本研究首次建立了简单、快速地测定乌骨鸡黑色素含量的荧光分析方法。乌骨鸡黑色素在碱性条件下经过氧化氢氧化后产生强烈的荧光。本研究优化了样品前处理条件以及氧化反应条件，对线性范围、检测限以及加标回收率进行了评价。结果表明，最佳氧化条件：氧化温度为55 ℃，过氧化氢溶液工作浓度范围为20%~25%，氧化反应时间为2 h；最佳样品前处理的条件：NaOH浓度为0.1~0.2 M，超声时间为40 min，超声温度为70 ℃。黑色素浓度在50~600 μg/mL范围内呈良好线性关系，相关系数r=0.9986。与传统检测方法相比，荧光分析法无需从样品中提取黑色素，极大地加快了分析速度，简化了分析操作，并且该方法相对于紫外分光光度法的检测限降低了至少10倍。样品添加不同浓度的黑色素工作标准品的平均回收率为102.87%，RSD值为4.51%。采用该方法测定了乌骨鸡鸡皮、腿肌、胸肌中的黑色素含量，结果显示乌骨鸡肉中的黑色素含量：鸡皮>腿肌>胸肌，分别占鲜重的1.08%、0.44%、0.34%。以上结果表明该方法较快速、准确、检测限低，适用于乌骨鸡中黑色素含量的测定。

For the first time, a simple and rapid fluorescence analysis method was established in this study for determining the melanin content in Black-bone Silky Fowl (BSF). The melanin in BSF could produce strong fluorescence after oxidation by H2O2 under alkaline conditions. In this study, the conditions for sample pretreatment and oxidation reaction were optimized, and the linear range, detection limit and spiked recovery rate were then evaluated. The results showed that the optimal oxidation conditions were: oxidation temperature 55 ℃, working concentration range of hydrogen peroxide solution 20%~25%, oxidation reaction time 2 h. The optimal sample pretreatment conditions were: NaOH concentration 0.1~0.2 M, ultrasonic time 40 min, ultrasonic temperature 70 ℃. The melanin concentration showed a good linear relationship in the range of 50~600 μg/mL, with the correlation coefficients as 0.9986. Compared with the traditional detection method, the fluorescence analysis method did not require the extraction of melanin from the sample, which greatly speeded up the analysis and simplified the analysis operation, and enabled at least 10 times lower detection limit as compared to the ultraviolet spectrophotometric method. The average recovery of the sample spiked with different concentrations of melanin working standard was 102.87% with the RSD value as 4.51 %. Using this method, the contents of melanin in BSF’s skin, thigh meat and breast meat were found to follow the order of chicken skin>thigh meat >breast meat (accounting for 1.08%, 0.44% and 0.34% of fresh weight, respectively). The above results showed that the established method is fast and accurate with a low detection limit, thus is suitable for the determination of melanin content in BSF.

国家自然科学基金地区科学基金项目（21162018）；食品科学与技术国家重点实验室自由探索资助课题（SKLF-ZZB-201520）