MadSci Network: Biochemistry |
This is a very violent treatment of tomatoes! When you raise the pH to 11, you will be denaturing all proteins present, and the open configurations may allow rapid reactions that were impossible at normal pHs (~ 4.5). Reducing the pH back to 4 with HCl is simply a restoration of the normal pH. Most likely some irreversible reactions or conformational changes have occurred. Heat would only accelerate the effects. The particular chemicals used to change pH are irrelevant, although getting to pH 11 wouldn't be easy with weaker bases. You mention "burnt" smell and taste, so I'd suspect a Maillard-reaction between the tomato proteins and the sugars present. This type of reaction is responsible for the broiled flavors of meat and fish and caramels. Most flavors and odors are developed from aldehydes and ketones generated from oxidation or reduction products. pH 11 or higher is a very harsh treatment. In food with fats, you'd saponify the fats and make soap of them. I doubt if any food would have its flavor profile survive intact from such a treatment.
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