1. Aniqua Jafri*, Dr Clay King*, Robert Vowell, and David Casper
TWU Nutrition and Food Sciences
Denton, Texas
SEPARATION AND ANALYSIS OF COTTONSEED OIL DEODORIZER DISTILLATE (CODD) USING MOLECULAR DISTILLATION
Aniqua Jafri*, Dr Clay King*, Robert Vowell, and David Casper
DISCUSSION
ABSTRACT
PURPOSE
RESULTS
Results of Molecular Distillation of CODD with a KDL6 glass still with 0.06 m 2s Evaporator for Stage1
Stage2 cut 4 used as a feed for 10 different trials.
Stage2 cut 8 had a good separation of unsaponifiables consisting of 24.80% of tocopherols and 59.72% of sterols, leaving all the 97.14% of diglycerols with a negligible amount of tocopherols and 2% sterols in the residual.
Stage2 cut 8 at a feed temperature of 205 degree C resulted in successful distillation of tocopherols and sterols into the distillation stage.
Cut 4 and 5 produce an acceptable results in stage1 while cut 8,9 and 10 showed a good recovery of tocopherols and sterols in stage2.
Successful removal of FFA which were up to 45% with a one pass using wiped film and all tocopherols and sterols retained into residue.
Also other trials 9 and 10 distillate the same but did not increase the yield significantly.
The results indicate a good recovery of unsaponifiables is obtainable.
The FFA has a market value as a stand-alone product. The tocopherols and sterols mixture in the Stage2Distillate is also now more concentrated and suitable for use as a mixed product in human food applications.
A molecular distillation (MD) method was developed to separate the unsaponifiables from Cottonseed oil deodorizer distillate (CODD), which contains free fatty acids (FFA), mono/diglycerols, including tocopherols and sterols. Using a model KDL6 MD still with 0.06 m2 evaporator, five cuts were conducted using different evaporator temperatures and with the condenser temperature held at 60°C and vacuum at 0.22 mmHg. With the feed rate of 0.2 kg/hr, at a temperature of 60°C, samples of the CODD was separated into the distillate and residue portion. Using a gas chromatography silylation method, quantification of the components was determined. The cut-4 distillate was composed of 90.8% of FFA and only 4.3% of unsaponifiables while the residual had 63% of unsaponifiables. Using this residual for stage-2, unsaponifiables were 84.5% of the distillate while the residual had 97.14% diglycerols. Thus, this laboratory method using a 2-stage process successfully distilled the unsaponifiables from the components of CODD.
The purpose of this study is:
To separate and recover unsaponifiables from cottonseed oil deodorized distillate especially the volatile compounds such as tocopherols and sterols.
To achieve <1% FFA in Stage1Distillate and >95% purity of the tocopherols/sterols mixture in the Stage2Distillate.
Thus, it will be feasible to separate and analyses by using MD.
Parameters 1 2 3 4 5
Feed Rate (kg/hr)
0.2
Feed °C 60
Evap °C
135
145
155
165
175
% Yield distillate
26.4
43.8
52.2
55.6
59.2
% Yield residue
73.6
56.2
47.8
44.4
40.8
FFA content in the distillate (%)
83.1
83.4 80
73.3
FFA content in the residue (%)
32.3
16.2
4.6
2.2
1.4
Tocopherol content in the distillate (%)
0.3
2.1
Tocopherol content in the residue (%)
12.8
18.2
18.6
Sterol content in the distillate (%)
1.1
2.3
4.3
Sterol content in the residue (%)
26.2
34.8 51
METHODOLOGY
Processing of CODD using SMPD:
Sample analysis using silylation:
Gas Chromatography:
Silylated samples will be injected on a capillary column CP-Sil 8 CB
Detector: 0.1µm Flame Ionization Detector
Temperature: injection temperature: 60°C, detector temperature: 360°C, carrier gas: nitrogen
Stage1
Feed will flow from the top of the still down into the heated evaporator chamber
FFA will be driven into the Stage1Distillate leaving the Toc/Sterols/Mono’s/Di’s in the Stage1Residue.
Stage 2
Stage1Residue will be use as feed.
All the tocopherols and sterols will be driven into Stage2Distillate leaving portion of Mono’s and almost all of the Di’s and any unknowns in Stage2Residue.
Results of Molecular Distillation of CODD with a KDL6 glass still with 0.06 m 2s Evaporator for Stage2
INTRODUCTION
Cottonseed Oil Deodorizer Distillate (CODD)
By-product from the edible cottonseed oil.
CODD is produced during deodorization of cottonseed oil.
Contains a large amount of free fatty acids (FFA), some mono/diglycerides, and a collection of healthy compounds such as tocopherols and sterols ranging between 6-8% and 14-17%, respectively.
Tocopherols and Sterols are in great demand in food market due to healthy food ingredient.
Short Path Molecular Distillation (SMPD)
Separating, purifying, and concentrating applications.
Easy separation of heavy molecules at specific temperatures, short heat exposure times for feed material.
Advantages: Fats and Oils, Food/Flavor/Fragrances, Chemical/Petrochemical
Unsaponifiables:
Found dissolved in fats and oils, but cannot be saponified.
HEALTH BENEFITS:
Phytosterols: anti-inflammatory, anti-cholesterol, anti-oxidative and anti-carcinogenic activities. Tocopherols: scavengers of lipid peroxyl radicals, prevention of Alzheimer’s disease and cancer.
CONCLUSION
The Stage2 cut-4 distillate contains over 90.8% of FFA. Thus, the FFA were successfully separated.
Also all the tocopherols and sterols were remained in the residual which in turn could be used as for stage2.
In Stage2, it was successfully distilled and concentrated in distillate, leaving small amount in the residue.
Thus, FFA successfully separated from the CODD and the second stage successfully concentrated the sterols and tocopherols in to distillate.
Thus , 2-stage MD wiped film technology is a successful process for purification, removal of FFA and concentration of tocopherols and sterols.
0.2 gm of stage2distillate sample
Add 0.5 ml of pyridine
Add 1 vial of 1 ml of BSTFA+1%TMCS reagent
Heat the sample in oven for 20
Dilute the sample with 1.5 ml of chloroform
15 µL injected in GC
DISCUSSION
In stage1, five cuts were used using five different evaporator temperatures.
Various % yield of distillate and residues along with FFA, tocopherols and sterols were obtained which is given in the above table.
The % FFA in the residue in Stage1 cut 4 & 5 were 2.2 and 1.4%, respectively. Almost all of the tocopherols and sterols volatile into residue leaving minor amount in distillate.
% Yield distillate in Stage1 which is 55.6% and 59.2% in cut 4 and 5, allow the complete removal of FFA.
Stage1 cut 4 had a good separation of unsaponifiables consisting of 18.6% of tocopherols and 44.4% of sterols.
ACKNOWLEDGEMENTS
This work is supported by the Dochale Food Ingredients and Chemtech Inc, IL.
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