Thesis Type: Doctorate
Institution Of The Thesis: Suleyman Demirel University, Fen Bilimleri Enstitüsü, Gıda Mühendisliği Anabilim Dalı, Turkey
Approval Date: 2021
Thesis Language: Turkish
Student: SULTAN ACUN
Consultant: Hülya GülAbstract:
In this study, propolis obtained from different sources such as pine, flower and chestnut were extracted under suitable conditions and then microencapsulated with two different coating material complexes (maltodextrin / gum arabic and-cyclodextrin / gum arabic). The optimum ratio of maltodextrin / gum arabic and β-cyclodextrin / gum arabic combination used for microencapsulation process was determined and their properties were investigated. According to the principle of replacing with flour, microencapsules obtained in 4 different proportions (2.5, 5, 7.5 and 10%) and honey powder were added to produce cupcakes.The cakes produced were stored at room temperature for 7 days. The possibilities of using microencapsulated propolis and honey powder in cake production and physical and physicochemical changes in the cakes during storage were determined. To determine these properties, the total phenolic substance and antioxidant activity amount of extracts, microencapsules and cakes; The fluidity and compressibility values of microencapsules, protein, lipid and ash values of the cakes, texture parameters and sensory properties were determined. During storage, water activities, cake weights, volume values, textural properties, total phenolic substance and antioxidant activity values, bioavailability rates of the cakes were determined.
As a result of the study, it was determined that pine propolis from propolis obtained from different sources has higher total phenolic substance and antioxidant capacity (p <0.05). It has been determined that microencapsules produced using maltodextrin / gum arabic have higher phenolic substance, antioxidant activity and mineral substance content, but microencapsules using β-cyclodextrin / gum arabic are superior in terms of bioavailability. It has been determined that the microencapsule and honey powder used in cake production have higher total phenolic substance, antioxidant activity and mineral content with the increase in the rate of addition, but consumers generally do not prefer cakes with more than 5% in microencapsule addition. Especially the cakes with 10% microencapsule added got the lowest score in sensory analysis, it was determined that the acceptability of propolis, which was masked by microencapsulation with storage, decreased with the increase of its unique smell and aroma. As the rate of addition of honey powder increased, the like of the consumers increased and the honey powder added at the rate of 10% was preferred by the panelists. Although the cakes produced by adding microencapsule and honey powder have a softer texture with the increase in the rate of addition, the hardness of the cakes that lost water during storage increased during storage.
As a result, by adding microencapsules to the produced cakes, the phenolic substance and antioxidant activity values of the cakes increased and the cakes became more functional food. Although the increased addition rate has increased the benefit of cakes, the pungent taste and smell of propolis has limited consumer preference. Addition of microencapsule and honey powder negatively affected the textural properties of the cakes, it was determined that the additions made at the rate of 2.5% gave the closest values to the control group. When the chemical, physical, textural and sensory properties of cakes were examined in general, it was determined that the production of pine propolis, which was microencapsulated with 5% maltodextrin / gum arabic combination, increased the bioavailability of cakes. It was concluded that propolis, one of the important bee products, can be microencapsulated and used in the production of functional cakes. Nowadays, the importance of beekeeping and bee products is understood and the use of propolis in cereal products, which is an important part of the daily diet, will contribute to the increase of the value of the products.