Microbial Evaluation of Pineapple Slices using Different Drying Methods.
Abstract
The study was about comparing the microbial quality of pineapple slices dried using different
drying methods. This was guided by general objective which was to; assess the microbial quality
of pineapple slices under different drying methods. The fresh pineapple slices were subjected to
three drying methods (solar, convection and refractance window drying). After drying, the dried
pineapple slices were packaged in different packaging materials that is Aluminum, polythene and
paper kept at room temperatures on a shelf and then monitored for microbial quality for 6 weeks.
Total plate count, E.coli enumeration and yeasts and molds enumeration were carried on the
samples at a 2-week interval and then result compared against international standards. Data
obtained was analysed by use of excel and presented in form of tables and graphs. Results indicated
that all tested samples had no E. coli colonies; the dried pineapple slices were free from the
pathogen and hence fit for human consumption. The study revealed a high microbial load in solar
dried samples compared to RW dried and oven dried fruit samples. The study concluded that the
refractance window drying and convection drying methods have better microbial quality compared
to solar drying. The study suggested that aluminium and polythene had better barrier properties
compared to paper. The researcher recommends the use of aluminium for packaging of pineapple
fruit slices due to stronger barrier properties. The study recommends that a comparative study be
done to compare refractance window drying and freeze drying for the drying of the fruits.