Ion-Trap Mass Spectrometric Analysis of Bisphenol A Interactions With Titanium Dioxide Nanoparticles and Milk Proteins

Abstract

Quantitative analysis of endocrine-disrupting molecules such as bisphenol A (BPA) in freshwater to determine their widespread occurrence in environmental resources has been challenged by various adsorption and desorption processes. In this work, ion trap mass spectrometry (ITMS) analysis of BPA was aimed at studying its molecular interactions with titanium dioxide (TiO2) nanoparticles and milk whey proteins. Addition of sodium formate prevented TiO2 nanoparticles from sedimentation while enhancing the electrospray ionization (ESI) efficiency to produce an abundance of [BPA + Na]+ ions at m/z 251.0. More importantly, the ESI-ITMS instrument could operate properly during a direct infusion of nanoparticles up to 500 μg/mL without clogging the intake capillary. Milk protein adsorption of BPA could decrease the [BPA + Na]+ peak intensity significantly unless the proteins were partially removed by curdling to produce whey, which allowed BPA desorption during ESI for quantitative analysis by ITMS.

Effects of Replacing Butter with SPAN80-Tailored Soywax/Rice Bran Oil Oleogel in Food Product: A Study on Whole Wheat Cookies

“…OG50, OG75, and OG100 had a similar moisture content ( p > 0.05); however, the values were significantly lower than those of OG0 and OG25 ( p < 0.05). Butter usually contains ∼16–17% water, ∼ 80–82% milk fat, and 1–2% milk solids other than fat . The decrement observed in the moisture content of the OG50, OG75, and OG100 dough samples can be ascribed to a reduced butter content with a correspondingly increased oleogel content in the dough samples.…”

“…Butter usually contains ∼16−17% water, ∼ 80−82% milk fat, and 1−2% milk solids other than fat. 37 The decrement observed in the moisture content of the OG50, OG75, and OG100 dough samples can be ascribed to a reduced butter content with a correspondingly increased oleogel content in the dough samples. Additionally, the presence of the emulsifier (Span80) in the dough system might have better assisted the formation of the complex waterdough systems, resulting in the increased affinity of water to the wheat flour.…”