Objective versus Sensory Evaluation of Foods

Abstract

The overall quality of food can be divided into three main categories: quantitative, hidden, and sensory (Kramer 1966). Some quantitative aspects of food quality are primarily of interest to the processor, for example, yield of product obtained from a raw material; others are of interest both to the consumer and manufacturer, for example, the ratio of more expensive to less expensive foods or components in a processed food. In some cases the ratio can be evaluated roughly by sensory methods. Hidden quality attributes include the nutritional value of a food or the presence of toxic compounds that, generally, cannot be determined by sensory evaluation. They include, for instance, the vitamin C content of juices, or the presence of trace amounts of pesticides from spraying fruits and vegetables. Sensory attributes of quality guide the consumer in his selection of foods. Such attributes are measured by the processor to determine consumer preference in order to manufacture an acceptable product at maximum production economy. Sensory attributes are measured also in determining the conformity of a food with established government or trade standards and food grades (Pigott, et al. 1988; Zeuthen et al. 1990).