Characterization of iron capsules obtained using different methods and their use in food fortification

In this thesis, iron sulfate was encapsulated using methods such as alginate hydrogels, liposomes, and liposome-filled alginate gels was investigated for their effectiveness in food fortification. In the first stage, the methods of liposomes and alginate hydrogels were optimized, and the physical and chemical characterization of the capsules was conducted. Iron capsules with a 95% encapsulation efficiency were produced using liposomes, and the optimal formulation was determined to include 18 g/L phosphatidylcholine, 0.8 g/L cholesterol, and 2 mM iron concentration in a phosphate buffer. However, higher iron concentrations accelerated oxidation in the liposome membrane. In the alginate hydrogel method, factors such as sodium alginate concentration, air pressure, and iron concentration were optimized. The most suitable formulation comprised 20 g/L sodium alginate, 1 bar air pressure, and 2.5 g/L iron, resulting in iron capsules with a 77% encapsulation efficiency. In the second stage, the liposome and alginate hydrogel methods were combined to produce iron-liposome gels with a 99% encapsulation efficiency, and their effects on oxidative stability were examined. It was determined that iron-liposome gels enhanced the oxidative stability of liposomes. To assess the physical stability of iron capsules during storage, the capsules were stored for thirty days at 4°C. Alginate hydrogels could not maintain their integrity in the presence of phosphate ions, and for long-term physical stability, these hydrogels needed to be stored in a calcium ion-rich environment. Storage stability was found to be high for both iron liposomes and iron-liposome gels. In the third stage, iron-liposome gels produced from the optimal formulation were added to kefir, and their effects on the oxidative stability of kefir were evaluated. The presence of iron capsules in kefir did not statistically differ in terms of physical and oxidative stability. In conclusion, iron sulfate was successfully encapsulated using alginate hydrogels and liposomes. The filling of iron-liposomes into alginate gels immobilized the liposome vesicles in the sodium alginate network, preventing oxygen contact. This successfully prevented the risk of oxidation in the unsaturated lipid membrane of liposomes.