Microbiological Analysis Of Potato Meltrote Agar And Univar

A. Daily Routines Before every microbiological analysis of the food samples, certain laboratory protocols are needed to be followed. First, disinfection of the isolation room where tests are performed would be done for every use. 70% ethanol is used to kill unwanted microorganisms. This concentration of the ethyl alcohol is believed to be the most effective to kill bacteria since higher concentrations of ethyl alcohol deprives the bacterial cell of water which prevents the alcohol itself to destroy the bacterial cell wall, thus inhibit their death (Lorian, 2005). It will be applied to surfaces of the laboratory, tables, and apparatuses. Then, ultraviolet light (UV) is introduced on the laminar flowhood, an equipment or area that is sterile
In this study, three general media will be used for the detection of microorganisms on the equipment, personnel, raw materials and the finished goods. These are Potato Dextrose Agar (PDA), Plate Count Agar (PCA) and Violet Red Bile Agar (VRBA) under the Univar brand. The amount of each prepared medium or dehydrated medium depends on the number of samples to be tested. PDA is usually used for the presence of yeasts and molds which are the most common food contaminants. PCA and VRBA are used for cultivating bacteria such as Escherichia coli and other coliforms. According to Parija (2009), these different media is sterilized using an autoclave under normal conditions (121ºC, 15 min.).

C. Sample collection For personnel samples, their hands will be swabbed every time they will be using or handling food products. For the equipment and environment (air) samples, which will be done twice a month, level of sanitation will be recorded using an AccuPoint 2 which is an ATP Sanitation Monitoring System as well as swabbing. Raw materials should also be checked however, for the food products in URC, only potato starch will be tested every delivery. One sample of each finished goods (Nova, Piattos, Chippy and Maxx) are also taken from every batch produced for sampling.

D. Microbiological
Personnel/Equipment Analysis
1. Personnel responsible for handling equipments should wash their hands properly prior to swabbing.
2. Swabbing is done only on both hands of the personnel and the conveyor machines using sterilized swab sticks then it is placed in a screw-capped tube with peptone buffer.
3. The samples are mixed using a vortex to ensure the even distribution in the peptone buffer.
4. Pour plating will be done by depositing a 1 ml sample into each sterile Petri plates of PDA, PCA and VRBA using a 1ml pipette.

II. Raw Materials/Finished Goods