## 4 Discussion
### Effect of Addition of CFS from LAB on Beef Quality  
The assessment of the microbiological quality of beef can be determined by evaluating the quantity of microorganisms present, notably pathogens. This pertains to the security of beef intake by humans. The two primary microbiological features of food that were commonly examined were the total plate count (TPC) and the count of _E. coli_. The utilization of biopreservatives has been shown to effectively inhibit the growth and proliferation of microorganisms in food products during the storage period [7]. However, certain bacteria have the ability to thrive in such conditions, thereby mitigating any potential harm. Refrigeration has the capacity to restrict or halt the growth and metabolic processes of microorganisms in food. The beef samples subjected to CFS treatment for a duration of 30 min on day 0 exhibited reduced microbial proliferation compared to the control beef samples in both the overall microorganism count and specifically in the presence of _E. coli_. Based on the provided information, it may be inferred that CFS exhibits antibacterial properties against microorganisms present in cattle. The survival rate of bacterial populations in beef is typically influenced by various environmental factors, such as the composition of the growth medium, temperature, pH levels, and food availability. Consequently, the duration of beef storage is often associated with the growth and proliferation of bacteria [29]. Throughout the storage period, the growth output of _E. coli_ from both treatments exhibited a consistent decline. The observed outcome could potentially be attributed to the utilization of storage protocols conducted at a relatively low temperature of 4 \({}^{\circ}\)C. The decrease in bacterial growth is attributed to cellular damage caused by a temperature shock [29]. _E. coli_ exhibits optimal growth within a temperature range of 10 to 45 \({}^{\circ}\)C, with 35 \({}^{\circ}\)C being identified as the most favorable temperature for its proliferation [29]. From the initial day of observation, the population of _E. coli_ in the control beef exhibited an increase on day 1, followed by a subsequent decline on each successive day until day 9. This phenomenon is feasible due to the ability of _E. coli_ to endure in low-temperature storage initially. However, once the temperature reaches a stable level of 4 \({}^{\circ}\)C, the growth of _E. coli_ is hindered and ultimately ceases. The beef subjected to a CFS treatment exhibited persistence from the initial day of storage to the ninth day. This phenomenon can be attributed, along with the influence of storage temperature, to the utilization of CFS, characterized by a pH value of 3.8, indicating its acidic nature. _E. coli_ is capable of thriving within a pH range of 6.5 to 9.0, with a pH level of 8.5 being considered optimal for its growth. The presence of _E. coli_ bacteria in beef treated with CFS is reduced due to the inhibitory effects or potential prevention of bacterial development below the optimal pH. The probability distribution for Y exhibits variation with each incremental change in X, as seen by the linear regression equation (Y = 1X + 0), where the slope (1) is a statistical measure [30]. The Y-intercept value of the regression line, denoted as the parameter \(\beta_{0}\), is equal to zero. The regression analysis of the changes in the number of bacteria (X) suggestsa positive relationship between storage time and total microbial count (Y). The R-squared (R2) value of the graph indicates the extent to which the regression model is able to explain the relationships between the variables being studied [30]. R2 levels that are near to one are indicative of favorable results. Based on the results obtained from the regression analysis of microbial growth, it was seen that the slope value of the control beef (0.3962) was greater in magnitude compared to the slope value of the beef subjected to CFS treatment (0.2643). This study illustrates the efficacy of CFS in inhibiting microbial proliferation in meat.