Date of Award:

1980

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Nutrition, Dietetics, and Food Sciences

Department name when degree awarded

Nutrition and Food Sciences

Advisor/Chair:

Charlotte P. Brennand

Abstract

Through telephone conversations with directors of 25 randomly selected sensory panels, it was established that the informed consent procedures of no-risk sensory panels vary greatly. The concern about biases of panelists' judgements, resulting from information given as part of the informed consent procedures, has been given as the reason for modifying or ignoring federally defined informed consent procedures. A series of three in-house and two separate consumer sensory panels were designed to test whether the ratings of altered flavor, altered viscosity, and unaltered milk could be affected by informed consent form usage. Two separate test situations included informed consent forms that were designed to induce participant apprehension. Another test condition included informed consent forms designed in such a manner as to emphasize the desirability of the samples. A control test situation that included no informed consent forms was also administered.

In each panel, the off flavor, viscosity, and hedonic rating means of all samples and of each type of sample did not differ significantly when the samples were presented with each of the informed consent forms. When apprehension-inducing informed consent forms stating that the milk samples were obtained from diseased cows were used, the effect of the in-house sensory panelists' previous dairy experiences was to significantly raise their intensity and lower their hedonic ratings of milk samples at p = 0.05 and p = 0.01, respectively . This effect of informed consent usage was not lessened or increased by repeated form usage. This biasing effect of informed consent procedures was not found in consumer panel data. It is believed that the less controlled environment of the consumer panels and general trust of panelists resulted in less panelist attention to details of the panel and, therefore, less comprehension of the implications of the informed consent form. The possibility of biases resulting from informed consent usage should be considered in interpreting results of experiments in which informed consent procedures are used.

The age of panelists in both the in-house and consumer panels was related to off flavor and hedonic ratings at p 0.01. In a linear manner, as panelists' ages increased, most liked the samples more and rated them as being less off flavored.

Additionally, hedonic ratings of bitter and control samples were found to differ significantly between smoking and nonsmoking panel participants. Panelists who smoked cigarettes, cigars, and/or pipes rated these samples as less off flavored (at p = 0.10) and higher on the hedonic scale (at p = 0.05) than did nonsmoking panelists.

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Included in

Nutrition Commons

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