Contaminants deodorization

HCF was especially widely used in Western countries. Until 1972, it was included as an active component in soaps, cleansing creams, shampoo, deodorants, creams, and toothpastes. HCF was used for medical purposes, to control staphyllococcus contamination, in particular in maternity hospitals and in the cosmetics industry it was also used as a preservative, etc. It was used in agricultural formulations as well [67]. Although HCF s toxicity was... 

The high sensitivity of modem instrumental techniques such as ICP-MS (Chapter 9) means that in many cases only small samples (typically, a hundred milligrams or less) need be taken for destructive analysis. However, this also means that the amounts of some individual elements may be very low, and problems of contamination can be significant. Common external contaminants include A1 from deodorants, Pb from paint or car exhausts, Zn from skin particles (and therefore from dust), and Na from sweat. The levels of contamination for each batch of samples will be revealed by the sample... 

Children are exposed to 1,4-diehlorobenzene primarily by inhalation of vapors from toilet deodorants, moth proofing crystals and moth balls used in the home or by consumption of moth balls. Consumption of 1,4-dichlorobenzene in foods (See Section 5.4.4) and drinking water (See Section 5.4.2) contaminated with 1,4-dichlorobenzene is thought to be a minor exposure pathway. There have been no body burden measurements made on children. 

Chapman PM, Downie J, Maynard A. 1996. Coal and deodorizer residues in marine sediments contaminants or pollutants. Environ Toxicol Chem 15(5) 638-642... 

DDT and PCBs remain the most widespread contaminants in human milk around the world. Other common contaminants of mother s milk include flame retardants, pesticides, wood preservatives, toilet deodorizers, and dry-cleaning fluids. 

A comment is that olive oil produced in a naturally contaminated area must contain contaminants, unless the oil has been subjected to deodorization. Thus an appropriate contaminant content is a sort of purity criterion for olive oil. 

Historically, the standard deodorizer held 60,000 lb of oil (one railroad tank car). Except for refineries making only a few kinds of oil, as for export, building of continuous deodorizers slowed with the advent of Just-In-Time (JIT) delivery, supplier self-certification, and customers buying on the basis of their projected production schedules. This has led to development of improved batch-continuous systems, which are designed to handle many batches of different oil blends per day, with minimum cross-contamination and delays for process. 

About 0.01 percent of citric acid is commonly added to deodorized oils to inactivate trace-metal contaminants such as soluble iron or copper compounds that would otherwise promote oxidation and the development of rancidity. 

Deodorization/Physical Refining Quality control is especially concerned with flavor, free fatty acid concentration, color, stability, and trace contaminants. With respect to routine flavor testing, two-three trained panelists test the flavor of small sample of the oil. The oil must be essentially bland, but very slight beany or grassy notes are tolerated. Free fatty acids, color, and stability testing is done by the AOCS official methods (76). 

Prevent cross-contamination of a higher quality recoverable product with a lower quality material whenever possible i.e., do not combine packaging area drainage with deodorizer cooling water blowdown. 

Although the process is commonly named deodorization, it is actually a combination of three different effects on the oil (1) stripping Stripping of volatile components (free fatty acids, odorous compounds, tocopherols, sterols, and contaminants such as pesticides and light polycyclic aromatic hydrocarbons, etc.), (2) actual deodorization Removal of different off-flavors, and (3) temperature effect Thermal destruction of pigments and unwanted side reactions such as cis-trans-iso-merization, polymerization, conjugation, and so on. 

Contaminants need to be removed during the refining process in order to achieve residual levels that are as low as reasonably achievable (ALARA-concept). In practice, this can be achieved by selective adsorption onto a suitable adsorbens or during the deodorization process. 

The vapor pressure of PCB can vary within a wide range. The more volatile PCBs have a vapor pressure around 40-75 mbar, which is similar to the vapor pressure of some organo-chlorine pesticides. Our own lab deodorization trials showed that PCBs and dioxins can be stripped from fish oil without degradation of the 00-3 fatty acids (eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) provided that the deodorization pressure is very low (>2 mbar) (Table 10). Other studies showed that deodorization at 230°C and 5 mbar was insufficient to remove a PCB heat-transfer agent from contaminated rice bran oil (28). 

Deodorizer distillates from physical refining consist mainly of free fatty acids (>80%) (Table 11) (29). This byproduct can have some value for use in feed products provided that it contains (very) low levels of contaminants. Where a higher degree of contamination exists, it can only be sold as a source of technical-grade fatty acids. 

Deodorizer distillate flow in physical refining can be 5% or more of the oil flow to the deodorizer, depending on the initial FFA content of the oil. Consequently, the theoretical concentration factor of the volatile contaminants in the deodorizer distillate will be around 20. Knowing that the concentration of light PAH in crude coconut oil can be high, levels of up to 10 ppm can be expected in coconut oil deodorizer distillate (Table 12). 

Deodorizer distillate flow is much lower in the case of chemical refining (0.2-0.5% of the oil flow to the deodorizer). Consequently, contaminant concentration in the distillate can theoretically become 200-500 times higher than in the crude oil. For pesticides, the observed concentration factor is significantly lower, mainly because of thermal decomposition of some pesticides and incomplete condensation of volatile pesticides in the vapor scmbber. The limited amount of data available in the literature, combined with our own research figures, indicate that pesticide concentration in soybean, sunflower seed, and rapeseed deodorizer distillate is usually... 

Semicontinuous deodorizers are basically batch systems designed for larger capacities. Their main application is in plants with frequent feedstock changes of oils sensitive to cross contamination. In most designs, a batch of oil is transferred into... 

Today, even for small capacity plants (10-50 TPD), semicontinuous deodorizers are clearly more suitable than conventional batch deodorizers. The shorter hold-up time in a semicontinuous deodorizer is a good argument in its favor, even in cases when small capacities with very frequent feedstock changes are required. Compared with continuous systems, the main advantages of semicontinuous deodoriza-tion are its shorter time for feedstock change as well as its much lower cross contamination. Heat recovery is, however, less efficient than in continuous operation. 

Optimizing deodorization technology and process conditions for the removal of specific contaminants (pesticides, PAH, dioxins, PCB, mycotoxins, ) and maxi-... 

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