Metal Oxide Sensors for Electronic Noses and Their Application to Food Analysis

Abstract

Electronic noses (E-noses) use various types of electronic gas sensors that have partial specificity. This review focuses on commercial and experimental E-noses that use metal oxide semi-conductors. The review covers quality control applications to food and beverages, including determination of freshness and identification of contaminants or adulteration. Applications of E-noses to a wide range of foods and beverages are considered, including: meat, fish, grains, alcoholic drinks, non-alcoholic drinks, fruits, milk and dairy products, olive oils, nuts, fresh vegetables and eggs.

Food Analysis: Present, Future, and Foodomics

“…Biosensors have been developed for determining major and minor food components, preservatives, food colors and sweeteners, toxins, pesticides, antibiotics, and hormones [69]. They have also found use in tracking microbial contamination [70], to follow food safety [71], processing, and to certify food quality and control including the development of the so-called electronic nose [72] or electronic tongue [73] that have a large impact on flavor analysis. The advantages of these methods are the rapid response time, the high degree of specificity and sensitivity, and the possibility of being used for inline processes monitoring food manufacturing.…”

Quality Control Through Electronic Nose System

“…This chapter deals specifically with MOX sensors built with semiconductor materials such as Tin oxide (SnO2), Zinc oxide (ZnO), Titanium oxide (TiO2), among others. Their operating principle is based on the change of conductivity of a sensitive material when it absorbs or reacts with the gases in the environment, Figure 2 shows several commercial sensors of this type (Berna, 2010). The majority of gas sensors are general purpose and usually have high sensitivity, detecting very low concentrations of volatile, but have disadvantages when trying to determine concentrations of a single component, because the output signal cannot be unambiguously assigned to the component by its generality (Duran, 2005(Duran, , 2009).…”

Analysis of volatile organic compounds in exhaled breath for lung cancer diagnosis using a sensor system

“…To overcome the limitations of GC-MS analysis, various types of electronic nose have come into use for analyzing breath gas. In the previous studies, quartz microbalance (QMB) gas sensors [21], surface acoustic wave (SAW) gas sensors [22], colorimetric sensor array [23], polymer/carbon composite [24], conducting polymer gas sensors [25], ion mobility spectrometry [26], exhaled breath condensate (EBC) [27], and metal oxide gas sensors [28] were applied to lung cancer detection through breath gas. Among them, the metal oxide sensors are known to possess several advantages with high sensitivity, very fast response, and low cost [29].…”