Date Published: January 30, 2019
Publisher: Public Library of Science
Author(s): Krzysztof Damaziak, Adrian Stelmasiak, Julia Riedel, Żaneta Zdanowska-Sąsiadek, Mateusz Bucław, Dariusz Gozdowski, Monika Michalczuk, Arda Yildirim.
Visual assessment is one of the key criteria in the sensory evaluation of foods. The appearance of food products may affect their perception by other senses, sometimes giving a false picture of their quality. A true assessment of such sensory attributes as aroma, taste, tenderness, and juiciness, which are components of the overall liking of food, without the use of instrumental methods is feasible only by blind people. We have advanced a hypothesis that blindness may modify the impressions perceived through other senses used in food evaluation. To confirm this hypothesis, a sensory testing of cooked breast and leg meat from various poultry species was conducted by normal sighted and blind panelists aged from 18 to 26 years. It has been demonstrated that the lack of sight is compensated by other senses, the intensified perception of which enables a more precise sensory evaluation of food in terms of such parameters as the aroma, tenderness and juiciness. Thus, blind people can be recommended as panelists evaluating the sensory profile of food products. Scores given by the sensory panel allowed the conclusion that the most desirable poultry meat was BM of broiler chicken and capon, followed by Guinea fowl. Lower scores were given by the panelists to meat of water fowl (goose, duck), whereas the lowest ones were assigned to cooked ostrich meat.
Until recently, one of the most important criteria for food choice was its price. However, increased nutritional awareness by consumers, especially in developing countries, has made quality a new driving force behind purchase decisions. The concept of quality encompasses a multitude of headwords, the most common of which being: methods of food acquisition/production, health safety of food, its nutritive value, and sensory properties. The latter factors–despite being regarded as the most important quality traits of food products–are the most difficult to measure and the most subjective. Of course, there are several analytical and instrumental methods employed for food product assessment, including microbiological procedures, instrumental analyses of tenderness, springiness, color, taste, and other traits of the widely understood food quality. Unfortunately, many food products differing in sensory attributes may achieve identical scores when assessed with these traditional methods. Therefore, sensory evaluation based on direct impressions remains a reference method and an invaluable measurement tool in food quality assessment .
All sighted participants signed informed consent prior to taking part in the study. All blind participants gave an oral consent, which was signed by a formal guardian–Director of the Elżbieta Róża Czacka Society for the Care of the Blind in Laski (PL). Data obtained within the study have been protected in accordance with the Security Policy assumed at the SGGW- Regulation of His Magnificence Rector No. 88/2013 of 3 December 2013. The study was approved by the Warsaw University of Life Sciences Ethics Committee for Scientific Research with Participation of People.
In summary, that the inclusion of the blind persons onto a panel evaluating the sensory profile of food–in our case of poultry meat–affords new methodological possibilities for the quality assessment of food products. In addition, our study results indicate many differences in the perception of sensory impressions used in food assessment between sighted and blind consumers. They also confirm the fact that blindness is compensated for by other senses responsible for food assessment. Although this study constitutes the first attempt at carrying out a sensory panel for products of animal origin with the participation of completely blind persons, the results are significant in terms of providing information on the quality of the product without its falsification with a visual impression. This is of great importance with regards to the pressure put by commercial enterprises on consumers through advertising, the positive reception of which oftentimes stems from the use of modern graphic techniques, and not the quality of the product itself. Finally, our study proves that the unlimited possibility for the visual assessment of food products affects the perception of other sensations. This offers significant opportunities not only for science and industry, but also for visually disabled persons as they may use their different perception capabilities in practice. In the future, however, a specific schedule of training for blind panelists should be elaborated in regard of particular groups of food products. The assessment of the sensory quality of cooked meat did not involve the use of the sense of hearing, which is perceived as the sharpest sense for blind persons, while sound analysis may be very useful in the assessment of such food products as bakery products, chips or some confectionery products. It would also be interesting to conduct sensory testing by blind panelists in other than hedonic scale models, e.g. in triangle tests.