Walnut Oil Refining

The process for walnut oil production includes the following steps: shelling, separation of the kernel from the shell, pressing, filtration, and cold pressing to obtain walnut oil. The crude oil obtained from pressing is called crude oil or "mao you" in Chinese. Crude oil contains water, sediment, coarse powder, fiber, free fatty acids, pigments, sulfur compounds, wax, and gum. Some poor-quality walnut kernels may also contain harmful substances such as benzopyrene. Therefore, crude walnut oil needs to be refined using refining equipment.

The process for refining walnut oil includes several steps: crude oil, degumming, decolorization, filtration, deodorization, heat exchange, heating, deacidification, deodorization, heat exchange, cooling, filtration, and finished oil.

(1) Deacidification: Removing fatty acids from the crude oil to meet national standards for acidity.

(2) Degumming: Removing gums from the crude oil.

(3) Decolorization: Treating the oil to make it clear and transparent.

(4) Deodorization: Removing any unpleasant odors from the oil.

(5) Dewaxing: Removing wax from the walnut oil using a dewaxing process.

The deodorization and deacidification section uses a distillation-based physical process with a combination tower. The oil enters the tower and forms a film on the packing section, flowing downward. It comes into contact with steam flowing in the opposite direction, which removes fatty acids and various volatile substances. These substances are then removed through distillation under vacuum and steam stripping, achieving the goal of deodorization (deacidification). This process is short, reducing production costs and helping to inhibit the formation of trans fatty acids while retaining residual vitamin E.