Modelling the influence of inulin as a fat substitute in comminuted meat products on their physico-chemical characteristics and eating quality using a mixture design approach

The effects of fat substitution using two commercial inulin products on the physico-chemical properties and eating quality of a comminuted meat product (breakfast sausage) were modelled using a specialised response surface experiment specially developed for mixtures. 17 treatments were assigned representing a different substitution level for fat with inulin. Sausages were formulated to contain pork shoulder, back fat/inulin, water, rusk and seasoning (44.3, 18.7, 27.5, 7 and 2.5% w/w). Composition, sensory, instrumental texture and colour characteristics were assessed. Fructan analysis showed that inulin was unaffected by heat or processing treatments. Models showed increasing inulin inclusions decreased cook loss (p < 0.0017) and improved emulsion stability (p < 0.0001) but also resulted in greater textural and eating quality modification of sausages. Hardness values increased (p < 0.0001) with increasing inulin concentration, with panellists also scoring products containing inulin as less tender (p < 0.0112). Optimisation predicted two acceptable sausage formulations with significantly lower fat levels than the control, which would contain sufficient inulin to deliver a prebiotic health effect.