Fattyacid composition of Linum spp. collected from Southeastern of Turkey

Abstract

Linum is a member of the Linaceae family and includes about 200 species in the Mediterranean region, mild or subtropical regions of Asia Southwest, and North America [1–3], it is mainly centered in the Balkans and Anatolia [4]. Today, this plant is used mainly for its oil [5, 6], but in early times it was used by the Egyptians to make cloth and for flax spinning and weaaving. However, flax was utilized for medicinal purposes by the ancient Greeks and Romans. The production of linseed oil may have started thousands of years ago in central Anatolia. Linum spp. is native to Anatolia and flax seeds have been found at several Neolithic sites. The earliest historical documents concerning linseed oil mills are Ottoman tax records from 1500-I. [7]. The endemism percentage of Linum species in the flora of Turkey is 39.4% [3]. Similar studies have indicated that climatic conditions and geography of locations play a vital role in the synthesis of fatty acid composition, especially unsaturated fatty acid in vegetable oils. [8]. Flax oil is the richest plant source of linoleic and linolenic polyunsaturated fatty acids, which are essential for humans since they cannot be synthesized in the organism and must be ingested in food [9]. The fatty acid composition of linseed oil is dominated by C18:0 (stearic), C16:0 (palmitic) C18:1 (oleic) C18:2 (linoleic, 16% of oil), and C18:3 (linolenic, 50% of oil) fatty acids [10, 11]. Green and Marshall [12] stated that significant variation in seed weight, oil content, and fatty acid composition was found both among and within varieties in a diverse collection of 214 L. usitatissimum accessions. Oleic acid and linolenic acid varied between 13.3 and 25.2% and 45.5 and 64.2%, respectively in the study. In this study, eight L. hirsutum L., which were collected from different areas in Southeastern of Turkey, and two L. usitatissimum local populations were analyzed to determine the fatty acid composition of their seed oils (Table 1). Significant variation in fatty acid composition was found both among and within species in Linum samples. Fourteen fatty acids were completely identified and quantitated. However, γ-linolenic was not found in samples of L. hirsutum. Saturated fatty acids comprised about 25.01% for L. hirsutum and 11.37% for L. usitatissimum of the total fatty acids. Polyunsaturated fatty acids were predominant in all samples (67.02% for L. hirsutum and 65.10% for L. usitatissimum). Monounsaturated fatty acids were 6.74% for L. hirsutum and 22.93% for L. usitatissimum. While the dominant fatty acids of wild population were linoleic (38.76%), α-linolenic (28.27%), and palmitic acid (20.47%), α-linolenic (48.66%), oleic (22.68%), and linoleic (16.29%) were predominant in local populations. Some of fatty acids found in local populations were myristic, oleic (18:1n9), margaric, and icosenoic acids, but only in very small quantities (< 0.1%) (Table 2). There were found wild populations (L. usitatissimum) differing from local populations (L. hirsutum) in the fatty acid profiles. The content of palmitic acid was 20.47% in wild populations, whereas it was 5.95% in local populations. Stearic acid (2.79%) in wild populations was lower than that of local populations (4.9%). Linoleic acid was 38.76% and 16.29% in L. hirsutum and L. usitatissimum, respectively. α-Linolenic acid was determined to be 28.27% for wild flaxseed and 48.66% for local cultivars. The percentage of α-linolenic and linoleic acids shows close negative correlation [13]. The fatty acid composition of wild populations (L. hirsutum) shows significant variation. Palmitic acid and stearic acid varied between 19.57–20.68% and 2.61–3.24%, respectively. The Derik/Mardin sample had the highest value for oleic acid (7.87%) but a low value for linoleic acid (5.97%). There was a strong complementarity between oleic and linoleic acids in the oil seeds as cited by [14]. The percentage of α-linolenic acid ranged from 25.45% to 31.02%, and the highest α-linolenic acid content was for Malatya. However, Malatya had higher latitute than the other collecting areas, and the linoleic and α-linolenic acid contents were increased at high latitude [15].