Storage studies to predict shelf life are an essential part of every product development, improvement, or maintenance program. Sensory evaluations of shelf life should be conducted by a sensory analyst who thoroughly understands the following factors: 1) purpose of the experiment; 2) physical and chemical composition of the test products; 3) formula, processing, and packaging treatment variables; 4) storage conditions; 5) projected storage life; 6) experimental design; 7) anticipated sensory change; and 8) sensory evaluation procedures. The factors involved in the selection of a particular sensory evaluation procedure and the determination of failure criteria are discussed. Practical applications of product shelf-life information include the establishment of the: 1) sell-by or pull date; 2) use-by or expiration date; and 3) freshness or quality assurance date.

Sensory evaluation is an important means of testing for quality in all stages of product flow. Initial sensory evaluation of incoming raw materials and packaging materials may be performed by a quality control (QC) inspector or technician; suspect lots may be submitted to a panel for final decisions. Sensory panel testing is advised for in-process monitoring and final product inspection. QC inspectors trained in sensory evaluation should monitor product storage conditions.

The Quaker Oats Company established a formal program of sensory evaluation at five of its manufacturing plants. The company's Plant Sensory Program involves three levels of personnel: 1) a sensory leader from the Research & Development Center; 2) a sensory coordinator at the plant location; and 3) plant monitors from the plant quality assurance laboratory. The training programs for each level of personnel are described. Testing facilities are divided into two distinct areas - one for sample preparation and one for evaluation - but vary in size and shape in each plant. The Plant Sensory Program is applied to ingredients, in-process materials, packaging, and finished products.