kitchen and chemistry

A friend of mine told me that this blog is not written in correct English, but understandable, anyway I do my best. (If you like travelling you should visit Lisa's blog ).
You like to eat pasta, I know it, but you are bored to have it with tasteless sauces (or worse with ketchup!). Here is the best pasta ever; this recipe is from Lucia, my mum.
Ingredients:
red peppers, eggplants, tomato sauce, onion, (the quantity depends both from the shape of the vegetable and the quantity of pasta you want to cook ). Usually for five person you need 6-700 g of pasta, a couple of eggplants and three or four big peppers ).
Preparation :

Put in a frying pan some olive oil and the sliced eggplants (not too fine). In the first minutes the eggplants will absorb all the oil, but don't add other, they will give it back later .When the eggplants begins to soften and leaks oil, pour in the pan sliced onions and red peppers. Let them fry for a few minutes and than pour in some tomato sauce. Also here only practice can gives you the right amount: we don't want a red sauce, tomatoes should be at most 40 % the mass of the final product. Let it go on weak flame for a few minutes and finally (not before!) add some salt. Meanwhile you have boiled the pasta in salted water; strain it when is still somewhat raw. Pour it in the pan, rise the flame and let it go with the sauce untill it reaches a "to the tooth" texture.
Finally a couple handful of grated parmesan. Mmmmmhh...

Careful : around 100°C , Mn2O7 oxidize in explosive way organic substances ; for this reason you must prevent an overheating of the system .

Tools : 2 test tubes ( 16 x 160 mm ) , 2 supports whith clamps , becher 200 ml , pneumatic bath , glasses , gloves .

Reagents : KMnO4 , H2SO4 conc , ethanol

Experiment : the test tubes are fixed to the supports so as them are dipped in the water bath for about an half .Pour H2SO4 conc in the test tubes for about 2 cm height , then pour 4 cm of ethanol above the acid , avoiding the blending of the 2 fase .Now introduce in each tube a small cristal of KMnO4 , after a while , at the level of the liquids interface , are noticed yellow flash , which develops crackling .It seems that the flashes are produced under the water .
Gradually the mixture goes to green and brown .The experiment can go on for 15 min , during thath time the frequency of the flashes it's unpredictable .

Enlightenment : KMnO4 reacts first with the sulfuric acid to give Mn2O7 , that oxidize the alcol in a violent reaction .

2 KMnO4 + H2SO4 ------- K2SO4 + Mn2O7 + H2O
Mn2O7 ------- 2 MnO2 + 1/2 O2

Treatment : after cooling , neutralize with Ca(OH)2 and pour it in the inorganic salts waste .The water solution can be poured out in the sink .

Have you ever asked yourself : from where it comes the name of the propipette ?( I´m talking about the Italian and Swedish name of this tool , I don´t know if the English call it like this ) .Here you cam find the mytological origin of the word .
This are the only info I could found about Peleo ball , so I think the propipette is called like this just because of its shape .
Stat rosa pristina nomine , nomina nuda tenemus
( literally : the first rose remain only for the name , we keep only nude name ; it means the men are not able to know the thingh in their essence , just the name , the label )

As you can imagine , I love sweets ( but don´t worry there will be also salty dishes ) .I have had some requests so we have 2 recipes this week .This is my own creation ; now we can start with the main pourpose of this blog : apply chemistry in the kitchen .If you have ever baked a cake ( and you are not a skilled chef ) certainly you know the result is not always predictable .The main question is : will it swell ?
The normal baking powder contain mainly 2 substances : an acid and a base which reacts to give carbon dioxide .The alkaline component is almost universally sodium acid carbonate or sodium bicarbonate , the acidi could be tartaric acid or sodium pyrofosfate , which are both fast acting acid salts .(There are other powder containing acidic subsatnces which reacts at high temperature such as sodium aluminum sulfate ) .The acid-base reactions are known as the faster chemical reactions , so when you wet the powder , it suddenly give rais CO2 .That is the thing : we want the gas to rais and expand only when the batter is set enough to prevent the escaping or coalescence of the bubbles , this process can take a long time because the heat transfering in the oven is very slow .So I have planed a way to have a somewhat hardened and elastic dough from the beginning , before putting our pan in the oven .To obtain that we don´t need to use some strange ingredient or worse some kind of chemical .We have to change just the order of the ingredient , and the way we work the mixture .We can curdle the casein contained in butter with the acidic orange juice .If the pH is lowered to about 5 , the casein micelles lose their negative charge and clump together .This is normally avoided because you pour the orange juice in the mixture after the flour and , principally , the eggs : they have a quite basic pH (the moment the egg leaves the hen it begin to change his pH : the yolk jumps from 6 to 6,6 and the white from 7,7 to 9 or sometimes above ) .But now I think is enough for the chemistry .

Ingredients :
1 1/2 cup sugar
200 g butter
juice of 1 big orange
grated peel of 1 orange
4 eggs
3 cups flour
50 g dark chocolate in chips
2 tea spoon baking powder
rosemary

Preparation : Put in a large bowl the butter keeped at ambient temperature and the sugar .Blend it very well since you obtain a foamy mix .Then pour the orange juice and work it well with a whisk .Now you have a curdled mixture .Than pour in this order , blending with a spoon : the eggs ( one per time ) , the flour , rosemary ( I think rosemary-orange is a perfect combination of flavour and taste) , chocolate and finally the baking powder .You may need trained muscles to bland this dough ( don´t use the hands , it is very sticky ) .Now we have to wet the mixture with a small amount of milk ( 1/2 glass or less ) to start the reaction of the baking powder ( if the dough is too dry , perhaps the acidic and the basic compound will have problem to encounter ) . Now pour the dough in a basted pan and cook it at 170 °C for about 1h 10 min .In the first 1/2 h you may put a small pan with hot water in the oven to avoid the premature formation of the crust .Than you have to take it off .
I can ensure you that this cake will shoot up pretty good .( and also has a very good taste )

For a 30 cm diameter :
400 g dark chocolate
300 ml cream
100 ml milk
2 eggs
tart pastry
Preparation : cook well the tart pastry .Meanwhile melt on a water bath the chocolate and pour in it the cream previously boiled with milk .Last fold the eggs , one per time , building in much air as possible .Pour the mixture on the pastry and cook it at 110° C for about 40 min .The cake is ready when , shaking it gently , the chocolate creme tremble like a pudding .Enjoy it!