Four commercial emulsifiers, sodium oleate, sodium stearate, sodium stearoyl-2-lactylate, and calcium stearoyl-2-lactylate, were evaluated for their effectiveness as inhibitors of Pseudomonas lipases. Each emulsifier was incubated at 0.5, 1.0, and 2.0% concentrations with the individual as well as a mixture of the crude lipase extracts obtained from three Pseudomonas spp. (P. fluorescens, P. putida, and P. cepacia), in reconstituted nonfat dry milk (10%) for 30 min. At a 2% concentration, all emulsifiers tested were potent inhibitors (100%) of lipase activity. The effectiveness of lipolysis inhibition declined with decreasing emulsifier concentration. Sodium oleate demonstrated significant (P < 0.05) lipolysis inhibition at a 1% concentration regardless of initial lipase level. Synergism in inhibiting lipolytic activity between these selected emulsifiers was not evident.
Published as Paper No. 8922, Journal Series Nebraska Agricultural Experiment Station, Lincoln, NE 68583-0919.