Analysis of oil content of maize by wide‐line NMR

Abstract

A series of experiments to define feasibility, accuracy, and precision of wide‐line nuclear magnetic resonance spectroscopy as a nondestructive analytical tool for the oil content of living seeds is described. Corn samples, ranging from single seeds to 25 g, were scanned by NMR and gravimetrically analyzed. A high positive correlation (r = 0.99+) was invariably encountered. Single, 30‐sec NMR scans on 25‐g corn samples gave estimates within ŷ33 ing of the “true” oil content 95% of the time. Error associated with single, 30‐sec scans of individual corn kernels amounted to ŷ1.3 mg of oil at the same confidence level. Samples containing more than 4.5% moisture contribute to the NMR signal, and therefore oil content is overestimated. A new dimension is added to the breeding and genetics of oil crops by the application of the NMR technique in that the process is non‐destructive and feasible even for single seeds. The usefulness of the technique in studies involving the nature of water and its surrounding medium is suggested.

Inheritance and characterization of two low linolenic acid EMS-induced McGregor mutant flax (Linum usitatissimum)

“…To reduce anisotropic line broadening, the seeds were rotated at 1 kHz in a zirconium rotor oriented at 54.7°to the magnetic field. This NMR technique is a non-destructive method which provides a good distinction between the liquid and solid parts of the seeds, such that intensities of 1 H signals quickly determine the oil content (Alexander et al 1967). …”

Use of NMR for predicting protein concentration in soybean seeds based on oil measurements

“…Sample analysis can be conducted in a few seconds and the results are highly reproducible (10). Large sample sizes are not required, as accurate readings can be obtained from individual seeds (9). NMR has been used to measure the oil concentrations of many crops, such as maize (9), soybeans (12), flax, and canola (13).…”

“…NMR spectrometry is a rapid, nondestructive method that can be used to accurately determine the oil and moisture concentrations of whole seeds (2,9,10). The NMR technique measures the total hydrogen in a sample and is capable of distinguishing between hydrogen atoms in the oil fraction from those bound in water, carbohydrate, and protein (11).…”

“…Large sample sizes are not required, as accurate readings can be obtained from individual seeds (9). NMR has been used to measure the oil concentrations of many crops, such as maize (9), soybeans (12), flax, and canola (13). Oil readings generated by NMR were reported to be highly correlated with values obtained by extraction with petroleum ether (r = 0.993) (2) and with gravimetric oil analysis (r = 0.995 to 0.999) (9).…”

Genetic basis of maize whole kernel, embryo, and endosperm oil

“…Kernels were imbibed in water to facilitate removal of the pericarp and separation of embryo and endosperm. Following separation, the embryo and endosperm were air-dried overnight at room temperature, weighed and analyzed for oil percentage via nuclear magnetic resonance (Alexander et al, 1967) using a Maran Ultra-20 (Oxford Instruments) at Monsanto in St.…”