Soluble vitamins (vitamin B12 and vitamin C) microencapsulated with different biopolymers by a spray drying process

ABSTRACT Vitamins are important micronutritional compounds which are involved in many biochemical functions in the human body but are not synthesized by it; so, they have to be supplied through diet. However, vitamins are very sensitive which provoke a significant loss during the food processes and storage. So, microencapsulation can be used to minimize the loss of vitamins, to minimize the factors that interfere with their stability, to allow a controlled release process and to mask its undesirable taste, increasing their applicability In the present work, the microencapsulation of two vitamins, by a spray-drying process, was studied: vitamin B12, considering that is the most chemically complex and the largest of all the vitamins and vitamin C which is the most popular vitamin in the food industry The microparticles were prepared using a spray-dryer BUCHI B-290 (Flawil, Switzerland) with a standard 0.5 mm nozzle, under the following conditions: solution and air flow rates, air pressure and inlet temperature were set at 4 ml/min (15%), 32 m 3 /h (80%), 6.0 bar and 120 °C, respectively. The prepared microparticles were characterized and their physicochemical structures were analyzed by scanning electron microscopy (SEM) and by Fourier transform infrared spectroscopy (FTIR). The presence of vitamins in the microparticles was also evaluated by UV-method, validated and optimized for this objective. The evaluation of the vitamin B12 was based on absorbance values read at 361.4 nm, and for the vitamin C the absorbance was read at 260.6 nm A product yield ranging from 41.8 to 55.6% for the microparticles prepared with vitamin B12 and ranging from 43.6 to 45.4% for the microparticles formed with vitamin C was obtained and microparticles with a mean diameter around 3 μm were observed, for all the biopolymers tested (chitosan, modified chitosan and sodium alginate). The microparticles formed with chitosan presented a very rough surface; on the other hand, the particles formed with sodium alginate or modified chitosan presented a very smooth surface. The performed tests yield significant results and prove the success of the vitamins microencapsulation This work shows that it is possible to encapsulate vitamins using different biopolymers, through a spray-drying process