The pH level of food strongly affects its taste, texture, safety and shelf life. PH of 7 is neutral, like pure water. Value under 7 is acidic while everything above 7 is alkaline.
Most foods have pH between 2 and 9. Because the scale is logarithmic, every number represents ten-fold change of acidity. Like this, food with pH 3 is ten times more acidic than that with pH 4
How pH Affects Food Taste, Safety and Cooking
Most germs cannot grow if the pH is less than 4.5. Hence, in the ingredients of long-life products you commonly find ascorbic, citric or acetic acid to lower the pH and prolong the preservation. Botulism is a big risk in canned foods, because the spores of Clostridium botulinum thrive in environments without oxygen.
Even so, these spores do not grow if the pH is under 4.6, which makes that value the threshold for safe conservation.
According to the system HACCP, you must monitor three main spots: temperature, water activity and pH. Every type of germ has its optimum pH level for growth, and the limits of acidity and alkaline range between them.
Various differences exist between the way to grow and the methods of preparation. The data about foods relate to the edible part in its natural state. For instance, unbleached flour has pH between 5.8 and 6.1, but bleached flour is more acidic, between 4.6 and 5.1.
The food with the highest average pH in known lists is the Bird’s Nest soup.
Also while cooking you must consider the pH. If you add baking soda to the water to cook beans, they cook more quickly because of the higher alkalinity. Rather, cooking beans in acidic liquid, as tomato soup, slows the process.
Alkaline conditions help to destroy pectin, the glue that keeps the cells of vegetables together. Which softens the food and accelerates long cook times. If you add baking soda to the water, the pH rises and helps to break the pectin on the surface of potatoes.
That creates starchy slurry, that gives more crisp outside after roasting.
To reduce the strong acidity of a dish, you can use fats or sugars. Adding a base also adds mineral salts, as calcium, sodium or potassium, which can strongly alter the taste and make the food too salty or bitter. The difference between pH 3 and pH 7 is huge, it is a 10,000-fold difference because of the logarithmic scale.
During healing, a good target is to eat foods with pH over 5.0.