小花鬼针草黄酮的提取及在草莓保鲜中的应用研究

Extraction condition and preservation effect to strawberry of Bidens parviflora Willd. flavonoids

以小花鬼针草为原料,用乙醇浸提法,4因素3水平正交实验提取黄酮类物质,得出小花鬼针草总黄酮的最佳提取工艺条件为:提取温度为80℃,提取时间为2.5 h,料液比为1:20(g/mL),乙醇浓度为60%。在此条件下,提取率可达4.54%。再以草莓果实为试材,确定小花鬼针草黄酮对其采后的保鲜效果。先取部分草莓,用于各指标初始值的测定,再将其余的随机分为4组,分别用60%乙醇和小花鬼针草提取液稀释2、4、8倍的溶液喷雾处理。模拟货架期常温放置,每隔12 h测定相关指标。结果表明:小花鬼针草黄酮可在一定程度上减缓草莓腐坏速度、减慢Vc和可溶性固形物的分解、较好地保持超氧化物歧化酶的活性、减轻细胞质膜损伤、减少丙二醛的形成且随着提取液稀释倍数增加其效果减弱。

In order to optimize the extraction conditions of Bidens parviflora Willd. flavonoids, the four factors and three levels of orthogonal test was chosen with ethanol extraction. The optimal extraction condition was determined as following： extraction temperature is 80 ℃, extraction time is 2.5 h, solvent to material is 20 （mL/g）, ethanol concentration is 60%. At the conditions the yield of Bidens parviflora Willd. flavonoids was 4.54%. After that, various physiological index were determinated in order to make clear the preservation effect to strawberry of Bidens parviflora Willd. flavonoids. The small part of strawberry was at first, then the rest were randomly divided into 4 groups, they were dealed with spraying of 60% ethanol and different concentrations of Bidens parviflora Willd. flavonoids, and put at the normal temperature as selling. The physiological index were determinated every 12 h. The results showed that： the flavonoids reduced the decay of strawberry fruit relatively, slowed down the decomposition of Vc and soluble solid content, kept the activity of superoxide dismutase at a high level, reduced the permeability of cell membrane and the formation of malondialdehyde, and the effect was weaken with the dilution of the extraction .