James W. Hampson

Supercritical-fluid extraction of fungal lipids using mixed solvents: Experiment and modeling

Abstract Polyunsaturated fatty acids, notably eicosapentaenoic acid (EPA), have been purported to have beneficial physiological activity, including the prevention of arthritis and cardiovascular disease. A possible source of these fatty acids are filamentous fungi (e.g., Saprolegnia parasitica ). In this work, lipids are extracted directly from the fungal mycelia using supercritical CO 2 and CO 2 mixed with 10 wt % ethanol. Extractions are performed at temperatures from 40 to 60 °C and pressures from 205 to 680 bar. The recovery of lipid increases with increasing pressures and higher recoveries are obtained when a mixture of CO 2 with 10 wt % ethanol is used as the solvent (e.g., 89% recovered with 10% ethanol vs. 48% for 100% CO 2 ). The more polar CO 2 mixture is a better solvent since it is able to extract both the neutral and the polar lipid fractions. An unsteady extraction model which can give reliable representation of the entire extraction curve is presented. Mass transfer coefficients are computed using the experimental data, and these coefficients are correlated as a function of the interstitial velocity.

Heats of fusion for some triglycerides by differential scanning calorimetry

Heats of fusion of tristearin, tripalmitin, trimyristin, trilaurin and several standards were determined by the relatively new technique of Differential Scanning Calorimetry. The data obtained on the standards shows good precision and accuracy. The results obtained for the triglycerides are 1–10% lower than values which have been reported elsewhere.

Thermoanalytical studies of water on activated alumina, Brockmann I–V, (acid, neutral, basic) from −60° to +700°C

Abstract Iron and aluminum oxides, which are found in most soils, interact with soil contaminants in a manner depending on soil acidity and water content of the soil. It is important, therefore, to know how acidity and water content affect these oxides. A thermoanalytical study of activated aluminum oxides of three acidities and water concentrations corresponding to Brockmann activity I–V showed that three types of water could be detected on the aluminum oxide, namely free water, pore water, and bound water. Neutral and basic aluminum oxide apparently underwent hydration easily to form the mineral bayerite or gibbsite but acid aluminum oxide required a higher temperature and a longer reaction time for hydration.

Substitutability of fractionated beef tallow for other fats and oils in the food and confectionery industries: An economic evaluation

The United States is the most important beef tallow producer in the world, supplying ca. 5.5 billion pounds annually. Approximately half of this beef tallow is exported at relatively low prices when compared to other fats and oils. Only ca. 10% of the total is used in domestic edible products. On the other hand, cocoa butter, coconut oil, palm oil, and palmkernel oil are imported oils whose demand for use in food and confectionery products has been increasing over the past few years. The first of these is the most expensive fat in the world. Beef tallow contains specific triglycerides which are also contained in these imported fats and oils. Through modern technology, beef tallow has been fractionated into products which are compatible with or superior to the imported fats and oils. It is visualized that products from fractionated beef tallow can be used as substitutes and extenders to cocoa butter, palm oil, and other fats and oils in the food and confectionery industries. The economic evaluation in this paper, analyzed through time series data and multiple regression techniques, established the past relationships between per capita consumption of confectionery food fat, beef tallow, cocoa butter, adjusted per capita disposable income, and adjusted costs of confectionery, beef tallow, and cocoa butter from 1956 to 1973. The substitutability of fats and oils was evaluated and the potential uses of fractionated beef tallow investigated.

Improved film properties of radiation-treated medium-chain-length poly(hydroxyalkanoates)

Medium-chain-length poly(hydroxyalkanoates) (mcl-PHAs) were synthesized from coconut oil (PHA-C), tallow (PHA-T), and soybean oil (PHA-S) by bacterial fermentation using Pseudomonas resinovorans as the producer strain. Films were solution-cast and subjected to 50 kGy of γ-irradiation. This resulted in crosslink formation based on the number of olefinic groups present in the polymer side-chains. In each case, radiation improved the tensile strength (104% and 63%), percent elongation (49% and 13%), and Youngs modulus (30% and 76%) of PHA-C and PHA-T films, respectively. The greatest effect was on PHA-S, which was converted from an amorphous, liquid-like material to a solid elastomeric film.

Comparison of the solubility in supercritical fluids of the polycyclic ether antibiotics: Lasalocid, monensin, narasin, and salinomycin☆

Abstract Solubility measurements for the polycyclic ethers (lasalocid, monensin, narasin, and salinomycin) were determined as sodium salts in pure CO2 and with CO2 modified with methanol and water at temperatures of 60–80 °C and 140–400 bar using an SFE instrument with a recirculating-loop fluid system. Wide variations in solubility within this antibiotic class were observed. Narasin and salinomycin were found to have almost identical solubilities in supercritical CO2, 1.35 × 10−3 mol/L (80 °C and 390 bar) while monensin was much lower in solubility, 2.34 × 10−4 mol/L (80 °C and 390 bar). Lasalocid showed no measurable solubility under similar experimental conditions. Similar differences were observed when solubilities were determined in CO2 modified with methanol and water. These variations in measured solubilities were attributed, in part, to dissimilarities among the conformations of the polycyclic ether/cation complexes in solution.

High performance liquid chromatographie separation of fatty imidazolines from their diamide hydrolysis derivatives

A reverse-phase high performance liquid Chromatographic method is described which separates long-chain fatty dialkyl imidazolines from their corresponding diamide hydrolysis derivatives. This permits fol-lowing the synthesis of these compounds and their storage stability. With a mobile phase of methanol/dilute acetic acid and a differential refractometer, both qualitative and quantitative analysis can be done quickly. Elution order follows chain length with the imidazo-line eluting before the diamide. Capacity and selectivity factors are presented for the imidazoline-diamide pairs from pelargonic to lauric acid.