Effect of Selected Antioxidants on the Activity of a Mixture of Crude Pseudomonas Lipases

: Commercially acceptable concentrations (0.02%) of butylated hydroxytolulene (BHT), butylated hydroxyanisole (BHA), tertiary butylhydroxyquinone (TBHQ), Tenox 4, and Tenox 8 were evaluated for their effect on the lipolytic activity of mixed Pseudomonas crude lipases (MCLs). MCLs were prepared from lipases produced by raw milk isolates of Pseudomonas fluorescens , P. cepacia , and P. putida . GRAS antioxidants, 1-ascorbyl 6-palmitate (AP) and d-α-tocopherol (AT), at 0.5, 1.0, and 2.0% concentrations, were also evaluated for their effect on lipase activity. Antioxidants and enzyme preparations were incubated for 30 min at 25 or 40°C. At 25°C, all antioxidants tested inhibited lipase activity to some extent. At 2% concentration, AP completely (100%) inhibited lipolytic activity, and AT inhibited lipolytic activity by 89%. At 40°C, the effectiveness of AP and AT as lipolytic inhibitors decreased, and the low concentrations of BHT, BHA, TBHQ, Tenox 4, and Tenox 8 stimulated lipolytic activity.