hey everybody how's it going this mini lecture will be on taste now taste has a fancy name and that is gustation so if you ever hear the term gustation or gustatory know that it's referring to taste now taste is different obviously from the other senses but it's also different uh from vision and hearing in the way that it detects and encodes the information taste is a chemical sense which means it's going to be picking up on molecules right that come from the food that we're consuming this is different from vision which uses wavelengths and hearing which uses sound waves so both of those use a type of waves but taste and smell when we talk about it are different and that they are chemical senses they pick up on molecules in the environment that's what they detect and encode and you'll notice over here that there are taste molecules but you'll also notice there are odor molecules because when we eat a lot of what we perceive in terms of taste comes from the actual odor molecules more on that in a different mini lecture all right now the receptors for taste are called taste buds and if we take a look here on the tongue we see all these bumps right and those bumps themselves are not our taste buds or the receptors for taste those bumps are called papele and the taste buds are located there on the papillae and the vast majority of our taste buds are on our tongue but we have some on the sides of the mouth and the roof of the mouth and as i'll talk about in a future slide they regenerate if you um brush your tongue you slough off some dead taste buds and if you've ever burned your tongue uh it may feel funny for a while kind of slippery but you don't lose your sense of taste right because our taste buds as you'll learn will regenerate so those taste buds are located on the papele and uh the number of taste buds may differ from person to person the more taste buds you have the more sensitive you are to tastes and a person with a lot of taste buds may be called a super taster and a person with fewer taste buds may be called an undertaster all right now taste buds respond to what are called the basic tastes and if i look over here you'll see sweet and sweet and sour and sour those are some basic taste and in addition to that we can add salty and bitter now when i was going to school and when i was first teaching these were considered the four basic tastes but in 1996 another basic taste called umami or glutamate was added you may know this as savory and it's really interesting because when i ask students today hey what are the basic tastes they always add in savory because they you know if you were born after 1996 that was just part of your normal learning one thing that i think is interesting about umami is actually in the early 1900s a japanese chemist by the name of ikeda was working in his lab and his wife brought him some miso soup and he was eating it going man this is delicious right this is wonderfully delicious but it's not it's not just salty or bitter it's got this great mouth feel it feels very rich he said i think that we have an additional receptor and he called it umami for meaning deliciousness after his wife's miso soup and the scientific community at the time pooh-poohed him no there is no you know there aren't receptors for glutamate and then in 1996 they're like you know what ikeda was right and i believe that he was proposing that like in 1906 so it just took a while for science to catch up what he had proposed earlier those basic tastes that we have have survival function for us you know we've talked about or you've learned in your book about how vision and hearing are conducive or helpful for survival but taste is as well and here's why when we eat sweet things at some point in our evolutionary history we may have realized when i eat sweet things like fruit or sugary things i get a jolt of energy right so sweet provides us with energy salty it says sodium essential is essential to physiological processes one thing that salty foods will do is help us preserve water and may help us from becoming dehydrated when you drink electrolyte drinks when you're working out a lot of them have sodium in it to help prevent dehydration both sour and bitter taste could warn us that we're eating something that may not be good for us and to stay away from it you see sour toxins and bitter poisons now when we look at the taste buds that we have they're kind of scattered across our tongue they're not all chunked together with sweet and one airy and salty in another but when we look at the number of taste buds we have for a specific basic taste there are more that respond to bitter than respond to sweets salty sour and umami probably because of this idea of uh the potential that uh it bitter may indicate that we're eating something poisonous and we should stop eating it uh and bitter things include coffee dark chocolate those are some bitter flavors umami we find in broths bone broth chicken broth uh beef broth miso cheese uh fish and so on and all of those things have protein and you know they're sources of protein cheese is another example of umami or savory and as you see there proteins help us grow and repair tissue so those basic tastes we have do have survival function for us and i should say that every flavor every taste that you experience is a combination of these basic tastes right here everything is a combination of those basic tastes i mentioned that your taste buds regenerate and they regenerate about every two weeks so again when you're brushing your teeth if you brush your tongue you're slopping them off so we get those taste buds every two weeks and they send information to our parietal lobe this is where taste takes place in this green circle right here recall that your parietal lobe is also has our sensory cortex on it so when you feel things sensations on your skin that's where that's happening as well and so take a minute to think about that when you have coffee in the morning or when you're eating maybe a dessert that's just so delicious for you and it feels like that's happening in your mouth but it's actually happening because of that green circle right there on your parietal lobe that's allowing you the sensation of taste wait i just said something wrong it's allowing you the perception of taste so we use those taste buds to detect and encode the information and then it's here in our parietal lobe on the gustatory cortex the gustatory complex that perception of taste takes place now there are some things that influence taste like our age as we get older that baby boy if you put like grapefruit or something sour into that baby's mouth they'd spit it out they'd get it out but those older grandparents may have a completely different perception they may not find it as sour for example or bitter and that's because as we get older the number of our taste buds decrease they don't generate regenerate rather at the same rate and if you've ever eaten with an older relative you may find that they are heavily seasoning their food or salting their food and it's to stimulate those remaining taste buds and so you might find it too spicy or salty but that heavy seasoning is there to stimulate the the taste buds that an older person still has and influence their perception of flavor smoking and alcohol both also will reduce the number of taste buds and can slow down their regeneration and then loss of smell and nausea anybody recognize this it if you experience allergies if you have experienced a cold where you're super congested you may be eating food but find that's not flavorful it's not really tasty at all it's just kind of there in your mouth i mean you know it's there you can feel textures but it's not very flavorful ben and jerry's ice cream has tons of different things in their ice cream right goldfish chunks of brownie chunks of banana and so on and that's because one of the founders cannot smell and texture becomes very important when eating so while i may not be able to necessarily have a lot of flavor the mouth feel is good so pick up a pint of ben and jerry's and think of it eat it as an educational as an educational activity concentrate on those textures in your mouth and think about how they contribute to your experience of taste um there's something oh spicy for example is not a taste it's considered a texture spicy is considered a texture and contributes to our experience of taste okay i'm gonna go to my next slide and i think yep all right the next slide is on smell so i'll save that for a different mini lecture i hope you find this in this information helpful and interesting and if you have any questions please be sure to let me know bye you