Lecture 8: Flavors and Beverages Flashcards
How did early humans rely on taste and smell to determine if something was edible?
- Sweetness = nourishing
- Bitterness = toxic alkaloids
- Foulness = dangerous decay
How do humans biologically detect smells?
Chemical compounds stimulate olfactory receptor neurons, which are special nerve cells in the olfactory bulb located in the nasal passages
Aroma and volatility
- Aroma chemicals of herbs and spices are volatile (molecules that can evaporate easily)
- Allows them to rise with the breath into the nose
- High temps make volatile molecules more volatile –> cooking releases aromas
Herbs vs. Spices
- Herbs = leafy, green plant parts (fresh or dried
- Spices = bits of dried seed, bark, or root
How were herbs and spices used before modern times
- Before refrigeration, food often was a bit spoiled when eaten –> herbs and spices used to cover up bad tastes
- Many plants produce essential oils to used to make incense/perfumes
In which kind of food are aromas used most?
Beverages
Maillard reaction
Cooking of meat, bread crust, coffee, roasted nuts to get that browning effect
Name the primary flavor familes of herbs and spices
- Terpenes
- Phenolics
- Pungent chemicals
Terpenes
- Defense compounds in plants –> pine-like, leafy, citrusy, floral
- Very volatile –> each nose first, readily boiled off during cooking
- Built from 5 carbon molecular blocks called isoprenoid units
Phenolics
- Natural compounds found in plants
- Constructed from a cyclohexane and at least one fragment of a water molecule (-OH)
Pungency
- Hotness, chemical irritation
- Not a taste or smell
What are the 2 major groups of chemicals that cause pungency?
Thiocyanates: -small molecules that easily escape from foods -effect the nose -mustard, horseradish, wasabi Alkylamides: -large molecules that stay in the food -effect the mouth -chilies, black pepper, ginger
How did tea come to be?
- Accidentally
- Chinese Emperor Shen Nung had an upset stomach from poisonous grasses
- Wind blew tea leaves his way and he boiled them in water, drank them, and felt better
How is tea made?
By infusing leave of the tea plant Camellia sinensis in hot water
Name the 3 main types of tea.
- Green tea (unfermented)
- Oolong tea (semi-fermented)
- Black tea (fermented)
Green tea
- Unfermented
- Green leaf, clear water
- Longest history of all teas and ranks 1st in output and variety today
- Liked for its freshness and natural fragrance
- Preparation: harvest, wither, pan fire, roll, press, and dry
Oolong tea
- Semi-fermented
- Leaves are withered until they become significantly wilted
- Lightly agitated to bruise leaves and let enzymes convert some of the simple flavonols into red-brown tannins
- Pan fired, rolled, and dried
Black tea
- Fermented
- Stronger fragrance
- Leaves significantly withered
- Rolled to bruise leaves and let enzymes convert simple flavonols into red-brown tannins
- Fermented 1-4 hours
- Dried
Tea and caffeine content
Tea leaves contain more caffeine than coffee, but tea generally contains less per cup
Where and from what did coffee originate?
- Trees native to east Africa
- First roasted on Arabian peninsula in Yemen (have been growing coffee there for 14 centuries)
- Comes from the Arabic word “qahwah” for Mocha
Coffee plants
- Coffee grows on large bushes or small trees that take 3-5 years to produce fruit –> will produce fruit for up to 15 years
- Coffee bean = seed of the fruit
- Fruit develops over 6-9 months
What are the 2 types of coffee grown commercially?
- Coffee arabica (Yemen)
- Coffee robusta (Africa)
Largest exporters of coffee today
Brazil, Vietnam and Columbia
Mineral water and soft drinks
- Soft drinks can be traced back to mineral water found in natural springs (healthy, curative powers)
- Scientists found out CO2 made it bubble
- Wanted to drink this healing water
Joseph Priestley
- English clergyman and chemist
- Invented the first drinkable manmade glass of carbonated water
- First chemist to prove that oxygen was essential to combustion
- Co-credited with the discovery of oxygen
American soda fountain
- People would go to the local drug store for a fountain drink supposed to cure or aid some physical malady
- Drugs like cocaine and caffein were among the most famous additives
- Bromides and plant extracts also commonly dispensed
Coca Cola
- Invented by Dr. John Pemberton in Atlanta, GA in 1886
- Combined cocaine and caffeine to cure headaches
- Problem = resulting rebound headache meant that patients were always back for more
- 1877: formula sold to Asa Candler for $2300
- 1890: most popular drink in America
Harrison Act (1914)
Banned use of cocaine and opiates in over-the-counter products
