Potassium cinnamate is a commonly used food preservative with the advantages of broad-spectrum, high efficiency, safety and low toxicity. Adding appropriate amount of potassium cinnamate in food processing can inhibit the growth and reproduction of various microorganisms in food and prolong the shelf life of food. Specifically, potassium cinnamate can affect the shelf life of food through the following aspects:

1. Inhibition of microorganisms: potassium cinnamate can inhibit the growth of bacteria, yeasts and molds in the food, thus reducing the microorganisms caused by the phenomenon of food spoilage and deterioration.

2. Antioxidant: Potassium cinnamate has strong antioxidant effect, which can slow down the oxidation rate of food and prevent food spoilage and corruption.

3. Regulate acidity: Potassium cinnamate has a certain regulating effect on the acidity and alkalinity of food, which can keep the food in a suitable range of acidity and alkalinity, and prevent the growth and reproduction of microorganisms.

4. Improvement of taste: appropriate amount of potassium cinnamate can improve the taste and texture of food, improve the taste quality of food and extend the shelf life of food.

It should be noted that potassium cinnamate as a food preservative is not omnipotent, it can only prolong the shelf life of food, but can not prevent all the food deterioration and corruption. In order to ensure food safety and hygiene, other measures should be taken to control microbial contamination and oxidative deterioration of food along with proper use and storage of potassium cinnamate.