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Oil Transesterification in Cocoa Butter Analogues

Vegetable oils such as palm oil and rapeseed are widely used in products like creams and, in this example, a cocoa spread. In this case, palm oil is used as it is a cost effective alternative to cocoa butter. The problem that arises from using these alternatives is that they don't have the same physical properties. Cocoa spreads need to be in a semi-solid form, whereas, vegetable oil is a liquid.

To achieve the desired characteristics (i.e. the product should melt in your mouth, not in your hands), the oil undergoes transesterification using an immobilized lipase. This results in the palm oil becoming a semi-sold oil that now melts at 37°C.   

These lipases are immobilized by adsorptive immobilization.

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  • Production of palm oil - 6.5 million t/y

  • Butter fat - 5.5 million t/y

  • Cocoa butter fat is a high value product because TAGs are high in stearates, which give a melting point of 37 ◦C. Palm oil TAGs are high in palmitate and they give a melting point of 23°C so is oil at room temperature (low value product)

  • Conversion of palm oil into cocoa butter fat substitute can be achieved by interesterification