Evaluation of cultivars diversity and lipid composition properties of Idesia polycarpa var. vestita Diels

Idesia polycarpa var. vestita Diels is a perennial deciduous tree widely distributed throughout China. Four I. polycarpa fruit of different cultivars with different fruit issues during the growth process were compared, which were on the basis of morphological characteristics and chemical compositions. The influencing factors of oil accumulation in I. polycarpa fruit and the correlation between different components were investigated, and the results revealed a negative correlation between oil content and total sugar (r = -0.930), ash (r = -0.606), and crude fiber (r = -0.952). Except for oil, none of the chemical components changed substantially during the growing phase, and most cultivars showed higher oil content in the pulp portion (14.14-43.99 g/100 g). Linoleic acid was the most abundant fatty acid in I. polycarpa oil (IPO), with values ranging from 52.18% to 66.65% (fruit), 55.44% to 65.15% (pulp), and 68.99% to 78.76% (seed). Principal component analysis revealed that Hubei varieties are more advantageous. Besides, the lipid composition of IPO was identified by ultrahigh-performance liquid chromatography coupled with electrospray ionization Q-Exactive Focus mass spectrometry. The glyceride components of IPO were mostly composed of 22 triacylglycerols, 30 diacylglycerols, and 8 monoacyglycerols. Meanwhile, linoleic acid was mainly distributed in sn-2 and sn-3 positions. PRACTICAL APPLICATION: Morphologic characteristics, chemical compositions, oil fatty acid profiles, and oil correlation factors of I. polycarpa were analyzed. The comprehensive score of oil quality by PCA in Hb fruit was the highest. The glyceride components of I. polycarpa oil were mainly composed of 22 triacylglycerols, 30 diacylglycerols, and eight monoacyglycerols.