ANALYZING THE EFFECTS OF OLIVE LEAVES ON SENSORY AND CHEMICAL PROPERTIES OF REFINED OLIVE OILS USING IMAGE PROCESSING METHODS

Abstract

Olive leaves are an important source of phenolics and pigments, that leaves are wastes of olive oil industries that enterprise producing olive oil. The main object of this study is to evaluate the chemical and sensory properties of refined olive oils containing different rates of olive leaves that obtained from olive oil factory, which were washed, dried, milled, and sieved, in comparison to virgin olive oil. The second object is to determine the optimal range of olive leaves to be added. The methods used for optimization is transforming the experimental results into images then processing the obtained images. The total phenols, antioxidant activity, chlorophyll and carotenoid, extinction coefficients (K-232 and K-270), bitter index (K-225) and positive attributes of sensory evaluations of refined olive oils containing 10 and 15% olive leaves exhibited higher properties than virgin olive oils. These results emphasize the high potential of dried olive leaves as the phenolic constituent's source for refined olive oil and to improve the chemical and sensorial attributes of refined olive oils. Furthermore, the determined optimal olive leaf addition range that will equally satisfy all olive oil constituents is between 12.5%-15%. Practical application. Adding the olive leaves between 12.5-15% improve the physicochemical and sensorial attributes of refined olive oil and this range is optimal since the lightest gray tone means the optimal. In this case, the center of optimal range is 13.75% and it can be said that this percentage should be preferred to satisfy all attributes equally.