Fresh pineapple cannot be used in gelatin desserts because it contains an enzyme that hydrolyzes the proteins in gelatin, destroying the gelling action. Canned pineapple can be added to gelatin with no problem. Why?

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Hello, everyone. Let's look at the next problem. It says fresh fruits such as mango kiwi and papaya cannot be used in gelatin desserts because using them fresh prevents the gelatin from setting. However, canned or cooked versions of these fruits can be added to gelatin with no problem. Provide a brief explanation of this phenomenon. A cooking the fruits removes the high acidity of the fruit that prevents the gelatin from setting b, cooking the fruits, destroys the enzymes in the fruits that prevent the gelatin from setting c cooking the fruits, eradicates the micro organisms that prevent the gelatin from setting or d cooking the fruits catalyzes the process of setting gelatin. So we can use a little logic to help rule these out. And then we'll think through this process a little more thoroughly. So when we think about canning or cooking, we're thinking about using quite high heat on whatever we're doing. And of course, high heat will be enough to denature most enzymes and affect most proteins. So when we look at our answer choices and think about what might be happening as we heat the fruit to prevent it from preventing the setting of gelatin. When we look at choice A it says cooking the fruits removes the high acidity. Well, just adding heat doesn't change the acidity of something. So we'll cross that out twice. B says cooking the fruits destroys the enzymes. Well, that's promising because enzymes, proteins get denatured by high heat. Joy C says cooking the fruits eradicates the microorganisms. Well, cooking does eradicate microorganisms. So it could be a possibility. But when we're thinking about what causes gelatin descent, we're not talking about yogurt, we're not talking about something that ferments. So we'll just write not fermentation where we would have microorganisms. So the C is unlikely and then choice d cooking the fruits catalyzes the process of setting gelatin. Well, we need enzymes to catalyze something and we just finished discussing how that heat is going to denature most enzymes. So just in a logical process with a little bit of knowledge, we could pick B as the most likely answer. And this is correct. But let's just discover discuss that a little more thoroughly. How does gelatin set? Well, gelatin consists of, of a mixture of collagen proteins. And these are long strands of collagen. The first step in making gelatin is you heat it after adding water and that heat breaks the collagen not completely down but into sort of intermediate size strands like smaller pieces. And then when it is cooled, those longer strands reform slightly differently. But with water molecules trapped inside which gives you your jello jelly like uh structure or texture. So how would fresh fruits interfere with this in having enzymes? Well, fruits like mango, Kiwi and papaya contain enzymes called proteases and proteases completely break down proteins into their component amino acids. So if you throw a bunch of protease containing fruit into the gelatin, it will not just break it into intermediate size strands, but it's going to break down the collagen completely. So it will prevent it from reforming. So if it's the protease enzymes that are the problem cooking your fruit canning your fruit denatures those enzymes. And as choice B says, our explanation will be choice B cooking the fruits, destroys the enzymes in the fruits, the proteases that prevent the gelatin from setting. See you in the next video.

Fresh pineapple cannot be used in gelatin desserts because it contains an enzyme that hydrolyzes the proteins in gelatin, destroying the gelling action. Canned pineapple can be added to gelatin with no problem. Why?

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Key Concepts

Enzymatic Activity

Gelatin Structure

Canning Process