absorption and metabolism of modified amino acids in processed foods

• Published in: Journal of AOAC International 2005-05, Vol.88 (3), p.894-903
• Main Author: Finot, P.A
• Format: Article
• Language: English
• Subjects: Absorption; alkali treatment; Amadori products; amino acid composition; Amino acids; Amino Acids - analysis; animal models; Animals; dietary protein; digestible protein; Flavonoids - analysis; Flavonoids - chemistry; Food Analysis - methods; food composition; Food Handling; food nutrient losses; food processing quality; free amino acids; Fructose - chemistry; Fructose - urine; Glucose - chemistry; heat treatment; Hot Temperature; Humans; intestinal absorption; Isomerization; Kinetics; Lysine - analogs & derivatives; Lysine - analysis; Lysine - chemistry; Lysine - urine; Lysinoalanine - analysis; Nitrogen - chemistry; nutrient availability; Oxygen - chemistry; Peptides - analysis; Peptides - chemistry; Phenols - analysis; Phenols - chemistry; Physiological aspects; Polymers - chemistry; Polyphenols; processed foods; protein value; Rats; Sulfur compounds; Swine; Tannins - analysis
• ISSN: 1060-3271; 1944-7922
• DOI: 10.1093/jaoac/88.3.894

The chemical reactions involved in the modifications of amino acids in processed food proteins are described. They concern the Maillard reaction, reaction with polyphenols and tannins, formation of lysinoalanine during alkaline and heat treatments, formation of isopeptides, oxidation reaction of the sulfur amino acids, and isomerization of the L-amino acids into their D-form. Information on the digestion, absorption, and urinary excretion of the reaction products obtained by using conventional nutritional tests is given. The studies that have been made on the metabolism of these molecules by using a radioisotopic approach to follow their kinetics in the organism after ingestion are also reviewed. This approach provides unique data on the quantitation of the metabolic pathways and on the kinetics of the metabolic processes involved.