Evaluation of saline treatments on bacteriological quality of Tiger nut (Cyperus esculentus L.) for consumption post purchase

Abstract

Food-borne diseases are usually caused by ingestion of contaminated food. One of such foods susceptible to microbial contamination is Tiger nut (Cyperus esculentus L.). We evaluated the bacteriological quality of Tiger nuts under various consumer treatment conditions post purchase.Three tiger nut samples each from 7 vendors were obtained by convenient sampling in Ho,the capital of the Volta Region of Ghana. The samples were subjected to vigorous washes in 1%, 2% and 3% sterile saline with tap water as control. The resulting liquids were analysed for microbial load and species using specific media and standard microbial methods. Data obtained from the study were analysed by ANOVA, and significant differences among means were defined at p<0.05. The mean bacterial count for the fresh tiger nut in tap water ranged from 1.95×106 to 1.59×107 cfu/mLwhilst that in tap water only (control), 1%, 2% and 3% saline solutions recorded a range of 7.08×105 to 1.18×107, 7.31×105 to 1.34×107, 4.0×104 to 1.13×107 and 1.11×105 to 9.62×106 cfu/mL respectively. The higher bacterial load from the tiger nut in the sterile tap water was above the acceptable reference limit of 105 cfu/mL by the National Administration for Food Drugs and Control (NAFDAC). The mean bacterial count of Escherichia coli and Staphylococcus aureus in all the 21 samples was 6.15 log10 and 6.18 log10 cfu/mL respectively, all of which exceeded the acceptable range from 102 to 103 cfu/mL by the International Commission on MicrobiologicalSpecifications for Foods (ICMSF).To improve the bacteriological quality of tiger nut, proper farming practices, handling and treatment regimens under hygienic conditions should be employed to reduce or eliminate the occurrence of contaminants to ensure the protection and safety of the consumer.