Oilseed Processing for Small Scale Producers

Farmers and small business owners are always asking if it is possible and profitable to add value to their oilseeds and nuts by processing these oilseeds into oils. It doesn't have a definite answer for there are so many variables, but in most cases,there are usually some ways for oilseed processing for small scale producers.

Detailed Oilseed Processing for Small Scale Producers

1. Seed Preparation:

Preparation of the raw material often includes removing husks or seed coats from the seeds and separating the seeds from the chaff. There are a wide variety of small- to intermediate-scale approaches to and technologies for effective seed cleaning. Approaches range from using various sizes of hardware cloth screens in tandem (Clothier) to using a compact fanning mill such as the Clipper Office Tester and a spiral separator for small farms (Small Scale Grain and Pulse Production forum, 2008). See the Resources section for examples, types and sources of equipment.

2.Oilseed Pressing:

Oil can be extracted mechanically with a ram press, an expeller or even a wooden mortar and pestle, a traditional method that originated in India. Presses range from small, hand-driven models that an individual can build to power-driven commercial presses. The ram press uses a piston inside a cage to crush the seed and force out the oil. There are many manufacturers of single-cylinder presses. Most presses are sold in European countries and designed primarily for rapeseed, or canola. For example, the Täby Press is a screw press manufactured in Sweden. It is similar to the Komet Oil Expeller described below. Various models are available for cold pressing rapeseed, linseed, flaxseed, sunflower seed, sesame seed, peanut, groundnut, mustard seed, poppy seed, cotton seed, jojoba and more.

3. Oil Extraction:

Oils can also be extracted with solvents, but solvent extraction is a complex and costly operation. Solvent extraction isn't suited for small-scale processing because of high capital and operating costs, risks due to fire and explosions from solvents, and the sheer complexity. Management of solvents such as hexane is a problem as well.

4. Oil Refining:

The vegetable oil produced and processed to this point does not need refining, bleaching or deodorizing as long as the natural taste, smell and color are acceptable to the user. However, getting the oil to commercial food grade may be an important step in oilseed processing if your market demands it. For example, restaurants require oils that have a relatively high smoke temperature and may or may not want the taste of the natural oil. Getting the oil to food grade will add value and can make small-scale biodiesel from oilseeds more feasible for those who intend to use the oil in a manner similar to the full-cycle farming story at right.

5. Oil Filling and Storage:

Use clean, dry containers to package and store oils. Sealed glass or plastic bottles are adequate for small quantities. Colored containers in a dark box help increase shelf life. Steel or plastic tanks work well for large quantities. The shelf life of oil is usually six to 12 months if it is properly packaged and kept away from heat and sunlight.

Keeping air away from oil is perhaps the most important step to prevent rancidity. Completely fill whatever size container you chose so there is no air space and then cap the container tightly.

If the stored vegetable oil does not reach sustained temperatures of 100° F or more, its vital components will be preserved. Therefore, vegetable oil is excellently suited for natural nutrition. As long as the oil is stored in a dark, cool place, it will have a long shelf life.