Lard being an edible fat could be used in different forms in food systems. In this study, composition and thermal analysis of lard stearin (LS) and lard olein (LO) were undertaken to determine some common parameters which would enable their detection in food. A sample of native lard was partitioned into LS and LO using acetone as solvent and the fractions were compared to the original sample with respect to basic physico-chemical parameters, fatty acid and triacylglycerol (TAG) composition, and thermal characteristics. Although LS and LO displayed wider variations in basic physico-chemical parameters, thermal properties and solidification behavior, they do possess some common characteristic features with regard to composition. In spite of the proportional differences in the major fatty acids, both LS and LO are found to possess extremely high amount of palmitic (C16:0) acid at the sn-2 positions of their TAG molecules. Similar to native lard, both LS and LO contained approximately equal proportions of TAG molecules namely, linoleoyl-palmitoyl-oleoyl glycerol (LPO) and dioleoyl-palmitoyl glycerol (OPO). Hence, the calculated LPO/OPO ratio for LS and LO are comparably similar to that of native lard.
Crotalaria pallida Aiton is an herbaceous legume from the family Fabaceae. In the present study, one new cyclopentyliene, crotolidene (1) and seven known compounds, i.e. hydroxydihydrobovolide (2), octacosane (3), trans-phytyl palmitate (4), linoleic acid (5), methyl oleate (6), ethyl palmitate (7), and palmitic acid (8) were isolated from the C. pallida collected from Perak, Malaysia. These compounds were isolated and characterized using extensive chromatographic and spectroscopic methods.
In a double-blind crossover study, 17 normocholesterolemic male volunteers were fed carefully designed whole-food diets in which 5% of energy was exchanged between palmitic (16:0) and lauric + myristic acids (12:0 + 14:0) whereas all other fatty acids were held constant. Resident males received each diet during separate 4-wk periods. The test diets supplied approximately 30% of energy as fat and 200 mg cholesterol/d. Compared with the 12:0 + 14:0-rich diet, the 16:0-rich diet produced a 9% lower serum cholesterol concentration, reflected primarily by a lower (11%) low-density-lipoprotein-cholesterol concentration and, to a lesser extent, high-density-lipoprotein cholesterol. No diet-induced changes were noted in the cholesterol content of other lipoproteins, nor did exchange of saturated fatty acids affect the triglyceride concentration in serum or lipoprotein fractions. These data indicate that a dietary 12:0 + 14:0 combination produces a higher serum cholesterol concentration than does 16:0 in healthy normocholesterolemic young men fed a low-cholesterol diet.
To compare the effects of dietary palmitic acid (16:0) vs oleic acid (18:1) on serum lipids, lipoproteins, and plasma eicosanoids, 33 normocholesterolemic subjects (20 males, 13 females; ages 22-41 years) were challenged with a coconut oil-rich diet for 4 weeks. Subsequently they were assigned to either a palm olein-rich or olive oil-rich diet followed by a dietary crossover during two consecutive 6-week periods. Each test oil served as the sole cooking oil and contributed 23% of dietary energy or two-thirds of the total daily fat intake. Dietary myristic acid (14:0) and lauric acid (12:0) from coconut oil significantly raised all the serum lipid and lipoprotein parameters measured. Subsequent one-to-one exchange of 7% energy between 16:0 (palm olein diet) and 18:1 (olive oil diet) resulted in identical serum total cholesterol (192, 193 mg/dl), low-density lipoprotein cholesterol (LDL-C) (130, 131 mg/dl), high-density lipoprotein cholesterol (HDL-C) (41, 42 mg/dl), and triglyceride (TG) (108, 106 mg/dl) concentrations. Effects attributed to gender included higher HDL in females and higher TG in males associated with the tendency for higher LDL and LDL/HDL ratios in men. However, both sexes were equally responsive to changes in dietary fat saturation. The results indicate that in healthy, normocholesterolemic humans, dietary 16:0 can be exchanged for 18:1 within the range of these fatty acids normally present in typical diets without affecting the serum lipoprotein cholesterol concentration or distribution. In addition, replacement of 12:0 + 14:0 by 16:0 + 18:1, but especially 16:0 or some component of palm olein, appeared to have a beneficial impact on an important index of thrombogenesis, i.e., the thromboxane/prostacyclin ratio in plasma.