A method for preparing cyperus esculentus oil by reverse water extraction

Abstract

The application provides a method for preparing cyperus esculentus oil by adopting reverse water extraction with cyperus esculentus as raw material. First, the cyperus esculentus is screened, peeled and crushed; then 40-60 mesh cyperus esculentus powder is uniformly stirred with water at a material-water ratio of 1:5-6, and cellulase and pectinase are added for sugar extraction at 45-55 DEG C. After solid-liquid separation of the sugar extraction liquid, a sugar liquid phase and a wet solid phase containing oil, starch and the like are obtained; the wet solid phase is subjected to rolling and extrusion treatment to loosen its structure, then 10-20 DEG C cold water is added at a material-water ratio of 1:4-5, and gentle stirring is carried out for oil and starch resolution, and then the resolution liquid is subjected to secondary separation to obtain cyperus esculentus oil (oil phase) and crude starch (solid phase), and the water phase can be used for sugar extraction water.

Description

Technical Field

[0001] This invention relates to the field of vegetable oil extraction technology, and in particular to a process for preparing tiger nut oil by reverse water extraction. Background Technology

[0002] Tiger nuts ( Cyperus esculentus Cyperus rotundus (also known as oilseed sedge, ginseng fruit, tiger nut, etc.) is an oilseed crop belonging to the genus Cyperus in the family Cyperaceae. Its oil content ranges from 15% to 35%. It also contains 20% to 35% starch, 13% to 20% sugar, and 5% to 10% protein. Furthermore, it has low requirements for planting environment, soil, and water, making it a promising new multi-purpose oilseed crop.

[0003] Tiger nuts oil is rich in unsaturated fatty acids, including 71.6% oleic acid and 11.2% linoleic acid. It is a polyunsaturated fatty acid oil, which is pale yellow in color and has a higher fatty acid content than rapeseed oil.

[0004] The sugars in tiger nuts are mainly sucrose, which accounts for more than 50% of their content. They also contain glucose, fructose, and raffinose, among others. This is a key characteristic that distinguishes tiger nuts from other oilseed crops.

[0005] The composition of tiger nuts and the functional characteristics of their oils determine the uniqueness of their oil extraction process. Summary of the Invention

[0006] The purpose of this invention is to provide a method and process for preparing tiger nut oil by reverse water extraction suitable for industrial production. The method uses water at different temperatures as a solvent to extract sugars from tiger nuts and to analyze the starch and oils in tiger nuts. The oil is obtained through mechanical separation, while the sugars and starches of tiger nuts can also be extracted.

[0007] To achieve the above objectives, the present invention provides a method for preparing tiger nut oil by reverse water extraction suitable for industrial production, specifically including the following steps: Step 1: Screening, peeling, and crushing the tiger nuts. Select plump tiger nuts free from disease, pests, and mold using a screening machine; peel the tiger nuts using a peeling machine, controlling the peeling rate at 10%~15%; crush the peeled tiger nuts using a crusher, controlling the particle size at 40~60 mesh.

[0008] Step 2: In an extraction tank, mix the tiger nut powder obtained in Step 1 with water at a material-to-liquid ratio of 1:5-6 and perform saccharide extraction. When the liquid temperature reaches approximately 50℃, add 0.05%-0.15% cellulase and 0.03%-0.10% pectinase. Control the stirring speed at 100-200 rpm, the temperature at 45℃-55℃, and the extraction time at 30-50 minutes.

[0009] Step 3: Perform solid-liquid separation on the extract obtained in Step 2. Use a horizontal centrifuge (3000~4000rpm) to separate the liquid phase (containing sugars) and the wet solid phase (50%~65% water, containing oils, starch, proteins and cellulose, etc., used for extracting oils and starches).

[0010] Step 4: The wet solid phase obtained in Step 3 is rolled using a rolling mill to loosen its structure. The speed is 10~20 rpm, the gap can be adjusted to 1.5mm~2.5mm, and the number of times is 1~2. Then, a single screw extruder (water-cooled type) is used for extrusion treatment, with a pressure of 6~10MPa, a speed of 60~100 rpm, and a temperature ≤55℃.

[0011] Step 5: Add cold water at 10℃~20℃ to the wet solid phase obtained in step 4 after rolling and extrusion in the desorption tank at a material-to-liquid ratio of 1:4~5, and stir gently for 5min~10min to desorb the oil and starch.

[0012] Step 6: Perform solid-liquid separation on the eluent obtained in Step 5. Use a horizontal centrifuge (3000~4000rpm) to obtain tiger nut oil (oil phase) and crude starch (solid phase), etc. The aqueous phase can be used for sugar extraction. Attached Figure Description

[0013] Figure 1 This is a flowchart of the process for preparing tiger nut oil. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to specific embodiments. The described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0015] According to the analysis, the peeled tiger nuts used in the embodiments of the present invention are composed of 30.6% oil, 34.2% starch, 16.1% sugar, 7.1% protein and 10.2% water. Example

[0016] Step 1: Take 500 kg of tiger nut flour that has been screened, peeled and crushed to obtain a 40-mesh sieve.

[0017] Step 2: Add tiger nut powder and warm water to the extraction tank at a material-to-liquid ratio of 1:5.5, and simultaneously start stirring (200 rpm) and jacket heating. When the liquid temperature reaches approximately 50℃, add 0.15% cellulase (≥10000U / g) and 0.05% pectinase (≥50000U / g). Maintain the extraction temperature at 50℃~55℃ for 45 minutes.

[0018] Step 3: Use a horizontal centrifuge (3500 rpm) to separate the solid and liquid phases of the extract to obtain a liquid phase (total sugar 72.40 kg, sugar extraction rate 89.94%) and a wet solid phase (moisture 58.15%).

[0019] Step 4: The wet solid phase is rolled twice using a rolling mill at a speed of 10-20 rpm and a gap of 1.5 mm; then it is extruded using a single screw extruder (water-cooled type) at a pressure of 8 MPa, a speed of 100 rpm, and a temperature of 55℃.

[0020] Step 5: Add the wet solid phase that has been rolled and extruded to cold water at 15°C in the desorption tank at a material-to-liquid ratio of 1:5, and gently stir for 10 minutes to desorb the oil and starch.

[0021] Step 6: Use a horizontal centrifuge (4000 rpm) to perform three-phase separation of oil, water and solid in the eluent to obtain tiger nut oil and crude starch, etc.

[0022] Step 7: The tiger nut oil obtained by extrusion and centrifugation of the single-screw extruder and the extract was weighed together to a total weight of 141.65 kg, with an oil extraction rate of 92.58%.

Claims

1. A method for preparing tiger nut oil by reverse water extraction, characterized in that, The specific operating steps include the following: (1) Tiger nuts pretreatment, including screening, peeling, and crushing. A screening machine selects plump tiger nuts free from disease, pests, and mold; a peeling machine peels the tiger nuts, controlling the peeling rate at 10%~15%; a crusher crushes the peeled tiger nuts, controlling the particle size at 40~60 mesh. (2) (Enzymatic) Sugar extraction: Add the above-mentioned tiger nut powder and warm water to the extraction tank at a material-to-liquid ratio of 1:5~6. When the liquid temperature reaches about 50℃, add 0.05%~0.15% cellulase and 0.03%~0.10% pectinase. Control the stirring speed at 100~200 rpm, the temperature at 45℃~55℃, and the extraction time at 30min~50min. (3) Primary solid-liquid separation: A horizontal centrifuge is used to separate the liquid phase (containing sugars) and the wet solid phase (50%~65% water content, containing oils, starches, proteins, and cellulose, etc., used for extracting oils and starches); (4) Rolling and extrusion of wet solid phase: The wet solid phase is rolled using a rolling mill to loosen its structure. The speed is 10~20 rpm, the gap is adjustable to 1.5mm~2.5mm, and the number of times is 1~2. Then, a single screw extruder (water-cooled type) is used for extrusion treatment. The pressure is 6~10MPa, the speed is 60~100 rpm, and the temperature is ≤55℃. (5) Oil and fat separation: The wet solid phase that has been rolled and extruded is added to cold water at 10℃~20℃ in a separation tank at a material-to-liquid ratio of 1:4~5, and gently stirred for 5min~10min to separate the oil and starch; (6) Secondary solid-liquid separation: The eluent is separated into oil-water-solid three phases using a horizontal centrifuge to obtain tiger nut oil and crude starch, etc. Rotation speed: 3000~4000 rpm.

2. The method for preparing tiger nut oil by reverse water extraction as described in claim 1, characterized in that... The liquid phase obtained from the primary solid-liquid separation in step 1 can be used for sugar concentration. The tiger nut oil obtained from the secondary solid-liquid separation can be refined to obtain high-grade edible oil; the crude starch can be separated and dried to prepare tiger nut starch; and the aqueous phase can be used for sugar extraction.

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