Shimelis, Admassu (Assoc. Prof.)Debebe, Worku2019-11-142023-11-102019-11-142023-11-102019-06http://etd.aau.edu.et/handle/12345678/20116Bioactive compounds are secondary metabolites of the plant, which are produced to increase their overall ability to survive and withstand the harsh environment and resists to diseases. Moringa stenopetala plant contains bioactive compounds, which have antihypertensive, anti- inflammatory, antihyperglycemic and prevention of cancer. However, during food processing such as thermal processing, these bioactive compounds can to be destructed. Hence, encapsulation might be an alternative technology to maintain the functionality of the active compounds. Therefore, the aim of this research was to develop microencapsulated nutraceutical product from M. stenopetala leaves extract. The microencapsulation was done using spray and freeze-drying encapsulation techniques. In addition, maltodextrin (MD) and mixtures of maltodextrin and high methoxyl pectin (MDHP) were used as coating materials. Then, the physical and functional properties, encapsulation efficiency, bioactive contents and antioxidant activities of the microencapsulates were measured. Moreover, the storage stability and in vitro digestibility of the microencapsulated product was determined. Finally, the medicinal values of the microencapsulated bioactive product were also evaluated using animal experiments. According to the results, the spray- and freeze-drying encapsulation techniques, and coating materials showed significant (P < 0.05) differences in the physical and functional properties, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activities of the microencapsulates. The encapsulation efficiency (EE) of spray dried microencapsulate was significantly more (83.52–87.93%) than freeze-dried microencapsulate (71.44–82.12%). Moreover, the EE was also significantly affected when the coating material was MDHP (87.93%) compared to MD (83.52%). On the other hand, the TPC, TFC and antioxidant activities of the freeze-dried microencapsulate were significantly (P < 0.05) higher when it was compared to the spray dried microencapsulate. Moreover, TPC, TFC and the antioxidant activities of the microencapsulates coated with MDHP were significantly more than the MD coated product. The storage stability of the spray dried microencapsulate were better than the freeze-dried microencapsulate. This might be due to the higher EE of the spray dried microencapsulate which in turn the destruction of the bioactive compounds of freeze-dried microencapsulate would be more during storage. Regarding the in vitro digestibility of the microencapsulate, the release of TPC (73.08–75.20 mg GAE/g dm) and TFC (34.72–36.19 mg CE/g dm) from the freeze dried microencapsulated product were more when it was compared to the release of TPC and TFC from the spray dried microencapsulate, which were 63.49–70.42 mg CE/g dm and 26.08–33.81 mg CE/g dm, respectively. This probably is related to the lower EE of the freeze-drying process and the more porous structure of the freeze-dried materials. On the other hand, the digestibility of the microencapsulate coated with MDHP was significantly (P < 0.05) higher in simulated intestinal fluid (SIF) compared to the simulated gastric fluid (SGF). On the contrary, the higher digestibility of the microencapsulate coated with MD was founded in SGF. Although the TPC, TFC and antioxidant activities of the freeze-dried microencapsulate were higher, the EE and storage stability were lower when it was compared to the spray dried microencapsulate. Therefore, spray drying microencapsulation process using MDHP as coating material can be an alternative method to develop microencapsulated nutraceutical product from M. stenopetala leaves extract. When the medicinal values of the microencapsulate product are concerned, there were no toxicity signs were observed on the animals’ behavior, body weight and growth pathology up to the dose of 5000 mg/kg of the body weight and on the control groups. In addition, the animal experiments showed that the microencapsulated bioactive product of M. stenopetala leaves extract had antihyperglycemic, vasodilator (up to 74.17% of relaxation) and diuretic activities (up to 56% of urinary excretion). Therefore, it can be concluded that the microencapsulation technologies use for the development of nutraceutical product from natural resources for global marketing values. However, further studies are recommended for chronic toxicity test and human trial for the medicinal values of the microencapsulated bioactive product.en-USMoringa stenopetalaextractionmicroencapsulationmicroencapsulation techniquesquality analysismedicinal valuesThesis