EFFECT OF PH AND SOLUBLE SOLIDS ON THE SERUM VISCOSITY AND SERUM COLOR OF TOMATO JUICE AT ELEVATED-TEMPERATURES

Effects of heating time and temperature, pH, and soluble solid levels on serum viscosity and serum color of tomato juice were studied. The s amples were canned in 18 mL TDT cans and exposed to processing tempera tures of 88C, 102C, and 112C for 30, 60, and 120 min. Depending upon t he time and temperature of heating, and initial viscosity of the serum , the losses in viscosity ranged from 3.0-55.6% being higher in serum with higher initial viscosity. Percent losses in serum viscosity durin g heating of juice increased (6-60%) with increase in pH (3.8-4.9) and soluble solids (6 degrees-24 degrees) in the juice. An increase in pH and soluble solids also enhanced heat induced browning in the serum w ith values varying from 0.1-2.69.