Fatty Acid Composition of Flax Sprouts

The oil and fatty acid profile of flax (Linum usitatissimum) sprouts and seed were compared to determine nutrition potential of sprouts. Equal quantities of seed from three flax cultivars (Rahab-94, Pembina and Linott) were sprouted twice in three replications and were analysed for oil and fatty acid contents during summer 2011. Three flax cultivars were observed with high oil content on dry weight basis in sprouts (15.9%) and seeds (33.99%). Significant variations (P<0.0001) between seed and sprout values for contents of unsaturated, polyunsaturated (UFA, PUFA) and saturated (SFA) fatty acids (P=0.0002) and non-significant (P>0.05) variation among three cultivars was observed. The percentage of PUFAs in cultivars Pembina and Linott was 68.7 and in Rahab-94 was 67.7. The percentage of linoleic acid (C18:2) was significantly high in sprouts (19.51%) compared to seed (17.7%). The percentage of linolenic acid (18:3) was high in seed (52.8%) compared to sprouts (48.8%). The ratio of PUFA/SFA in sprouts was high in Pembina (6.97%) and Linott (6.82%) compared to Rahab-94 (6.38%). The fatty acid profile was similar in all the three cultivars with significant (P<0.0001) reduction (<1%) in PUFA/SFA ratio of sprouts compared to seed (7.4%). Flax sprouts are equally potential to seed for viable natural resources of essential fatty acids (18:2 and 18:3).

The amount of triglycerides, free fatty acids (FFA), phospholipids and the fatty acid compositions were determined in flax seed and an increase in FFA and linolenic acid in the phospholipids with germination were observed (Zimmerman & Klosterman, 1965).A report on fatty acid (FA) composition of flaxseed revealed Omega 3 / Omega 6 ratio of 4:1 was higher than the ratio (1:2) required for humans (www.curezone.com).
Flax sprouts were reported with 22.3% protein, 17.0% crude fiber and 8.1% total sugars on dry weight basis (Narina et al., 2012).There were no reports to date on fatty acid composition of flax sprouts.Therefore, our objective is to analyze the oil content and fatty acid profiles for both flaxseed and sprouts of three cultivars and compare those values with other related crop seed sprouts like Canola and soybean.

Materials and Methods
Three flax cultivars (Rahab-94, Pembina and Linott) from germplasm collections of the New Crops Program were grown at the Randolph farm at VSU-ARS, Petersburg, VA.The matured seed from these three cultivars was used for raising sprouts.The sprout experiment was replicated thrice with three cultivars and conducted twice during 2011.An ample quantity of sprout was achieved for analysis from six biological sample replicates of six grams in each variety.The standard laboratory procedures (Narina et al., 2012) were used to raise sprouts from the seeds of three flax cultivars.The sprouts were harvested on the fourth day and were immediately freeze dried and stored in -80 degrees for further biochemical analysis.
The fine ground powder of freeze dried sprouts and seeds of the three cultivars were used to determine oil contents (gram/100g dry weight basis) and fatty acid composition (wt % of total fatty acids) using previously published protocols (Bhardwaj & Hamama, 2009).The chemicals and reagents used for analysis were HPLC grade and were obtained from Sigma-Aldrich Corporation (St. Louis, MO, USA) and Fisher Scientific (Pittsburgh, PA).

Statistical Analysis
Analysis of variance procedures (PROC GLM) in version 9.3 of SAS (SAS, 2012) were used to analyze the data generated.The sprout nutrient data was compared with those of seed and other related new crop sprouts (Table 2) to determine the potential of flax sprouts for nutritional values.

Results and Discussion
The average fresh sprout yield was 28.27 g from six grams seed.There were no significant differences observed among the three cultivars for major fatty acid (FA) and oil contents analyzed (Table 1).The oil content of sprouts (15.9%) was significantly low to that of seed (33.9%).The seeds are with very low water content compared to sprouts with high water content asthe process of germination will change the triglycerides composition to hydrolysis free fatty acids like linoleic acid (Marton et al., 2010).Most of the oil lost from seed was used as energy necessary for the growth of sprout (Orhan et al., 2007;Bhardwaj & Hamama, 2009).
There were non significant differences among three cultivars for saturated or unsaturated fatty acid contents.We observed non-significant variations (P=0.07) for polyunsaturated fatty acids (18:2 and 18:3) and monounsaturated fatty acids (18:1 and 20:1) for seed and sprout values.The variety Pembina was with high contents of 18:3 (49.6%) and Rahab-94 was with 18:2 (20%), were significantly different from Linott at 7% level of significance.The monounsaturated fatty acids were relatively similar in seed and sprout (20% oleic and 0.22% eicosanoic acid) values of all the cultivars.These results indicate that the sprout could be as viable as ground seed to provide equal quantities of fatty acids and could impact human health by protecting against cardiovascular diseases (Bhardwaj et al., 2012) or osteoporosis in humans (Orhan et al., 2007).
The saturated and unsaturated fatty acid compositions of sprouts (10.2% and 89.1%) were significantly different (0.0002<P<0.0001)from those of seed (9.5% and 90.4%).The present investigation revealed highest levels of UFAs in sprouts (89.1%) due to high levels of antioxidants that help to protect humans from oxidative stress (Lampi et al., 2002;Orhan et al., 2007).Similar findings were reportedin sprouts of soybean (Orhan et al., 2007) and flax (Narina et al., 2012) with significant amount and number of anti-oxidants.
Comparision of fatty acid and oil traits of flax sprouts with those of canola and soybean sprouts (Table 2) revelaed that Canola sprouts were high in contents for all the components analysed except for 18:3 (48.8%) and 18:2 (19.51 %), the proportions of fatty acids analysed on percent weight basis, showing the siginificance and impact of flax sprouts in nutrtion as dietary source.The reason for high levels of C18:3 in flax sprouts (48.8%) might be due to highest accumulation of γ-tocopherol at seed maturity (Herchi et al., 2011;Kamal-Eldin & Appelqvist, 1996) compared to those accumulated in canola seed.*The Oil and FA content were expressed in g/100g dry weight basis.The sprout data for canola and soybean was retrieved from peer reviewed publication of Bhardwaj andHamama (2009) andOrah et al. (2007) for fatty acid profile comparisons.

Conclusion
Significantly low oil content in sprouts compared to seed and relatively similar fatty acid profiles for seed and sprout with equally potential values for essential fatty acid compositions (Omega 2 and 3) were observed in the study.The possible potential use of flax sprouts as supplementary dietary source to replace the different forms of flaxseed.Evaluations for seed sprouts to study the influence of seed maturity on fatty acid contents, tocopherols, sterols and other bioactive compounds will give better understanding of nutritional quality of sprouts.Analysis of sprouts from more cultivars including golden yellow seed will aid for future crop improvement for nutrition quality.

Table 1 .
Major fatty acid composition of seeds and sprouts of three flax cultivars

Table 2 .
Comparison of fatty acid and oil traits of flax seed sprouts with those of Canola and soybean