Functional properties of spray-dried animal plasma in canned petfood

Abstract

Over the last 15 years, spray-dried animal plasma (SDAP) has become a commonly used gelling ingredient in canned petfood diets. However, little is known about the functional properties of this product in this application. SDAP is a concentrate of proteins with the property of producing a very stable and compact gel when submitted to high temperatures. High gel strength capacities are obtained at temperatures above 90 °C, with peak strength at 121 °C (force needed to break a 100 g/kg gel was 5.29 N). The water retention capacity of the gel formed is stable at temperatures above 80 °C. When compared with other gelling and binding agents, SDAP is a soluble product with better gelling properties than egg albumin (EA), wheat gluten (WG), and porcine products (PP), but less than carrageenan (CM) (force needed to break 100 g/kg water gels were 7.02, 3.45, 2.11, 0 and 10.20 N, respectively). When used in a complete loaf type of canned petfood, SDAP maintains a more compact texture compared with the other binding agents at the same inclusion level, and reduces the exudation associated with these products. This exudation was significantly reduced compared with WG and CM, which gave 156 and 125%, respectively, more exudation than SDAP in the same loaf recipe. According with the results obtained, SDAP can replace other binding or gelling agents at the same formula cost, helping in the reduction of exudation from the meat block and maintaining or increasing the texture of the final canned petfood. The addition of plasma contributed to enhancing the palatability, particularly in cats, over the standard diet in which it replaced wheat gluten. The total intake in cats after 2 consecutive days comparing loaf containing SDAP or WG at the same inclusion (20 g/kg) was statistically improved with the inclusion of SDAP (141 and 78 g, P < 0.001). Similar results were obtained for first choice and in another study comparing loaf containing SDAP at 10 g/kg or WG at 30 g/kg (total intake 151 and 61 g, P < 0.001, respectively).