Nuts & Berries Flashcards
Botanical definition of Nuts
- Indehiscent dry fruit
- Pericarp does not split at maturity
- 1-seeded w/ bony pericarp (exo, meso, endo)
True nuts:
- Walnut, Chestnut, Hazelnut, Pecan
Walnut
- Juglans spp., Juglandaceae, walnut family
- Trees allelopathic
Allelopathy, example of plant that has this feature
- Produce chemicals that have biological influence on other plants
- Walnut trees inhibit growth of other plants w/ chemicals from leaves leaching into ground
Why are walnuts good for health?
- According to the Doctrine of Signature (middle ages) relating plant shape to body parts
- Possibly lower cardiovascular diseases
- Antioxidant activity 2x more than other nuts
- High in a-linolenic acid, essential omega-3 fatty acid
Antioxidant activity of walnuts
- 2x greater than other nuts in testing
- Oxidative reactions can cause cell damage
- Antioxidant effects are mostly measured in laboratory reactions
What other foods have a-linolenic acid?
- soy, canola, chia seeds
Other tree nuts that are not true nuts
Cashew, Almond, Pistachio
What is the difference between tree nuts and true nuts?
- Only endocarp hardens in tree nuts
- True nuts have dry, hardened fruit in exo, meso, and endocarps
Cashew
- Anacardium occidentali, Anacardiaceae, cashew family
- Nut is seed embryo inside hard seed coat
- Cashew apple is accessory fruit, not from ovary so not a true fruit
Pistachio
- Pistachia vera, Anacardiaceae, cashew family
- Can grow in desert and saline soils
Almond
- Prunus dulcis, Rosaceae, rose family
- Contain amygdalin, cyanogenic glycoside
- Requires lots of water to grow
What nut causes concerns for water consumption? Explain.
- Almond
- California grows 82% of world almonds
- 1.1 gallon/single almond
- Problem for huge growth increase, 450,000 acres in 20 years
California almond industry
- Consumes massive amounts of water
- 450,000 acre increase in 20 years
- 6.5 billion dollar industry
- Top export crop to India
What fruit is, perhaps surprisingly, in the same family as cashew and pistachio?
- Mango
Which country exports the second most almonds?
- China
What are 2 essential fatty acids that the human body cannot make and must get from diet? Which is considered ‘better’?
- Omega-3 (best) and Omega-6
- Omega-3 found in walnuts
Antioxidants
- Inhibits oxygenated effects that damage cells and DNA
- Oxygen is important for body but chemical effect of oxidation can have negative effects as well
Fleshy fruit berries: Simple
- Blueberry, Huckleberry, Cranberry
- All Vaccinium spp. Ericaceae, heather family
Fleshy fruit berries: Aggregate
- Strawberry, Raspberry, Blackberry
- All Rosaceae, rose family
- Each ‘bubble’ comes from one ovary
- Strawberries are ‘fused’
What are the 2 types of fleshy fruit berries?
- Simple
- Aggregate
Why are berries desirable?
- Sweet and pretty
What is a feature many berries have and what does it do for the plant?
- Bright pigments, often phenolic compounds
- Anthocyanins, tannins which act as antioxidants
- Acts as attractant for consumption by animals to spread seeds?
What are 2 successful berry crops in BC, recently?
- Blueberry and cranberry
Cranberry
- Grown in bogs, harvested by flooding
- High in Vitamin C
- Harvested by native people in Fraser valley
- Juice treats bladder infections
- Highest antioxidant activity
Why were cranberries so profitable during the gold rush?
- Shipped to San Francisco during gold rush because high Vitamin C content wards off scurvy
Antioxidant effects of cranberry
- Highest of phenolic extracts from 20 fruits (second was red grape)
- Fruit extract antioxidant effect better than mixtures of vitamins or phenolic compounds
Which berry is used to treat bladder infections, and how does this work?
- Cranberry, better than other fruit juices
- Reduces adhesion of bacteria to bladder surface because it does not increase acidity
- High in alpha type proanthocyanidin (PA, tannin)
- 20x more active than beta type PA from grape juice
Blueberry
- High in antioxidant levels
- Popular health food b/c easier to package and market
Salal
- Local ‘super’ berry, better than blueberry
- Gautheria shallow, Ericaceae, Heather family (simple berries)
Which berry is more ‘super’, Blueberry or Salal?
- Salal
- Contains 1200mg tannin/100g fruit weight
- Substantially more than 250mg/100g fr. wt of blueberry
