pH值及金属离子对樟树果实红色素吸收光谱的影响

以樟树果实为材料,运用800～400 nm光谱扫描分析了pH值、金属离子、加热时间及温度、光照等稳定性因子对樟树果实红色素吸收光谱的影响。结果表明:最大吸收波长是517 nm,酸性条件对色素吸收光谱无明显影响,当pH为8.6的强碱性环境,红色素结构变化,最大吸收峰漂移至402 nm;100℃内,色素性质稳定,当加热时间延长至120 min,最大吸收峰在512.5 nm;红色素耐光性较好,但避光更利于保存;金属离子对红色素吸收光谱的影响强弱为:Fe3+>Al3+>Mg2+>Ca2+>Na+>K+,Fe3+短时内引起色素变色、发生沉淀,最大吸收峰漂移,浓度越高影响越大,Na+、K+对红色素吸收光谱无明显影响。

The Effect of pH Value and Metal Ions on Absorption Spectra of Red Pigment from Fruits of Camphor Tree

A study on the effect of pH,metal ions,heating time,temperature and light on absorption spectra of red pigment from fruits of camphor tree was carried out using 800～400 nm spectral scanning analysis.The results showed that the maximum absorption wavelength was 517 nm;acidic conditions had no significant effect on the pigment absorption spectrum.When pH was 8.6 the strong alkaline environment,red pigment structural changes;when pH 8.6,the structure of red pigment changed greatly,its maximum absorption peak shifting to 402 nm;below 100℃,the pigment remained stable,but the maximum absorption peak was at 512.5 nm when the heating time extended to 120 min;red pigment had good photostability,but keeping in dark place was first choice;the effect of metal ions on the absorption spectra of red pigment varied as follows：Fe3＋ Al3＋ Mg2＋ Ca2＋Na＋K＋;within a short time Fe3＋ caused pigment discoloration,precipitation and the maximum absorption peak shifting,aggravating this effect with ion concentration;Na＋ and K＋ had no significant effect on absorption spectrum of the red pigment.