Effects of melamine on the Maillard reaction between lactose and phenylalanine

Effects of Wet-Blending on Detection of Melamine in Spray-Dried Lactose

“…A carbinolamine addition product [m/z 469.1881, (M + H) + ] and its two condensation products [m/z 451.1776, (M + H − H 2 O) + ; m/z 433.1673, (M + H − 2H 2 O) + ] were only detected in the WB-Lac and DB-Lac (Figure 6 and Supplemental Figure S4 of the Supporting Information) samples. This high mass resolution detection (R = 140 000) of the carbinolamine and monodehydration ions confirmed the original molecular assignments made in a low-resolution MS study by Ma et al 17 Extracted ion chronograms of melamine, lactose, and their early Maillard reaction products are presented in Figure 7. No differences were observed as a function of the blending technique in the melamine, lactose, and carbinolamine addition product ion abundance distributions via one-tailed t tests at the 95% confidence level.…”

“…Qualitative DART–FTMS analyses of DB and WB samples were performed directly on the powders to detect melamine reaction products with lactose (Scheme ). Because negative ionization yielded less intense spectra and failed to detect a previously reported melamine addition product (carbinolamine) with lactose, subsequent analyses were performed under positive ionization conditions. , Control samples yielded no evidence of cross-contamination and produced the expected signature ions (Table ) in full-scan mass spectra (Figure ). For example, the lactose DART spectrum acquired was virtually identical to those reported elsewhere, and protonated melamine was the base peak ion in all lactose admixtures.…”

“…13,14 Although lactose serves well as an inactive ingredient in many pharmaceuticals, studies have documented unwanted interactions of lactose excipients with drugs that contain amines. 15,16 Maillard reaction products have been characterized in protein-free model systems containing melamine and lactose, using reverse-phase LC−MS/ MS. 17 Related studies have also evaluated the kinetics of reactions between melamine and a variety of aldehydes. 18 Previous efforts to understand the cause(s) of the WB effect in MP were limited as a result of the complexity of the MP matrix.…”

“…Controlling such reactions between lactose and amines is important in the food and pharmaceutical industries because these determine the organoleptic properties and nutritional quality of foods as well as the stability of drug commodities. As such, these reactions have been well-studied, including work on milk protein lactosylation as a function of pasteurization and MP storage conditions. , Although lactose serves well as an inactive ingredient in many pharmaceuticals, studies have documented unwanted interactions of lactose excipients with drugs that contain amines. , Maillard reaction products have been characterized in protein-free model systems containing melamine and lactose, using reverse-phase LC–MS/MS . Related studies have also evaluated the kinetics of reactions between melamine and a variety of aldehydes …”

Relationship of Glucosinolate Thermal Degradation and Roasted Rapeseed Oil Volatile Odor

“…Nonanal is the main volatile carbonyl derived from oleic acid and imparts a tallow flavor to oil. Benzeneacetaldehyde (responsible for the floral, sweet, and green flavor), 2-methylbutanal, and 2-methylpropanal (described as a nut-like flavor) were products of the Strecker degradation reaction. , Furan derivatives generated by lipid peroxidation and carbohydrate degradation have a malt, caramel-like flavor . With a prolonged roasting time, these volatile compounds gradually increased.…”