白玉米粉的营养成分和抗氧化性能的研究

Study on Nutritional Components of the White Cornmeal and Its Anti-Oxidation Activity

摘要:

采用紫外分光光度法，测定白玉米粉中维生素A(V_A)、维生素C(V_C)、总黄酮、总生物碱；采用索氏抽提法提取白玉米粉中的脂肪和抗氧化成分，并测定其脂肪含量；用原子吸收分光光度法测定白玉米粉中钾、钠、镁、铁、钙、锰、锌、铜、锶等9种微量元素的含量，并观察了白玉米粉乙醇提取物、V_C和芦丁(Rutin)对油脂的抗氧化性，将其分别添加到棉籽油、羊油脂中，利用Na₂S₂O₃-I₂滴定法分别测定乙醇提取物、V_C和芦丁对棉籽油、羊油脂的过氧化(POV)值；用分光光度法分别对白玉米粉乙醇提取物，维生素C，芦丁的清除羟自由基(·OH)的能力进行了测定和比较。实验结果表明，白玉米粉乙醇提取物、V_C和芦丁分别对棉籽油、羊油脂均有抗氧化作用，其中0.02%芦丁的抗氧化作用大于0.02%V_C和0.01%或0.05%的乙醇提取物，随着提取物浓度的增加，抗氧化性能逐渐降低；白玉米粉乙醇提取物、维生素C、芦丁均有清除羟自由基的能力，其中0.02%芦丁标准品的清除能力最好，其次是0.02%维生素C和白玉米粉乙醇提取物；通过测定得知每100 g白玉米粉中V_A和V_C分别为286.50 μg和763.0 μg；总黄酮含量为365.0 μg；总生物碱含量为173.50 μg；总糖和膳食纤维的含量分别为4.48 g和7.30 g；微量元素K和Na含量较高；白玉米粉乙醇提取物具有一定的抗氧化性和清除自由基的能力，可有效地延缓油脂的脂质过氧化反应。本文测得数据为进一步研究和综合开发利用这一维吾尔传统药食两用作物提供了依据。

Abstract: Abstract: Nutritional Components of white-cornmeal (Zae mays L.) including Vitamin A, Vitamin C, total flavonoid, total alkaloid, microelements, total fat and total sugar were determined. UV spectra was applied for the determination of the Vitamine A (V_A), Vitamine C (V_C), flavonoid, alkaloid and cholesterin. Antioxidative components and total fat were extracted by soxhlet method. AAS was applied to determine the mineral elements such as K, Na, Zn, Ca, Fe, Cu, Mn, Mg, Sr in Cornmeal. Antioxidant activity of the ethanol extract and V_C on cotton seed oil and suet were studied through measuring peroxide value (pov) by Na₂S₂O₃-I₂ titrimatric method. The results showed that 0.02% Rutin has higher ac- tivity than the 0.02% V_C and 0.01% or 0.05% ethanolic extract. With increasing of ethanolic extract concentration, the antioxidatant activity is decreased. Hydroxyl free radical (·OH) scavenging ability was tested and compared by UV spectraphotometric method. The results were: 0.02% standart Sample of Flavone (Rutin) had stronger ·OH eliminating ability than the 0.02% V_C and ethanolic extract. There were 286.50 μg of V_A and 763.0 of V_C in every 100gCornmeal. The amount of the total flavonoids, alkaloids in every100 gCornmeal, was 365.0 μg, 173.50 μg and 21.43 μg respectively. The amount of total sugar and meal cellulose was4.48gand 7.30 mg respectively. It has comparatively high amount of K and Na elements. Ethanolic extracts of Cornmeal can delay lipid peroxidation of the oils and had the abil- ity of free-radical elimination. This article provided preliminary data for the further investigation and exploitation of the Uyghur traditional health medicinal materials.