Preparation of Interesterified Plastic Fats from Fats and Oils Free of Trans Fatty Acid

Authors: LEE, JEUNG - UGA; AKOH, CASIMIR - UGA; Himmelsbach, David; LEE, KI-TEAK - CHUNGHNAM NAT. UNIV.

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2008
Publication Date: 5/14/2008
Citation: Lee, J.H., Akoh, C.C., Himmelsbach, D.S., Lee, K. 2008. Preparation of Interesterified Plastic Fats from Fats and Oils Free of Trans Fatty Acid. Journal of Agricultural and Food Chemistry. 56(11):4039-4046.

Interpretive Summary: The production of fats that have the desirable characteristics of texture, mouth feel, incorporation of air and extended shelf life has been difficult to achieve without producing undesirable trans-fatty acids that have been associated with coronary heart disease. Fats with the desirable properties that are suitable for table margarine or shortening have now been prepared from initially trans-free fats without these properties into those with these desirable properties by an enzyme catalyzed reaction. The resulting fats are still trans-free. These fats, called plastic fats, are essential to the baking industry. The ability to produce them in this manner provides an alternative to using partially hydrogenated fats for baking.

Technical Abstract: Interesterified plastic fats were produced with trans-free substrates of fully hydrogenated soybean oil, extra virgin olive oil, and palm stearin in a weight ratio of 10:20:70, 10:40:50, and 10:50:40, respectively, by lipase catalysis. The major fatty acids of the products were palmitic (32.2-47.4%), stearic (12.0-12.4%), and oleic acid (33.6-49.5%). After storage at 5 °C (refrigerator temperature) or 24 °C (room temperature) for 16 h, the physical properties were evaluated for solid fat content, texture, melting, and crystallization behavior, viscoelastic properties, crystal polymorphism, and crystal microstructure. The interesterified fats contained desirable crystal polymorphs (beta' form) as determined by X-ray diffraction spectroscopy. They exhibited a wide plastic range of solid fat content of 52-58% at 10 °C and 15% at 40 °C. The physical properties were influenced by the ratio of palm stearin and olive oil. Harder and more brittle texture, crystallization and melting at higher temperature, higher solid fat contents, and more elastic (G') or viscous (G') characteristics were observed in the produced fats containing a higher content of palm stearin and lower content of olive oil. The produced fats stored at 5 °C consisted mostly of beta' form crystal together with a small content of beta form, while those at 24 °C had only beta' form. The produced fat with a higher amount of palm stearin appeared to have more beta' form crystal and small size crystal clusters. Thus, the physical properties of the produced plastic fats may be desirable for use in a bakery product