DETERMINATION OF QUALITY CHARACTERISTICS OF OLIVE VARIETIES WHOSE BITTERNESS DECREASES NATURALLY
Project no. 21036 · Status: Kapanmış · 2019
Summary
Olive fruit (Olea europea L.), consumed as table olive or by processing to olive oil, has an important place in our country and in the world. Oleuropein, the dominant phenolic component in olive fruit, causes bitterness. While there is no need to remove oleuropein in olive oil production, it is removed in table olive production by brine or dry salting method. However, some special olive varieties in Turkey can be consumed as table olives without any pre-treatment (brine or dry salting). There are four olive varieties in Turkey, Attun, Butko, Hurma and Nizip Yağlık which can be consumed in this way. Attun is debittered by falling of Kilis Yağlık olives on the soil in Kilis region, Butko is debittered on the tree in Yusufeli district of Artvin, Hurma is debittered on the trees in the Izmir region, and Nizip Yaglik olive is debittered by falling on the soil in Nizip district of Gaziantep. The aim of this study was to determine some of the quality characteristics of of these olives which can be consumed as table olives without any pre-treatment. For this purpose, the moisture, oil, protein, and reducing sugar content, antioxidant activity, total phenolic content, fatty acid composition, volatile compounds, texture analysis and color analysis of Attun, Butko, Hurma and Nizip Yağlık olive varieties were determined. The moisture content of Attun, Butko, Hurma and Nizip Yağlık were determined as 6.84, 50.01, 38.61 and 27.92%, respectively. The protein content of the olive samples varied between 0.19-18.13%, and the oil content were between 16.66-68.46%. The reducing sugar content of the olive samples were between 0.91- 1.08%. DPPH radical scavenging capacity of Attun, Butko, Hurma and Nizip Yağlık were determined as 87.83, 77.56, 79.87, 83.46%, respectively. ABTS (mM trolox/g olive) values of Attun, Butko, Hurma and Nizip Yağlık were determined as 77.67, 26.00, 34.90, 51.62 and total phenolic content (mgGAE/100g) as 458.87, 152.09, 109.73, 234.33, respectively. The unsaturated fatty acid content of the olives was determined between 16.00-21.10%, whereas saturated fatty acid content of the olive samples was determined between 78.90-84.08%. When the volatile component analysis results of olive varieties were examined 24 volatile components were detected in Attun olives, 23 in Butko olives, 16 in Hurma olives and 17 in Nizip Yaglik olives. The hardness values of the olive varieties were found between 677.44(g)-3688.06(g), the chewiness values between 3.12(gs)-16.41(gs) and the gumminess values between 48.92(g)-235.90(g). L* values of olive varieties were found between 26.14-32.05, a* values between 2.02-4.78, b* values between 2.37-7.18.