Cooking Chemistry Question


#1

I’ve been making some baked goods using Fuyu persimmons (breads, muffins, cookies); I’m using different recipes and they all call for stirring baking soda into the persimmon pulp and letting the mixture sit for several minutes (two to five minutes, depending on the recipe) before incorporating into the wet ingredients.

The addition of the soda to the pulp causes the mixture to, well, it’s almost like adding gelatin: it solidifies into a quivering mass (which easily breaks apart when stirred into the other ingredients).

Was wondering what’s happening, chemically, to cause the coagulation - and why the recipes specify this step (I’ve contemplated skipping it, but hate wasting food!).


(For the Horde!) #2

I wonder if this answer help:

“…When persimmons are beaten to a pulp, tannins form complexes with carbohydrates, causing the pulp to stiffen to a gel-like consistency. When baking soda is added, a reaction with the moist and slightly acidic persimmon creates carbon dioxide (CO2), which also plays a role in encouraging the pulp to thicken…”

Ironically, it sounds like it is more important for non-Fuyu persmimons.

http://www.exploratorium.edu/cooking/icooks/02-05-04.html


#3

This makes for interesting reading; thank you! (I wonder if people don’t often cook with the Fuyu persimmons.)


#4

That is interesting. So in effect the baking soda is there to really neutralise the astringency of the tannins rather than as a primary raising agent - although obviously the CO2 trapped in the Gel does add some rise to the mixture


#5

Interesting. The first thought to my mind dealt with pH and the soda being a base. Guess you got your answer