Determination of Microbiological Quality, Proximate Composition and Physicochemical Parameters of Margarine Produced from Oil Blends of Palm Kernel, Coconut and Melon

Abstract

The potential of margarine production from blends of melon, coconut and palm kernel oil, and the microbiological qualities and physicochemical parameters of the product were studied. The microbiological evaluation was carried out at the Microbiology Laboratory, Cross River University of Technology, Calabar, Nigeria, using pour plate and spread plate methods to ascertain the viable cell counts. The physicochemical composition, proximate properties were determined using standard methods. The enumeration of total heterotrophic bacterial count revealed low microbial count of 2.6 x 103 CFU/g, total coliform count was 2.5 x 102   CFU/g and total fungal count. 2.4 x 102 CFU/g. The value was within permissible limit of 104 CFU/g.  The biochemical characterization and identification revealed Staphylococcus spp, Bacillus spp, Salmonella spp, Escherichia coli, and Micrococcus spp are the suspected bacterial isolates. While the fungal isolates are Aspergillus spp, Fusarium spp, Penicillium spp and Rhizopus spp. The percentage occurrence revealed that Staphylococcus spp had the highest prevalence of 33.3%, followed by Escherichia coli (26.7%), Salmonella spp (20%), Bacillus spp (13.3%), Micrococcus spp (6.7%). While the fungal isolates had the following prevalence; Aspergillus spp (50%), Penicillium spp (16.7%), Rhizopus spp (16.7%) and Fusarium spp (16.7%). Proximate analysis revealed moisture (15.0±0.5), ash (35.0±0.5), crude (17.50±0.25), lipid (22.50±0.03), protein (2.218±0.01), and carbohydrate (7.78±0.01). Results for physicochemical analyses showed that Iodine value was 0.372, saponification value was 22.103 and acid value, 1.159. This result indicates that palm kernel oil, melon oil and coconut oil had the best potential for the production of margarine which would be acceptable due to the low microbial count. However, the presence of Staphylococcus spp and Salmonella spp renders the product a potential health hazard in line with FDA guidelines. Therefore, maximum hygienic conditions during production is advocated and further analysis recommended on these samples to discover their maximum importance and industrial utilization.