EXAM 4: Fibers And Plant Structure Overview Flashcards
Overview of plant cell structure, what are some important organelles and their functions
Chloroplasts/chromoplasts
- color - green or red/orange/yellow
Intracellular spaces
- air, volume/crispiness
Amyloplast
- starch storage
Vacuole
- water
- flavor compounds
- phenolics, sugars, acids, proteins
Cell wall
- structure, rigidity
The plant cell wall is made of what fibers
Cellulose, lignin, hemi-cellulose, some pectins
What are the following fibers, the green, light brown and yellow
Green - pectin
Light brown - hemicellulose
Yellow - cellulose microfibril
What are cellulose fibers
Chains of glucose
Joined together by beta one four
Indigestible
What is lignin
A fiber that reinforces the cell wall
It is more prevalent in older plants
- ex: celery gets bendier over time
Fiber is classified by its _______ and __________
Fermentability
- how readily bacteria in lower gi tract are going to feed off of it and ferment
Solubility
What are examples of readily fermentable fibers
Pectin
Gums and seaweed
Mucilages
What are examples of semi-fermentable fibers
Cellulose
Some hemi cellulose
What are examples of non-fermentable fibers
Lignins
________ _________ are a unique set of polysaccharides polymers of galacturonic acid
Pectin substances
What is the pectic substance found in unripe fruit
Protopectin
What is the pectic substance found in optimally ripe fruit
Pectin
This can form a gel - making it good for jams and jellies
What is the pectic substance found in overripe fruit
Pectinic Acid
Pectins in fruit purées (like applesauce) allow for it to be a substitute for ________ and _________ in baked goods
Fat and eggs
What are sources of lignin
Wheat bran, whole grains, seeds and stems of vegetables
What are the types of plant components that are used as thickening agents
Pectin: from oranges or apples
Carrageenan and Agar: hydrocolloids derived from seaweed
Gums: gum Arabic and locust bean gum
What are the 5 characteristics the thickening agents/gums impart on food
Viscosity
Stabilize gel or coagulum (like yogurt: prevents water from weeping out)
Improves texture (making it smoother)
Reduces ice crystals
Helps thicken
