紫甘薯天然色素的微波提取及性質研究

食品科學論文編號:SP030 論文字數(shù):8258,頁數(shù):20

摘要 1
目錄 2
1 前言 2
2 材料與方法 3
2.1 試驗材料 3
2.1.1 植物材料及溶劑 3
2.1.2 主要設備 4
2.2 色素提取與初步純化主要流程 4
2.3 紫甘薯色素含量的分析方法 4
3 結果與分析 4
3.1 微波提取的單因素試驗 4
3.1.1 微波功率對色素提取的影響 5
3.1.2 微波提取時間對色素提取的影響 5
3.1.3 提取體系料液比對色素提取的影響 6
3.2 微波提取工藝的正交試驗優(yōu)化 7
3.2.1 正交試驗表設計 7
3.2.2 試驗結果與分析 8
3.3 微波輔助提取次數(shù)的確定 9
3.4 色素性質研究試驗 9
3.4.1 色素粉效能的試驗 9
3.4.2  pH值對吸收光譜影響的試驗 11
3.4.3  pH值對紫甘薯色素顏色影響的試驗 12
3.4.4  pH值對紫甘薯色素穩(wěn)定性影響的試驗 12
3.4.5  光照對色素穩(wěn)定性影響的試驗 13
3.4.6  溫度對色素穩(wěn)定性影響的試驗 13
3.4.7  各種金屬離子對色素穩(wěn)定性影響的試驗 15
3.4.8  糖、鹽對色素穩(wěn)定性影響的試驗 16
3.4.9  防腐劑、H2O2對色素穩(wěn)定性影響的試驗 16
4　討論與小結 16
參 考 文 獻 18
致       謝 20
摘要：紫甘薯中含有豐富的花色苷類物質，是一種極具開發(fā)價值的天然色素資源。本文對紫甘薯天然色素的微波輔助提取條件及性質進行初步研究。結果表明，用微波輔助提取紫甘薯天然色素，不僅節(jié)省時間，而且提取效果好。通過單因素和正交試驗得出微波提取紫甘薯天然色素的最佳條件是：微波功率60%（480 W），提取時間60 s、料液比（g：ml）1：3，提取次數(shù)為3次。紫甘薯天然色素的濃度與其OD值之間有很強的正相關性；pH值對色素最大吸收峰有明顯影響，pH3.0以下色素最大吸收波長為520 nm；色素在酸性條件下較穩(wěn)定，隨著pH值升高，穩(wěn)定性逐漸下降，強堿性條件下易被破壞；光的直接照射會影響色素的穩(wěn)定性；金屬離子Cu2+、Ca2+、K+、Mg2+、Fe2+和Fe3+對色素的影響不明顯；同時，糖、鹽和防腐劑對色素的影響也較小，但H2O2對紫甘薯天然色素影響較大。
關鍵詞：紫甘薯；天然色素；微波輔助提取；性質

Microwave Assisted Extraction and Properties of Natural Pigment
 from Purple Sweet Potato

Abstract：    The microwave assisted extraction conditions and some physical and chemical properties of the natural pigment from the purple sweet potato were preliminarily investigated. The results showed that the microwave assisted extraction was effective method in this study. Based on a series of single factor and their orthogonal experiments, it was found that the best conditions of extraction for natural red pigment from purple sweet potato were：microwave power 480 W, extraction time 60 s and the ratio of solid to liquid 1：3（g：ml）. The pigment was significantly affected by the pH value, and it was very stable under acidic conditions, when the peak of absorption wavelength was at 520 nm. Additionally, sugar （5% sucrose and 5% glucose）, salt （1%NaCl） and antiseptic （1% Sodium benzoate）, and some metal ions such as Cu2+, Ca2+, Fe2+, K+, Fe3+ and Mg2+ had little effect on its stability. However, H202 had a significant effect on the stability.

Key words：purple sweet potato；natural pigment；microwave assisted extraction；properties