In August, 2018, the State Administration for Market Regulation (SAMR) issued the Food Safety Practices for Food and Beverage Services (Revised Edition), which for the first time defined “high-risk perishable food” as food with high protein or carbohydrate content (generally, pH>4.6 and Water activity (Aw)>0.85) that is prone to spoilage at room temperature.

1. What effect do pH and Aw have on food preservation?

An important phenomenon in food preservation is the homeostasis of microorganisms. The interaction of Aw, pH, temperature and other factors has crucial influence on inhibiting the growth, propagation and toxigenicity of microorganisms. The interaction effect of pH and Aw on food preservation is reflected in the “high-risk perishable food”.

Aw: generally, the suitable Aw for bacteria growth is 0.94-0.99, for moulds is 0.73-0.94, for yeasts is 0.88-0.94.

pH value: moulds and yeasts could grow at low pH value, generally, pH<4.6 could inhibit pathogens from growing and producing toxins.    

2. What kind of food belongs to high-risk perishable food?

In the report of evaluation and Definition of Potentially Hazardous Foods from US, the Aw and pH value of common foods are listed (details can be seen in tables below). 

The common animal products that belong to high-risk perishable food are egg, milk and dairy products, fish, poultry and meat of livestock and their processed products. Plant products are fresh fruits and vegetables, etc.  

Coutersy: evaluation and Definition of Potentially Hazardous Foods

3. Control measures

US
“Time/Temperature Control for Safety Food” (TCS):  using T/T control as the key factor for food safety control, taking pH, Aw, interaction of pH and Aw, heat treatment and packaging into consideration, which is relatively simple to determine whether the food requires T/T control to ensure food safety.

China
Food Safety Practices for Food and Beverage Services (Revised Edition): specific requirements of food safety risk prevention and control for high-risk perishable foods are established, involving several production processes from thawing, cooling after cooking, to reheating. 

Noteworthy, slightly differences exist in the regulation requirements of Temperature Danger Zone: US (5℃-57℃), China (8℃-60℃).   

4. Advices from Global Foodmate

High-risk perishable food could easily trigger food safety incidents. Global Foodmate strongly suggest relevant companies should fully understand the regulations on high-risk perishable food to avoid foodborne diseases. 


Please note: Original article of Global Foodmate of Information Service and Business Department, please indicate the source from the Global Foodmate if reprint.