13: Plants that give flavour Flashcards
what are the functions of human taste (2) main ish
- taste sensory inputs influence our thinking, deciding and behavior toward sampled foods, both consciously and unconsciously, to guide ingestion!
- determines what foods enter out body (ie if bad smell, you don’t want to eat it) - taste inputs influence our physiological and metabolic processing and signaling of nutrients and toxins once ingested
- determines how these nutrients are handled once they enter it
what are the 5 tastes and what molecules induce them?
- sweet: simple carbs
- salty: sodium and a few other actions
- sour: acids
- bitter: toxic compounds
- umami: glutamate, aspartate, some RNAs
bitter taste
- caused by which types of compounds (6)
- what are always associated with bitter
- when can humans tolerate bitterness? (2)
- bitterness can also indicate what?
- alkaloids, phenols, flavonoids, isoflavones, terpenes, glucosinolates
- nutrients in plants are ALWAYS associated with bitter, potentially toxic phytochemicals
- humans can tolerate low levels of bitterness if they co-occur with nutrients in plants OR if they are paired with positive metabolic/pharmacological outcome (ie chocolate, coffee, wine)
- medicinal qualities
*understand
which physiological state can change taste response?
- describe taste responses
- why?
- pregnancy!
- chief among these changes are increased sensitivity to bitter stimuli and feelings of nausea in response to bitter foods
- protective response at a time when major fetal organs are first forming and are highly sensitive to low levels of toxins
*maternal vomiting may be beneficial –> women who experience nausea during T1 experience fewer miscarriages and tend to have larger and healthier babies
*understand
what compounds cause anticipatory responses to keep toxins to upper digestive tract?
- explain 3 anticipatory responses
STRONG BITTER COMPOUNDS!
1. causes nausea, sickness, malaise –> serves as psychological response to punish our behaviour and to protect us
2. stomach contractions become chaotic to contain toxins to stomach and to prepare to vomit
3. detoxification enzymes may be upregulated
which animals ish cannot synthesize vit C?
why?
- humans, monkeys and apes
due to loss of functional gluconolactone oxidase gene
- which animal cannot taste umami? only who can taste it?
- umami taste not obvious in what? vs only in (2)
- humans have developed taste for (2 ish) as markers of what?
- what other foods are also high in (one of the component of umami taste) –> markers for what?
- chimps (bc never controlled fire)! only early hominids and modern humans can taste it
- not obvious in fresh meat –> only in aged and cooked meats
- for glutamate, ribonucleotides and umami taste –> markers of easily digestible protein
- fermented foods also high in glutamate –> improved nutrition and probiotic bacteria
EVOLUTION OF SWEET:
- advent of WHAT (how long ago) significantly increased role of (2) in our diets
- all mammals produce why enzymes BUT only (2) have this other enzyme
- humans are unique in what?
- agriculture (8-10 0000 years ago) –> increased role of grains and starch in our diets
- pancreatic a-amylase –> only great apes and some rodents have salivary a-amylase (as soon as glu comes in our mouths, we’re so greedy that we start absorbing it immediately)
- large scale copy number polymorphism of salivary amylase gene AMY1
*starch doesn’t taste sweet, but it activates brain reward centers just like glucose (ie chips)
EVOLUTION OF SOUR:
- acids may indicate presence of what? (humans lack what?)
- mixture of (2) enables to identification of fruit ripeness
- mixture of (2) are also markers of __________
- vitamin C! (lack functional gluconolactone oxidase gene)
- mixture of acids with sugar = ripeness
- acids and sour = fermentation –> which humans around the globe clearly seek and ingest
EVOLUTION OF SALTY
- compare omnivores, carnivores and herbivores
- do humans have higher or lower salt intake vs other omnivores? why?
- moderate concentrations are highly attractives to omnivores
- carnivores ingest salt with every meal, but herbivores can easily become salt depleted and seek out salt licks
- humans lose salt through sweating, so we prefer a higher salt intake than other omnivores
what is the most popular flavor worldwide?
- how is the extract obtained?
- how many taste and aroma compounds in extract? most are destroyed at what?
- source can only be obtained from what?
- what are its substitutes? from what?
VANILLA!
- by steeping vanilla beans in alcohol
- 250 –> most are destroyed at elevated temps
- vanilla beans can only be obtained from hand-pollinated flowering orchids
- bulk of vanilla substitutes are actually nature-identical vanillin and vanillin derivatives synthesized on a multi-ton scale from guaiacol or lignin extract, which can be isolated from wood pulp
