MODIFIED MILK FAT TO PROTECT AND VEHICLE PROBIOTIC MICROORGANISM

Although anhydrous milk fat is not considered as a good encapsulating material due to its low melting point (32°C), the fully hydrogenated anhydrous milk fat (FHAMF) has higher melting point (46°C) and thermal resistance, and may be an effective alternative. The objective of this study was to evaluate the encapsulating potential of FHAMF to protect the probiotic microorganism during storage. The FHAMF was melted, Lactobacillus acidophilus (11.2 log CFU/g) and 1% soy lecithin (w/w) was added, and the resulting emulsion was subjected to atomization with a double fluid atomizer nozzle (Ø = 0.7mm) and sprayed in a cold chamber (2°C). The microparticles were stabilized at 5°C/24h and evaluated after 1 and 7 days of storage(5°C) for morphology by scanning electron microscopy (SEM), thermal behavior by differential scanning calorimetry (DSC) and particle size by laser diffraction. The enumeration of viable cells was performed by deep plating technique.The experiment was repeated three times and the results evaluated by ANOVA.The process did not significantly affect the Lactobacillus acidophilus counts, which was on average 10.9 log CFU/g (p=0.3463) After 7 days of storage at 5°C, no significant losses in viability of probiotics (< 1 log cycle) were observed (p=0.1414). The encapsulation did not affect the thermal melting behavior of the FHAMF, which had a maximum melting peak around 45°C. During 7 days of storage, the average particle size increased significantly (p=0.0085), from 96.59 μm to 140.0 μm. The particles presented spherical shape and a smooth surface, and the increase in size may be associated with agglomeration as observed by scanning electron microscopy. The FHAMF presented potential as encapsulating material to deliver probiotics. The reduction of Lactobacillus acidophiluscounts during storage at 5°C was possibly due to the presence of large amounts of fat crystals, which may have ruptured the cell wall, leading to microorganism inactivation.