PARTITIONING OF PRINTING INK SOLVENTS ON CHOCOLATE

Partitioning (Kp) of printing ink solvents was studied in three types of chocolate with different fat content and degrees of crystallinity. At 25 degrees C, chocolate liquor (48% fat and medium crystallinity) showed a higher Kp than chips (25% fat and higher crystallinity), but cream (29% fat and lowest crystallinity) showed the highest Kp. Order appeared to depend on degree of crystallinity. At 35 degrees C and 45 degrees C as samples became increasingly molten, effect of crystallinity diminished and order of increasing Kp depended on fat content. Kp order of solvents was the same in all chocolates and temperatures: toluene > isopropanol > methyl ethyl ketone > ethyl acetate > hexane in accord with Hildebrand solubility parameter differences.