Integrating spatial and chromatic properties for a better definition of food appearance

NURIA ACEVEDO; CAROLINA SCHEBOR; SILVIA MATIACEVICH; MARCELA AGUDELO; JOSÉ LUIS CAIVANO; MARÍA DEL PILAR BUERA

Porto, Portugal

Congreso; ISEKI; 2008

st1:*{behavior:url(#ieooui) } <!-- /* Font Definitions */ @font-face {font-family:"Arial Narrow"; panose-1:2 11 5 6 2 2 2 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:647 0 0 0 159 0;} @font-face {font-family:AdvEPSTIM; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Introduction             Color measurement is important for different aspects in the stages of food processing, quality control, grading of fruits, legumes, juices, dairy products, canned foods, and analysis of deteriorative reactions and is included in undergraduate or graduate classes. However, spatial properties (cesia: a combination of translucency, gloss and clarity), which are commonly analysed in areas such as architecture, art and design, affect the perception of chromatic attributes but have not been considered for a better definition of food appearance. Objective Transfer the knowledge and experience on color and spatial properties measurement acquired through research in diverse areas and materials to undergraduate and graduate food science classes in the School of Exact and Natural Sciences of the University of Buenos Aires. Results and discussion The color of transparent samples is analyzed employing a spectrophotometer or a tristimulus colorimeter. In the case of opaque samples, the color measurement is done through the classical and practical measurement employing a hand-held tristimulus colorimeter; and using a newer methodology, the computer vision system. Measurements of inhomogeneous surfaces have very low reproducibility by means of a tristimulus colorimeter; however, the computer vision system is very useful in these cases. Most foods are translucent to some degree. This case is considered for translucent solids, measuring thin layers of material with white and black backgrounds and analyzing the data through the Kubelka-Munk theory. The measurement of gloss and clarity were also explored by image analysis, and by available cesia charts. Conclusions The experiments allow the students to conclude that the combination of spectral and spatial attributes are essential for a proper evaluation of food appearance.  It is important to open food science courses to the input from different areas of knowledge. On the other side, students feedback could also be valuable for the food industry.