What is the pH of lemon juice

Why lemons have an alkaline effect in the body

Anyone with an acid-sensitive stomach knows from their own experience: Lemons are sour, and so is coffee. Nevertheless, according to the acid-base table, both foods are basic. What seems paradoxical has a simple explanation.

Lemons taste sour, as do oranges, apples and white wine. An acid-sensitive stomach reacts accordingly to these foods. Nevertheless, according to an "acid-base" table, these foods are basic. What seems paradoxical has a simple explanation. The acid acts in the mouth and stomach, and in the rest of the organism what remains after digestion.

Many fruits contain organic acids that are metabolized in the respiratory chain. Energy is obtained from them, while CO2 is created and exhaled. The basic minerals in fruit get into the blood, e.g. B. Potassium and Magnesium. Vegetables are also rich in basic minerals. Protein-rich foods such as meat, fish, milk and grain products, on the other hand, contain many acidic amino acids, from which sulfate is formed in the metabolism. Together with phosphorus and chloride, this ultimately has an acidic effect in the body.

If the acidic minerals are in the majority, the body's own buffer system in the blood becomes active. It prevents the optimal pH from deviating from 7.4. The resulting acids bind to sodium from the sodium bicarbonate buffer system. The acid residues neutralized in this way are excreted in the urine via the kidneys.

The Pral value of a food in the acid-base tables indicates the acidity of the kidneys through minerals and protein. It is calculated using the average proportion of these substances and relates to 100 grams of the food. The Pral value does not say anything about the pH value of the undigested food. Therefore, the acid-base table is the wrong source of information for heartburn.

According to one hypothesis, the body becomes over-acidic through an acid-heavy diet, i.e. with many foods that produce acid, which is said to be harmful to health in the long term. However, this connection has not been scientifically proven.

This «acid-base» table shows the Pral value

negative values ​​for bases, positive values ​​for acids
Food Pral value
Potatoes- 4.0
spinach- 14.0
tomatoes- 3.1
pineapple- 2.7
Apples- 2.2
Lemons- 2.5
Organs- 2.7
Beer, light0.9
coffee- 1.4
red wine- 2.4
Rice, peeled4.6
Brown rice12.5
wheat flour6.9
Whole grain bread1.8
Beef, lean7.8
Hazelnuts- 2.8