通过交叉验证和偏最小二乘法(PLS)方法,建立了茶鲜叶的近红外光谱(NIRS)与其含水量、粗纤维总量和全氮量之间相关性模型。当主成分数为7时,3个指标的R值分别为0.92、0.86和0.90;交互验证均方根方差(RMSECV)分别为0.769、0.332和0.742。提出了基于鲜叶含水量、粗纤维总量和全氮量的茶鲜叶原料的质量系数方程,得出了鲜叶的质量系数。鲜叶质量系数越大,其质量越高。本文开发了一种基于NIRS技术评价茶鲜叶原料质量的新方法。
In order to estimate the quality of the fresh tea leaves by near infrared spectrum (NIRS) technique, the correlative model equation between near infrared spectrum of the fresh tea leaves and their corresponding moisture, crude fiber and total nitrogen amounts respectively through cross-validation and partial least squares (PLS) method were established in this paper. When the dimension was 7, the three indicators of R value were 0.92, 0.86 and 0.90, root mean square error of cross-validation (RMSECV) were 0.769, 0.332 and 0.742, respectively. A quality coefficient equation was suggested depending on the contents of moisture, crude fiber and entire nitrogen of fresh tea leaves. According to the quality coefficient equation of fresh tea leaf raw material, the quality coefficient of fresh tea leaves was obtained. The larger quality coefficient is, the higher quality of fresh leaf is. Thus, we developed a new method for the evaluation for the quality of fresh tea leaves by using NIRS was developed.
[1] Smiechowska M, Dmowski P.Crude fiber as a parameter in the quality evaluation of tea[J]. Food Chemistry, 2006, 94(3): 366-368.
[2] Shou-he Yan. Review: Evaluation of the composition and sensory properties of tea using near infrared spectroscopy and principal component analysis[J]. Journal of Near Infrared Spectroscopy, 2005, 13(6): 313-325.
[3] 中华全国供销合作总社. GB/T 8310—2002,茶叶中粗纤维的测定[S]. 北京: 中国标准出版社, 2002.
[4] 卫生部食品卫生监督检验所. GB/T 5009.5—1985,食品中蛋白质的测定方法[S]. 北京: 中国标准出版社, 1985.
[5] 江泽慧, 胡安民.木材中的水分及其近红外光谱分析[J]. 光谱学与光谱分析, 2006, 26(8): 1464-1468.
[6] 李勇魏益民, 张波, 等. 近红外水分稳健分析模型研究[J]. 光谱学与光谱分析, 2005, 25(12): 1963-1967.