VANE METHOD TO EVALUATE THE YIELD STRESS OF FROZEN ICE-CREAM

The ability of ice cream to be dipped or scooped is a direct consequen ce of yield stress; however, yield stresses of frozen ice cream have n ot been quantified because of the lack of suitable testing equipment. This work presents the experimental equipment and methodology to solve this problem. A vane tester was designed, constructed, and then used to measure the yield stress of ice cream at typical scooping temperatu res of -16 to -14 degrees C. The moisture and fat contents of each bra nd varied significantly. Yield stresses ranged from 2.5 to 8.0 kPa. In general, the-yield stress of chocolate was higher than the yield stre ss of vanilla ice cream. Also, yield stresses decreased as temperature increased. Yield stress and temperature were highly correlated in the higher fat ice cream; the lower fat brand did not show a strong corre lation.