Studies on Absorption and Elimination of Dietary Maillard Reaction Products

Abstract

A nine-day dietary study involving 18 healthy volunteers was performed in order to investigate the influence of nutrition on the urinary excretion of the Maillard reaction products (MRPs) fructoselysine, pyrraline, and pentosidine. From day two through day eight, most types of Maillard product-containing food had to be avoided. On day five, participants were divided into four groups, three of them receiving a test meal (pretzel sticks, brewed coffee, or custard) containing defined amounts of MRPs. The fourth group served as a control. Urine samples taken over a 24-h period were analyzed for MRPs using chromatographic means. As a result of the MRP-free diet, urinary excretion of free pyrraline and fructoselysine, which was calculated from furosine analysis, were lowered about 90%. Excretion of pentosidine decreased about 40%. Consumption of pretzel sticks and coffee on day five resulted in increased amounts of pyrraline and pentosidine in urine samples on days five to seven. Related to the supplied amounts of pyrraline, about 50% were recovered in the urine samples after ingestion of the pretzel sticks. For pentosidine, 60% of the ingested free derivative from coffee brew and 2% of the peptide-bound amino acid ingested with the bakery product were recovered in the urine samples, indicating a better bioavailability for free pentosidine compared to the protein-bound form. For peptide-bound Amadori products, no influence on the excretion was observed after ingestion of the test foods, indicating degradation in the intestine or plasma to yet-unknown metabolites. In conclusion, differences concerning the excretion rate of individual MRPs point to individual resorption and metabolic pathways. These results are of importance for the discussion of a possible (patho)physiological role of dietary advanced glycation end products (AGEs).

The Maillard reaction and pet food processing: effects on nutritive value and pet health

“…Urinary pyrraline is almost exclusively of dietary origin, and pyrraline is most probably not metabolised post-absorption. Approximately 2·0 % of dietary pentosidine is recovered in urine in the peptidebound form; however, approximately 60·0 % is recovered in the free form (98) . The remainder may have been metabolised into unknown compounds and also excreted in the urine.…”

Produtos da reação de Maillard em alimentos: implicações para a saúde

“…Cerca de 70% dos PRM metabolizados acumulam-se em vários tecidos, como pâncreas, fígado e, principalmente, rins; já os PRM que não foram absorvidos são degradados pelas bactérias no intestino ou eliminados. Enquanto há evidên-cias de que altas concentrações de PRM no intestino aumentam a concentração local de nitrogênio, favorecendo o desenvolvimento de doenças intestinais como colite, alguns PRM, por outro lado, apresentam efeito prebiótico, indicando que o tema é controverso e pouco se conhece sobre a biotransformação desses compostos pela microbiota intestinal [22][23][24][25] . Nos últimos 50 anos o consumo desses produtos aumentou cerca de cinquenta vezes na dieta ocidental 24,25 , em especial na alimentação de adolescentes 26 , o que tem levado diversos autores a sugerir a necessidade de estabelecer limites de ingestão, ou, ainda, utilizar métodos culinários que reconhecidamente minimizem a formação desses compostos 14,20,27,28 .…”

Diabetic threesome (hyperglycaemia, renal function and nutrition) and advanced glycation end products: evidence for the multiple-hit agent?

“…More precisely, approximately 10-30 % of the ingested AGE are intestinally absorbed, mainly in the form of glycation-free adducts and peptides, and are subsequently found in the circulation (121)(122)(123) , where the peptides undergo rapid degradation to free adducts, as shown by comparing the concentration of glycated peptides in the portal and systemic venous circulation (99) . Absorbed AGE are excreted rapidly in the urine by subjects or experimental animals with normal renal function, as indicated by balance studies quantifying recovery in the urine of CML, pyrraline and pentosidine from different foods or after injection of labelled compounds (123)(124)(125)(126) . In these studies £ 80 % of AGE were recovered in the urine, predominantly in the glycation-free adduct form, although it may have been as low as 2% in the case of protein-bound AGE (e.g.…”