in this video, we're going to begin our lesson on chemical preservation of perishable products. And so most of the chemicals that we've covered so far in our previous lesson videos can really only be used to clean disinfect or sterilize nonfood items. But a lot of those chemicals are really not safe to ingest or to eat. And so those chemicals really cannot be used to preserve food items. And so the chemicals that are used in food preservation must be nontoxic and safe for ingestion or safe to eat. And so, recall from our previous lesson videos that we define preservation as the process of delaying spoilage of perishable products and perishable products are simply items that are likely to go bad quickly, such as vegetables and fruits and things of that nature. And so chemicals such as organic acids, nitrates and nitrates are all chemicals that are commonly used in food preservation. And so moving forward in our course, we're going to focus on those chemicals. We'll first talk about the organic acids and then later in a separate video, we'll talk about the nitrates and nitrates. And so I'll see you all in our next video

in this video, we're going to begin our lesson on organic acids used in food preservation. And so organic acids, as their name implies, are going to be any organic compound that is going to have acidic properties. And so examples of these organic acids that serve as anti microbial agents to kill microbes include Ben's OIC acid, sor bic acid and probe cryonic acids. And so Ben's OIC acids, ascorbic acid and probiotic acids are all weak organic acids that can be added to food products such as bread and juices in order to prevent microbial growth. And what they do is they create an acidic environment. And this acidic environment that these acids create are going to prevent the growth of most bacteria and molds by affecting their cell membranes. And so if we take a look at our image down below, we can see we're showing you the structure of a specific organic acid and this is Ben's OIC acid, the structure of the Benz OIC acid. And so notice that it is an organic molecule that contains carbon and hydrogen and it is containing a carb oxalic acid group right here. So it has acidic properties. And so notice here, we're showing you some bread that has been treated with organic acids and it looks pretty safe and healthy to eat. And notice over here on the right, what we're showing you is some bread that has no organic acids in it. And so notice that lots of mold and microbes are able to grow on that bread. And this bread is not really safe to eat. And so this shows how organic acids can be used as chemicals for preserving uh foods. Uh and so this here concludes our brief lesson on organic acids used in food preservation. And we'll be able to talk about the nitrates and nitrates in our next lesson video. So, I'll see you all there.

in this video, we're going to talk about the use of nitrate and nitrite and food preservation. And so nitrate is actually the reduced form of nitrate. And so nitrate nitrate are very similar in their structures otherwise. And so nitrate and nitrite are primarily used for preserving processed meets in two specific ways. The first way is that they inhibit the germination of endo spores formed by the bacteria clostridium botulinum. And so by inhibiting the germination of these endo spores is preventing the growth of this bacteria clostridium botulinum, which could otherwise otherwise be very toxic. And so the second way in which these nitrates and nitrates are primarily used for preserving processed meats, is that at really high concentrations these nitrates and nitrates can actually be used to preserve the pinkish colour that is associated with meats, for example, hot dogs. And so uh if you take a look at the image down below, what you'll notice is on the left hand side, we're showing you a nitrate. The chemical structure for the nitrate. And on the left hand side we're showing you a fresh steak that has been treated with these nitrates. And so notice that it has the pinkish color and that there are no clostridium bacteria growing on it. Now on the right hand side, we're showing you a rotten steak. And this is because uh is not treated with nitrates. And so it is going to have growth of clostridium botulinum on there. And so it's not going to be safe to consume safe to ingest. And so once again, if you have high enough concentrations of these nitrates and nitrates, it helps to create that pinkish colour that is associated with processed meats such as hot dogs and fresh steaks and things like that. Now, it is also worth noting that one of the drawbacks of using nitrates and nitrates is that they can actually be converted to nitro PSA means by improper cooking or by certain gut bacteria. And these nitro PSA means ultimately can be carcinogenic, meaning that they can contribute to the development of cancer. And so although they can be used in helping to make sure that our foods are uh safe to eat in terms of controlling microbial growth, um at times they can also uh contribute to the development of cancer if once again, they are improperly cooked, or if there are specific gut bacteria that can convert these nitrates and nitrates to nitrites, amines. And so this year concludes our brief lesson on the use of nitrate nitrate and food preservation, and we'll be able to get some practice applying these concepts as we move forward. So I'll see you all in our next video.