Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2019Scopus SJRQ1/r/gumushane/12879
  Ohmic heating assisted hydrodistillation of clove essential oil

  Tunç, Merve Tuğçe; Koca, İlkay

  Ohmic heating assisted hydrodistillation is a novel green technology for the extraction of essential oils. In this study, clove bud essential oils (CEO) were extracted by ohmic heating assisted hydrodistillation (OAHD) and compared with conventional hydrodistillation (HD) process, in terms of extraction yield, energy consumption and chemical properties. Ohmic heating assisted hydrodistillation process conditions were optimized by response surface methodology. Voltage gradient (7.5–12.5 V/cm, A), process time (30–120 minutes, B) and mass of clove bud (20–40 g, C) were varied in order to maximize CEO yield and to minimize energy consumption. Optimized extraction conditions were determined as, 12.5 V/cm voltage gradient, 97.967 min for process time and 40 g of mass of clove bud. Yield of CEO and energy consumption were found 13.18 ± 1.50% and 0.214 ± 0.030 kW h/g CEO at optimum extraction conditions, respectively. Under optimum conditions, both OAHD and HD methods were used for CEO extraction. Yields of CEO obtained by OAHD, HD-D (distilled water) and HD-S (salted water) were 13.18 ± 1.50, 8.23 ± 0.35 and 7.88 ± 0.60 respectively. Energy consumptions of OAHD and HD methods were not significantly different (P > 0.05). The main chemical component of CEO was eugenol and the yield of eugenol (g/100 g clove bud) was found higher with OAHD (6.95±0.6) method than HD-D (5.16 ± 0.20) and HD-S (5.13 ± 0.28). Antioxidant and antimicrobial properties of CEOs were investigated by FRAP, DPPH and disk diffusion method. Antioxidant properties of CEOs obtained by different extraction methods were not significantly different (P > 0.05) according to FRAP and DPPH analysis. Although inhibition zones of CEOs extracted with different methods were not significantly different (P > 0.05) for gram positive bacteria's, CEO obtained by OAHD and HD-D have significantly higher (P < 0.05) inhibition zones for K. pneumonia and E. coli, respectively. The results of this study showed that OAHD method is applicable for CEO production.

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  AtıfScopus87·WoS66·OpenAlex90

  İncele
• MakaleYalnız künye2016Scopus SJRQ1/r/gumushane/15130
  Application of response surface methodology for optimizing the recovery of phenolic compounds from hazelnut skin using different extraction methods

  Odabaş, Halil İbrahim; Koca, Ilkay

  Hazelnut skin which is a rich source of phenolic compounds is a by-product of hazelnut roasting process. In present study, ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) and supercritical carbon dioxide extraction (SCE) methods were applied for recovery of phenolic compounds from hazelnut skin. Response surface methodology was used to estimate optimum extraction conditions. Extraction studies were performed according to Box-Behnken Design. Temperature (UAE)/power (MAE), time and ethanol concentration were independent variables for UAE and MAE. The independent variables selected for SCE were temperature, time and pressure. The optimum extraction conditions were 45 min and 67.2–67.6% ethanol concentration, 600 W, 6 min and 55.03–56.23% ethanol concentration and 42.72–49.10 °C, 59.83–60.00 min and 10.01–11.48 bar, for UAE, MAE and SCE respectively. Total phenolic content, FRAP and 1/EC50 values at the optimum conditions were 122.99–123.01 mg GAE/g, 612.20–613.25 mmol Fe(II)/g and 4.36 mL/mg for UAE, 111.53–111.55 mg GAE/g, 582.44–582.52 mmol Fe(II)/g and 2.48 mL/mg for MAE and 69.59–72.64 mg GAE/g, 426.25–465.52 mmol Fe(II)/g and 2.18–2.27 mL/mg for SCE, respectively. Maceration was performed for comparison with novel methods. UAE was found to be the best method of the extraction of phenolic compounds from hazelnut skin with the highest total phenolic content and antioxidant activity values.

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  AtıfScopus89·WoS78·OpenAlex97

  İncele