西梅花色苷浸提工艺及降解特性

Extraction technology and degradation characteristics of anthocyanin from Prunus salicina L.

为取得较好的浸提效果,获得西梅花色苷浸提工艺条件及相关降解动力学参数,研究浸提溶剂、乙醇体积分数、料液质量浓度、pH值、浸提温度和浸提时间对西梅花色苷浸提效果的影响,同时研究了pH值、抗坏血酸、葡萄糖对西梅花色苷稳定性的影响及降解动力学过程.发现在浸提溶剂为60%酸性乙醇溶液、料液质量浓度1/10 g·mL-1、浸提时间2.0 h、pH2.0、浸提温度60℃时获得较好的浸提效果(浸提得率1.52 mg·g-1新鲜西梅).在西梅花色苷中添加质量分数0.01%抗坏血酸或10%葡萄糖,并进行加热处理研究其降解过程活化能、反应速率常数及半衰期的变化,同时对西梅花色苷的热降解动力学进行研究,结果表明:西梅花色苷在本研究条件下降解过程符合一级动力学反应,其热降解活化能在pH3.0时为69.12 kJ·mol-1,增加或降低pH都使其活化能减小;在添加质量分数0.01%抗坏血酸、10%葡萄糖后,其活化能分别为下降86.49%和73.15%,表明西梅花色苷添加抗坏血酸或葡萄糖稳定性降低.

To achieve good extraction efficiency and acquire extraction technology with related kinetic pa- rameters of anthocyanin from Prunus salicina L. , the effects of operating conditions of solvent, ethanol concentration, solid-liquid ratio, pH value, extraction temperature and time on extraction yield were in- vestigated. Thermal degradation kinetics and stability of anthocyanin from Prunus s. were discussed with adding aseorbic acid and glucose at selected extraction pH, temperature and time. The maximal antho- eyainin yield of 1.52 mg . g- 1 fresh weight from Prunus s. was obtained at the conditions of 60% hydro- chloric in ethanol, pH of 2.0, extraction time of 2.0 h, solid-liquid ratio of 1/10 g . mL-1 and tempera- ture of 60 ℃. The degradation kinetics of anthocyanin were also discussed by adding common food addi- tives with 0.01% ascorbie acid or 10% glucose to obtain kinetic parameters of activation energy of E, rate constant of k and half-life of t 1/2. The results show that the degradation of the anthoeyanin is followed by first-order reaction kinetics, and the maximal Ea of anthocyanin degradation is 69.12 kJ . mol - 1 at pH value of 3.0. By adding 0.01% aseorbie acid and 10% glucose into the reaction system, the degradation process can be promoted with reduced E by 86.49% and 73.15% , respectively.