Abstract: Objective: To prepare a biodegradable antimicrobial packaging material from polybutyrolactam (PA4) by casting method for use as a sausage casing. Methods: The mechanical properties, water and oxygen barrier properties, heat shrinkage, tear resistance, overall migration and antibacterial properties of the PA4 film as well as its potential in preserving pork sausages were evaluated in comparison to a commercially available nylon composite casing and a commercially available collagen casing. Results: The PA4 sausage casing had a tensile strength of 84.42 MPa, an elongation at break of 73.34%, and an oxygen permeability coefficient of 2.448 × 10-16 cm3·cm/(cm2·s·Pa), which indicates high oxygen barrier capacity. Besides, with the antibacterial ingredient chitosan, the casing film had good antibacterial performance, and its antibacterial performance value was 3.13 (lg(CFU/cm2)). At 4 ℃, the storage period of pork sausages stuffed in this casing was 28 days. Conclusion: The comprehensive performance of the PA4 sausage casing was close to that of the commercially available nylon composite casing and significantly better than that of the commercially available collagen casing. The PA4 sausage casing can be applied to low-temperature meat packaging and is promising for application in the field of meat packaging.

Key words: polybutyrolactam; sausage casing; antibacterial properties; preservation; degradable material; packaging