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Pilot‐Scale Production of Conjugated Linoleic Acid‐Rich Soy Oil by Photoirradiation
Author(s) -
Jain V.P.,
Proctor A.,
Lall R.
Publication year - 2008
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2008.00718.x
Subject(s) - conjugated linoleic acid , chemistry , linoleic acid , food science , conjugated system , safflower oil , soy protein , biochemistry , organic chemistry , fatty acid , polymer
Conjugated linoleic acid (CLA) is found naturally in dairy and beef products at levels of 0.2% to 2% of the total fat. A more concentrated source of dietary CLA, low in saturated fat, would be highly desirable to obtain optimum CLA levels of about 3 g/d. We recently reported photoisomerization of soy oil with iodine catalysis to be a simple way of producing CLA in laboratory without high‐energy input or expensive enzymes and microorganisms. However, a long irradiation time of 144 h has been a limitation for this technique to be of practical value. The objectives of this study were to build a pilot plant unit to rapidly produce high‐CLA soy oil by photoirradiation and optimize the processing parameters to obtain high‐CLA soy oil. Degassed oil with dissolved‐iodine catalyst was irradiated by UV lamps in an illuminated laminar flow unit (ILFU). The ILFU consists of 2 borosilicate glass plates in a silicone lined stainless steel frame. The static mode of operation yielded 5.7% of total CLA isomers and performed twice as well than the continuous mode with 2.5% of total CLA. Irradiating oil in a static mode with reflective surfaces increased the CLA yields 3‐fold to 16.4%. About 22% of total CLA isomers can be rapidly produced from soy oil linoleic acid with 0.35% iodine catalyst in a 0.5‐cm‐thick oil layer maintained at 48 °C for 12 h. The peroxide value and GC‐MS analysis did not identify any volatile compounds characteristic of lipid oxidation. This study is a definitive step toward the commercialization of large‐scale production of CLA‐rich soy oil.