Determination of oil content in whole corn (Zea mays L.) seeds by means of near infrared reflectance spectroscopy

• The combination of near infrared reflectance spectroscopy and chemometrics was evaluated to measure oil in whole corn.
• The interpretation of the data generated allowed to identify regions in the NIR related to oil.
• The result of this study showed that NIR spectroscopy can be used to predict oil content in corn.

The objective of this study was to evaluate the ability of near infrared reflectance (NIR) spectroscopy to determine oil content in whole corn (Zea mays L.) samples sourced from a breeding program. Kernel samples were analysed in reflectance in the VIS and NIR regions (400–2500 nm) at 2 nm intervals using a scanning monochromator. Samples were scanned in a circular cell cup and reflectance data were stored as logarithm of the reciprocal reflectance (log 1/R). Samples were not rotated when spectra collection was made. The coefficients of determination (R2) and the standard error of cross validation (SECV) obtained for the prediction of oil content in the calibration set were 0.90% and 0.17%, respectively. The residual predictive deviation (RPD = SD/SECV) value obtained was 2.3, indicating that these calibrations can be used for qualitative determination of oil content (e.g. low, medium and high) or preliminary screening in whole corn.