Food Lipids: Chemistry, Nutrition, and Biotechnology

LML) or two (LMM, MLM) medium chain fatty acids, in random order (Fig. 2),
and small quantities of pure unreacted MCTs and LCTs (19).
The starting molar ratios of the MCTs and LCTs, and the source or type of
TAG, can be varied to produce new desired SL molecules. Coconut oil is a good
source of MCTs, and soybean and safflower oils are excellent sources of (n-6)containing
fatty acids for SL synthesis. Isolation and purification of the products is
tedious because of unwanted coproducts. SLs are also produced by physical blending
of specific amounts of MCTs and LCTs, except there is no exchange or rearrangement
of fatty acids within the same glycerol backbone. When consumed, the blend will
retain the original absorption rates of the individual TAG. Positional specificity of
fatty acids on the glycerol molecule is not achieved by chemical transesterification,
and this is a key factor in the metabolism of SLs. A possible alternative is the use
of enzymes—specifically lipases—as described later in this chapter (Sec. II.B.3).
2. Examples of Commercial Products
a. Caprenin. Caprenin is a common name for caprocaprylobehenin, a structured
lipid containing C8:0, C10:0, and C22:0 fatty acids esterified to glycerol moiety. It
is manufactured from coconut, palm kernel, and rapeseed oils by a chemical transesterification
process. The MCFAs are obtained from the coconut oil and the LCFAs
from rapeseed oil. Caprenin’s caloric density is 5 kcal/g compared to 9 kcal/g for a
conventional TAG. Behenic acid is partially absorbed by the body and thus contributes
few calories to the product. The MCFAs are metabolized quickly, like
carbohydrates.
Procter & Gamble filed a Generally Recognized as Safe (GRAS) affirmation
petition to the U.S. Food and Drug Administration (FDA) for use of caprenin in soft
candies such as candy bars, and in confectionery coatings for nuts, fruits, cookies,
and so on. Caprenin is made up of 95% TAGs, 2% diacylglycerols (DAGs), and 1%
monoacylglycerols (MAGs) with C8:0 � C10:0 contributing 43–45% and C22:0
40–54% of the fatty acids. Caprenin has a bland taste, is liquid or semisolid at room
temperature, and is fairly stable to heat. It can be used as a cocoa butter substitute.
The structure of Caprenin is shown in Figure 6. Swift et al. (43) showed that
Caprenin fed as an SL diet to male subjects for 6 days did not alter plasma cholesterol
concentration but decreased HDL-chol by 14%. However, the MCT diet raised
plasma TAGs by 42% and reduced HDL-chol by 15%.
b. Benefat/Salatrim. Benefat contains C2:0-C4:0, and C18:0 esterified to glycerol
moiety. Benefat is a brand name for Salatrim (short and long acyl triglyceride
molecule), developed by Nabisco Foods Group (Parsippany, NJ), but now marketed
as Benefat� by Cultor Food Science (New York, NY). Benefat is produced by base-
Figure 6 Structure of Caprenin (caprocaprylobehenin) with three randomized acyl groups:
R 1,R 2,R 3 = acyl part of capric acid, C10:0, caprylic acid, C8:0, and behenic acid, C22:0 in
no particular order.
Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.