Oxidative Stability of Oil Obtained from a Low‐Erucic Acid Pennycress (Thlaspi arvense L.) Mutant with Potential for Food Use

Abstract

The oilseed cover crop field pennycress (Thlaspi arvense L.) can be grown during the off-season for summer crops such as corn and soybeans. However, high erucic acid contents make oil from wild-types unsuitable for human consumption. Recent breeding efforts now offer a mutant strain (fae1-rod1 pennycress) with an altered fatty acid composition. In this study, fae1-rod1 pennycress oil is assessed for its fatty acid profile and tocopherol contents using gas chromatography and normal phase high-performance lipid chromatography, respectively. Oils are incubated at 30, 40, and 50 °C, and changes in the peroxide value (PV), para-anisidine value (pAV), and free fatty acid (FFA) content are monitored. FFA contents of all samples remained <1% throughout the incubation period. PVs and pAVs rapidly increase in oils stored at 50 °C. The pAVs of oils stored at 40 °C only differ to those of fresh oil after day 15 and are significantly lower than of oil stored at 50 °C throughout storage. PVs remain <15 when stored at 30 °C up to day 54. Pseudo-first order rate constants to model PV increase are used to generate an Arrhenius plot. The activation energy is estimated as 68 kJ mol −1 , comparable to other culinary oils. Practical applications: There is interest in cultivating oil from pennycress seeds for use in foods. Its cultivation could have environmental benefits, e.g., reduce soil erosion, improve nitrogen sequestration, and provide nutrients for pollinators in the spring. However, the wild-type strain is high in erucic acid, which potentially elicits toxic effects when ingested. Fae1-rod1 mutant strains contain only traces of erucic acid, but little is known about pennycress oils in general and characteristics related to food use of fae1-rod1 oils in particular. To the best of the authors' knowledge, this is the first study predicting fae1-rod1 storage stability. The data reported here can be used by processors and consumers to estimate the time interval during which cold-pressed fae1-rod1 pennycress oil can be expected to maintain its quality attributes at ambient temperature, provided it is stored appropriately, e.g., protected from light.