GRAININESS, CRYSTAL SIZE, AND FIRMNESS OF STORED CANOLA OIL MARGARINES

Abstract

Canola oil margarines from two different manufacturers displayed distinctly different patterns of crystal growth and sensory graininess during 22 to 24 weeks of storage at 4°C. A seven‐member sensory panel examined both margarines biweekly and found that the product of one manufacturer remained essentially smooth throughout the storage period while that of the other manufacturer was less stable in texture. The latter was detectably grainy after 12 weeks of storage. Changes in crystal size in the less stable margarine were positively correlated with graininess frequency (r = 0.89) and with storage age (r = 0.84). The threshold for crystal size detection for the panel was estimated as 22 microns. While margarine firmness which was measured with the texturometer showed some inclination to increase with storage age, changes in crystal size explained only 31% of the variability in firmness measurements of the less stable product.