(583aw) Low Level Soymeal Aerobic Catalyzed Lipoxygenation of Soybean Oil

Low Level Soymeal Aerobic Catalyzed Lipoxygenation
of Soybean Oil

CAI Yan

School of Chemistry
and Chemical Engineering, Nantong University, Nantong
226019, Jiangsu China

Abstract  Lipoxygenase (LOX) can catalyze the
oxidation of polyunsaturated fatty acids with cis,cis-1,4-pentadiene to synthesize the corresponding hydroperoxides (HPOD) of conjugated (trans, cis)-dienes. Soybeans are reported to contain LOX in the largest amount in numerous plants.The
catalytic performance of low level soymeal (m(soymeal)/m(soybean oil)=10%) in catalyzing the hydroperoxidation
reaction using soybean oil as substrate was evaluated, and surfactants as well
as ultrasonic wave were introduced to improve the lipoxygenation
reaction yield. The optimal conditions for soybean oil were 0.5 g soybean oil in
3.3 mL phosphate buffer solution of pH 6 with 0. 15 mL ethanol as co-solvent reacting for 3
h at 15 ^oC. Under these optimal
conditions the yield reached 15%. The addition of surfactants such as CTAB and b-CD reduced the hydroperoxide
yield. The employment of ultrasonic irradiation during the lipoxygenation process reached equilibrium after 60 min
with the yield of 35%, which could both accelerate the enzymatic reaction and improve
the reaction yield.

Keyword:  Soymeal; Lipoxygenase; Soybean oil; Hydroperoxidation