preservative treatment

例句：

1. 1. The use of preservatives in food is regulated to prevent spoilage.
   食品中使用防腐剂是为了防止变质。
2. 2. Preservatives are used to extend the shelf life of food.
   防腐剂被用来延长食品的保质期。
3. 3. In some cases, preservatives may be necessary to ensure food safety.
   在某些情况下，防腐剂可能是确保食品安全所必需的。