Microbiological Quality of Beef Subprimals as Affected by Lactic Acid Sprays Applied at Various Points during Vacuum...

Beef strip loins were sprayed with 1.5% (vol/vol) lactic acid before and/or after 14, 28, 56, 84, and 126 days of vacuum-packaged storage at -1.1 or 2°C to assess the effects on bacteria. Five different treatment combinations including a control (no spray treatment) and one treatment with prestorage acid spray followed by poststorage water spray (A/W) were evaluated. Compared to the controls, 97% of all acid-treated loins had lower microbial counts throughout the storage period. Prestorage acid spray (A/0) was more effective than poststorage acid spray (0/A)with the greatest effects (P < 0.05) being observed on day 28, where the bacterial population was reduced by 1.9 and 1.5 log CFU/cm² for loins stored at -1.1 and 2°C, respectively. Microbial counts for loins with A/A(acid spray both before and after vacuum storage) or A/W treatments were lower than but not significantly different from A/0 (P > 0.05). Poststorage washing resulted in a minimal decontaminating effect, irrespective of the washing agent used. In addition, single spray treatment immediately after fabrication seems more effective and practical than a double spray. Temperature main effects showed that colder temperature (-1.1 versus 2°C) reduced (P < 0.03) microbial growth throughout the storage period. Salmonella contamination was not detected in any samples; however, 28% of the control and 4% of the spray-treated loins were positive for Listeria spp. Appropriate time of acid application in combination with colder storage temperature improved the microbiological quality of meat for at least four weeks.