Browsing by Subject "Chinese chives"
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    Antioxidant activity of Allium tuberosum Rottl. ex Spreng under different extraction methods
    ( 2015-11) Patchanee Yasurin ; Napatsorn Lawthienchai ; Aussama Soontrunnarudrungsri
    The Bang-Phae organic vegetable grower community enterprise group, Ratchaburi province is one of the big Chinese chives (Allium tuberosum Rottl. ex Spreng) grower in Thailand. However, some Chinese chives did not meet standard and were sorted out. The Chinese chives essential oil, which contains many new and known bioactive compounds, is valued product from sorted out Chinese chives. Therefore, this experiment was aimed to study the antioxidant activity of Chinese chive extracts using 17 different extraction conditions (Steam distillation for 1.0, 2.0, 2.5, 3.0 hour; Ohmic pretreatment with steam distillation for 1.0, 2.0, 2.5, 3.0 hour; 95% ethanol, hexane, oil extract using dry, fresh, freeze Chinese chives). The ferric reducing antioxidant potential assay was used to evaluate antioxidant activity of Chinese chive extracts. The results showed that the highest antioxidant activity was 1.756 ± 0.008 µmol Fe2+/ mg sample of freeze Chinese chives extracted with hexane. The antioxidant activity was vary from 0.098 ± 0.005 - 1.756 ± 0.008 µmol Fe2+/ mg sample depend on the extraction condition.
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    Effect of ohmic pretreatment on tissue integrity and extraction yield of Chinese chives (Allium tuberosum) leaf oil
    ( 2015-11) Patchanee Yasurin
    Chinese chives (Allium tuberosum Rottl.) are known for its antimicrobial and antioxidant properties. However, extract from Chinese chives was not commercially available due to very low extraction yield of the conventional method, steam distillation. This study focused on effect of ohmic pretreatment at different electric field strengths on tissue integrity and extraction yield of Chinese chives leaf oil. The field strength was varied at E = 0, 25, 50, 75 and 100 V/cm. For all treatment, the cut-off temperature was fixed at 60 °C. The tissue integrity was determined by an electrical conductivity disintegration index (Z) and viable staining using neutral red dye. It was found that as the field strength increased, Z value increased indicating a higher degree of tissue damage. The highest degree of tissue damage (Z ~ 0.8) was obtained when E > 75 V/cm were applied. The viability test showed agreeable results to the Z values. More red cells were observed at the lower field strength. At E = 25 v/cm, the amount of viable cells were comparable to the control (fresh tissue) while there was almost no viable cell left at E > 75 V/cm. When ohmic pretreatment at E = 75 V/cm was applied prior to 2.5 h of steam distillation, the extraction yield was increased from 0.12+0.01% to 0.16+0.02% by fresh leaf weight or about 33%. Thus, ohmic pretreatment was suggested to increase the permeability of any biological materials prior to extraction process in order to enhance the extraction yield.