Microgreens are a special type of vegetal product, born as a culinary novelty (traditionally used to garnish gourmet dishes) and then progressively studied for their potentially high content in nutraceuticals, like polyphenolic compounds, carotenoids, and glucosinolates, also in the perspective of implementing their cultivation in space stations/colonies. Among further potential nutraceuticals of microgreens, lipids have received very limited attention so far. Here, glycerophospholipids contained in microgreens of typical oleaginous plants, namely, soybean, chia, flax, sunflower, and rapeseed, were studied using hydrophilic interaction liquid chromatography (HILIC), coupled to high-resolution Fourier transform mass spectrometry (FTMS) or low-resolution collisionally induced dissociation tandem mass spectrometry (CID-MS2) with electrospray ionization (ESI). Specifically, this approach was employed to obtain qualitative and quantitative profiling of the four main classes of glycerophospholipids (GPL) found in the five microgreens, i.e., phosphatidylcholines (PC), phosphatidylethanolamines (PE), phosphatidylglycerols (PG), and phosphatidylinositols (PI). Saturated chains with 16 and 18 carbon atoms and unsaturated 18:X (with X = 1-3) chains emerged as the most common fatty acyl substituents of those GPL; a characteristic 16:1 chain (including a C═C bond between carbon atoms 3 and 4) was also found in some PG species. Among polyunsaturated acyl chains, the 18:3 one, likely referred mainly to α-linolenic acid, exhibited a relevant incidence, with the highest estimated amount (corresponding to 160 mg per 100 g of lyophilized vegetal tissue) found for chia. This outcome opens interesting perspectives for the use of oleaginous microgreens as additional sources of essential fatty acids, especially in vegetarian/vegan diets.
Keywords: hydrophilic interaction liquid chromatography-mass spectrometry; lipidomics; microgreens; oleaginous crops; phospholipids.