USE OF ORGANIC-ACIDS TO IMPROVE THE CHEMICAL, PHYSICAL, AND MICROBIALATTRIBUTES OF BEEF STRIP LOINS STORED AT -1-DEGREES-C FOR 112 DAYS

Twenty-one beef strip loins (Institutional Meat Purchasers Specificati on #180) were cut into equal halves. One-half of each loin was sprayed with a mixture of 2% lactic acid and 2% (vol/vol) acetic acid and the corresponding half was used as a control. The strip loins were stored at -1 degrees C for 0, 7, 14, 28, 56, 84, or 112 days and evaluated f or chemical, physical, and microbial properties. The internal pH incre ased significantly (P < 0.05) beginning at day 56 for all products. Va cuum scores and visible purge scores showed that these qualities becam e less desirable over storage time. There were no significant differen ces (P > 0.05) for meat color, fat color, or odor over storage time. A cid-treated strip loins had significantly lower (P < 0.05) visible pur ge scores than control strip loins. Internal and external pH, vacuum, meat color, fat color, and odor were not affected by acid treatment. I n a calculation of time-by-treatment interaction (P < 0.05), acid-spra yed strip loins had less percentage of purge than corresponding contro ls at 56 and 112 days of storage. Water-holding capacity decreased ove r 84 days of storage. Anaerobes, lactic acid-producing bacteria, and p sychrotroph populations increased significantly (P < 0.05) over storag e time but anaerobes and lactic acid-producing bacteria were reduced b y acid treatment. Acid-sprayed strip loins had significantly lower aer obic (P < 0.05) and psychrotrophic (P < 0.1) populations than controls after 14 days. These data indicate that an acid spray immediately pri or to packaging can reduce some species of bacteria without adversely affecting the physical properties of products stored for 112 days at - 1 degrees C.