Investigation of controlled release microcapsule production for fortified food with phytosterols

Phytosterols are lipophilic compounds found in plants, and their chemical structure is quite like cholesterol. Plant sterols reduce total serum and low-density lipoprotein concentrations in humans. The use of phytosterols is restricted due to their high melting temperature, low water solubility, and chalky taste. In addition, due to its structure, it is easily oxidized and its absorption and bioavailability by the human body decrease. For these reasons, the phytosterol mixture was encapsulated by electrospraying and spray drying. The release of the capsules obtained by optimizing various parameters of these methods in the gastrointestinal tract was investigated. In order to obtain maximum benefit from phytosterols, capsules that can be released in the intestinal tract have been obtained. As a result of the optimization of the electrospraying and spray drying process, the most suitable wall material composition is respectively; 7.19 g PSP/100 mL distilled water, 9.03 g IN/100 mL distilled water, 3.78 g DN/100 mL distilled water, and 9.21 g PSP/100 mL distilled water, 7.13 g IN/100 mL distilled water, 3.66 g DN/100 mL of distilled water was determined as 120°C inlet temperature. It has been observed that phytosterol capsules are released 115.19 mg/kg in the stomach and 312.49 mg/kg in the intestinal under optimum conditions in the electrospray process, and 102.63 mg/kg in the stomach and 319.73 mg/kg in the intestinal in the spray-drying process under optimum conditions. The capsules produced under optimum conditions by both methods were stored for 60 days at two different temperatures (4 and 25°C), and moisture, water activity and oxidation stability tests (peroxide, p-anisidine and hexanal) were performed. In addition, morphological image analysis was performed on the capsules produced according to the mixture design by the electrospraying method, and particle size analysis on the capsules obtained by the spray drying method according to combined optimal custom. It was observed that the peroxide values of the capsules obtained by the electrospraying increased by 65% in the samples stored at 4°C on the 60th day of storage and by 70% in the samples stored at 25°C, and the peroxide values were well above the safe limit for consumption. It has been determined that D[4,3] values of 13.11-23.78 μm, D[3,2] values of 10.07-16.38 μm, span values of 1.2-1.74 μm of capsules produced according to spray drying method, and capsules obtained according to electrospray method particle size varies between 0.199 and 3.984 μm. By using electrospraying and spray drying methods, capsules with small particle size, stable and releasable in the intestine were obtained. The obtained phytosterol capsules have the potential to be a commercialized functional food additive that can be added to various food formulations as well as directly as a food supplement.