carrots used herein for comparison. Overall, this work highlights the Cuevas Bajas black carrots as rich sources of anthocyanins with significant antioxidant capacities and good nutritional value.     

Cold storage of blueberry (Vaccinium spp.) fruits and juice: Anthocyanin stability and antioxidant activity

Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and antioxidant activity of refrigerated whole blueberry juice stored at 4 °C for 10 d, and of fruits stored frozen (−18 °C) for 6 months, in order to determine the changes occurring during storage. The frozen fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the 10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice (83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or condensation reactions with other phenolic compounds. More studies are required to optimize the storage time and temperature of these products with respect to nutrient stability.     

Identification and quantification of flavonoids in traditional cultivars of red and white onions at harvest

Onions are rich in different types of phenolics, mainly flavonols, and in red varieties anthocyanins are also present. This is significant because these classes of phenolics are antioxidants and hence may impart important functional properties to onions. The aim of the present work was to simultaneously determine flavonol and anthocyanin concentrations in different onion varieties, two white (Branca da Póvoa and the hybrid SK409) and three red (landrace Vermelha da Póvoa, a selected line of Vermelha da Póvoa and Red Creole). Flavonols (quercetin 7,4-diglucoside, quercetin 3,4-diglucoside, isorhamnetin 3,4-diglucoside, quercetin 3-glucoside, quercetin 4-glucoside and isorhamnetin 4-glucoside) were the predominant polyphenolic compounds. White cultivars had the lowest total flavonol content, with values of 89.3 ± 38.5 and 101.0 ± 18.9 mg quercetin/kg fresh weight for Branca da Póvoa and the hybrid SK409, respectively. The red onions had the highest levels of flavonols, especially the selected population of Vermelha da Póvoa and Red Creole, with values of 280.2 ± 41.5 and 304.3 ± 81.2 mg quercetin/kg fresh weight, respectively. Red onions are not only richer in flavonols, but also contain anthocyanins. Four anthocyanins (cyanidin 3-glucoside, cyanidin 3-laminaribioside, cyanidin 3-(6″-malonylglucoside), and cyanidin 3-malonylaminaribioside) were quantified in all red onions, with Red Creole presenting the highest concentration (28.6 ± 8 mg cyanidin/kg fresh weight). Red onions may be recommended for their major potential functional properties. A distinct gradient in total flavonoid content was found between the outer, central and inner edible scales and along the longitudinal axis of the bulb. Differences in flavonol levels between small- and large-sized onions were also found. All of these factors are of paramount importance for sampling and characterizing onions with regard to flavonoids.     

Antioxidant activity of Potentilla fulgens: An alpine plant of western Himalaya

Antioxidant activities of the methanol extract, fractions and isolated compounds from the roots of Potentilla fulgens Lodd. were evaluated by three in vitro experiments, namely, ABTS, DPPH, and FRAP assays. PF-2 was characterized as a new biflavanoid and designated as Potifulgene on the basis of NMR and mass spectrum, whereas PF-1 was identified as epicatechin. The activities of aqueous methanolic extract and fractions could be correlated with their respective total phenolic content and compared with standard natural antioxidants such as quercetin, vitamin C and pyrogallol. The root powder of the plant was extracted with methanol/water (80:20) by cold extraction and its extract was further partitioned with ethyl acetate, butanol and water fractions. Among the three fractions (ethyl acetate, butanol and water fraction) and the total aqueous methanolic extract, the butanol fraction exhibited good scavenging response measured in terms of TEAC (mM Trolox equivalent/mg extract). The butanol fraction was found to possess strong antioxidant activity (2.54 ± 0.69, 2.41 ± 0.53, 3.57 ± 0.05 mM Trolox equivalent/mg extract) with ABTS, DPPH and FRAP assays, respectively. The chemical composition of extracts, studied in terms of total polyphenol content (TPC), was found in the range of 20.61 ± 0.38 to 33.28 ± 0.11 mg/g gallic acid equivalent. A significant correlation was observed between total polyphenolics and antioxidant activity, indicating participation of phenolics in antioxidant activities of extract and fractions. The antioxidant activity of new biflavanoid (Potifulgene) was found to be higher, i.e. 6.85 ± 0.38, 4.24 ± 0.41, 5.35 ± 0.53 than that of epicatechin, 2.13 ± 0.05, 1.50 ± 0.02, 1.57 ± 0.03 with ABTS, DPPH and FRAP assays.     

Anthocyanins from the fruits of Rubus croceacanthus and Rubus sieboldii,wild berry plants from Okinawa,Japan

Anthocyanins from the fruits of Rubus croceacanthus and Rubus sieboldii, wild berries from Okinawa, Japan, were extracted using 80% methanol containing 0.5% acetic acid, and the extracts were separated by a DIAION HP-20 column. The major anthocyanins were purified by preparative HPLC and their structures were determined by NMR and MS spectrometry. Cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside were identified from R. croceacanthus, and their contents were 81.44 ± 1.01 mg and 170.02 ± 4.36 mg/100 g fresh weight, respectively. Pelargonidin-3-O-glucoside and pelargonidin-3-O-rutinoside were identified from R. sieboldii, and their contents were 10.04 ± 0.34 mg and 15.08 ± 0.48 mg/100 g fresh weight, respectively. An ORAC assay indicated that the two Okinawan wild berries, especially R. croceacanthus, had potent antioxidant activity compared to raspberry (Rubus idaeus).     

Changes in total phenolic and monomeric anthocyanin composition and antioxidant activity of three varieties of sorrel (Hibiscus sabdariffa) during maturity

Three varieties of sorrel (Hibiscus sabdariffa) were analyzed for total phenolic, monomeric anthocyanins and antioxidant activity at five stages of maturity. The varieties designated traditional red (TRED), early bearing red (ERED) and white (WHTE) were sampled at the pre-flowering stage, as well as 3 days, 7 days, 21 days and 35 days after flowering. The total phenolic composition ranged from 5 to 24 mg/g and, while found in all varieties, was highest for TRED and ERED. Anthocyanins were only observed in the red varieties and ranged from 0.5 to 3.5 mg/g. The levels of both total phenolics and monomeric anthocyanins fluctuated, initially declining then increasing with maturation. The three sorrel varieties exhibited antioxidant activity, inhibiting lipid peroxidation between 69 and 79%. Increasing maturity at harvest tended to increase antioxidant activity for all varieties. A linear relationship existed between antioxidant activity and stage of maturity (r = 0.59). This research has implications for the sorrel industry as the antioxidant phytonutrients of sorrel could add value to sorrel currently produced and consumed.     

Application of non-supervised pattern recognition techniques to classify Cabernet Sauvignon wines from the Balkan region based on individual phenolic compounds

Phenolic compounds in sixteen Cabernet Sauvignon wines from different wine-growing sub-regions in the Balkan region were investigated using HPLC with DAD and fluorescence detector and spectroscopic analysis, as well as statistical PC/F and cluster analysis. The HPLC analysis of investigated red wines showed that the content of total hydroxybenzoic acids, detected at 280 nm, was the highest in wines from Tikveš wine-growing subregion, Macedonia (127–140 mg L⁻¹). Total hydroxycinnamic acids, detected at 320 nm, were the highest in wines from Župa wine-growing subregion, Serbia (43–45 mg L⁻¹). The concentration of total flavonoids (flavan-3-ols, flavonols, flavons and flavanon), detected at 280, 360 and 322/275 nm, respectively, was the highest in wine from Katarzyna Estate wine-growing subregion, Bulgaria (167 mg L⁻¹). Finally, the concentration of total anthocyanins, detected at 520 nm, was the highest in wine from Šumadija wine-growing subregion, Serbia (1463 mg L⁻¹). The results of PCA and cluster analysis together confirmed that the content of phenolic compounds in Cabernet Sauvignon wines depends on agro-climatic factors, oenological practice in different wineries and the growing season in the Balkan region that were investigated. The areas in the Balkan region in this study with similar agro-climatic characteristics showed shorter clustering distance, indicating similar phenol profiling in the red wines tested.     

Antioxidant activity of different white teas: Comparison of hot and cold tea infusions

The study investigates the antioxidant characteristics of various white teas steeped in either hot or room-temperature water in relation to grade of tea and brewing conditions. Antioxidant activity, chelating activity, total phenol (TPC), flavonoids (TFC), theaflavins and individual catechin content were examined. The results confirm that extraction of tea leaves carried out with water at room temperature leads to the formation of infusions particularly rich in compounds with antioxidant activity. In fact, for all the white teas studied, cold infusions had a higher content of phenols (4.77–7.63 mmol/L Gallic Acid Equivalents, GAE), flavonoids (1.47–2.53 mmol/L Catechin Equivalents, CE) and catechins (441.5–1328.2 μg/mL) compared to hot infusions (1.43–4.02 mmol/L GAE, 0.70–1.13 mmol/L CE, 83.4–534.8 μg/mL, respectively). The same trend was also observed for antioxidant activities examined using the ABTS assay (cold: 17.09–34.23; hot: 5.26–17.07 mmol/L Trolox Equivalents) and by monitoring the effects of the infusions on LDL oxidation (lag time, cold: 172.4–271.2; hot: 88.4–145.9 min). A general trend in antioxidant activity and in polyphenolic compound content can be delineated between Chinese teas, i.e. Bai Mu Dan ≥ Xue Ya ≥ White Lung Ching > Anji Needle Mao Feng > Yhin Zhen Bai Hao and between African teas, i.e. White Salima Peony > Thyolo Bsp > Bvumbwe Bsp. Concerning metal chelating activity, all the white teas displayed similar levels (0.3–0.6 mmol/L EDTA Equivalents) with no significant differences between the hot and cold infusions (except Bvumbwe Bsp and Thyolo Bsp). This paper contains key information on the antioxidant properties, TPC, TFC, and individual catechin content of several white teas commercially available and the outcomes suggest that preparing tea infused in room temperature water for approximately 2 h may constitute an alternative tea beverage potentially richer in healthful bioactive compounds compared to the more commonly consumed hot tea infusions.     

Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits

The present study sought to determine the nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits from different districts in Malaysia, namely Kanowit, Sarikei, Kapit and Song in Sarawak. Two varieties of the fruits were investigated. Lipid (21.16 ± 4.71 to 25.76 ± 3.03 g/100 g FW) was the major macronutrient in dabai fruits, while the predominant minerals were calcium, sodium and potassium. The fruit protein was rich in aspartic and glutamic acids which accounted for 45–49% of total amino acids. Purple dabai fruits from Kapit were found to contain the highest total phenolic levels, flavonoids and anthocyanin contents (p < 0.01) and to exhibit the most significant antioxidant activities (p < 0.01), using trolox equivalent antioxidant capacity (TEAC) and ferric reducing ability (FRAP) assays. Antioxidant activities were highly correlated with total phenolic and flavonoid contents of dabai fruits.     

Polish wines: Characteristics of cool-climate wines

The aim of this work was to characterize the physical, chemical and antioxidant properties of selected Polish wines, produced from grapevines cultivated in the cool climate of Podkarpacie. Most of the analysed wines were characterized by a small amount of total extract (less than 4%), by ethanol concentration ranging from 9.9 to 11.0% and by titratable acidity from 4.0 to 8.7 g of malic acid/L. The total polyphenol content was closely correlated with antioxidant activity (R² = 0.96). Red wines were distinguished from white wines by 4–5 times higher antioxidant activity (671–746 mg of Trolox/100 mL) and by increased total amount of polyphenols (127–135 mg of catechin/100 mL). The prevailing volatile compounds of wines were amyl alcohols and isobutanol. Especially high concentrations of the above compounds were present in liqueur wines (>220 and 180 mg/L, respectively). Polish wines contained also high levels of ethyl acetate (11–161 mg/L).     

Antioxidant and antimutagenic activities of Cinnamomum zeylanicum fruit extracts

Recently, a number of studies on the health benefits associated with natural compounds have been demonstrated. Phenolics in fruits, vegetables, herbs and spices possess potent antioxidant, anti-inflammatory, antimutagenic and anticarcinogenic activities. In the present study, the dried fruits of cinnamon were extracted with ethyl acetate, acetone, methanol and water using a Soxhlet extractor. The total phenolics content of the extracts as determined by Folin–Ciocalteu method were found to be the highest in water extract (44.5%) and the lowest in ethyl acetate (14.4%). The antioxidant activity (AA) of the extracts was evaluated through in vitro model systems such as β-carotene-linoleate, and 1,1-diphenyl-2-picryl hydrazyl (DPPH); the antimutagenicity of these extracts was also assayed against the mutagenicity of sodium azide by Ames test using tester strain of Salmonella typhimurium (TA100) at different concentrations. In both the model systems, the AA of the extracts was found in the order of water>methanol>acetone>ethyl acetate. All the extracts decreased sodium azide mutagenicity in S. typhimurium strain (TA100). At 5000 μg/plate all the extracts showed strong antimutagenicity. The antimutagenicity of water extract was followed by acetone, methanol and ethyl acetate. The results of the present study indicate that under-utilized and unconventional part of cinnamon is a good source of antioxidant and antimutagenic phenolics.     

Optimization of cheese sample preparation methodology for free amino acid analysis by capillary isotachophoresis

The objective of this work was the evaluation of different conditions for the selected free amino acids extraction from cheese samples, followed by capillary isotachophoresis analysis. Parameters of the extraction: concentration and type of extraction reagents (solvents: methanol, ethanol and mineral acids: perchloric acid, trichloroacetic acid, sulphuric acid and hydrochloric acid), time and temperature, and isotachophoretic separation conditions (voltage, time) were studied. Repeatability, reproducibility and stability of this method at different conditions are discussed. The best yield of free amino acids was obtained after triple extraction (30 min each process) with 0.1 M hydrochloric acid at 50 °C. Histidine, lysine, arginine, ornithine, tyrosine, and phenylalanine were determined using calibration curves and the standard additions method in different types of cheeses. The highest level of amino acids was determined in semi-hard cheese (2626.3 mg 100 g⁻¹ – calibration curve, and 2679.2 mg 100 g⁻¹ – standard additions method), whereas the lowest were found in sheep cheese (426.3 mg 100 g⁻¹ and 455.7 mg 100 g⁻¹, respectively), and Gouda type cheese samples (441.5 mg 100 g⁻¹ and 472.8 mg 100 g⁻¹, respectively).     

Chemical composition,antioxidant activities and total phenolic content of Arbutus andrachne L. (Fam. Ericaceae) (the Greek strawberry tree) fruits from Turkey

Arbutus andrachne L. and A. unedo L. are two members of the Ericaceae family. The species are distributed in coastal parts of Anatolia and have edible fruits. We determined several characteristics of eight A. andrachne accessions collected from different parts of the Mediterranean regions of Anatolia. A. unedo is also represented with a sample. Notable differences were found among A. andrachne accessions. On average, the fruit width and length were 12.3 and 10.8 mm, respectively. All of the element concentrations that were tested varied considerably. The average of the total organic acids was 0.47 g/100 g fruit. Among the organic acids measured, malic acid had the highest content (0.34 g/100 g fruit) followed by ascorbic (0.10 g/100 g fruit) and citric acids (0.03 g/100 g fruit). The average for total sugars of the A. andrachne accessions was 16.38 g/100 g fruit. Fructose was the main sugar (average of 9.75 g/100 g fruit) followed by glucose (5.33 g/100 g fruit) and sucrose (1.19 g/100 g fruit). Among the A. andrachne accessions tested, the total phenolics ranged from 2422 to 4102 μg gallic acid/g fresh weight (fw) with an average of 3343 μg gallic acid equiv. g/fw. Antioxidant activities, determined by TEAC (Trolox equivalent antioxidant capacity) and FRAP (Ferric reducing ability of plasma), reached up to 36.1 and 29.5 μmol Trolox equiv. (TE) g/fresh weight, respectively. It can thus be concluded that A. andrachne is a good source of phenols and antioxidants.