ERIC Number: EJ1043298
Record Type: Journal
Publication Date: 2014-Oct
Abstractor: As Provided
Making Sense of Olive Oil: Simple Experiments to Connect Sensory Observations with the Underlying Chemistry
Blatchly, Richard A.; Delen, Zeynep; O'Hara, Patricia B.
Journal of Chemical Education, v91 n10 p1623-1630 Oct 2014
In the last decade, our understanding of the chemistry of olive oil has dramatically improved. Here, the essential chemistry of olive oil and its important minor constituents is described and related to the typical sensory categories used to rate and experience oils: color, aroma, bitterness, and pungency. We also describe experiments to explore some of the characteristics of olive oil related to its status as a new health food. Simple qualitative experiments on olive oil can be done in conjunction with tastings of the oil. First, we establish the relationship between the color of an object and the absorption of light by its molecular constituents using gummy candies and laser pointers. Then, the color of the various oils can be measured quantitatively using an iPhone app (Irodori). Illuminating the oil with a green laser produces a startling red fluorescence in the presence of the natural chlorophyll in some olive oils. Relatively straightforward colorimetric assays can reveal the presence of unsaturated fatty acids, healthy antioxidants such as phenols (unique to olive oils), contaminating peroxides, and the level of free fatty acid that is a telltale sign of poorly treated or stale oils. A final comparison of the sensory observations from tasting with the chemical and spectroscopic analysis provides an introduction to the science behind food standards and the sensitivity of our own sensory apparatus.
Descriptors: Chemistry, Science Experiments, Food, Sensory Experience, Classification, Color, Light, Lasers, Hands on Science, Spectroscopy, Qualitative Research, Statistical Analysis, Science Instruction, Secondary School Science, College Science
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Secondary Education; Higher Education; Postsecondary Education; High Schools
Authoring Institution: N/A