Abstract #M2

# M2
Hunter versus CIE color measurement systems for analysis of milk-based beverages.
Ni Cheng*1, David Barbano2, MaryAnne Drake1, 1North Carolina State University, Raleigh, NC, 2Cornell University, Ithaca, NY.

Both Hunter (L, a, b) and International Commission on Illumination (CIE; L*, a*, b*) color measurement systems are used for instrumental measurement of food color but which system is best for fluid milk is not known. The objective of our work was to determine the differences in sensitivity of Hunter and CIE methods at 2 different viewer angles for measurement for whiteness, red/green, and blue/yellow color of milk based beverages. Sixty combinations of milk-based beverages were formulated (2 replicates) with a range of fat level from 0.2 to 2%, true protein level from 3 to 5%, and casein as a percent of true protein from 5 to 80% to provide a wide range of milk-based beverage color. In addition, commercial skim, 1% and 2% fat HTST pasteurized fluid milks were analyzed. All beverage formulations were HTST pasteurized and cooled to 4°C before analysis. Measurement viewer angle (2 versus 10°) had very little impact on objective color measures of milk-based beverages with a wide range of composition for either the Hunter or CIE color measurement system. Temperature (4, 20, and 50°C) of color measurement had a large impact (P < 0.05) on the results of color measurement in both the Hunter and CIE measurement systems. The effect of milk beverage temperature on color measurement results was the largest for skim milk and the least for 2% fat milk (P < 0.05). This highlights the need for proper control of beverage serving temperature for sensory panel analysis of milk-based beverages with very low fat content and for control of milk temperature when doing objective color analysis for quality control in manufacture of milk-based beverages. The Hunter system of color measurement was more sensitive to differences in whiteness among milk based beverages than the CIE system (P < 0.05), while the CIE system was much more sensitive to differences in yellowness among milk based beverages (P < 0.05). There was little difference between the Hunter and CIE system in sensitivity to green/red color of milk based beverages. In defining milk based beverage product specifications for objective color measures for dairy product manufacturers, the viewer angle, color measurement system (CIE versus Hunter) and sample measurement temperature should be specified along with type of illuminant.

Key Words: color, milk, whiteness