Bacteria in the production of cheese?

I am writting an essay on the role that bacteria has in the production of cheese. I have the body on the essay, but what points could I add in the intro and conclusion? Is bacteria essential in making cheese? And could anybody help me form a thesis statement?

Bacteria in the production of cheese?
Good Bacteria in Food





Most people would think bacteria in or on food can only be harmful. True, food poisoning caused by bacteria and their products is a serious problem, and how to ensure food safety is treated in a different exhibit. However, certain bacteria are safe in food, and are required for the desired taste and texture. This exhibit describes some of the applications of bacteria and their products in the food industry.





Bacteria are commonly used in dairy products. Sour cream and Creme fresh (make your own! Creme fresh (Source: Splendid Table) are both the products of cream after bacteria were allowed to grow in it. The difference in flavour, texture, and behavior (sour cream will curdle when heated, creme fresh will not) all result from the differences in bacteria required to produce the two products. Buttermilk (Source: DB Frankhauser) is low in fat, cheese comes many variations (Source: Franceway.com). Yogurt (Source: Life.ca) is probably one of the oldest forms of fermented milk.


Is it not dangerous to eat food containing bacteria? Certainly not, as long as they are the right kind of bugs. It may even be benificial to eat diary products with living cultures, although the evidence is still controversial (Source: NewYork Times Sciene Q%26amp;A). True or not, fermented milk products are often suitable for people with a lactose intolerance (Source: Regional Health Science Center) though the product should not be heated after fermentation.


Fermented milk products are not completely fluid because casein, the major protein in milk, is insoluble in acid (Source: DB Frankhauser). Casein is also the protein that makes cheese solid. Fermented diary products taste different due to the bacteria used to make them. So what kind of bacteria are used for these foods? Most manufacturers will not release their magical strain of bacteria, producing just the right flavour, but here are their general characteristics:





Table on diary bacteria and their products (Source: Science-projects.com)


What makes Limburger cheese so smelly? Isolate Brevibacterium linens (Source: Indiana Lab).


How Propionibacter shermanii makes the holes in Swiss cheese (Source: NewYork Times Science Q%26amp;A)


View images of the Yogurt bacteria L. bulgaricus (Source: unknown).


Vegetables can be fermented too. Read about an ancient tradition (Source: FAO). For instance, bacteria are the working lot to produce sauerkraut. The word 'sauerkraut' is German and means sour cabbage. And that is what it is: finely cut white cabbage leaves, left fermenting by lactic acid bacteria. Believe it or not: kraut only contains cabbage and salt. It doesn't taste salt because of the acid produced by the lactic acid bacteria, and the salt prevents fouling bacteria to grow. The bacteria used for sauerkraut is Leuconostoc mesenteroides (Source: FAO). The same principle is used with pickling other foods, such as onions, olives, or meat. Almost always do lactic acid bacteria their little jobs to 'pickle to perfection' (Source: FoodProductDesign).





Have you ever thought that bacteria were used to produce chocolate and coffee? Although bacteria are not present in the final products containing chocolate (Source: ScienceNews online), yeasts and bacteria degrade the pulp that covers fresh chocolate beans (Source: CL Case) Did you know that chocolate may not be bad for you in contrast to what your mother made you believe? (Source: Manbir-Online).





Another example of bacteria helping to produce food products is vinegar. Whether good or bad depends on what the product should be. Wine makers will do their best to inhibit Acetobacter ferminting their grape juice: in order to produce wine, yeast should grow but not bacteria. However, if the desired product is vinegar, bacteria have their chance. Read more about wine and vinegar making in our special feature file.





Fermenting bacteria are used in the production of sausage. Again, lactic acid bacteria do their job. All you want to know about sausage (Source: The Cook's Thesaurusi). Don't worry, you can still enjoy your meat snacks (Source:FoodProductDesign) since bacteria used in sausages are not at all related to E. coli or Salmonella, the enemy of every butcher. In fact, lactic acid bacteria are able to kill Listeria, a newly discovered ability that supports the safety of cured meats (Source: INRA).