Project Report
Project: The mechanisms of food preservatives
Class: 744 Date: 2/7/17 Mrs. Goldfisher IS.125Q
Names: Rakin, Adib, Janina, and Gary
Question: How do food preservatives function and how do they differ from each other?
Claim: Food preservatives work by either destroying enzymes, starving the bacteria from the enzymes, slowing down their reproduction rate, or completely killing them.
Evidence: Refrigerating foods will slow down enzymes and bacterial reproduction, making the food last longer. As enzymes slow down, the food stays fresh longer. By boiling foods, bacteria are killed, which can get rid of harm for the food, thus preserving the food. Dehydrating, foods kill bacteria as a result of the removal of an atmosphere. Also, salting foods dehydrates the moisture around the atmosphere of the bacteria. Pasteurization in general heats up liquids to kill a certain amount of bacteria and disables enzymes. UHT (ultra-high temperature processing) pasteurizing sterilizes the liquid or product. Chemicals inhibit the activity of bacteria and enzymes. Cheese making creates acids to solidify proteins, and also destroys the inside of Bacteria. Nuclear radiation, also destroys bacteria, without changing the food’s flavor, due to the radiation. Acids like vinegar create an unsurvivable environment for enzymes and bacteria. However, not all bacteria are bad. There are some good bacterium that can inhibit or kill the activity of other micro-organisms.
Salt is a type of preservative Heating up food can kill bacteria
Reasoning: When the enzymes (fun fact: enzyme names end with -ase) slow/destroy the bacteria, it slows down the spoiling process. For example, the enzyme rennet slows down the spoilage of cheese. When the spoiling process is slowed down the food stays fresh longer. When food is preserved, it also keeps fungi and bacteria from harming the food further. Enzymes also make sure that we don’t get sick from bacteria and fungi that infect our food during the spoiling process. When, the bacteria infects our food and we eat the food the bacteria will make us sick and depending on the bacteria and the type of bacteria, like botulism, (A rare poisoning caused by toxins of the bacteria Clostridium Botulinum) we could get seriously sick.
Rebuttal: Food preservatives do not work on food.
We believe that this claim is incorrect. Back when we didn’t have any types of food preservatives food would usually need to be eaten as soon as possible because the Bacteria, Fungi, and enzymes would break down and spoil the food quickly. Look at the Native American’s for example. They didn’t have any food preservatives to preserve food for a long amount of time so most of their culture’s respect for animals and food made them try to use as many parts as possible. They didn’t take food for granted. This idea was also part of the Old World until we discovered spices and salt. Another example would be milk. Back then, without any type of refrigeration, milk would go bad quickly(about 3-6 hours). However, now with our current technology of food preservation milk can stay fresh for days, sometimes even months if you just freeze it. This is because food preservatives work against the very organisms that cause spoilage, either by destroying or slowing down enzymes and bacteria
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