Answer To: Explain why the standard plate count is used in food quality control. 2. Determine the number of...
Robert answered on Dec 27 2021
COMPARATATIVE STUDY OF BACTERIAL COUNT IN A FOOD PRODUCT (RAW MEAT)
ABSTRACT:
Micro-organisms need a favorable culture to grow in colonies. This experiment aims at application of standard plate count method to analyze food quality and to calculate the number of bacteria in a food sample (raw meat). Finally, to compare the number of bacterial growth between food samples statistically. One of the limitations of the heterotrophic plate count method is that only bacteria capable of growing in the culture medium under the environmental conditions provided are counted. As a result, a medium that supports the growth of most heterotrophic (requiring organic carbon) bacteria is commonly used. The result should show that refrigerated raw fresh meat has less number of bacterial colonies than raw meat at room temperature (RT). Moreover, dilution also plays a significant role in controlling bacterial growth in raw meat. As the dilution increases, the number of bacterial colonies starts decreasing in a quite linear manner.
INTRODUCTION:
The term ‘‘heterotrophic bacteria’’ includes all bacteria that use organic nutrients for growth. These bacteria are universally present in all types of water, food, soil, vegetation, and air. Heterotrophic plate count (HPC) bacteria represent those microbes isolated by a particular method, whose variables include media composition, time of incubation, temperature of incubation, and means of medium inoculation.
Means and other (1981) concluded that the Pour Plate Method, also known as the standard plate count, is simple to perform and is commonly used to determine heterotrophic bacteria density. Reasenor and others (1985) supported that this method does, however, have disadvantages that limit recovery of the maximum number of organisms. Tempered medium at 44 to 46 °C may cause heat shock to stressed bacteria and the nutritionally rich medium may decrease recovery of starved bacteria. The standard plate count attempts to provide a standardized means of determining the density of aerobic and anaerobic heterotrophic bacteria in food. Bacteria occur singly or in pairs, chains, clusters or packets, and no single method, growth medium, or set of physical conditions can satisfy the physiological requirements of all bacteria in any sample. However, the heterotrophic plate count is a good measure of water treatment plant efficiency, after growth in transmission lines, and the general bacterial composition of sample.
Wadhwa and others (2002) concluded that based on both observed microbial content and the potential of large numbers of pathogens or their indicators in food, that food is more of a health risk than drinking water. The plate count method means diluting bacteria with a diluents solution until the bacteria are dilute enough to count accurately when spread on a plate. The assumption is that each viable bacterial cell will develop into a single colony. The standard plate count method consists of diluting a sample with sterile saline or phosphate buffer diluents until the bacteria are dilute enough to count accurately. That is, the final plates in the series should have between 30 and 300 colonies. Downes and Ito ( 2001) discussed about the bacterial growth in dairy products and concluded that bacterial growth colonies were increased by time and with dilution.
METHOD:
The methodology used in the...