Aqueous fractionation of mucilage and protein from camelina seeds

Authors: Evangelista, Roque; Hojilla-Evangelista, Milagros - Mila; Gesch, Russell - Russ; Cermak, Steven - Steve; Isbell, Terry

Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/31/2019
Publication Date: 9/8/2019
Citation: Evangelista, R.L., Hojillaevangelist, M.P., Gesch, R.W., Cermak, S.C., Isbell, T. 2019. Aqueous fractionation of mucilage and protein from camelina seeds [abstract]. Association for the Advancement of Industrial Crops Conference.

Interpretive Summary:

Technical Abstract: Camelina sativa (L.) Crantz (Brassicaceae) is an ancient oilseed crop that was grown extensively in Europe in the 19th century. Camelina has several agronomic advantages for production, including early maturity, adaptability to freezing temperatures, and resistance to common cruciferous pests and pathogens, making it suitable to be grown on lands where food crops such as corn and soybean may not be feasible. Camelina seeds contain 30-45% oil with a-linolenic acid (30-40%), linoleic acid (15-25%), and eicosenoic acid (13-18%) as major fatty acids. The oil also contains high amounts of tocopherols, which imparts oxidative stability to the highly polyunsaturated oil. The seed meal contains 43.6% (fat free dry matter) protein and has a good balance of amino acids. In addition, the seed coat contains mucilage accounting for =10% of the seed weight. Renewed interest in camelina production has brought attention to the mucilage and protein as value-added co-products. In this study, we evaluated two schemes of producing mucilage and protein from camelina seeds in addition to the oil. One process started with separating the mucilage from hydrated (1:30, w/v solid to liquid ratio) intact camelina (var. Joelle) seeds (ICS). The protein was extracted from the defatted degummed camelina seeds (DDCS) at pH 9.5 and then precipitated at pH 4.0. In another process, the seed oil was extracted by cold pressing and hexane extraction to produce defatted camelina press cake (DCPC). The mucilage and protein were extracted simultaneously from DCPC at pH 9.5. The liquid fraction containing the protein and soluble mucilage was recovered by filtration and the protein was precipitated at pH 4.0. The protein extracts were dialyzed (3 kD MWCO) against water and then freeze-dried. The mucilage fractions were dried in a forced-air oven at 80oC. The mucilage recovered from ICS accounted for 8.8% of the starting seed and contained 0.9% oil and 14.6% crude protein. The protein fraction obtained had 88.6 % crude protein and accounted for 11.8% of the DDCS. The mucilage extracted from DCPC accounted for 27.0% of starting material and contained 0.1% oil and 48.5% crude protein. Although a considerable amount of protein was absorbed by the mucilage, a significant protein fraction was still recovered (8.6% of DCPC) containing 75.4% crude protein. The difference in composition of the mucilage and protein produced by each process will determine the application of these products.