水媒法提取食用油技术研究进展

该文提出了水媒法提油技术的概念。水媒法提油技术是指以水为主要媒介的提油技术(水媒法),可辅以或不辅以与水互溶的可食用物质(例如乙醇)、食品级酶、超声波、微波等处理以破坏油料细胞壁和/或破乳的食用油提取方法。水媒法的提油过程主要分为分成破碎、提取、破乳和分离四个阶段。水媒法发展至今60余年,已全面发展了水代法、水酶法和乙醇水提法等多种制油技术。目前水媒法的产业化还存在一些问题,如油料的预处理、酶的种类与成本等。但是,水媒法绿色健康、符合可持续发展要求,随着工艺设备、分离技术等的发展,该技术将更加完善,成为未来未来取代传统工艺的新主流。该文将水媒法研究领域的成果进行归纳总结并为其未来发展提供理论参考。

Summarization on vegetable oil extraction technology by aqueous medium method

Abstract: Vegetable oil is an exceedingly important and indispensable part of the modern diet. Most of the production methods of vegetable oils in traditional commercial company are the hot-pressing method and/or the solvent extraction method. The hot-pressing method is a conventional oil production method in which oilseeds are firstly treated under hyperthermal condition and then exuded by mechanical extrusion. This method has the characteristics of simple equipment and universality on the production of different oils, but its oil yield is relatively low. In addition, during the long-time hyperthermal treatment, oil may be oxidized, and then the oxidation product would degrade and generate some harmful compositions, such as trans-fatty acid and polycyclic aromatic hydrocarbons. The solvent extraction method applies hexane as extraction solvent chiefly, and has a high oil yield (>96%). But in hexane extraction, many byproducts would be dissolved out with the oil, which leads to the inferior physical-chemical characteristics of crude oil. Hence, the deep refining is needed, however, excessive refining not only causes the loss of nutrients, but also may bring new harmful substances, such as plasticizers, heavy metals and chlorine propanol esters. Furthermore, hexane has been identified as the hazardous air pollutant. Because of the toxicity and flammability of hexane and the increasing demand of food safety, the development of alternative green production process of vegetable oils is becoming extraordinarily urgent. The aqueous extraction method is recently receiving considerable attention, in which pure water is employed as main extraction medium. It is a new developed green and efficient oil extraction technology. Compared with traditional technology, this method is mild and safe due to the relatively low temperature and the complete avoidance of organic solvents. Based on the decades of our team's research work on the aqueous medium extraction technology, we have established the concept of aqueous medium method of vegetable oil extraction technology firstly in this review. The so-called aqueous medium method of vegetable oil extraction technology employs pure water as the main extraction medium, with or without the assistance of edible substances that are miscible with water like ethanol, food-grade enzyme, supersonic and microwave. The effects of these supplements were to destroy the cell wall of oil-bearing materials or prevent the formation of highly-creamed emulsion in extraction process. This method contains aqueous extraction method, aqueous enzymatic extraction method and aqueous ethanol extraction method. In this review, the technological process, technical features, development history, existing problems and promising prospects are also discussed in detail.