农业工程学报2018，Vol.34Issue(3)：309-314,6.DOI:10.11975/j.issn.1002-6819.2018.03.041
黏质物脱除工艺优化及其提高亚麻籽提油率的效果
Removal processing optimization of flaxseed mucilage and its improved effect on extraction rate of flaxseed oil
摘要
Abstract
Flaxseed, which is also called linseed, is an kind of important oilseed in the world. The nutritional components of flaxseed are oil, protein, lignans, soluble fiber, minerals, and vitamin, and so onetc. It is known as the richest source of the n-3 fatty acid, alpha linolenic acid (n-3 fatty acid), which comprises approximately 55% of the total fatty acids, and this percentage is 5.5 times higher than that in the second next-highest sources. Flaxseed plays an important role in functional foods for its nutritional and pharmaceutical values. In recent years, aqueous enzymatic extraction, an emerging alternative to hexane-based oilseed extraction regarding product safety and simultaneous recovery of high quality protein products and high yield of vegetable oils has drawn increasing attentions over decades. However, due to the high water-holding capacities, stabilization and emulsification properties of flaxseed mucilage, extraction and separation of flaxseed oil from raw flaxseed by aqueous enzymatic method are proved to be inefficient and even prohibitive. In order to improve the yield of flaxseed oil extracted by aqueous enzymatic method, the effect of demucilage on the aqueous enzymatic extraction of flaxseed oil was investigated by comparing the yield of flaxseed oil before and after removal of flaxseed mucilage through hot water extraction. Results showed that the mucilage on the surface of flaxseed significantly impeded the separation of oil from aqueous enzymatic extraction system, thus resulting in a low extraction yield of flaxseed oil. More specifically, the oil yield of raw flaxseed was only 69.20%±1.51% and residual oil content in insoluble phase was 26.00%±1.24%, while after removal of 94.69%±1.94% mucilage by hot water extraction treatment at 100 ℃ (the removal rate of 94.69%±1.94%), the yield of flaxseed oil significantly increased to 84.26%±0.63% and residual oil content in insoluble phase decreased to 10.45%±0.89%. Mucilage removal conditions were optimized by single- factor experiments and the optimal conditions were obtained as follows:eExtraction temperature was 85 ℃, pH value was 3, flaxseed- to- water ratio was 1:7 g/mL, extraction time was 60 min and extraction was repeated twice. Under the optimum conditions, the mucilage removal efficiency was 97.88%±0.69%, the yield of the flaxseed oil reached to 84.47%±0.53%, and the loss ratios of flaxseed oil and protein were 0.70%±0.16% and 10.78%±0.41%, respectively. Acid value and peroxide value of the flaxseed oil before and after demucilage by hot water extraction treatment were determined and it was found that the demucilage process had no obvious influence on the quality of flaxseed oil extracted by aqueous enzymatic method. In addition, after the hot water extraction process, the content of cyanogenic glycosides in flaxseed was significantly decreased from 242.6±0.8 mg/kg to 7.1±0.6 mg/kg. The proposed flaxseed demucilage -method was simple and efficient, which not only significantly improved the yield of flaxseed oil with aqueous enzymatic method, but also laid a good foundation for preparation of flaxseed gum from the extract and further utilization of the flaxseed meal. Therefore, it presentsed a promising technology for the comprehensive utilization of flaxseed on industrial scale.关键词
浸出法/工艺/优化/亚麻籽/亚麻籽油/黏质物/生氰糖苷Key words
pressing/process/optimization/flaxseed/flaxseed oil/mucilage/cyanogenic glycosides分类
轻工纺织引用本文复制引用
孙红,张文斌,杨瑞金,华霄,赵伟..黏质物脱除工艺优化及其提高亚麻籽提油率的效果[J].农业工程学报,2018,34(3):309-314,6.基金项目
国家"863"计划项目(2013AA102104) （2013AA102104）
国家自然科学基金(31401635) （31401635）
