Submitted to: Journal of Food Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/19/2003
Publication Date: 8/1/2003
Citation: MEYER, J.D., CERVENY, J.G., LUCHANSKY, J.B. INHIBITION OF NON-PROTEOLYTIC PSYCHROTOPHIC CLOSTRIDIA AND ANAEROBIC SPOREFORMERS BY SODIUM DIACETATE AND SODIUM LACTATE IN COOK-IN-BAG TURKEY BREAST. JOURNAL OF FOOD PROTECTION. Journal of Food Protection. 2003 v. 66. No. 8. pg 1474-1478. Interpretive Summary: Sous vide or cook-in-bag products have become quite popular in recent years because such products contain little or no preservatives, have an extended shelf life, and retain more of the original flavor, aroma, and texture than conventionally cooked foods. Because refrigeration is the primary antimicrobial barrier, undesirable microbes, such as clostridia, capable of fgrowth at low temperatures in vacuum-packaged foods are often implicated i the spoilage of such products. We evaluated the antimicrobial potential of sodium lactate and sodium diacetate in cook-in-bag turkey breasts. In the absence of any antimicrobials, off odors occurred in 7 weeks and counts of anaerobic bacteria increased to about 8 log10 cfu per gram. Turkey containing both sodium diacetate (0.25 percent) and sodium lactate (1.5 percent) did not spoil after 22 weeks of refrigerated storage. Future studies will optimize formulations to achieve the desired taste and optimal lantimicrobial activity.
Technical Abstract: Non-proteolytic, psychrotrophic Clostridium strain OMFRI1 was recovered from cook-in-bag turkey breasts (CIBTB) that displayed an intense pink discoloration and an off odor. Strain OMFRI1 was subsequently evaluated in CIBTB containing sodium diacetate (0, 0.25, and 0.5 percent) and/or sodium lactate (0, 1.25, and 2.5 percent). Raw CIBTB batter was inoculated with spores (9 30/g) of strain OMFRI1, vacuum-packaged, cooked to an internal temperature of 71.1 deg C, chilled, and incubated at 4 deg C for up to 22 weeks. In the absence of the food-grade antimicrobials, spoilage (i.e., off odor) occurred within 6 weeks and anaerobic plate counts reached 6.6 log10 cfu/g. The CIBTB containing sodium diacetate (0.25 percent) or sodium lactate (2.5 percent) required 12 weeks to spoil and for anaerobic plate counts to reach 7.0 log10 cfu/g and 6.0 log10 cfu/g, respectively. When used in combination, no off odor was detected in CIBTB containing sodium diacetate (0.25 percent) and sodium lactate (1.25 percent) and anaerobic plate counts did not exceed 2.3 log10 cfu/g through 22 weeks of storage at 4 deg C. In related experiments, sodium diacetate, sodium lactate, and combinations of both ingredients were evaluated in uninoculated CIBTB incubated at 25 deg C for up to 22 days. In the absence of antimicrobials and in CIBTB containing sodium diacetate (0.5 percent), spoilage occurred within 8 days and anaerobic plate counts reached 7.0 log10 cfu/g. In CIBTB containing sodium lactate (2.5 percent) and sodium diacetate (0.25 percent) spoilage was not evident and anaerobic plate counts were less than 1.0 log10 cfu/g within 22 days. These data validate the efficacy of sodium lactate and sodium diacetate for extending the shelf life and enhancing the safety of CIBTB.