DETERMINATION OF SEED OIL CONTENT AND FATTY-ACID COMPOSITION IN SUNFLOWER THROUGH THE ANALYSIS OF INTACT SEEDS, HUSKED SEEDS, MEAL AND OIL BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY

A methodological study was conducted to test the potential of near-inf rared reflectance spectroscopy (NIRS) to estimate the oil content and fatty acid composition of sunflower seeds. A set of 387 intact-seed sa mples, each from a single plant, were scanned by NIRS, and 120 of them were selected and further scanned as husked seed, meal, and oil. All samples were analyzed for oil content (nuclear magnetic resonance) and fatty acid composition (gas chromatography), and calibration equation s for oil content and individual fatty acids (C-16:0, C-16:1, C-18:0, C-18:1, C-18:2) were developed for intact seed, husked seed, meat, and oil. For intact seed, the performance of the calibration equations wa s evaluated through both cross-and external validation, while cross-va lidation was used in the rest. The results showed that NIRS is a relia ble and accurate technique to estimate these traits in sunflower oil ( validation r(2) ranged from 0.97 to 0.99), meal (r(2) from 0.92 to 0.9 8), and husked seeds (r(2) from 0.90 to 0.97). According to these resu lts, there is no need to grind the seeds to scan the meal; similarly a ccurate results are obtained by analyzing husked seeds. The analysis o f intact seeds was less accurate (r(2) from 0.76 to 0.85), although it is reliable enough to use for pre-screening purposes to identify vari ants with significantly different fatty acid compositions from standar d phenotypes. Screening of intact sunflower seeds by NIRS represents a rapid, simple, and cost-effective alternative that may be of great ut ility for users who need to analyze a large number of samples.