Optimization of Process Conditions for Lactobacillus plantarum Encapsulation by Double Emulsion

LIU Cui; LYU Jiali; DU Qianru; CHU Jingying; XU Shuangshuang

doi:10.13982/j.mfst.1673-9078.2025.9.1003

Abstract：Lactobacillus plantarum 330G4 was encapsulated using natural food-grade materials such as water-and oil-phase materials.An ultrasound-assisted double emulsion method was combined with single-factor experiments and response surface methodology to determine the optimal conditions for preparing water-in-oil(W/O)and water-in-oil-in-water(W/O/W)encapsulated emulsions.The results revealed that rapeseed oil was an effective oil-phase encapsulating material,whereas pectin and whey protein were water-phase encapsulating materials in the double emulsion method.The volume fraction of the oil phase,mass fraction of the emulsifier,and ultrasound power strongly influenced the encapsulation rate of W/O emulsions.According to response surface optimization,the optimal conditions for W/O emulsion preparation were as follows:whey protein volume fraction of 8％,rapeseed oil volume fraction of 64％,glyceryl ricinoleate mass fraction 3.30％,ultrasound power of 505 W,and reaction time of 30 s.Additionally,the volume fraction of the W/O emulsion,ultrasound power,and reaction time markedly affected the encapsulation rate of W/O/W emulsions.Based on response surface optimization,the optimal conditions for W/O/W emulsion preparation were as follows:pectin mass fraction of 0.25％,W/O emulsion volume fraction of 16.60％,ultrasound power of 75 W,and reaction of time 3 min.The viable count of the encapsulated bacteria was 10.34 lg CFU/mL.The encapsulation rate was 92.82％,stability was 99.06％,and average particle size was 10.53 μm.Compared with the viable count of unencapsulated bacteria after simulated digestion,that of encapsulated bacteria increased by 7.34 lg CFU/mL.Similarly,after heat treatment at 50,70,and 90℃ for 30 min,the numbers of viable encapsulated bacteria were 4.17,3.20,and 4.58 lg CFU/mL higher than those of their unencapsulated counterparts,respectively.After storage at 25℃ for 30 days,the number of viable bacteria increased by 6.05 lg CFU/mL because of encapsulation.Ultrasound-assisted double emulsion to encapsulate L.plantarum improves the activity of probiotics.These findings provide a reference for encapsulation of other probiotics and the enhancement of their activities,while also offering new directions for the development of high-activity probiotic products.