Seasonal and regional variation in triglyceride composition of French butterfat

In the present study, high-performance liquid chromatography analysis of butterfat allowed separation of 46 peaks at 32°C. Knowing the theoretical carbon number value of each triglyceride (TG), 32 peaks of the butterfat chromatogram were identified. These TGs were determined by extrapolation of their capacity factor values, and their identifications were confirmed with some standard TGs. Analysis of winter and summer butterfat from five different French areas showed significant seasonal and regional variation in the TG composition. However, the most important contribution to this variation was provided by TG groups represented by only four peaks. To approximately select the predominant TGs in these four peaks, a random distribution hypothesis was used to predict the amount of each TG. This hypothesis allowed the prediction of the TG components that seem to provide the most important contribution to both seasonal and regional variation.     

Quantitative high resolution13C nuclear magnetic resonance of the olefinic and carbonyl carbons of edible vegetable oils

The acyl distribution and acyl positional distribution (1,3-acyl and 2-acyl) of triacylglycerols derived from edible vegetable oils has been examined by¹³C nuclear magnetic resonance (NMR) spectroscopy. The acyl profile of three natural oils (corn, peanut, canola) and one specialty oil (high oleic sunflower oil, Trisun^® 80) has been defined from the high resolution (medium field 75.4 MHz) spectrum of the carbonyl and olefinic regions. The quantitative integrity of the NMR derived acyl profile is substantiated by gas chromatographic (GC) analysis. The positional distribution data of the three natural oils indicates that polyunsaturates are replaced in the 1,3-glycerol position exclusively by saturates, while the oley distribution remains, for the most part, randomly distributed. The same is not true for Trisun^® 80, which shows a more random distribution of the linoleyl groups as well.     

Naturally functionalized triglyceride oils in interpenetrating polymer networks

The use of naturally functionalized triglyceride oils in interpenetrating polymer networks (IPNs) is reviewed. An oil bearing either hydroxyl or epoxide functionality may be crosslinked to form a soft elastomer in the presence of another monomer or network to form an IPN, or in the presence of a linear polymer, to form a semi-IPN. Polymerization and characterization of naturally functionalized triglyceride oils are mentioned, with emphasis on the distribution and effect of nontrifunctional triglycerides on elastomer properties. The simultaneous synthesis of polystyrene/functional triglyceride oil IPNs is reviewed, and several factors influencing IPN morphology and mechanical properties are discussed. The synthesis and properties of poly(ethylene terephthalate)/functional triglyceride oil semi-IPNs are emphasized, with the importance of ester interchange in the synthetic procedure, and factors influencing crystallinity and morphology are introduced.     

A detailed triglyceride analysis ofLesquerella fendleri oil: Column chromatographic fractionation followed by supercritical fluid chromatography

The triglyceride structure of oil fromLesquerella fendleri, a potential new U.S. crop, rich in C₂₀ hydroxy fatty acids, was examined by silica gel column chromatographic fractionation followed by supercritical fluid chromatography. The analysis confirmed previous findings derived by our research group, but provided further detail. The analysis demonstrated the presence of trihydroxy triglyceride, which contained all of the oil’s C₁₈ hydroxy acyl groups (present at less than 0.5% in the oil). Lipolysis indicated that these groups were located solely at the 2-position. In addition, a strong correlation was detected between the presence of α-linolenic (18:3^9,12,15) and auricolic (20:2^11,17 OH¹⁴) acids in triglycerides.     

Comparative nutritional quality of palmstearin-liquid oil blends and hydrogenated fat (vanaspati)

An attempt was made to use high-melting lowdigestible fat palmstearin as a vanaspati substitute by blending it with polyunsaturated fatty acid-rich liquid oils. This blending produced fat products of zero-trans fatty acid content and melting points below the human body temperature, so that they can be digested easily. The new blended products were fed to male albino rats (Charles Foster strain); the coefficients of digestibilities were 94.2% for palmstearin and rapeseed oil blend, 95.1% for palmstearin and sunflower oil blend, and 96.2% for palmstearin and soybean oil blend, which were somewhat better than the digestibility coefficient of conventional vanaspati (93.6%). Feeding experiments for three months showed comparable results in terms of serum lipid profiles. The blended products significantly increased the total cholesterol level but not the free cholesterol level in serum and liver of rats when compared with those of the conventional vanaspati group of rats.     

Enzymatic glycerolysis and transesterification of vegetable oil for enhanced production of feruloylated glycerols

Novel functional groups can be introduced into vegetable oils using enzymes, resulting in value-added products. The transesterification kinetics of ethyl ferulate with MAG, DAG, and TAG were examined. Transesterification was catalyzed by immobilized Candida antarctica lipase B in solventless batch and packed-bed reactors. Initial reaction rates with TAG were slightly sensitive to water activity, whereas rates with MAG and DAG were water activity independent. Transesterification was also three-to sixfold faster with MAG and DAG. These observations indicate that the reaction is rate limited by the acyl acceptor, and that oils with free hydroxyl groups are preferred acyl acceptors in comparison with TAG, which must undergo partial hydrolysis before becoming reactive.     

Determination and certification of the relative mass fractions of triglycerides and cholesterol in pure and adulterated butter oil

Pure butter oil and adulterated butter oil (5% coconut oil added) were certified for the relative mass fractions of triglycerides C₂₄‐C₅₄ and cholesterol by employing a reference method defined in EC‐regulation 454/95 based on gas chromatographic separation of the triglycerides on packed or capillary columns. Four data sets each of packed‐column and capillary‐column methods were accepted and utilised to establish the certified values. Technical evaluation of the data revealed that calibration is a critical issue in terms of composition of the calibrant and possible precipitation. Recalculations of submitted data were carried out, which mainly involved linear interpolation to calculate the response factors of components not present in the calibrant. This procedure decreased the overall variation of results. Data derived from capillary‐column methods differing in column length, diameter, coating, and temperature program were found to be comparable to those obtained by the more uniform packed‐column methods as regards precision, repeatability, and obtained S‐values. The presented results shall provide a basis to further refine the existing reference method.     

On-line chemical database for new crop seeds

Since the 1950s, a database of the chemical composition of seeds, collected throughout the world, has been generated at the National Center for Agricultural Utilization Research. Information contained in the database is primarily selected chemical and physical properties of seed oils. Over more than 38 years, 15,738 accessions of 7,924 species of 2,339 genera from 225 families were collected and analyzed. This database is now accessible on the Internet at http://www.ncaur.usda.gov/nc/ncdb/search.html.ssi. This paper gives an overview of the database, describes the information available, and illustrates how to do searches. Retired USDA/ARS.     

Improved lipase-catalyzed incorporation of long-chain fatty acids into medium-chain triglycerides assisted by supercritical carbon dioxide extraction

Displacement of the equilibrium of the lipase-catalyzed interesterification between medium-chain triglyceride (MCT) and long-chain polyunsaturated fatty acid was accomplished by the removal of by-products with continuous supercritical carbon dioxide (SC−CO₂) extraction at 60°C and 100 kg/cm². The incorporation of eicosapentaenoic acid to MCT was appreciably improved by this method and was 1.3 times higher than that of the equilibrium state (47 wt%) that was obtained in a closed system. The immobilizedMucor miehei lipase was stable for more than 180 h in SC−CO₂ at 60°C and 100 kg/cm². Presented at ISF-JOCS World Congress, Tokyo, Japan, September 26–30, 1988.