Effects of freezing and thawing on microbiological and physical-chemical properties of dry-aged beef.

This study evaluated the effects of freezing, prior to and after dry aging, on the microbiological and physical-chemical quality of beef. Strip loins (n = 24) from 12 carcasses were assigned to four treatments: non-frozen dry aging (Dry); dry aging, steak fabrication, freezing and slow thawing (Dry + ST); freezing, fast thawing (FT; 20 °C/15 h) and dry aging (FT + Dry); freezing, slow thawing (ST; 4°C / 48h) and dry aging (ST + Dry). Freezing conditions were - 20°C/28 days and dry aging conditions were 2°C/70% relative humidity, for 28 days. Freezing prior to dry aging did not affect the microbial counts compared to Dry. However, FT + Dry and ST + Dry increased (16%) total process loss (P < .05) compared to Dry and Dry+ST. Moreover, freezing changed volatile compounds profile. Thus, freezing prior to dry aging was not a feasible process due to increased process loss, while freezing after dry aging was considered a viable alternative to preserve the steaks without compromising beef physical-chemical traits