Chemosensor (electronic nose) for food quality evaluation

One of the most critical food-quality attributes is the smell or aroma of the food as it determines the acceptability of the food by the consumers even before they place the food in their mouth. Several food products have specific aroma attributes associated with them, and any alteration to the perceived aroma characteristics will result in the rejection of the food product and, subsequently, the success of the food product in the marketplace. Traditionally, the food industry relies on trained and untrained consumer panels for aroma validation of food products for compliance, for aiming to produce acceptable aroma profiles, and for quality assurance. The aroma attribute has many descriptive terms: smell, aroma, odor, and flavor, and they are used interchangeably. Of these terms, “flavor” refers to the combined volatiles released during smelling and during mastication. The smell is the result of the reaction between volatile chemicals and the nose. The volatiles are often released from food due to both physical and chemical changes occurring in the food material. Primarily, the volatile compounds defining a particular smell are organic in nature and are comprised of aldehydes, ketones, and esters. In addition, other volatile compounds that are not organic in nature also contribute to the smell or odor. Inorganic chemical compounds that are associated with smell include sulfur-based compounds and ammonia, hydrogen sulfide, etc.