Vitamins molecular distillation

Molecular distillation is used in the separation and purification of vitamins and other natural products, and for the distillation of high-boiling synthetic organic compounds. 

Molecular distillation occurs where the vapor path is unobstmcted and the condenser is separated from the evaporator by a distance less than the mean-free path of the evaporating molecules (86). This specialized branch of distillation is carried out at extremely low pressures ranging from 13—130 mPa (0.1—1.0 p.m Hg) (see Vacuum technology). Molecular distillation is confined to appHcations where it is necessary to minimize component degradation by distilling at the lowest possible temperatures. Commercial usage includes the distillation of vitamins (qv) and fatty acid dimers (see Dimeracids). 

VACUUM DISTILLATION. Distillation at pressure below atmospheric but not so low that it would be classed as molecular distillation. Since lowering the pressure also lowers the boiling point, vacuum distillation is useful for distilling high-boiling and heat-sensitive materials such as heavy distillates in petroleum, fatty acids, vitamins, etc. 

Commercial production of vitamin E tocopherols is by way of molecular distillation from vegetable oils. 

Index Entries Molecular distillation vitamin E deodorizer distillate of soya oil DISMOL property estimation. 

Taking all of these concerns into consideration, in the present work, we propose a molecular distillation process for tocopherol (vitamin E) recovery using as a raw material the crude deodorizer distillate of soya oil (DDSO). The determination of several physical-chemical properties must be made through correlations and/or predictions, in order to have a better characterization of the system that will be studied. Then, the DISMOL simulator can be used to evaluate tocopherol recovery from crude DDSO, in order to determine the feasibility of the process and the best experimental conditions for the falling film molecular distillation. The simulator used was a DISMOL, which was developed by Batistella (12). Tocopherols need to present a low acidity level (< 2%) and purity according to their application (from 30 to 90%). The price varies according to this concentration. Squalene is tolerable in tocopherol concentration, but fatty acids must be eliminated during the process. 

An expired U.S. patent describes molecular distillation of WGO (47). Initially, WGO was degummed by using phosphoric acid and water. Bleaching was carried out with activated clay followed by distillation using a centrifugal molecular distillation unit. Free fatty acids were removed at 140-200°C and below 50 mTorr. It was claimed in the same patent that a Vitamin E concentrate was prepared from purified WGO by a second-stage molecular distillation process carried out at 220-300°C and pressures less than 25 mTorr (47). 

Baker (98) to improve the separation efficiency by increasing the number of theoretical plates. Privett et al. (99) have used this device and were able to fractionate methyl esters of pork fiver lipids into 38 distilled fractions with chain lengths ranging from C14 to C22. Technical improvements of this distillation method were developed into molecular distillation and isolation of Vitamin D (100), esters of fish oil (101, 102), cholesterol, tocopherol (103), and fish oil to obtain high-purity DHA (104). 

These compounds often occur as acetate or succinate esters and, for a total analysis, these esters are cleaved by a KOH saponification. Vitamin E is obtained commercially by molecular distillation. This does not provide a pure product, but it does separate vitamin E from most of the other materials associated with it such as chlorophyll, xanthophylls, carotenes, ubiquinol, ubichromenol, steroids, and quinines, but not vitamin A and the beta carotenes. 

Figure E9-1. Apparatus used for the molecular distillation of vitamin E from margarine.

Crude palm oil is consumed in some countries as a source of vitamin A. To retain these carotenes in the oil, processes are currently available to produce a red palm oil. These are either molecular distillation (Ooi et al. 1992) or chemical neutralisation followed by modified refining. 

Molecular distillation is widely used in the laboratory for analytical work, as well as in the chemical industry for improvement of flavours and fragrance, pharmaceuticals and edible products e.g. distilling vitamin A esters from dog-fish liver and shark liver oils. 

Vitamin E-free animal fat, stripped by molecular distillation (Distillation Products Division, Rochester New York). 

Malaysia Palm Oil Research Institute patented the physical refine method that involves degumming and bleaching, followed by clarification and desodorisation by molecular distillation using lower temperatures (< 170 C) and pressure (100 mTorr), obtaining an oil comparable to the RED (bleached and deodorized) with less than 0.1 % of acidity and impurities, but with vitamin E retention and 80 % of carotenoids, called carotino [28, 29, 33, 34], It is also observed the use of crude palm oil in Bahia (Brazil) and Africa, being part of many culinary dishes [36]. The crude palm oil is reddish because it contains a high amount of y9-caroten (500-1000 mg-kg ) [37]. 

Investigation and operating costs make molecular distillation an expensive separation method. It is used mainly in the pharmaceutical industry to treat high-grade substances such as vitamins, hormone concentrations, fats, oil, and waxes. 

Molecular distillation Liquid mixtures Heat and vacuum Liquid and vapor Difference in kinetic theory maximum rate of vaporization Separation of vitamin A esters and intermediates 18, 42... 

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