C18 Saturated Acids Research Articles

The effect of temperature on in vitro digestibility, fat globular size and free fatty acid bio-availability in milk fat

The rate at which a particular fat is digested has an effect on its bioavailability and on the lipid profile of the blood. Milk fat is a very complex mixture of triacylglycerols, resulting in a very wide melting range (from –40 to +40°C). Because temperature has a pronounced effect on the physicochemical state of milk fat (i.e. crystallisation of different fat fractions), this study analysed the bioavailability of milk fat at different temperatures. A simplified model simulating digestion in the intestine at various temperatures was used. The released fatty acids and the changes in the emulsion of milk fat under the effect of lipase were compared. The amount and profiles of the released fatty acids varied depending on the incubation temperature of the studied sample. At lower temperatures, the fractions which were hydrolysed to a greater degree were those which contained more unsaturated oleic acid, but contained less C14, C16 and C18 saturated acids. Changes in the emulsion system also differed depending on temperature. The obtained results indicate that, depending on the temperature, not only different amounts, but also different fractions of milk fat were hydrolysed by lipase, which indicates the role of the physico- chemical state of milk fat during its digestion.

Lipids and Saponins ofPhaseolus coccineus

AbstractThe lipids obtained from the roots, rhizomes and stems of Phaseolus coccineus were separated into saponifiable and unsaponifiable fractions. Analysis of the saponifiable fraction by gas-liquid chromatography (GLC) of the methyl esters showed the presence of a series of C8 to C18 saturated acids and C12 to C18 unsaturated acids. Oleic acid was the predominant fatty acid detected in the roots (22.3%) and rhizomes (34.4%). However, in the stems palmitic acid (30.0%) was the major component. Stearic acid, which was present in a fairly high concentration in the rhizomes, was not detected in either the roots or the stems.β-Bergamotane, 18α-oleanan-3-one and β-Sitosterol have been isolated from the roots, rhizomes and stems of unsaponifiable fraction.In all these three plant materials, the presence of saponins was also revealed. Two sapogenins were isolated from the roots and were identified as soyasapogenol-C and Ursa-12,15-diene-3,24-diol. Soyasapogenol-C was also isolated from the rhizomes and the ste...

Fatty acid composition of Bifidobacterium and Lactobacillus strains.

Normal C(14), C(16), and C(18) saturated acids and C(16) and C(18) monoenoic acids are the main fatty acids of nine strains of Bifidobacterium. Their lactobacillic acid content was less than 5%. Lactobacillus strains contained the same fatty acids as main compounds except for octadecanoic acid, which was present only in very low amounts. Eight of nine Lactobacillus strains contained in the stationary phase more than 15% lactobacillic acid. No correlation was observed between the fatty acid composition and other physiological characteristics used in the literature for classification of strains of one genus. Aging of the culture, which involved a decrease of the pH, caused a lengthening of the chain length of the fatty acids of B. bifidum var. pennsylvanicus but only a conversion of octadecenoic to lactobacillic acid in the lactobacilli. Lowering of the temperature of cultivation decreased the chain length of the fatty acids of B. bifidum var. pennsylvanicus. L. lactis did not show any influence of the temperature on the chain length of the fatty acids. The percentage of unsaturated acids was temperature independent in both organisms.

Fatty acids of geochemical significance in microscopic algae

Fatty acids ranging from 14:0 to 18:4 were found in eleven different species of green and blue-green algae. In general, the unsaturated C18 fatty acids predominate in all the species of green algae analyzed while with some exceptions the C16 saturated acids are predominant in the blue-green algae. By the nature of their as chromatographic patterns, there appears to be no direct correlation between the fatty acids and the hydrocarbons within the same species of algae. The fatty acids are distributed in a narrower molecular weight range (C14C18) than the hydrocarbons (C15C33) and do not show any significant qualitative variations between species. All assignments of structural identities are supported by gas chromatographic and mass spectrometric data.

Desaturation of palmitate and stearate by cell-free fractions from soybean cotyledons.

AbstractHomogenates of cotyledons from immature soybean seeds were fractionated by centrifugation. Cell‐free preparations actively desaturated 1‐14C‐palmitate and 1‐14C‐stearate to produce 9,10‐unsaturated acids. The 9‐desaturase activity was present mainly in supernatant fractions (22,000 and 105,000 xg). These fractions also desaturated oleate to linoleate and elongated C14, C16 and C18 acids. In view of this versatility of desaturase systems in the soybean, including the 9‐desaturase(s) for C14, C16 and C18 saturated acids, there would not seem to be further need to consider a separate plant pathway for biosynthesis of unsaturated fatty acids.

Phospholipids of the South African pilchard(Sardina ocellata Jenyns)

AbstractChromatographic resolution of phospholipids from the flesh of the South African pilchard(Sardina ocellata Jenyns) revealed the presence of cardiolipins, cephalins, inositol phosphatides, cerebrosides, sphingomyelins, lecithins, lysoleci‐thins and plasmalogens. Column and paper Chromatographic techniques were used to identify ethanolamine, serine, cho‐line, sphinogsine and inositol in pilchard phos‐pholipid hydrolysates. The fatty acids of pilchard phospholipids com‐prised large amt of C22 hexaenoic, C20 pentaenoic and C16 saturated acids, with smaller amt of C18 dienoic, C18 monoenoic and C18 saturated acids.

The lethal effect of cotton-wool lipid on tubercle bacilli in acid conditions and its prevention by surface-active agents

Long-chain fatty acids are not appreciably bactericidal to tubercle bacilli at neutral pH, but become so even in slightly acid solution. In this way tubercle bacilli, normally resistant to 0·1 N hydrochloric acid (pH 1·0), are rapidly killed at this pH if traces of fatty acid are present, such as can be found inside test tubes that have been plugged with cotton wool and sterilized by dry heat.The lethal effect is largely prevented by non-ionic, cationic, and to a lesser extent anionic detergents, which probably take up the fatty acid into the micelles so that it can no longer attack the bacilli.The various fatty acids identified in the deposit from heated cotton wool were tested individually and found to be bactericidal. They comprised the usual C12to C18saturated acids and also oleic acid. The latter, however, showed no particular lethal toxicity in excess of that shown by, for example, palmitic acid. Shorter chained fatty acids than those represented in the deposit were less lethal.We wish to thank Dr A. T. James for the chromatographic analyses and for advice; Dr R. J. W. Rees for carrying out counts of total acid-fast bacilli in two experiments; Messrs. Robinson & Sons Ltd, Chesterfield, for information on the industrial processes involved in the preparation of cotton wool; Mr E. J. Latham for advice on preparing glassware; and Dr J. Marks for helpful criticism of the manuscript.

Evolution of animal fats.

USING the theory of evolution as a general background, Hilditch and Lovern1 have directed attention to the gradual simplification in the fatty-acid composition of animal fats as one proceeds from the lower forms of life to those that are more highly organized. In particular, they have noted the striking difference between the complexity of the fats of aquatic animals, which contain, in addition to C14, C16 and C18 saturated acids, a wide range of unsaturated acids of the C14, C16, C18, C20 and C22 series, as compared with the fats of the more highly evolved land mammals, which generally contain as major components only three acids, palmitic, stearic and oleic.