Team:NEFU China/Practices
Visiting a dairy factory
Yogurt is popular to millions of people all over the world. It can benefit people mainly due to the "live" bacteria that are good for intestinal health. In order to maintain the nutritive components and original taste, raw milk should be treated by pasteurization during yogurt production to kill most pathogens. Unlike sterilization, the relatively low temperature (up to 80 °C) used in pasteurization may allow a very small amount of pathogenic bacteria to survive this treatment.
Since we were working on a project related to the fermentation and quality inspection process of yogurt, we already explored very much relevant knowledge. We were becoming increasingly clear to the gap between theory and actual practice. So we visited a dairy factory in order to know more about yogurt production.
During this visit, a guide showed us around the workplace and informed us the procedure of actual yogurt production. It was the first time for us to see the huge production equipment in person! Then, to achieve the primary goal of this visit, we consulted with a quality control inspector to learn about the main pathogens in yogurt and the current inspection procedure. We learned that a cup of eatable yogurt may contain certain amount of coliform bacteria, but must not have other common pathogens such as Salmonella or Bacillus. We also learned that coliform bacteria are the most common pathogens in yogurt. So in our subsequent experiments, we chose E. coli to validate the function of our device. Moreover, quality control inspectors utilized plate count to detect coliform bacteria in yogurt. Later on, we applied this method to our tests for the quality of yogurt under different storage conditions in our own experiments. Last but not least, we realized that the conventional detecting methods cannot be easily used in our daily life due to the complicated steps and demands of facilities.
This visit had a great influence on us. We realized the urgent need for a handy method of detecting pathogens in yogurt and this promoted us to proceed with confidence. Certainly, we knew we still had a long way to go.
