| Abstract |
Sensory investigations of products are performed to find out how products are perceived by human senses. On one hand humans act as “instruments” (as members of a sensory panel) giving objective product information, and on the other hand give their subjective opinion (as a member of a sample of consumers) of a product.
Humans can provide information about which attributes vary between samples, but also give information about how products are liked or disliked. To provide product information the humans need to verbally communicate sample descriptions.
The main purpose of this thesis is to analyse information gained from verbalisation of perceptions in sensory descriptive analysis. This is done by combining results from sensory analysis with results gained through chemical and instrumental measurements, and focusing on how product knowledge can influence verbalisation of results. Degree of product acceptance by consumers is often the end goal for investigations where human senses are used as a tool for product information. Hence, verbalisation in connection with consumer descriptors is of interest. In this thesis nine papers are investigated, with a view to put focus on choice and nuances of vocabulary in sensory description of various products.
Generally, choice of descriptors is of importance with respect to the amount of detailed information obtained through sensory analysis. Trained panellists given the opportunity to verbalise their sensory perception of products will produce product information hardily available by any other methods.
Information obtained from instrumental or chemical measurements are found to be inferior compared to information obtained from sensory analysis with respect to product quality information. This is demonstrated in analysis of flavour and appearance in two of the investigated papers. Flavour descriptors vary in specificity; some flavour descriptors represent collective terms i.e. rancidity which in more detail can be verbalised by descriptors such as grass, hay, stearin, paint and off-flavour. Each of these descriptors gives detailed and understandable information about perception of the product analysed. Sensory analysis of appearance of wooden surfaces is likewise shown to give detailed product information not available by other methods.
Consumers’ evaluation of products showed the use of few objective descriptors which were of a broad meaning and not very detailed, and in addition consumers’ choice of words was most often in terms of subjective descriptors. Words chosen by a trained panel gave more detailed information and involved words easily interpreted in relation to the consumers’ subjective descriptors. An example is the objective descriptor warmed-over flavour analysed by a sensory panel in relation to consumer descriptors like “bad off-taste” and “absence of taste”.
Assessors’ product knowledge with respect to ingredients and production process as well as sensory familiarity to the product itself was shown to be beneficial to the sensory result. Familiarity with verbalising sensory impressions of chocolate proved to be beneficial for a panel with chocolate product knowledge. This panel discriminated chocolate samples by means of acidic flavour, something panels with no special product knowledge of chocolate failed to do.
The commissioning parties of research and development projects will benefit from spending time on sensory analysis where panellists are asked to verbalise detailed perceptions of products. Sensory descriptive analyses conducted by trained panellists naturally will give more precise information about products as seen by consumers, but also give information of important criteria vital for consumer purchase. |
Marit Rødbotten
