Use of nisin and microwave treatment reduces Clostridium sporogenes outgrowth in precooked vacuum-packaged beef

Nisin (NS), microwave (MW), and nisin plus microwave (NS + MW) treatments were applied to precooked beef semitendinosus muscles inoculated with spores of Clostridium sporogenes. Samples were then vacuum packaged and stored at 4 degrees C or 10 degrees C for 21 or 70 days. After 21 days of storage at 10 degrees C, NS and NS + MW reduced viable vegetative cell (VVC) counts by approximately 3 log cycles compared to the control. After 70 days storage, WC counts were higher (P < 0.05) at 10 degrees C than 4 degrees C only for the control. However, at 4 degrees C, WC counts for each treatment were not different (P > 0.05) from those of the control. After 70 days of storage at 10 degrees C, WC counts were lower (P < 0.05) for NS and NS + MW treatments than for the control.