Enhancement of freezing stability in mashed potatoes by the incorporation of kappa-carrageenan and xanthan gum blends

BACKGROUND: To ameliorate the detrimental effects of freezing and thawing, blends of kappa-carrageenan (kappa-C) and xanthan gum (XG) were added to frozen/thawed mashed potatoes (F/TM potatoes). Product was tested by textural and rheological measurements, other quality parameters and sensory analyses. The effects of variation in levels of kappa-C (1.5-4.5 g kg(-1)) and XG (0.5-2.5 g kg(-1)) concentrations were studied. RESULTS: Instrumental measurements and sensory analyses indicated that 4.5 g kg(-1) kappa-C and 2.5 g kg(-1) XG provided better thickening. kappa-C provided the appropriate texture, while XG imparted creaminess to the product, which could be associated with an increase in the amount of XG-water interactions. Addition of kappa-C had a major impact on textural properties, gel strength and viscoelastic behaviour, whereas XG influenced steady properties, colour, water-holding capacity (WHC) and overall acceptability (OA). CONCLUSION: The OA of F/TM potatoes was mostly improved by addition of cryoprotectant blends, which is ascribed to improvement of F/TM potatoes texture by retarding starch retrogradation, increasing WHC, and enhancing the principal characteristics determining consumer acceptance. Creaminess was the most crucial factor for OA of the products. Addition of both polysaccharides at a low concentration (each cryoprotectant at 1.5 g kg(-1)) is recommended. (C) 2009 Society of Chemical Industry