Lysine reactivity and starch gelatinization in extruded and pelleted canine diets

• Published in: Animal feed science and technology Vol. 138; no. 2; pp. 162 - 168
• Main Authors: Tran, Q.D., van Lin, C.G.J.M., Hendriks, W.H., van der Poel, A.F.B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2007
• Subjects: antinutritional factors; carbohydrate content; digestion; dogs; dried foods; Extrudate; extruded foods; extrusion; feed; feed processing; food; gelatinization; lipid content; Lysine; nutritive value; Pellet; pelleted feeds; pellets; Pet food; pet foods; pets; quality; rats; resistant starch; Starch; Netherlands; SGD; Pellet; ADF; Lysine; Starch; Pet food; DM; Extrudate; OMIU
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/j.anifeedsci.2007.06.021

Fifteen dry adult canine diets ( i.e., dinners, extrudates, pellets) were collected from retailers in Wageningen, The Netherlands, and chemically and physically characterized. Quality measurements were lysine O-methylisourea (OMIU) reactivity and starch gelatinization degree (SGD). In general, extruded diets had a higher crude fat and starch content than pellets. Mean values for starch gelatinization were higher in pellets and ranged between 0.78 and 0.91. The mean reactive/total lysine ratio in extrudate samples was about 5–10% higher than in pellet samples, suggesting the presence in commercial diets of about 200 g bound lysine/kg in pellets and 120 g/kg in extrudates with bound lysine levels of canine dinners about 170 g/kg. Variation of analysed nutrients in pellets was larger than in extrudates. Inclusion of animal or vegetable ingredients, and the process variables during extrusion or pelleting, are the likely causative factors for the variation in lysine reactivity and starch gelatinization.