摘要
建立准确性高、稳定性好的绿茶全氮量的偏最小二乘定量分析模型.在4 691～3 959、5 126～4 848 cm-1波段区间内,光谱经过一阶导数与平滑处理后,模型的预测性能最好,外部验证集样品的预测值与实测值的预测均方差（RMSEP）为0.092 5％,相关系数为0.993 9.根据嫩度等级,建立了绿茶全氮量子模型,提高了模型的预测性能.嫩度为3级的子模型预测结果最好,验证集样品的全氮量的预测值与实测值的RMSEP值最小,为0.037 9％,相关系数为0.996 1.绿茶全氮量近红外光谱检测技术是一种绿色、快速、高效的新型分析技术,能够实现快速测定绿茶全氮量,评价绿茶品质.
A highly accurate and stable calibration model of total nitrogen content in green tea was established based on partial least square regression.The model demonstrated great predictive performance after the first derivative processing and smoothing in the spectral range of 4 691-3 959 cm-1 and 5 126-4 848 cm-1.The correlation coefficient of predicted and chemically measured values in the validation set was 0.993 9 and the RMSEP was 0.092 5％.The prediction performance was improved by developing sub-models of total nitrogen in green tea according to different tenderness.The prediction performance of the tenderness level 3 model was the best.The RMSEP in the validation set was the smallest,0.037 9％,and the correlation coefficient was 0.996 1.Thus,near infrared spectroscopy can provide a green,rapid and efficient technique for the detection of total nitrogen in green tea and quality evaluation.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2014年第8期147-151,共5页
Food Science
基金
国家现代农业(茶叶)产业技术体系建设专项(CARS-23)
关键词
近红外光谱技术
绿茶
全氮量
子模型
near infrared spectroscopy
green tea
total nitrogen content
sub-model
