Improvement of rapeseed oil body stability with a new strategy employing planting density

Reports on the effects of planting density on rapeseed oil body (OB) characteristics are limited. Herein, the composition and structure of OBs extracted from six rapeseed ( Brassica napus L.) genotypes with radically different plant architectures under the planting density of 45 × 10 4 and 75 × 10 4 plants ha −1 were studied. Compared with 45 × 10 4 plants ha −1 , the lipid, unsaturated fatty acid, and hydrophobic amino acid contents of OBs under the density of 75 × 10 4 plants ha −1 were increased by 2.49%, 0.10−1.54%, and 0.36−3.99%, respectively. With increasing planting density, the protein content decreased by 0.73%, and the secondary structure of protein became loose. These changes weakened protein–protein interactions while enhancing protein–lipid binding on the OB surface, leading to an increase in the absolute zeta potential by 15.66% and a reduction in the average particle size by 22.80%. An increased planting density may improve the stability of rapeseed OBs; however, interspecific differences in OB stability were also observed, which was attributed to the synergistic effects between composition changes and interaction properties of OBs. Rapeseed OBs derived from the tall-stem plant type (Chuanyou20) under dense planting may be appropriate for commercial applications due to their superior nutrient content and stability. These findings provide new insights into the dense planting of rapeseed and the selection of suitable rapeseed genotypes for manufacture OB-based products. • The stability of rapeseed OB could be improved through increasing planting density. • OB stability depended on the composition and structure of OB interfacial proteins. • OB properties response to planting density were influenced by plant architecture. • Tall-stem rapeseed OBs had superior nutrient content and stability.