Lysine bioavailability

Pellet machine Temperature, humidity, pellet size Lysine bioavailability Mavromichalis and Baker (2000)... 

Mavromichalis, L, Baker, D.H. 2000. Effects of pelleting and storage of a complex nursery pig diet on lysine bioavailability. Journal of Animal Science 78 341-347. 

Plants contain to some extent less bioavailable forms of vitamin B6, e.g., glycosylates, or biologically inactive metabolites, e.g., e-pyridoxin-lysin-complexes. In addition, the release of vitamin B6 from foods rich in fiber is assumed to be delayed. The bioavailability of vitamin B6 from animal-derived foods is therefore overall higher than from plant-derived foods. Good dietary sources of vitamin B6 include chicken, fish, pork, beans, and pulses [1]. 

Calvo et al. [63] studied ehitosan (CS)- and poly-L-lysine (PLL)-eoated poly-e-caprolactone (PECL) nanocapsules for oeular application. In comparison with commercial eye drops, the systems investigated (uncoated, PLL-coated, and CS-coated nanocapsules) significantly increased the eoneentrations of indomethacin in the cornea and aqueous humor of rabbit eyes. The ehitosan-eoated formulation doubled the ocular bioavailability of indomethacin over the uncoated partieles, whereas the PLL coating was ineffective. The authors eoneluded that the speeifie nature of CS was responsible for the enhaneed indomethaein uptake and not the positive surfaee eharge. Both the PLL- and CS-eoated nanoeapsules displayed good oeular toleranee [63]. 

If acetylsalicylic acid is administered i.v. as the lysine salt, its bioavailability is complete. Therefore, i.v. injection may be advisable in acute attacks. 

The most important nutritional use of sesame protein is as a methionine source for complementation of other protein consequently, the low lysine content is not an important consideration with proper complementation (69). Here we see a case where reduced bioavailability of an amTrib acid is documented but is of little practical importance in the mixed diet in which the protein will be only a part. 

Nutritional Availability of Acylated Lysine and Proteins. The successful use of chemically derivatized proteins as food ingredients requires that they be digestible and nontoxic, and that the modified amino acid residues should be available nutritionally. Nutritional studies using modified food proteins are limited. The nutritional availability of several acylated lysines were studied by Bjarnason and Carpenter (105) and Mauron (106) and the results are summarized in Table III. The bioavailability of the acylated lysine varied significantly with the type of the acyl groups (see Table III). In addition acylated proteins (acetylated and succinylated) gave lower responses to the growth activity for the rats than equivalent supplements of unmodified proteins... 

The adverse effects of PPO on noctuid larvae result from reduced bioavailability of amino acids caused by the covalent binding of oxidized chlorogenic acid to protein. When dietary protein (casein) was treated with PPO and chlorogenic acid, a substantial reduction in in vitro protein digestibility occurred. This reduction in digestibility may result from alkylation of lysine and/or protein cross-linking, which may impair the ability of the insect s trypsin to hydrolyze the protein. 

Thrombin is a proteolytic enzyme and has a remarkable similarity in its overall three-dimensional structure to the digestive serine proteases, trypsin, and chymotrypsin [11-13]. Trypsin and thrombin share a common primary specificity for proteolysis next to arginine or lysine residues. Structural data of thrombin and trypsin have demonstrated strong resemblance in their substrate sites, and many small organic inhibitors are comparably active against both the enzymes [14,15]. For this reason, no or low inhibition of trypsin is viewed as a required condition for a compoimd to be a successful orally bioavailable thrombin inhibitor [16]. 

Care must be taken in the processing and purchasing of blood meal. These different processing methods produce different types of blood meal, which may vary in crude protein and amount and bioavailability of lysine and other amino acids (6, 7). 

Abebe W 2002 Herbal medication potential for adverse interactions with analgesic drugs. Journal of Clinical Pharmacy and Therapeutics 27 391-401 Anfossi P, Villa R, Montesissa C et al 1997 Intramuscular bioavailability of ketoprofen lysine salt in horses. Veterinary Quarterly 19 65-68 Avouac B, Teule M 1988 Ketoprofen the European experience. Journal of Clinical Pharmacology 28 S2-S7... 

All nutrients (except water) may undergo either chemical or physical changes during processing that render them inactive or less bioavailable. This occurs for macro- as well as micronutrients. During browning, the amino acid lysine can react with carbohydrates to lower the biological value of protein. 

Nielsen, H. K., Finot, P. A., and Hurrell, R. F., Reactions of proteins with oxidizing lipids. 1. Influence of protein quality on the bioavailability of lysine, methionine, cysteine, and tryptophan as measured in rat assays, Br. ]. Nutr., 53, 75, 1985. 

Fernandez, S.R., Parsons, C.M. 1996. Bioavailability of digestible lysine in heat-damaged soybean meal for chick growth. Poultry Science 75 224-231. 

Cooking starch in the presence of amino acids may favour the occurrence of Maillard reactions, lowering the bioavailability of lysine in the diet. 13C CPMAS was used to follow the effect of Maillard reactions on the bioavailability of potato starch.124 A loss of crystallinity was found for the three samples studied starch, amylopectin, and amylose, being more marked for amylose. A similar study on chestnut starch indicated that Maillard reactions do not influence significantly its digestibility.125 NMR was used to characterize some Maillard reaction products extracted from model reactive mixtures such as starch-glucose-lysine 126 and lactose-lysine.127... 

With respect to the mixed findings on fortification of cereals with free lysine, attention was drawn by the 2002 WHO/FAO/UNU Expert Consultation (2007) to the issue of Maillard reactions between amino acids, especially lysine, and sugars that can occur during food processing. Maillard reactions adversely affect the bioavailability of amino acids. Lysine, as a free amino acid, is particularly susceptible to loss through the Maillard reaction (Ajandouz and Puigserver, 1999). 

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