Component optimization by response surface methodology in mixture of bee products: Determination of functional properties and shelf-life qualities

The awareness and consumption of non-honey bee products have increased in recent years due to their functional qualities and nutritional content. Non-honey bee products can be listed as pollen, propolis, royal jelly, bee bread, bee venom, apilarnil, beeswax. Honey is a natural product of animal origin which has an important place in human nutrition in many aspects. Propolis is a natural and sticky material, also known as bee glue, produced by honey bees (Apis mellifera) from sap, resin and mucilage collected from various parts of the plant such as leaves, flower buds and tree barks, and then mixed. Due to its carbohydrate content, it is an important energy source with a high absorption rate. The botanical origin of honey and the geographical region where it is collected play an important role in the chemical composition of honey. Pollen is the flower dust collected by bees, which is the male reproductive cell of plants. Pollen, which is the main food source of bees, is collected by worker bees to be used in the production of royal jelly and to meet the protein needs of the colony to be used in brood feeding. In this thesis, the amounts of pollen and propolis in the mixture of bee products prepared using two different honeys, chestnut and flower, were optimised using the Surface Response Method, Central Trial Design. In the optimisation, antioxidant activity, total phenolic content, total mineral content and sensory evaluation scores were taken as response variables and pollen and propolis amounts were taken as independent variables. In the optimisation, it was desired to optimise the independent variables and maximise the responses. As a result of the optimisation, the expected results for the mixture with chestnut honey and flower honey were validated and the results were statistically interpreted. In the second stage of the thesis, the optimized chestnut and flower honey mixtures were compared in terms of nutritional, physicochemical and some storage parameters. As a result of the optimisation, for the chestnut honey blend, when the optimised pollen amount was 10.24 g and propolis amount was 4.07 g, the antioxidant activity was 86.30%, total phenolic matter was 1215.33µg/g, total mineral matter was 0.870% and the sensory evaluation score was 3.62. Optimised pollen amount of 10.24 g and propolis amount of 1.73 for the flower honey mixture was determined as 66.34% antioxidant activity, 780.33µg/g total phenolic content, 0.443% total mineral content and 3.84 sensory evaluation score. When the flower and chestnut honey mixtures prepared according to the optimum results were compared, it was determined that the amount of antioxidant activity, total phenolic matter and total mineral matter content of the chestnut honey mixture was higher, but the sensory score was lower than the flower honey. The products obtained for both blends were characterised in terms of phenolic substance content, substance composition, amino acid composition and structure elucidation study was carried out. When the phenolic substance content of the mixture with chestnut honey was evaluated, trans ferulic acid was detected and the highest caffeic acid was detected in the mixture with flower honey. Pollen and propolis significantly affected the phenolic substance composition. When the raw materials used and the mineral matter contents of the mixtures obtained were evaluated together, it was determined that pollen was an important source of mineral matter and significantly affected the final mineral matter composition of the mixture. The highest K element was determined in the mixture with chestnut and flower honey, followed by Ca, Na and P elements. It was determined that Na, Mn, Fe, K and Ca elements of chestnut honey mixture were higher than flower honey mixture. It was determined that the pollen used as raw material contained all 17 amino acids analysed and flower honey had higher levels than chestnut honey. Accordingly, the amino acid levels of the mixture with flower honey were also found to be higher.