To control sample temperature during transportation and testing, a box was constructed for each panellist using 1.5″ inter-locking styrofoam SM (Dow Corning), freeze-thaw stable glue and exterior duct tape for reinforcement. Each box measured 5 5/8″ in depth, 9 1/8″ in width, and 10 7/8″ in length. Box lids were properly fitted and the boxes were lined with industrial strength plastic. On each testing day, sample boxes were loaded with crushed ice and the appropriate samples for judging. The temperature of samples at the time of loading the boxes was −28°C, and by judging time, 2 h later, the sample temperatures had risen to between −20 and −18°C. At the completion of judging, sample temperatures had risen further to between −13 and −11°C. Arbuckle (1986) indicated that the ideal ice cream temperature for sensory evaluation is between −13 and −16°C. Specter and Setser (1994) presented their sample to panellists at −12±1°C. Thus, satisfactory sample temperature control was achieved during the study.
Samples were randomly coded with three digit numbers and the serving order of samples presented to panellists was completely randomized following the procedure provided by Watts, Ylimaki, Jeffery and Elias (1989). The samples were evaluated in individual booths and four test sessions were required to complete the testing.