Evaluation of factors affecting at preparation of nanoliposomes containing nisin using Response surface methodology

Nisin has numerous applications as a natural preservative in foods، including dairy product، canned food، processed cheese and milk. Several studies demonstrated that proteolytic degradation and the interaction of nisin with food components might result in decreased its antimicrobial activity. Encapsulation of antimicrobial peptides into nanoliposomes may offer a potential alternative to protect antimicrobials، enhancing their efficacy and stability for food applications. In first stage of this research، Response Surface methodology was used for optimization of nanoliposomes produced by heating method. A central composite design (CCD) consisting of 18 experimental run with three independent variables: phospholipid concentration (2-30 mM)، stirring speed (500-1360 rpm) and processing time (30-90 min) were used and their effects on size of nanliposome were evaluated. In the next stages، stability of nanoliposomes was investigated during 2 month. The optimum operating conditions obtained from the quadratic form of RSM model for particle size were phospholipids 30 (mM)، stirring speed 930 (rpm) and process time 90 (min). The results of stability indicated that samples in the range of 400 to 500 nm were stable up to 2 month (P > 0/05) but samples larger than 500 nm were unstable during 2 month but stable up to 1 month (P> 0/05).