Microbiological and Biochemical Analysis of Soymilk Produced and Sold within Calabar Metropolis

Abstract

This study was aimed at evaluating the microbiological and biochemical content of soymilk produced and sold locally within Calabar metropolis. Samples of soymilk were obtained from five areas in Calabar metropolis namely: Bogobiri, Watt market, Akim barracks, Army barracks and Marian market. Standard microbiological techniques including the pour plate method and relevant biochemical tests were used to isolate, characterize and identify the found microrganisms. The probable bacterial isolates were identified as: Pseudomonas, Bacillus and Klebsiella species while the fungi species were that of Yeast and Aspergillus. There was significant differences in bacterial and fungal count across the locations sampled (P<0.05). The mean bacterial counts were highest in samples from Army barracks 6.90±0.01x108 cfu/ml and lowest in Marian market 4.80±0.04x108 cfu/ml while the mean fungal count was highest in Army barracks 6.50±0.17x108 cfu/ml and lowest in Akim barracks 3.50±0.22x108 cfu/ml. Proximate composition analysis of the foods sampled revealed high carbohydrate content (41.32±0.04% - 53.70±0.04%), lipid content (1.50±0.03% - 5.00±0.04%) and fibre content (1.00±0.08% - 1.60±0.04%) while the range for other proximate composition indices such as ash (1.60±0.01% - 3.10±0.02%), moisture (31.80±0.04% - 36.50±0.15%), and protein content (10.68±0.30% - 19.08±0.30%) were relatively low. Elemental analysis of the soymilk samples showed relatively good amounts of calcium, zinc, iron and sodium which were within the permissible limits set by WHO guidelines for food standard. Lead, Mercury and Cadmium were not detected indicating that the source of water was portable and the soil or cultivation was devoid of harmful/toxic metals. Samples from Marian market however had the highest nutritional and mineral composition.