Lysine, nutritionally blocked

When lactose reacts with protein in dairy products, lactulosyllysine residues are formed. On hydrolysis, these give yields of 40% recovered lysine and 32% furosine. The lysine residues nutritionally blocked can then be calculated as follows ... 

Bjamason and Carpenter (38, 52, 53) studied the use of formylation, acetylation, and propionylation for blocking amino groups in food proteins. Many of these chemical modifications could be easily applied on a commercial scale. The formyl and acetyl derivatives were nutritionally utilized at least partially. The propionylated lysine was not utilized however the propionylated lactalbumin was partially utilized (Table VII). The acylation procedure lowered considerably the extent of the Maillard reaction. Previous investigations, in support of the observations of Bjamason and Carpenter, have shown deacylase in the kidney (51). 

Amino acids are used as additives to food and feed because they play important roles in human and animal nutrition as building blocks of proteins [1]. Additionally, amino acids are involved in antioxidative responses, the regulation of gene expression, cell signaling, neurotransmission, and immunity [2]. Nutritional uptake of L-lysine and other essential amino acids, as well as an overall balanced amino acid ingestion, is important for growth, health, development, and survival of animals and humans [2-5]. 

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