Probiotics are known due it beneficial effects on health, especially in intestinal activity. However, factors such as pH, digestive enzymes and bile salts may reduce the microorganisms’ viability. Alternatively, microencapsulation with gastro-resistant materials is an option in the probiotics preservation. The objective of this study was to microencapsulate Lactobacillus rhamnosus in carrageenan and a blend of rice bran protein (RBP) and bovine serum albumin (BSA). A full factorial design (FFD) was used to evaluate the effects of RBP/BSA-blend (1:1) (1.5% to 2.5%, w/v) and microorganism concentration (0.6% to 1.4%, w/v) on encapsulation efficiency (EE). Carrageenan (0.5%, w/v) and Tween-80 (3 drops) concentration was fixed on all runs. Carrageenan was suspended in distillated water (60 °C), stirred (30 min) and cooled ( 30 °C). Each single protein was suspended in distilled water by stirring (15 min). Microorganism, Tween-80 and carrageenan suspension were added into the RBP/BSA-blend suspension and stirred (30 min). A temperature of 84 °C, 0.6 mL/min air flow rate and spray nozzle of 0.70 mm were employed on spray drying process. EE was determined by plate count in MRS agar for total and encapsulated microorganism. EE varied from 37.7% (RBP/BSA, 2.5%; microorganism, 1.6%) to 99.7% (RBP/BSA, 1.5%; microorganism, 0.6%) on runs. Mean (effect = 83.2%, p <0.00001) and curvature (30.1%, p = 0.0001) had a positive effect. In contrast, RBP/BSA (-32.6%, p <0.00001), microorganism concentration (-29.5%, p = 0.0001), and their interaction (-29.1%, p <0.0001) had a negative effect. Thus, ranging from high to low FFD level (RBP/BSA, 2.5% to 1.5%; microorganism, 1.4% to 0.6%) the EE was increased. To ensure greater cell viability it is ideal to obtain an EE close to 100%. According to the results, both factors and their interaction generated effects on EE. Significant positive curvature suggests an EE maximum point in the experimental conditions.