Rice bran oil is an edible oil extracted from rice bran, a byproduct of rice processing. Rice bran is rich in various nutrients and physiologically active substances, with a fat content of 16%-22%. Rice bran oil is nutritious, easily absorbed, and has good oxidative stability, making it a recognized healthy oil both domestically and internationally.
Rice bran itself has a relatively low oil content, and the rice bran oil extraction method is often the main process used for rice bran oil production. Because rice bran contains lipase and lipoxygenase, these two enzymes are the main reasons for the rapid rancidity of rice bran, affecting subsequent rice bran oil extraction and oil quality. Therefore, rice bran needs to be treated promptly to stabilize its quality before extraction.
In rice bran oil extraction plant, the choice of pretreatment process directly affects oil yield, oil quality, and economic benefits. Common rice bran pretreatment processes include softening and condition pretreatment and extrusion pretreatment. In recent years, extrusion pretreatment has been widely used in rice bran oil extraction line. Compared with traditional steaming and roasting pretreatment, what are the advantages of extrusion pretreatment? Henan Huatai Cereals and Oils Machinery Co., Ltd. Manufacturer will briefly introduce them. Compared with the steaming and roasting process, the rice bran extrusion process has the following three advantages:
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Restructuring The Oil Material’s Structure
Traditional steaming and roasting processes use wet heat treatment to denature rice bran proteins and soften the cell structure, but the integrity of the cell wall is still partially preserved, limiting the release channels of the oil. However, rice bran extrusion pretreatment uses high temperature, high pressure, and high shear mechanical energy for instantaneous transformation, achieving the reconstruction of the material’s microstructure. In the rice bran extruder cavity, the material experiences a pressure drop from high pressure to normal pressure instantaneously, and the internal moisture vaporizes instantly, forming a uniform honeycomb-like porous structure. The mechanical shear force generated by puffing is far greater than that of steaming and roasting, which can more thoroughly destroy the cell wall, changing the oil from an encapsulated state to a surface-attached state. The porous structure increases the specific surface area of the material, creating ideal conditions for solvent contact.
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Passivating Enzymes in Rice Bran to Stabilize Raw Material Quality
Rice bran contains active lipases, which rapidly catalyze oil hydrolysis after crushing, leading to a sharp increase in acid value. Traditional steaming and roasting partially denature lipases through moist heat, but complete inactivation is difficult, and residual enzyme activity often leads to a rebound in acid value during storage; rice bran extrusion pretreatment utilizes instantaneous high temperatures far exceeding the thermal inactivation critical point of lipases, combined with high pressure and high shear, to achieve the destruction of the lipase system, resulting in better stabilization.
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Improving Rice Bran Extraction Efficiency
The physical characteristics of the pre-treated material directly affect the rice bran oil extraction efficiency. Steamed and roasted materials have higher density and greater resistance to solvent penetration; expanded materials are porous and loose, forming penetration channels; steamed and roasted materials have strong liquid retention, resulting in a small concentration gradient of mixed oil; the interconnected pores inside the expanded material promote solvent-oil exchange; the expanded material has good structural rigidity and is not easily compacted in the extractor, resulting in more thorough solvent recovery.
The extrusion-extraction pretreatment process for rice bran not only solves the inherent problems of insufficient lipase inactivation and extraction efficiency bottlenecks that are difficult to overcome with traditional steaming and roasting processes, but also creates a better foundation for rice bran oil extraction through the reshaping of the material’s microstructure. The comprehensive benefits in terms of oil yield, product quality, energy savings, and increased value of by-products make it a widely used pretreatment process in rice bran oil production.
However, a mature rice bran oil production line includes the coordination of various links and the connection of preceding and succeeding processes. To achieve ideal production results, multiple factors need to be considered in the selection of equipment, processes, and equipment manufacturers. Huatai Cereals and Oils Machinery Co., Ltd. provides customers with a full-process service from design to customization to installation and commissioning. We are committed to providing customers with high-quality equipment and services. The manufacturer has rich cooperation cases and project experience, provides free on-site installation and commissioning, and offers training services. The rice bran oil equipment runs stably, and has a good customer reputation. Welcome to visit our factory for on-site inspection.
Website: https://ricebranoilpress.com/
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