**9.2.1 Enzymatically catalyzed process**

Tangkam and coworkers (Tangkam *et al.*, 2008) described the enzymatic esterification in a solvent free medium of different deodorizer distillates resulting from the refining of various vegetable oils. A direct esterification of mixed distillates (61 % FFA and 39 % acylglycerols) with glycerol using immobilized lipase B from *Candida Antarctica* (Novozym 435) led to moderate proportions (46 %) of DAG. Application of a two-stage reaction consisting of a hydrolysis step of deodorizer distillate to increase the FFA content followed by esterification with glycerol led to a higher formation (>61 %) of DAG. Furthermore, it was observed that the high initial concentration of free fatty acids in the distillate has a positive influence on the concentration of DAG in the final product (>71 %). This observation is consistent with other literature data (Yamada *et al.*, 1999). Enrichment of DAG in the final products by shortpath vacuum distillation led to concentrates containing up to 94 % DAG, ~ 5 % TAG and no unesterified fatty acids and MAG.

#### **9.2.2 Non-catalytic process**

Smet (Smet, 2008) described a process for the esterification of fatty acid distillate (93 % FFA) with technical grade glycerol. The reaction was carried out in a high pressure Parr reactor

Extraction and Enzymatic Modification of

oxyphytosterols on human health is needed.

Vol. 10, No. 2, pp. 497-500.

Patent 2.263.550.

pp. S53-S60.

No. 8, pp. 763-766.

production.

**11. References** 

tocopherols concentrate with improve solubility in SC-CO2.

Functional Lipids from Soybean Oil Deodorizer Distillate 473

Regarding supercritical fluid fractionation SODD is not adequate feed material to work with SC-CO2 for tocopherol enrichment, owing to its poor SC-CO2 solubility. So, to concentrate tocopherols from SODD, pre-treatment of the raw material is needed to obtain the primary

Alternatively, deodorizer distillates have also non-food applications, such as biodiesel or can be used mixed with the fuel oil to fire the steam boilers. The use of deodorizer distillate instead of refined vegetable oils is an important alternative as a feedstock for biodiesel

Two main degradation products from sterols can be observed in SODD, namely dehydration and oxidation products. The degree of sterol dehydration is mainly influenced by deodorization temperature giving rise to a variable concentration of steradienes in the distillate. The content of oxidized sterols in deodorization distillate fractions from edible oil refining processes fluctuates depending on both the temperature applied during vacuum distillation and the breakdown and transformation of oxidized sterols into other unidentified degradation products. Finally, formation of oxidized sterols can be partially prevented by the high amounts of natural antioxidants in acid oil obtained from physical refining distillate. The current knowledge on the possible biological effects of oxyphytosterols is limited and further research to clarify the possible impact of

Andrews, J. S. (1941). Process for preparation of vitamin e concentrate and antioxidant. U. S.

Awad, A. B., Roy, R., & Fink, C. S. (2003). Beta-sitosterol, a plant sterol, induces apoptosis

Balazs, I. (1987). Refining and use of byproducts from various fats and oils*. Journal of the* 

Batistella, C. B., Moraes, E. B., Maciel Filho, R., & Maciel, M. R. (2002). Molecular distillation:

Batistella, C. B. & Wolf Maciel, M. R. (1998). Recovery of carotenoids from palm oil by

Bjorkhem, I., Meaney, S., & Diczfalusy, U. (2002). Oxysterols in human circulation: which role do they have? *Current Opinion in Lipidology*. Vol. 13, No. 3, pp. 247-253. Block, G. & Langseth, L. (1994). Antioxidant vitamins and disease prevention*. Food* 

Bondioli, P., Mariani, C., Lanzani, A., Fedeli, E., & Muller, A. (1993). Squalene recovery from

*American Oil Chemists' Society*. Vol. 64, No. 8, pp. 1126-1128.

*Biochem. Biotechnol.* Vol. 98-100, No. pp. 1187-206.

Bockisch, M. (1998). *Fats and oils handbook*. (AOCS, Champaign, IL.

*Technology*. Vol. 48, No. 7, pp. 80-84.

and activates key caspases in MDA-MB-231 human breast cancer cells*. Oncol Rep.*

rigorous modeling and simulation for recovering vitamin E from vegetal oils*. Appl.* 

molecular distillation*. Computers & Chemical Engineering*. Vol. 22, No. Supplement 1,

olive oil deodorizer distillates*. Journal of the American Oil Chemists' Society*. Vol. 70,

(stirred and thermostated reactor of stainless steal). The following parameters have been checked: temperature, reactor design, agitation speed, molar ratio and influence of the catalyst. The best results were obtained at 200 °C, pressure of 90 mbar and agitation speed of 60 rpm. It was seen that by using a molar ratio 1:1 FFA:glycerol, a total glycerides content of 85.3 % was obtained within 345 min reaction time. The formation of MAG was faster in the first hours and than reached the plateau, while the formation of DAG was slower at the beginning of the reaction and faster at the end. Furthermore, an increase in the molar ratio of 1:2 FFA:glycerol slow down the reaction, the total glycerides content reaching 64.9 % within 345 min reaction time. A molar ratio 2:1 FFA:glycerol gave an increase of the MAG and DAG at the beginning of the reaction, followed by an decrease of MAG after 90 min, the glycerol being completely consumed in within 345 min reaction time. The percent of DAG and TAG increased gradually during reaction, reaching a final yield of 86.2 % of total acylglycerols.

However the FFA content was still high, a distillation step of the residual FFAs and glycerol was necessary in order to increase the purity of the synthesized acylglycerols. The byproducts of distillation were further re-used as reaction products in the synthesis of acylglycerols. The novelty of the process consists in synthesizing acylglycerols in a relatively short time (<6 h) in a catalyst free medium.
