Quantifying Sphingomyelin in Dairy through Infusion-Based Shotgun Mass Spectrometry with Lithium-Ion-Induced Fragmentation

Edible insects as a novel source of lecithin: Extraction and lipid characterization of black soldier fly larvae and yellow mealworm

Edible insects with high fat and phosphorus content are a potential novel source of lecithin, however, studies on their minor lipids are limited. In this study, lecithin was extracted from black soldier fly larvae and yellow mealworm. Herein, the effects of lecithin extraction method, matrix and ultrasound pretreatment were explored based on the fatty acid composition and phospholipid profile with soy lecithin as a reference. The use of a wet matrix and ultrasound pretreatment increased the extraction efficiency of total PLs from both insects. Insect lecithin contained a considerable amount of sphingomyelin compared to soy lecithin. In insect lecithin, a total of 47 glycerophospholipid and sphingomyelin molecular species, as well as four molecular species of fatty acyl esters of hydroxy fatty acid, were detected. This study is the first comprehensive investigation of insects as a new source of lecithin with applications in food, cosmetics and in the pharmaceutical industry.

Electrochemiluminescent determination of sphingomyelin in milk based on polyaniline hydrogel coupled with enzyme-functionalized Au nanoparticles

In this paper, sphingomyelin (SM) is detected by a polyaniline hydrogel and Au nanoparticles with enzyme modified electrode (GCE/PAniH/AuNPs@enzyme). After a battery of enzymic degradation, SM can generate H2O2 and enhance the electrochemiluminescence (ECL) response of luminol, which endows the sensor with good sensitivity, specifiity and repeatability. Additionally, the proposed ECL biosensor displays good analytical performances with a wide range from 10.0 μg·mL-1 to 250.0 μg·mL-1 as well as a low detection limit of 3.50 μg·mL-1 (S/N = 3). When the ECL biosensor is used in the detection of SM in milk samples, satisfactory results are obtained, indicating that PAniH/AuNPs@enzyme will serve as a promising ECL material in the applications of H2O2-related bioassay in the future.

Comparison of Workflows for Milk Lipid Analysis: Phospholipids

Milk is a rich source of lipids, with the major components being triglycerides (TAG) and phospholipids (mainly phosphatidylcholine (PC), sphingomyelin (SM), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI)). Liquid chromatography-mass spectrometry (LC-MS) is the predominant technique for lipid identification and quantification across all biological samples. While fatty acid (FA) composition of the major lipid classes of milk can be readily determined using tandem MS, elucidating the regio-distribution and double bond position of the FA remains difficult. Various workflows have been reported on the quantification of lipid species in biological samples in the past 20 years, but no standard or consensus methods are currently available for the quantification of milk phospholipids. This study will examine the influence of several common factors in lipid analysis workflow (including lipid extraction protocols, LC stationary phases, mobile phase buffers, gradient elution programmes, mass analyser resolution and isotope correction) on the quantification outcome of bovine milk phospholipids. The pros and cons of the current LC-MS methods as well as the critical problems to be solved will also be discussed.