Comparison of Descriptive Sensory Analysis with Electronic Nose Differentiation of Commercial Swiss Cheese

1. Comparison of Descriptive Sensory Analysis with Electronic Nose Differentiation of Commercial Swiss Cheese W. James Harper1, Josephine Kuo1 & MaryAnne Drake2 1 The Ohio State University, Columbus, Ohio, USA, 2 North Carolina State University, Raleigh, N.C., USA

2. Swiss Cheese Flavor Objectives Methods and materials Results Conclusions

3. Objectives To develop a lexicon of descriptors to describe the flavor of Swiss Cheese To compare the descriptive sensory analysis with electronic nose differentiation of commercial Swiss cheese

4. Selection of Cheeses and Sensory Evaluation Twelve Swiss cheeses of varying ages were obtained from 6 different factories together with imported Gruyere, Emmenthal and Jarlsburg. All cheeses were more than 3 months of age. A trained descriptive panel (n=10) experienced with analysis of cheese evaluated the cheeses in duplicate. The lexicon was modified from that previously developed for Cheddar cheese. Some terms were eliminated and others were added. A total of 23 different descriptors were utilized.

5. Descriptors Eliminated Catty Egg-like Match Like Whey Cooked Milk fat/lactone Cowy/Phenolic

6. Descriptors Added Acetic/vinegar Propionic acid Phenolic/medicine Caramel/cooked Sweet Prickle Olive

7. Descriptors Retained Free fatty acid Brothy Aged Bitter Salty Sour Umani Oxidized Nutty Fruity Sulfur Onion Diacetyl Soapy Cereal

8. Sensory Evaluation of 12 Swiss Cheeses

9. Descriptors Common to >80% of Cheeses caramel//cooked * Brothy* Nutty Fruity Acetic/vinegar * Present in all cheeses Propionic* Sweet* Sour Umani* prickle

10. Uncommon Descriptors -Present in Less than 30% of Cheeses Diacetyl Olive Faecal Onion Soapy Free fatty acid (butyric-like) Salty

11. Electronic Nose Agilent Technology Chem Sensor 4400 operating as an electronic nose with headspace auto-sampler unit and mass selective detector Mass scans were from mass 35 to 200 in NCI mode Grated cheese (2.5 g) held at 60C for 30 min Cheeses evaluated in triplicate

12. Comparison of Sensory and Electronic Nose Data

13. Comparison of Cluster Analyses for Sensory and Electronic Nose Cluster analysis separated the 12 cheeses into 5 distinct clusters The cheeses in the different clusters were different for the sensory analysis and for the EN data Removing taste components from the sensory data did not give better agreement with the electronic nose

14. Comparison of Cluster Analyses for Sensory and Electronic Nose Data

15. PCA Comparison for Sensory and Electronic Nose Data

16. PCA PLOT FOR SENSORY DATA WITH TASTE DESCRIPTORS

17. PCA PLOT FOR SENSORY DATA WITHOUT TASTES

18. PCA PLOT FOR ELECTRONIC NOSE DATA

19. Conclusions A descriptive sensory lexicon was developed that differentiated the flavor of 12 commercial Swiss cheeses A comparison of the Sensory method with the Electronic nose procedure showed that both differentiated the 12 cheeses The removal of the taste component from the sensory data did not bring the two methods into closer agreement

20. Conclusions For Swiss cheese the aroma component of the sensory evaluation appears to be based on different elements of the aroma than those used by the Electronic Nose Care needs to be taken in the interpretation of Electronic Nose data, even though good aroma differentiation can be achieved by EN