Microbiological Analysis and Nutritional Constituents of Achatina achatina Subjected to various Cooking Methods

Achatina achatina harbours many microorganisms which may cause diseases or spoil the  snail if not properly cooked. The study investigated the effect of some methods of cooking; frying,  boiling, smoke-drying and oven-drying on the nutritional constituents and microorganisms isolated  from snail to ascertain the best method which can reduce the or eliminate the unwanted organisms.  Microorganisms were isolated from the snail samples using pour plate technique and identified by  cultural, morphological and biochemical characterization. Proximate analysis of the snail samples was  determined. The bacteria isolated were Bacillus sp, Escherichia coli, Proteus sp, Vibro sp, Salmonella  sp, Staphylococcus sp, Pseudomonas sp,  Shigella sp, Klebsiella sp, Streptococcus sp and Citrobacter  sp while Mucor sp, Aspergillus sp and Rhizopus sp. were the fungal isolates. Salmonella sp, Vibrio sp  and Escherichia coli were present in all the snail samples whereas Proteus sp was inhibited by all the  cooking methods. Bacillus sp was sensitive to all the cooking treatments except boiling. Salmonella  sp, Vibrio sp and E. coli had very high counts. However, the cooking treatments reduced the bacterial  and fungal counts appreciably with smoke-drying having the least counts ranging from 1.20x101-  2.80x101cfu/g respectively. The fat and moisture contents were reduced but reduction of protein and  energy contents was minimal. There were varying degrees of reduction in both number and type of  organisms inhibited by the different cooking methods. Smoked-drying exhibited the highest potential  for the control of microorganisms and still maintained a healthy nutritional composition.