Role of malic acid
Malic acid can be widely used as food preservative. The effect of acids on microorganisms is not only determined by the concentration of hydrogen ions proportional to each other, but also related to the role of both acids, acid anions and un-ionized molecules. Malic acid is ionized under neutral conditions but not under acidic conditions, but the bactericidal ability under acidic conditions is more than 100 times greater than that under neutral conditions, mainly because the acid in molecular state is more likely to act through the cell membrane, while the acid in ionic state is not easily permeable through cells. In addition, it can promote the thermal denaturation of proteins.
Protect vitamin C, color preserving effect
The hue of the pigments contained in fruits and vegetables are often affected by the acidity and alkalinity, and in some discoloration reactions, often acid is the ingredient that plays a very important role. Such as chlorophyll in acidic conditions will become yellow-brown demagnetized chlorophyll, anthocyanin in the acidic to neutral range change, will gradually from red to purple, tannins in acidic substances will form pink "red powder" and so on. Therefore, L-malic acid can be used as a color preservative for some food products, such as natural fruit dew color preservative.
Salt reducing effect
L-malic acid can be used to make salty food and reduce the amount of salt. For example, sodium malate is moderately salty and can often be used to make salty foods.
Deodorizing and deodorizing agent
It is used as deodorant to remove fish odor, body odor and for food storage, and adding L-malic acid to milk can also improve the quality.