Masters Theses

Date of Award


Degree Type


Degree Name

Master of Science


Food Science and Technology

Major Professor

Genevieve Christen

Committee Members

J.L. Collins, B.J. Demott


The purpose of this research was to determine fatty acid profiles of P. fluorescens 32A and 22F and milk lipases by hydrolysis of butteroil. The lipases were extracted from the microorganisms and from milk and were purified. Fatty acid profiles were determined by gas chromatography.

Mean concentrations of fatty acids from all enzyme sources were significantly higher for 32A lipase at p ≤ 05. Milk lipase yielded mean fatty acid concentrations that were significantly different from 22F and the control. The mean fatty acid concentrations from the combined data for all enzyme sources, pH values and replications showed that butyric (C4), myristic (C14), palmitic (C16), stearic (C18), and oleic (C18:1) acids were present in the largest concentrations when compared to total fatty acids released. The lipase from 32A released more butyric (C4), caproic (C6), caprylic (C8), capric (C10), and oleic (C18:1) acids at pH 6.5 than at pH 8.8. It also released more fatty acids than any other lipase at either pH. Few differences were found among the other lipases.

Based on this research the lipase from 32A could have a significant effect on the quality and shelf life of milk and milk products since it released both short chain fatty acids which affect flavor and long chain fatty acids which affect acid degree values.

Files over 3MB may be slow to open. For best results, right-click and select "save as..."