Radiation sterilization of spices for hospital food services and patient care

ABSTRACT A survey of the commercial spices used by food services in a typical hospital environment revealed high contamination with microorganisms, i.e., 104 to 107 counts per gram. The predominant microorganisms were as followed (in colony counts/gram): (1) heat‐resistant bacterial spores in black pepper, 1 × 107; thyme, 2 × 106; anise, 7 × 104; curry powder, 4 × 105; poultry seasoning, 8 × 104; pickling spice, cardamom, and cumin, 1.5–3 × 104; (2) mixed populations of vegetative cells and bacterial spores in cumin, 1 × 106; (3) molds in cream of tartar, 2 × 104. Sterility of food may be important in a hospital setting, especially in the care of immunocompromised patients. To eliminate the organisms, we recommend radiation treatment, accompanied by appropriate microbiological quality control. On the basis of radiation survival data, the composite natural flora would be reduced to the level of “commercial sterility” (defined as less than 10 organisms per gram((Kiss 1982) by the following minimum radiation doses (in kGy): black pepper, 13; thyme, 13; cumin, 12; anise, 10; curry, 7.3; pickling spice, 7; poultry seasoning, 6; cardamom, 9.4; cream of tartar, 4. For practical purposes, two dose levels can be recommended for treatment of spices in the hospital environment, low = 6–10 kGy and high = 10–15 kGy.