Improving Detection Ability of Near Infrared Spectroscopy to Detect the Low concentration Phorbol esters in Jatropha seed

บทคัดย่อ

Phorbol esters (PEs) is the crucial toxic compound of jatropha that can be tumor promotors, even in low concentration. The reference method for determining the PEs was HPLC. The method requires an experienced analyst, chemical solvent, many steps of sample preparation, high cost and time consumption. However breeding jatropha for animal feed and biodiesel production needs rapid and efficient methods to determine the phorbol esters (PEs) content of a large number of seed samples. Near-infrared spectroscopy (NIRS) has been proven as a powerful analytical tool which is fast, accurate, cost-effective, non-destructive and less chemicals used. In the current study, a calibration set of 130 sample of jatropha interspecific breeding lines was investigated using NIRS technique to determine phorbol esters (PEs) contents. In the pre-concentration step, the effective performance of calibration models for PEs prediction were compared between with and without using dry-extraction spectroscopy for near infrared technique (DESIR). The model for the PEs obtained using DESIR showed the coefficient of determination (R_v), standard error of prediction (SEP) and ratio of standard error of validation to the standard deviation (RPD) of 0.80, 0.24 mg/g DW and 1.70. While the parameters without DESIR were 0.62, 0.27 mg/g DW and 1.26, respectively. Statistical testing for performance measurement based on ISO12099:2017 of the model for PEs prediction, the NIR-predicted values using DESIR were not different from the actual values at the 95% confident interval. Thus NIRS using DESIR could potentially be used for predicting PEs contents in jatropha seed.