Biochemical characteristics of DAG

The largest constituent of edible oils are TAG, but oils may also contain up to 10% (w/w) DAG, the level depending on the origin of the oil. Table 1 shows the content of DAG and other acylglycerols in edible oils of various origins (Abdel-Nabey et aL, 1992 D alonzo et al., 1982). For example, olive oil contains 5.5% DAG and crude cottonseed oil contains 9.5% DAG. 

Details of studies of the nutritional characteristics and beneficial health effects of this DAG-rich oil are detailed in Sections C and D below. A TAG-rich blend of rapeseed oil, soybean oil and safflower oil, with a similar fatty acid composition to the DAG-rich oil, was used as a comparative control in these studies. 

Component Soybean Cottonseed Palm Corn (maize) Safflower Olive Rapeseed  

The acylglycerol and fatty acid compositions of the oils used in our studies are shown in Tables 2 and 3. The fatty acid composition of the DAG-rich oil was very similar to that of the blended TAG-rich oil. The total DAG content of the DAG-rich oil was 87.0 g/100 g and the ratio of 1(3),2-DAG to 1,3-DAG was 32 68. 

The heat energy values of the oils (Table 3) were estimated using the approach outlined in the literature (Livesey, 1984 Peters et al., 1991), and calculated using the equation  

---