seal something in        
phrasal verb with seal verb [ T ] uk/siːl/ us/siːl/
 保持,使不丧失
to prevent a substance or quality from being lost from something during a process such as cooking
  Fry the meat quickly in hot oil to seal in the flavour/juices. 把肉在热油中迅速过一下,以保持它的原汁原味。