Odor evaluation of shrimp treated with different chemicals using an electronic nose and a sensory panel

An electronic nose with 12 conducting polymer sensors was used to measure odors of raw shrimp treated with different chemicals. Headless shell-on pink shrimp (Pandalus jordani) were treated with bleach (0, 25, 50, 100 and 200 ppm), phosphates (0, 2, 4 and 6% w/v) and sulfites (0, 0.75, 1.25 and 2% w/v) and stored at 2 degrees C for 48 hours. Odors were evaluated by sensory panels and an electronic nose. Aerobic plate counts were performed. Discriminant function analysis was used as the pattern recognition technique to differentiate samples based on odors. Results showed that the electronic nose could discriminate differences in odor due to chemicals present in shrimp. The correct classification rates for bleach, phosphate and sulfite treated shrimp were 92.7, 95.8, and 99.2%, respectively.