一株苦荞种子内生真菌红色素稳定性初报

Study on the stability of red pigments produced by a seedborne endnophytic fungus from Tartary Buckwheat

研究苦荞种子内生真菌TBSBEF-9的胞外红色素的生产特性及其色素的稳定性,结果表明,TBSBEF-9红色素为胞外色素,在发酵的第3 d红色素开始产生,第6 d达到最高水平;红色素最大吸收波长在510 nm;易溶于水、乙醇等极性溶剂,在酸性条件下呈现浅红色,碱性条件下为橘黄色;色素较耐热(<100℃);Ca2+、Ba2+、K+、A13+、Mg2+金属离子对该色素无明显影响;KMn O4、H2O2、Fe Cl3使色素色泽变化不明显,Vc对色素有较强的褪色作用;食盐、蔗糖对色素无明显影响而柠檬酸对其有褪色作用。可见,该红色素的理化性质比较稳定,是较理想的天然色素添加剂。

The ferment characterization and its red pigment stability of Tartary Buckwheat seed-borne endophytic fungi TBSBEF-9 were studied. The results showed that the pigment harbored in the extracellular of isolate TBSBEF-9,could be detected after 3 days ferment and reached its highest level at the sixth day. The whole wavelength scan showed that the maximal absorbtion was 510 nm. The pigment was soluble in water, ethanol and other polar solvents. And it showed pink under acidic conditions, orange under alkaline conditions. The pigment displayed a remarkable thermal（〈100℃） stability. Metal ions such as Ca^2＋, Ba^2＋, K^＋, Al^3＋, Mg^2＋had no significant effect on the pigment colour, the oxidants such as KMnO4, H2O2, FeCl3 would hence the red colour, while the reducing agent Vc made the pigment color lighter. Salt,sugar had no obvious effect on the colour change and under the citric acid it would fade. Therefore, the physicochemical properties of the pigment of Tartary Buckwheat were stable. The result also implied that the pigment was an ideal and natural color additive.