Glycerophospholipidomics of Five Edible Oleaginous Microgreens

Abstract

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-MS 2 ) 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.

Exploration of the Lipid Profile of Edible Oleaginous Microgreens by Mass Spectrometry-Based Lipidomics

“…20 The high mass resolution provided by such platforms allows the distinction of lipid ions that exhibit very slight differences in their theoretical m/z ratio, 21 and accurate m/z values can be employed to identify lipid molecules at the species level. 22 As shown in our previous study, 15 the reliability of HRMSbased studies can be supported by the adoption of a preliminary chromatographic separation. In the case of glycerophospholipids, hydrophilic interaction liquid chromatography (HILIC) separations, based on polar stationary phases, represent a very effective approach, since they provide a class-related separation.…”

“…Interestingly, the tandem MS (MS/MS) structural characterization of GPLs showed that the FAC 18:3 (i.e., a fatty acyl chain with 18 carbon atoms and 3 DB equivalents) was the most diffused fatty acyl unit in the main GPL classes encountered in chia and flax microgreens. 15 However, no information was retrieved for less polar lipid classes, such as TGs and SEs, that might also represent a source of that fatty acyl chain. Moreover, despite the recognition of 18:3 fatty acyl chains suggesting the possible presence of ALA, a confirmation could not be obtained since no additional evidence was provided to unveil the position of carbon−carbon double bonds.…”

Brassicaceae Microgreens: Phytochemical Compositions, Influences of Growing Practices, Postharvest Technology, Health, and Food Applications

“…BM have a fat content of less than 1 g/100 g FW, which enables their users to produce foods with low-fat contents. The contents of protein, total carbohydrates and calories in BM are lower compared to Fabaceae microgreens, according to Kowitcharoen et al BM are also a source of essential fatty acids that are not produced by the human body but are vital for human health . In the Brassica carinata microgreens, Nakakaawa et al reported that α-linoleic acid and linoleic acid were the most abundant compounds along with other fatty acid such as ethyl linolenate and palmitic acid.…”

“…In the Brassica carinata microgreens, Nakakaawa et al reported that α-linoleic acid and linoleic acid were the most abundant compounds along with other fatty acid such as ethyl linolenate and palmitic acid. The highest amount of phosphatylcholines and phosphatidylethanolamines, the main glycerophospholipids, have been detected in the rapeseed microgreens . Despite the tremendous health property functions of amino acids and fatty acids, few studies have addressed the presence and amount of these organic compounds in BM.…”

“…They enhance the color, texture, and flavor of food products and improve health functions. Microgreens are a rich source of different vitamins (A, C, E, and K), ,− minerals (K, Ca, Fe, Zn, P, S, Mg, Mn, Cu, and Na) − and health-promoting compounds such as phenolic compounds, amino acids, glucosinolates, and glycerophospholipids. ,,− …”