Abstract Spirulina platensis contain variety of pigments, such as chlorophylls, carotenoids, and phycocyanin. Phycocyanin (PC) exists in abundance, but due to its instability, the utilization of this pigment is still very limited. In this study, the PC was modified using formaldehyde crosslinks yielding phycocyanin-formaldehyde (PC-F), and its photostability was evaluated. The PC-F formation was designated by the distinctive alterations of the maximum absorption to 611 nm, which was 10 nm blue-shifted than those of the PC. Additionally, the sharp peaks of FTIR spectra at 1636 nm for C O and at 1019 nm for C O C, suggesting the interaction of phycocyanin with formaldehyde. The PC-F showed stabilization improvement up to 1.53-folds after 300 mins of yellow light exposure than those of PC. Contrary to yellow light irradiation, a severe decrease of PC-F absorbance was observed reach to 4.9-folds under UV-B irradiation. The poor stability of PC-F upon white light and UV-A irradiation were indicated by the decline of PC-F absorbance up to 1.72 and 1.80, respectively. Moreover, the present study suggests that the modification of phycocyanin by formaldehyde crosslink can increase photostability upon yellow light irradiation.

中文翻译：

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甲醛改性钝顶螺旋藻藻蓝蛋白的光稳定性

摘要 钝顶螺旋藻含有多种色素，如叶绿素、类胡萝卜素、藻蓝蛋白等。藻蓝蛋白（PC）大量存在，但由于其不稳定性，这种色素的利用仍然非常有限。在本研究中，PC 使用甲醛交联进行改性，产生藻蓝蛋白-甲醛 (PC-F)，并对其光稳定性进行了评估。PC-F 的形成是通过最大吸收到 611 nm 的独特变化来指定的，这比 PC 蓝移了 10 nm。此外，COC 的 FTIR 光谱在 1636 nm 和 COC 的 1019 nm 处出现尖峰，表明藻蓝蛋白与甲醛相互作用。PC-F 在黄光照射 300 分钟后的稳定性比 PC 提高了 1.53 倍。与黄光照射相反，在 UV-B 照射下观察到 PC-F 吸光度的严重下降达到 4.9 倍。PC-F 在白光和 UV-A 照射下的稳定性较差，PC-F 吸光度分别下降至 1.72 和 1.80。此外，本研究表明，通过甲醛交联修饰藻蓝蛋白可以提高黄光照射下的光稳定性。