Cholesterol from beef tallow

Four aspects of research involving the use of SFE for the improvement of quality of muscle food products are briefly discussed. These include supercritical CO2 extraction of lipids fi om fresh ground beef and from dried muscle foods the extraction and separation of lipid and cholesterol from beef tallow supercritical CO2 extraction of flavor volatiles from beef and pork lipids for use as additives in synthetic meat flavors and identification and quantitation of flavor volatiles extracted with SC-CO2. 

Extraction and Separation of Lipid and Cholesterol from Beef Tallow with SC-CO2. The cumulative yields of the fractions for various operating conditions used to extract 100 g of edible beef tallow are shown in Figure 2. The SC-CO2 used to extract all lipids charged in the extractor at 345 bar and 241 bar were 10 and 22 kg, respectively. At 138 bar, 22% of the total beef tallow was extracted after 20 kg CO2 was passed. These results indicate the high dependency of triglyceride solubility on the applied pressure and temperature and confirm the greater extraction efficiencies at the higher pressures. 

Multiple Separators for More EfOcient Separation of Cholesterol from Beef Tallow. Since the solvent power of CO2 depends upon its density, a step-wise reduction of separation pressure will alter the CO2 density so that the soluble components of beef tallow can be separated and collected in different fractions. 

Ethanol as a Co>Solvent with SC>C02 for Extracting Cholesterol from Beef Tallow. Figure 4 contains data for comparing the extraction of lipid and cholesterol with 5% ethanol as a co-solvent (entrainer) compared to extracting with SC-CO2 alone. 

Figure 5. Extraction of cholesterol from beef tallow with SC-CO2 at 345 bar/40 C in presence of activated alumina (AA), molecular sieve (MS), silica gel (SG) and without adsorbent (W/O),...

Use of ethanol as a co-solvent with SC-CO2 enhances the extraction of cholesterol from dried muscle foods. High extraction pressure coupled with multiple separation vessels for gradual reduction of SC-CO2 density reduces the separation time necessary for separating cholesterol from beef tallow using less CO2 than extractions at lower pressure. Ethanol is a good co-solvent used with SC-CO2 for separating cholesterol from other lipids in beef tallow. 

Ethanol, cosolvent for supercritical fluid extraction of cholesterol from beef tallow, 125,126/... 

Supercritical COj (SC-CO2) was used to reduce the lipid of meat and the cholesterol of meat and beef tallow. Lipids can be removed quantitatively from dried muscle foods by SC-CO2, but relatively high temperatures are needed. The use of SC-CO2 in conjunction with ethanol, adsorbents and multi-separators also reduced the cholesterol of beef tallow. SC-CO2 was also used to concentrate volatile flavor compounds from beef and pork fat. The volatile components in various extraction fractions were identified and quantitated. 

Cholesterol Extraction from Beef Tallow fay SC-CO2 in the Presence of Adsorbents. The utilization of SC-CO2 extraction in the presence of adsorbers enhances the fractionation of solutes dissolved in the supercritical fluid. This procedure has been reviewed by King (29). 

Figure 4. Cumulative yields of cholesterol and lipid extracted from beef tallow with SC-CO2 at 138 bar/40°C with and without 5% ethyl alcohol as solvent modifier.

Extraction of lipids from muscle foods is more predictable if the food has less than 10% moisture. Higb recoveries of glycerides can be obtained from dry meat products by extracting with SC-CO2 above 300 bar, but cholesterol is extracted less effectively. Cholesterol is extracted from beef tallow more efficiently at lower pressures than at higher pressures (<300 bar). 

Cholesterol can be extracted more effectively from beef tallow with the addition of adsorbents such as activated alumina, silica gel or molecular sieve to the extraction chamber, but flavor constituents are removed as well. 

Only one study thus far has evaluated the effect of CCM fortification of the diet on serum lipid profiles. It was a randomized, single-blind, crossover metabolic diet study with two 10-day periods separated by a 10-day washout (Denke et al, 1993). The subjects included 13 healthy men (mean SD 43 4 years) classified as moderately hypercholesterolemic (mean SD 6.19 0.37 mmol serum cholesterol at baseline) and with a low baseline Ca intake (mean SD 466 199 mg Ca/day). The low-Ca basal diet contained 34% energy from fat (primarily as beef tallow), 13% from saturated fat, 240 mg cholesterol/day, and 410 mg Ca/day. The high-Ca diet was similar in composition except that CCM... 

In one study, the three separators (Figure 1) were adjusted at 170 bar/ 40 C (SI) 102 bar/40 C (S2) and 343 bar/40 C (S3) during extraction of beef tallow at 345 bar/40°C. Table II is a tabulation of the yields of lipid and cholesterol and the cholesterol concentration from the fractions collected from the three separators during continuous extraction. Although the weight of the lipid extracted in each separator with progressive fractions (6,12 and 18 kg) of CO2 remains about the same from each separation, the concentration of cholesterol in these fractions decreased with increased CO2 weight. 

The effectiveness of pectin in lowering cholesterol in tissues can be influenced by many factors (1) The type of pectin - that with methoxy groups and with high viscosity (35, 36) was reported to be more effective. The results from a comparative study of several types of pectin by Mokady (36) are shown in Table IV. Neither a high degree of methylation nor high-viscosity alone was very effective (2) the level of dietary fat - with a high-fat diet (2% corn oil plus 18% beef tallow), pectin has no effect on serum cholesterol level (57). Tsai et al. also reported that with... 

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