Nonaethylene glycol monododecyl ether

25 μL of isooctane suspended total milk lipid was taken to dryness, were resuspended in 200 μL dichloromethane containing 15 μL of a 20% nonaethylene glycol monododecyl ether (Sigma Aldrich, St. Louis, MO) dissolved in dichloromethane (wt/vol), and samples were incubated for 5 minutes at 25°C. Samples were taken to dryness at 40°C for 25 minutes ensuring solvent was completely evaporated. Pellets containing triglyceride/nonionic surfactant complexes were reconstituted in 200 μL of ultrapure water without mixing and incubated at 40°C for 10 minutes, followed by a gentle vortex. A regression curve was prepared from 80 nmol of tripalmitin (Sigma Aldrich, St. Louis MO) combined with 25 μL of 20% nonaethylene glycol monododecyl ether in dichloromethane (wt/vol), processed as above, resuspended in 100 μL of ultrapure water, and a standard curve of 20, 10, 5, 2.5, 1.25, 0.625, and 0.3125 nmol tripalmitin was made. Triglyceride from the organic fraction was quantified relative to tripalmitin using a modified colorimetric assay [13 (link)]. Triglyceride Reagent and Free Glycerol Reagent were purchased from Sigma Aldrich (St. Louis, MO) and prepared according to the manufacturer's instructions.

Twenty-five µL of isooctane-suspended total milk lipid was evaporated to dryness, samples were resuspended in 200 µL dichloromethane containing 15 µL of a 10% nonaethylene glycol monododecyl ether (Sigma-Aldrich, St. Louis, MO) dissolved in dichloromethane (wt/vol). Samples were incubated for 5 min at 25 °C and taken to dryness at 40 °C for 25 min ensuring organic solvent was completely evaporated. Pellets contained triglyceride (TAG)/nonionic surfactant complexes, to which 200 µL of ultrapure water was carefully added without mixing and incubated at 40 °C for 10 min, followed by a gentle vortex. A standard regression curve 20, 10, 5, 2.5, 1.25, 0.625, and 0.3125 nmol was prepared from 80 nmol tripalmitin (Sigma-Aldrich) incubated with 25 µL of 10% nonaethylene glycol monododecyl ether, incubated, dried and resuspended in 100 µL of ultrapure water as above. Total TAG from the organic fraction was quantified using a modified colorimetric assay^{34 (link)} and expressed as mM concentrations. TAG Reagent and Free Glycerol Reagent (Sigma-Aldrich) were diluted according to the manufacturer’s instructions.