A process for preparing a curing agent outside a meat curing process that comprises the steps: (i) Selecting a plant material comprising at least 50 ppm nitrate； (ii) Contacting the plant material with an organism that can convert the nitrate to nitrite； and (iii) Converting a predetermined amount of the nitrate to nitrite and inactivating or removing the organism from the curing agent when the predetermined amount of nitrite is produced. The plant material can be celery and the organism can be Micrococcus varians or Staphylococcus carnosus.
