Analysis of Triacylglycerols in Sumac (Rhus typhina L.) Seed Oil from Different Origins by UPLC-Q-TOF-MS

Sumac (Rhus typhina L.) has long been used in folk medicine for many diseases. The sumac seed oil (SSO) has emerged as a functional ingredient. This study presents a method for identifying the triacylglycerol (TAG) profile of SSO. Sumac seeds collected from seven different origins were compared. Results showed the oil content was in the range from 9.42 to 10.26%. The higher acid value was found in the oils from Qinghai and Jiangxi, while no significant difference was observed in peroxide value (5.25 ~ 7.72 meq O2/kg). Ultra-performance liquid chromatography (UPLC) coupled to quadrupole time of flight mass spectrometry (Q-TOF–MS) was subsequently adopted to analyze the TAG profile. Compared to the low and elevated energy (MSE) scan mode, the data-dependent acquisition (DDA) scan mode selected the TAG precursor ions precisely. Finally, a total of 21 TAG species were quantified. Predominant TAG species were 18:2–18:2–18:2 (18.09 ~ 29.04%), 18:1–18:2–16:1 (11.94 ~ 14.34%), and 18:2–18:1–18:1 (9.75 ~ 15.34%). The SSO from cold northern regions showed different TAG profiles with less saturated fatty acyl chains. Overall, this work establishes UPLC-Q-TOF–MS as a powerful instrument for TAG structure identification and the obtained data may serve as a reference for SSO application in functional foods.