Detection of food pH value has important reference value for determining whether a food spoiled, this is because each food has a certain concentration of hydrogen ion (pH), when the growth of microorganisms in food after propagation, the pH value will change correspondingly. In our daily life, our common foods can be divided into 2 categories according to their pH value: acidic food or non acidic food.
It is generally considered that the pH value below 4.6pH is acidic food (e.g. fruit), and the pH value is above 4.6 for non acidic foods (e.g. vegetables). For acid foods, yeasts, molds are easy to grow; not acidic foods, bacteria are easy to grow. Therefore, in order to ensure the safety of food, regular detection of food pH value is very necessary.