Research On Extraction And Separation For Tenebrio Molitor And Its Anti-oxidant Characteristic

Tenebrio molitor has many useful nutrients and highly application value. This paperattempted to extract flavonoids from Tenebrio molitor with distilled water under the twomethods of thermal circumfluence extraction and ultrasound-associated extraction. Then, weused macroporous adsorption resin to purify the crude flavonoids and tested the antioxidantactivity in vitro of the final purified products. The mainly results as follows:（1） By using distilled water and different concentration of ethanol solution as extractionsolvent, flavonoids extracted from Tenebrio molitor under the same condition. Aftercomparing the yield of flavonoids, the results concluded that the yield of flavonoids reducedin turn with the increase of ethanol concentration, distilled water as extraction solvent wasbetter. Therefore, this study selected the distilled water as extracting agent to extract Tenebriomolitor flavonoids.（2） The article studied on the best extraction conditions by using two methods of thermalcircumfluence extraction and ultrasound-associated extraction. By using L₉（3⁴） orthogonalexperiment design, the optimal conditions of thermal circumfluence extraction flavonoidswere obtained as follows: Liquid-to-solid ratio of20:1（mL/g）, extraction time of3h,extraction temperature of40℃, Under the optimal extraction conditions, the actual yield offlavonoids was12.01mg/g. Box-Behnken experimental design was used to provideexperimental data for establishing a regression model describing the yield of flavonoids underultrasound-associated extraction, and after the Design-Expert7.0Trial software analysis, theoptimal conditions of thermal circumfluence extraction flavonoids were obtained as follows:Liquid-to-solid ratio of18.34:1（mL/g）, extraction time of30.06min, extraction temperatureof58.43℃, and ultrasonic power of380.62W. Under the optimal extraction conditions, theactual yield of flavonoids was11.47mg/g, which was in basic agreement with the theoreticalvalue of11.58mg/g. It found that the yield of flavonoids by thermal circumfluence extractionis generally higher than that of ultrasound-associated extraction. However, Ultrasound-associated extraction had advantages of saving time and high efficiency. （3） The characteristics of adsorption and desorption of Tenebrio molitor flavonoids onfour kinds of macroporous resins were compared, there were XDA-1, NKA-9, D101, AB-8.XDA-1was the selected resin to separate flavonoids considering the highest adsorptioncapacity and higher desorption ratio. Based on the characteristics of dynamic adsorption anddesorption, the optimal purification technology was as follows: sample concentration1.00mg/mL, sample loading flow rate2BV/h, sample pH5.0，sample loading amount of2BV,3BV of60%ethanol as the eluent at a flow rate of2BV/h. After the purification, the purity oftotal flavonoids increased from3.74%to16.34%. Tenebrio molitor flavonoids containedisoflavones and catechins by color reaction.（4） The in vitro antioxidant activity of Tenebrio molitor flavonoids before purifying andafter purified, the results showed as follows: The effect of deoxidization capacity werepurified flavonoids> crude flavonoids> V_C> rutin. The effect of scavenging hydroxyl freeradical were rutin> purified flavonoids> V_C> crude flavonoids. The effect of scavengingsuperoxide anion free radical were V_C> rutin> purified flavonoids> crude flavonoids. Theinhibitory effect of different antioxidant against lipid peroxidation were purified flavonoids>crude flavonoids> rutin> V_C. In four kinds of antioxidant experiment, the antioxidant effectof purified flavonoids was generally higher than that of curde flavonoids. The effect ofantioxidant activity of Tenebrio molitor flavonoids enhanced in turn with the increase ofadditive amount when adding among20to500μg.