Quality of mashed potatoes: Effect of adding blends of kappa-carrageenan and xanthan gum

摘要

Blends of kappa-carrageenan (K) and xanthan gum (X) were added to mashed potatoes. Product was tested by instrumental texture profile analysis and cone penetration tests, oscillatory and steady rheology, colour, drip loss, total soluble solids and sensory analyses. A central composite rotatable design was used to study the effects of variation in levels of K (1.5-4.5 g kg -1) and X (0.5-2.5 g kg-1) concentrations. Addition of K had a major impact on gel strength, viscoelastic behaviour, sensory attributes and overall acceptability, whereas addition of X influenced textural and steady properties and colour. Mainly, elastic modulus (G′) was strongly dependent on the K concentration in mashed potatoes containing amylose. As compared to mashed potatoes with 1.5 g kg-1 added X, additional incorporation of 5.12 g kg-1 K increased G′ approximately twofold, possibly due to exclusion effect of the swollen starch granules and synergistic effect of K and denatured protein. The function of X in the mashed potatoes may in fact be confined to that of a filler rather than a dynamic constituent, although it does affect yield stress behaviour. When K/X blends (each biopolymer at 1.5 g kg-1) were included in the formulation, the product exhibited very acceptable sensory quality. K provided the appropriate texture, while X imparted creaminess and mouthfeel to the product. © 2009 Springer-Verlag.