Sausages are common traditional food that served in every Egyptian house. Nine groups of beef sausages were prepared using either natural preservatives (cinnamon 1% and thyme 1%) or chemical preservatives (sodium lactate 1.5%, 3% and sodium nitrite 0.01%) and control samples (without the addition of any preservatives). Samples were stuffed into natural and artificial casing, then kept at freezing condition (-18 °C) until exceeding the permissible limits (became unacceptable). Sensory properties and microbial loads decreased gradually with freezing time in all groups, followed by gradual increase in aerobic plate count (APC) on day 14 for cinnamon, thyme, nitrite and control groups in natural casing (4.54, 4.56 4.47 and 4.45 log₁₀ CFU/g, respectively), while was on day 42 for lactate 1.5% and 3% groups (3.48and 3.41 log₁₀CFU/g, respectively). APC of all sausage samples exceeded the permissible limits on 97^th day of storage except for lactate 1.5% and 3% groups which were unfit on 104^th (14 days after the end of shelf life) and on 118^th day (28 days after the end of shelf life), respectively. The same manner was observed in total psychrotrophic count which decreased gradually with freezing time in all groups, followed by a gradual increase on day 14 for cinnamon, thyme, nitrite and control groups in natural casing (3.66, 3.72, 3.48 and 3.53 log₁₀ CFU/g, respectively), while was on day 42 for lactate 1.5% and 3% groups (2.85and 2.71log₁₀ CFU/g, respectively).
Chemical analysis revealed gradual increase in total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA) in all sausage samples until exceeded the permissible limits on the 97^th day of freezing, except samples treated with 1.5% and 3% SL. Acceptable values were clear for 3% SL even on 111^th day of freezing. Samples treated with 1.5% SL exceeded the permissible limits on day 104(21.07 mg/100g and 0.96 mg malonaldehyde/kg, respectively) which went on the same way with APC. Samples treated with cinnamon, thyme and nitrite had the best sensory scores among other groups at the beginning of storage, but declined quickly from the 14^th day of freezing. Samples packed in artificial (collagen) casing had lower bacterial load but less overall acceptability than those in natural sheep casing throughout the storage period. SL 3% improved the shelf life of frozen sausage. Thus, using sodium lactate works better as a food additive and preservative for beef sausages than other chemicals as nitrite and natural preservatives as cinnamon and thyme especially when stored under freezing condition (-18 °C) and packed in artificial casing.