Designs for sensory trials involving foods of animal origin

Abstract

Sensory quality is a basic factor that influences consumers while purchasing processed food of animal origin. Experimental designs will prove an effective tool in establishing a sensory fact in trials involving animal produce. To draw valid conclusion from a study, it is important to eliminate or minimize all sources of error and control all factors that may influence the inference. Hence, in addition to the potential sources associated with the preparation of the test products, variability due to measurement or assessment process, order effects, carryover effects and assessor fatigue are to be considered. When there are a large number of products, two operational constraints limit the choice of experimental designs viz., assessor constraint that sets a maximum number of products that an assessor can evaluate within a session before onset of sensory fatigue and preparation constraint that limits the number of products that can be prepared for a given session without loss of experimental control. Hence, it is many times necessary to split sensory evaluation into two sessions. Here, a general method to construct designs for sensory trials in two sessions, which are balanced for carry over effects within session, is proposed. The design is resolvable in the sense that panelist would get an opportunity to evaluate every product exactly once at the end of both the sessions.