Characterizing the Effects of Cooking Products on Chemical Reactions During Onion Caramelization
Chemistry- Grade:
- 11
- Teacher:
- Tommaso Cioni
In the following experiment, the caramelization reactions of onions were studied to determine if different cooking products (Salt, Sugar, Baking Soda) produce similarities/differences in results based on their amounts of chemical reactions that occur in the process of cooking them. Onions would be divided into 5 samples: caramelized with 0.1g, 0.5g, or 0.9g of cooking product of choice, one caramelized with no cooking product, and one of just raw onions with no cooking products. Samples that had to be caramelized were cooked using a beaker on a hotplate for 30 minutes each until they turned into a light-brown color. All the samples were then turned into slurries by having 10g from each sample blended with 50ml DI water. Once each sample had their own slurry, they were diluted with a 1 in 20 dilution, placed in separate cuvettes, and placed in a UV-vis spectroscopy machine to measure the amount of absorbance of pigments. Since caramelization causes the browning of onions, we can measure the amount of reactions that have occurred using the level of absorbance for each sample. Based on the results found, we can conclude that the type and amount of cooking product creates different results for the absorbance of onions. While salt causes the absorbance of the onions undergoing caramelization to increase as it increases, other cooking products such as sugar and baking soda cause it to decrease significantly.