Available (ileal digestible reactive) lysine in selected cereal-based food products.
True ileal total lysine digestibility was determined and compared with true ileal reactive lysine digestibility when applied to 20 cereal-based breakfast foods. Semisynthetic diets each containing a breakfast cereal as the sole protein source were formulated and fed to growing rats. Titanium dioxide was included as an indigestible marker. Digesta were collected from the rats and total (conventional amino acid analysis) and reactive (guanidination) lysine were determined in both diets and digesta. The true ileal reactive lysine digestibility ranged from 53 to 108% and was significantly higher than the true ileal total lysine digestibility for most of the breakfast cereals. Available lysine content (digestible reactive lysine content) ranged from 0.21 to 3.5 g/kg across the breakfast cereals. The conventional measure of digestible total lysine content significantly overestimated (on average 37%) available lysine for the majority of the cereals. Breakfast cereals undergo a significant degree of lysine modification probably as a result of processing during manufacture.
Rutherfurd
Shane M
SM
Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand. s.m.rutherfurd@massey.ac.nz
Torbatinejad
Nour Mohammad
NM
Moughan
Paul J
PJ
D000818:Animals; D004063:Digestion; D002523:Edible Grain / Q000737:chemistry*; D007082:Ileum / Q000378:metabolism*; D008239:Lysine / Q000032:analysis* / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
D008239:Lysine