Technology Of Flavonoids Extraction In Lingwu Long Date And Evaluation Of Its Antioxidizing Activity

Zyzypus Jujuba dates is one of fruits growing in china; it has long been considered as a health-protection products. Recently, it was thought that some special components in Jujube have higher biological functions. Through the extraction, separation and purification, functional components in Jujube could be used as natural food additives. This will enhance their health-promotion effect and application value.Falconoid in this study, was extracted from the Lingwu long date with different methods. Using the single factor and orthogonal test method, the optimum extraction conditions is investigated. Then, antioxidant activity of flavonoid isolated from Lingwu long date was investigated. The results showed that the optimal extraction parameters for flavonoids using ethanol as solvent were ethanol concentration 5%, extraction time 2h, temperature 80℃, liquid/solid ratio 20:1, number of extraction 2. Under the extraction condition, maximum yield could achieve 1680.27mg/100g; The optimal extraction parameters of flavonoids using NaOH as solvent were NaOH concentration 0.001mol/L, extraction time 2h, liquid/solid ratio 20:1, extraction twice. Under the extraction condition, the maximum yield could reach 710.34 mg/100g; The optimal extraction parameters for flavonoids using ultrasound-assisted method were ethanol 45%, extraction time 2h, the temperature 90℃, ultrasonic power is 200W, liquid/solid ratio 20:1, and number of extraction 2. Under the extraction condition, maximum yield can be achieved 1620.98mg/100g. The optimal extraction parameters of flavonoids with enzymatic method were pH5, extraction temperature 80℃, extraction time 2h, the concentration of enzyme 0.03%, extraction twice, Under the extraction condition, maximum yield could research 656.44mg/100g. Basing on these results, ethanol extraction t was the better extraction ways of flavonoids from Lingwu long date.Because macroporous resin AB-8 made in China has good abilities of adsorption and desorption for nuclear Dongzao flavonoids, it could be applied to adsorption and separation for Lingwu long date. Among three resins, relative elution volume of AB-8 was 9.2mg/ml, and the elution rate could reach 92%.Flavonoids in Lingwu long date has strong antioxidant activity in vitro. It could effectively scavenge the DPPH·and superoxide anion radicals in a dose-dependent manner. The DPPH·scavenging ability is 70.2-80% at the concentration of 43%. Flavonoid in Lingwu long date have a very good protective effect against the "Long ya 9th " oil oxidation. Exposured in the air, After 11 hours, peroxide values of control and treatment groups were 46.37 and 38.09, respectively. The difference of POV value between them reached 8.28. Peroxide values of treatment group was 18% lower than that of control group. It could be concluded that flavonoids in Lingwu long date have better antioxidant activity.