Identification of High Oleic Castor Seeds by Near Infrared Reflectance Spectroscopy

摘要

Castor oil contains a high proportion (80%) of the unusual hydroxy fatty acid ricinoleic acid. Additionally, a mutant with high oleic acid content (70%) has been developed. Both fatty acids differ in the presence of an OH group in the C18 tail (ricinoleic acid). The objective of this research was to evaluate whether near-infrared reflectance spectroscopy (NIRS) can be used to discriminate between high oleic and high ricinoleic acid seeds. Eight hundred and seventy-two individual seeds collected in 2008, 688 high ricinoleic and 184 high oleic, were scanned by NIRS and further analyzed by GLC. As high oleic/low ricinoleic acid content is recessive and no intermediate fatty acid levels occur, the spectral data was subjected to linear discriminant analysis, which correctly classified all the seeds. The discriminant function was validated with a set of 637 seeds collected in 2009 from segregating populations, which were correctly classified in all cases. NIRS discrimination between oleic and ricinoleic acid was mainly based on spectral regions around 1,400 and 1,914 nm, putatively associated with the absorbance of the OH group. The results confirmed that NIRS provides an effective means of discriminating between high oleic and high ricinoleic acid seeds.