Oils and fats originate from plant and animal sources. The plant-based oils and fats dominate in current food applications and will be the main focus of this chapter.
The supply chains of vegetable oils and fats consist of:
●
The growing of oil seeds, fruits, kernels or nuts.
●
Oil extraction to recover the oil, the by-product meal is mostly used as animal feed.
●
Purification and modification processes to optimize the properties of oils.
●
All transport from grower to end user.
Until the industrial revolution in the 19th century, rapeseed, linseed, olives and nuts were the main sources of vegetable oils. Today, the world market is dominated by palm and soybean oil, followed by rapeseed and sunflower oil. This has led to a change in the extraction and purification/modification processes. Originally, the oil extraction process consisted of cleaning, crushing, heating and pressing. From 1900 onwards solvent extraction was applied to recover the residual oil from the pressed cake or to replace the pressing process completely (e.g. for soybean oil). At more or less the same time, the oil purification process changed from a simple decanting and filtration to a combination of neutralization with caustic, bleaching with active clay and deodorization at high temperature under vacuum with steam. Using this refining process, minor components were reduced to improve taste and appearance while the removal of processing residues was required after the introduction of solvent extraction and nickel catalyzed hydrogenation.
Later, the introduction of improved analytical techniques showed that the refining process also reduces the levels of many of the contaminants present in the crude (extracted) oil. The refining process may also introduce side reaction products; some of these products may affect health. This chapter gives an overview of the most important contaminants in the crude oil, the validation of the refining process for the removal of these components, and the formation of potential hazardous by-products during refining.
Oils and fats originate from plant and animal sources. The plant-based oils and fats dominate in current food applications and will be the main focus of this chapter.
The supply chains of vegetable oils and fats consist of:
●
The growing of oil seeds, fruits, kernels or nuts.
●
Oil extraction to recover the oil, the by-product meal is mostly used as animal feed.
●
Purification and modification processes to optimize the properties of oils.
●
All transport from grower to end user.
Until the industrial revolution in the 19th century, rapeseed, linseed, olives and nuts were the main sources of vegetable oils. Today, the world market is dominated by palm and soybean oil, followed by rapeseed and sunflower oil. This has led to a change in the extraction and purification/modification processes. Originally, the oil extraction process consisted of cleaning, crushing, heating and pressing. From 1900 onwards solvent extraction was applied to recover the residual oil from the pressed cake or to replace the pressing process completely (e.g. for soybean oil). At more or less the same time, the oil purification process changed from a simple decanting and filtration to a combination of neutralization with caustic, bleaching with active clay and deodorization at high temperature under vacuum with steam. Using this refining process, minor components were reduced to improve taste and appearance while the removal of processing residues was required after the introduction of solvent extraction and nickel catalyzed hydrogenation.
Later, the introduction of improved analytical techniques showed that the refining process also reduces the levels of many of the contaminants present in the crude (extracted) oil. The refining process may also introduce side reaction products; some of these products may affect health. This chapter gives an overview of the most important contaminants in the crude oil, the validation of the refining process for the removal of these components, and the formation of potential hazardous by-products during refining.
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