BACTERIOLOGY AND RETAIL CASE LIFE OF PORK AFTER STORAGE IN CARBON-DIOXIDE

The effects of prolonged, anoxic storage, under CO2 at -1.5-degrees-C, upon the bacteriology and case life of pork on its subsequent transfe r to the aerobic conditions of simulated retail display at 8-degrees-C was examined. Brochothrix thermosphacta, lactic acid bacteria, enteri cs, and pseudomonads were enumerated. Panel scores for odor and appear ance acceptability were used to quantify retail case life. Lactic acid bacteria were the only bacteria found during loin storage in CO2 for up to 24 weeks. Those organisms reached maximum number of 10(7) CFU/cm 2 within 9 weeks. The number of lactic acid bacteria initially found o n the freshly cut surfaces of loin chops increased linearly during the first 9 weeks of loin storage in CO2. Thereafter, they continued to g row on the chops and dominated the spoilage flora during retail displa y. The pseudomonads grew rapidly and emerged as the next most numerous organism, while B. thermosphacta and enterics showed only limited aer obic growth. The acceptability of pork chop appearance and odor was ad versely affected by loin storage time. Each 6-week interval of loin st orage produced a 1 d reduction in case life. Should controlled atmosph eres be a practicable means of meat distribution to the retail marketp lace, efforts will be necessary to assure a maximum case life after th eir removal from preservative packagings.