Université catholique de Louvain, Earth and Life Institute - Agronomy (ELI-A), de Serres Building, Croix du Sud 2, L7.05.11, 1348 Louvain-la-Neuve, Belgium.
Walloon Agricultural Research Centre. Valorisation of Agricultural Products Department, Food and Feed quality Unit, Henseval Building, Chaussée de Namur 24, 5030 Gembloux, Belgium.
Sci Rep. 2016 Sep 16;6:33183. doi: 10.1038/srep33183.
Near infrared microscopy (NIRM) has been developed as a rapid technique to predict the chemical composition of foods, reduce analytical costs and time and ease sample preparation. In this study, NIRM has been evaluated as an alternative to classical chemical analysis to determine the nitrogen and carbon content of small samples of tomato (Solanum lycopersicum L.) leaf powder. Near infrared spectra were obtained by NIRM for independent leaf samples collected on 216 plants grown under six different levels of nitrogen. From these, 30 calibration and 30 validation samples covering the spectral range of the whole set were selected and their nitrogen and carbon contents were determined by a reference method. The calibration model obtained for nitrogen content proved to be excellent, with a coefficient of determination in calibration (R(2)c) higher than 0.9 and a ratio of performance to deviation (RPDc) higher than 3. Statistical indicators of prediction using the validation set were also very high (R(2)p values > 0.90). However, the calibration model obtained for carbon content was much less satisfactory (R(2)c < 0.50). NIRM appears as a promising and suitable tool for a rapid, non-destructive and reliable determination of nitrogen content of tiny samples of tomato leaf powder.
近红外显微镜（NIRM）已被开发为一种快速技术，用于预测食品的化学成分，降低分析成本和时间，简化样品制备。在这项研究中，NIRM 被评估为替代经典化学分析的方法，以确定小番茄（Solanum lycopersicum L.）叶粉样品的氮和碳含量。通过 NIRM 对在六种不同氮水平下生长的 216 株植物上采集的独立叶片样本进行了近红外光谱测量。从这些样本中，选择了 30 个校准样本和 30 个验证样本，涵盖整个光谱范围，并用参考方法测定它们的氮和碳含量。用于氮含量的校准模型证明非常出色，校准（R(2)c）的决定系数高于 0.9，偏差比（RPDc）高于 3。使用验证集进行预测的统计指标也非常高（R(2)p 值>0.90）。然而，获得的碳含量校准模型则差得多（R(2)c<0.50）。NIRM 似乎是一种有前途且合适的工具，可用于快速、非破坏性和可靠地测定小番茄叶粉样品的氮含量。
