Bachelorarbeit Auswirkungen von Garverfahren und Portionsgrößen ...

Abstract
This thesis investigates the loss of ascorbic acid in potatoes using different cooking
methods. The experimental results are compared with the content of ascorbic acid in
fresh, uncooked potatoes. Even the most careful method, cannot prevent a loss of
ascorbic acid. The comparison of different cooking methods allows to find the method
which minimizes the loss of ascorbic acid and to find indications whether or not the
loss of ascorbic acid depends on the serving size.
Therefore just after peeling, potatoes cut down in pieces of 60 g are boiled in a pot or
in modern domestic appliances like in a steam oven, in a pressure steam oven or in a
microwave. Apart from the cooking method, the serving size varies from 300 g over
600 g to 900 g. The microwave preserves vitamin C the best. Whereas steaming
preserves more ascorbic acid as conventional boiling, which take place in a lot of
water. Potatoes boiled in a pressure steam oven have the smallest amount of
ascorbic acid.
Concerning the different servings sizes the experiments revealed no correlations
between the loss of vitamin C and the increase of the serving size.
There are only small or no losses of ascorbic acid in each particular serving size
when the microwave is used. For boiling and using a pressure steam oven the
highest loss is found in the 300-g-portion. Steamed potatoes have a minimum
amount of ascorbic acid in the 600-g-portion.
In future analysis, potato species should be used which are mentioned in the majority
of experiments from literature. And the experiments should be reapplied.