ABSTRACT
Detecting food –avor and volatile components is important for quality control of food. Quality control of product fragrance and –avor is based on the comparison of instrumental analysis and sensory evaluation. Until now, gas chromatography (GC), mass spectroscopy (MS), and sensory evaluation have been used for analysis
9.1 Introduction .................................................................................................. 235 9.2 System of the Electronic Nose ...................................................................... 236
9.2.1 Gas Sensors ....................................................................................... 236 9.2.1.1 Metal Oxide Sensors (MOSs) ............................................ 237 9.2.1.2 Conducting Polymer (CP) Sensors ..................................... 237 9.2.1.3 Quartz Crystal Microbalance (QCM) Sensor .................... 237 9.2.1.4 Surface Acoustic Wave (SAW) Sensor .............................. 237 9.2.1.5 Fingerprint Mass Spectrometry ......................................... 237
9.2.2 Sensor Arrays ................................................................................... 238 9.2.3 Data Analysis and Pattern Recognition ............................................ 238
9.2.3.1 Pattern Recognition ........................................................... 238 9.2.3.2 Determination of Concentration Levels Using
Linear Regression .............................................................. 239 9.2.3.3 Arti€cial Neural Networks (ANNs) ................................... 239
9.3 Application of Electronic Nose ..................................................................... 241 9.3.1 Rancidity of Oils ............................................................................... 241 9.3.2 Freshness of Milk and Soymilk ........................................................ 243 9.3.3 Evaluation of Adulteration ................................................................244 9.3.4 Irradiation of Foods ..........................................................................246 9.3.5 Ripeness of Fruit and Vegetables .....................................................250 9.3.6 Freshness of Fish Products ............................................................... 252 9.3.7 Detection of Microorganisms ........................................................... 252 9.3.8 Quality of Control for Other Products .............................................. 253
References ..............................................................................................................254
