Efecto antimicrobiano de los aceites de comino negro turco

A series of five different oils from Turkish black cumin ( Nigella sativa ) used in foods mainly for their flavour, preservation and natural therapies were screened for their antibacterial effects at 0.5 %, 1.0 % and 2.0 % concentrations using the agar diffusion method against twenty four pathogenic, spoilage and lactic acid bacteria (LAB). All tested oils showed antibacterial activity against all the bacteria used in the assay. The oils at 2.0 % concentration were more effective than of the other concentrations. The most sensitive bacterium against all of the oil concentrations was Aeromonas hydrophila, while the most resistant was Yersinia enterocolitica. Generally, lactic acid bacteria had more resistance than pathogenic and spoilage bacteria against black cumin oils. Consequently, black cumin oil may be used as an antimicrobial agent in food products to prevent spoilage.Se ensayaron un total de cinco aceites diferentes de comino negro turco ( Nigella sativa L.), que se utilizan habitualmente en alimentos para darles sabor, ayudar a la conservación o por sus efectos terapéuticos, para estudiar sus propiedades antimicrobianas a concentraciones de 0.5 %, 1.0 %, y 2 %. Para ello se utilizó el método de difusión en agar, frente a veinticuatro microorganismos patógenos, causantes de alteraciones o bacterias ácido lácticas (LAB). Todos los aceites ensayados mostraron actividad antimicrobiana contra todos los microorganismos ensayados, siendo las concentraciones del 2 % las concentraciones más eficaces. Aeromonas hydrophyla fue el microorganismo mas sensible a todas las concentraciones mientras que Yersinia enterocolitica fue la más resistente. Generalmente las bacterias acido lácticas tuvieron más resistencia que los gérmenes patógenos y las bacterias que causan alteraciones. En consecuencia, el aceite de comino negro turco se puede utilizar como agente antimicrobiano en productos alimenticios para evitar su alteración

Efecto de la radiación gamma sobre la microbiología y las propiedades del aceite del comino negro (Nigella sativa L.)

Black cumin samples obtained from the market have been irradiated under 2.5 kGy, 6 kGy, 8 kGy, and 10 kGy doses, respectively. Along with the increase in the dose of irradiation, both the free fatty acid and peroxide values of the samples increased, whereas oil contents, iodine numbers, refraction index and Rancimat values decreased. In the composition of fatty acids, while the percentages of unsaturated fatty acids decreased; trans fatty acid levels increased. Microbial count of the samples decreased as the dose of irradiation increased. It has been observed that total bacterial count as well as total count of yeast and mould reduced to the undetectable limit.Muestras de comino negro adquiridas en el mercado fueron irradiadas a dosis de 2.5 kGy, 6 kGy, 8 kGy y 10 kGy, respectivamente. Coincidiendo con el aumento en la dosis de irradiación, se incrementaron tanto la acidez libre, como el índice de peróxidos de las muestras, mientras que se redujeron en el aceite el índice de yodo, el índice de refracción y la resistencia a la oxidación medida por Rancimat. En la composición de ácidos grasos aumentaron los niveles de ácidos grasos trans, mientras que se redujeron los porcentajes de ácidos grasos insaturados. El recuento de microbios presentes en las muestras descendió, conforme aumentaba la dosis de irradiación aplicada. Se observó como los recuentos totales de bacterias, hongos y levaduras se redujeron hasta un límite indetectable

Determination of FA Composition and Total Trans FA of Turkish Margarines by Capillary GLC

ABSTRACT: In this research, FA composition and total trans FA contents of 16 different brands of margarine (8 hard-type and 8 soft-type) sold in Turkey were determined by capillary GLC method. According to the results, the contents of saturated FA, monounsaturated FA, and PUFA were within the ranges of 23. 9-32.3, 44.0-61.9, and 14.2-24.1%, respectively, in hardtype margarines, and 27.0-39.9, 21.0-40.9, and 32.0-53.7%, respectively, in soft-type margarines. Hard-type margarines contained total trans FA concentrations of 20.1-34.3%, whereas softtype margarines contained less than 8.9% total trans FA. C 18:1 trans acid content was within the range of 18.5-29.8% in hardtype margarines, and it was significantly higher than the range in soft margarines (0.7-8.1%). C 18:1 trans acid was the major trans FA in all margarines, and C 18:3 trans acid concentrations were less than 0.2%. Trans FA, which are created by the partial hydrogenation of liquid vegetable oils in the manufacturing of margarine and vegetable shortening, increase serum levels of LDL cholesterol and decrease those of HDL cholesterol (1,2). The adverse effects of the trans FA on the ratio of total cholesterol to HDL cholesterol are twice that of saturated FA (3). Some epidemiological studies have also found a positive association between levels of trans FA intake and risk of cardiovascular disease (4,5). Owing to these concerns, the Food and Agriculture Organization and the World Health Organization recommended in 1994 that fats for human consumption contain less than 4% of the total fat as trans and urged the food industry to reduce the presence of trans fats in their products to these levels (6). Vegetable oil production was approximately 1.45 million tons per year between 1995 and 2000 in Turkey. About 30% of this production was used by the margarine industry. Total margarine production was 550 million kg, and consumption was 430 million kg per year. These results indicate that margarines have an important role in the consumption of vegetable oil in Turkey. Vegetable oil consumption is approximately 15.9 kg/person/year, and 6.3 kg of this value is from margarines (7). This paper presents the FA composition and total trans FA contents of Turkish margarines determined by capillary GLC. The trans isomers of the samples were evaluated in relation to health. EXPERIMENTAL PROCEDURES Sample selection. Seven different margarine companies are present in Turkey. Of these, five are major producers. Margarines produced by these companies are sold in all regions of Turkey. The five leading margarine companies produce 23 different brands (10 soft and 13 hard) of margarines. Of these, the top 16 best-selling brands (8 soft and 8 hard), which represented 85% of the market share, were selected for analysis and then purchased locally. Each brand was coded with a number Analysis. Each sample was homogenized and dehydrated with sodium sulfate, and the FA present were converted to methyl esters. Preparation of FAME. FAME were prepared from the margarines after alkaline hydrolysis, followed by methylation in methanol with 12.5% BF 3 as catalyst. The final concentration of the FAME was approximately 7 mg/mL in heptane (8). Capillary GLC. Analyses of the FAME by capillary GLC were carried out on a Hewlett-Packard 6890 chromatograph, equipped with an FID on a split injector (Chrompack, Middleburg, The Netherlands). A fused-silica capillary column (Chrompack) was used for the FAME analysis; CP TM -Sil 88, 50 m × 0.25 mm i.d., 0.2 µm film. GLC operating conditions were: temperature program of 130°C for 5 min, rising to 177°C at a rate of 2°C/min. Other GLC conditions were: injector temperature, 250°C; detector temperature, 250°C; carrier gas, helium at a flow rate of 1 mL/min. RESULTS AND DISCUSSION FA composition and trans FA of Turkish margarines are given i

Effect of Gamma Irradiation on Total Phenolic Contents and Antioxidant Activities of Satureja Hortensis, Thymus Vulgaris, and Thymbra Spicata from Turkey

In this study, the effect of gamma irradiation on the total phenolic content and antioxidant activity of Satureja hortensis, Thymus vulgaris, and Thymbra spicata was evaluated. Plants irradiated in a 60Co irradiator to 0, 1.2, 3.0, and 5.1 kGy at 25 degrees C. Control and irradiated samples were extracted with methanol. The antioxidant activity of methanol extracts was determined using phosphomolybdenum assay and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method. The total phenolic content in three spices was found to decrease with irradiation except at 5.1 kGy for S. hortensis. The DPPH radical scavenging activity of the extracts decreased after irradiation

Bacterial Dynamics of Hardaliye, a Fermented Grape Beverage, Determined by High-throughput Sequencing

Hardaliye is a traditional beverage produced by fermenting red grapes with mustard seeds and sour cherry leaves in the Thrace region of Turkey. Few studies have been conducted that have determined the microorganisms responsible for hardaliye fermentation, and those that have are limited to lactic acid bacteria (LAB) using culture-dependent techniques. This study aims to determine the bacterial dynamics of hardaliye fermentation using a culture-independent approach, high-throughput sequencing of 16S rRNA amplicons. Hardaliye was produced using the traditional method, and samples were taken and analyzed on days 0, 2, 4, 6, and 10 of fermentation. During the fermentation period, the pH decreased from 3.65 to 3.23. Amplicon sequencing showed that bacterial diversity was highest at 2 d, and lowest at 10 d, the final day. Although Enterobacteriaceae was the most dominant family at 0 and 2 d, Acetobacteriaceae, specifically Gluconobacter frateurii, became dominant with ~50% relative abundance at 4 d, and increased its abundance to >98% at 6 and 10 d. Although a slight increase in the relative abundance of ~1% (0 d) to ~5% (4 d) was observed in LAB, their presence was limited. This study showed that acetic acid bacteria should not be overlooked in hardaliye fermentation

Comparison of different solvent types for determination biological activities of myrtle berries collected from Turkey

In the present study, we investigated the effects of four extracting solvents (70% acetone:water (v/v), 80% ethanol:water (v/v), 80% methanol:water (v/v) and distilled water) on the total phenolic content and antiradical, antioxidant activity and antimicrobial activities of extracts of myrtle berries (Myrtus communis) collected from eight different locations in Turkey. The tested plant extracts were found to contain appreciable amounts of total phenolic contents (39.933 to 207.4 mg GAE/g dry extract) and have 1.1-diphenyl-2- picrylhydrazyl scavenging activity ranging between 6.73 and 65.6%. The antioxidant activity of the myrtle fruits was measured using the phosphomolybdenum spectrophotometric method. The highest antioxidant activity value (241.533 mg ascorbic acid equivalents /g dry extract) was observed in the methanolic extract of the fifth sample. The agar diffusion method was used to determine the antimicrobial activity of the extract samples. It was found that the methanol and acetone extracts were more efficient against six pathogenic bacteria including Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, Salmonella Typhimurium and Yersinia enterocolitica. The solvent systems used for extraction had an important effect on the bioactive compounds extracted. Based on the results, we conclude that myrtle berries can be considered as a good source of natural antioxidant and natural antimicrobial compounds