Lecture 3 Flashcards
What is the botanical definition of a fruit?
Produced from flowers and are the ripened ovaries and adjacent tissues of plants
What is the main reason for the decline in fruits and veggie consumption?
Food insecurities
-60% of adults consuming less than 5 servings of fruits and veggies/day
What are the 3 main classifications of fruits?
Simple
Aggregate
Multiple
How does a simple fruit develop?
Development from a single ovary and one flower
What are the 3 categories of simple fruits?
Citrus fruits
Drupes
Pomes
How does an aggregate. fruit develop?
Development from several ovaries and one flower
How does a multiple develop?
developed from a cluster of several flowers
What has an impact on the nutrient content?
The ripeness affects the nutrition content
Whether or not the fruit is ripened on the vine (more vit C) or not
What is the nutrient content of fruit (main groups)
Carbs (fructose) -Fibre: soluble and insoluble Fat (poor) Protein (poor) Vitamin C Vitamin A Fe/Ca (poor) Phytochemical
Why are phytochemicals good/
Can help prevent chronic disease by stabilizing unstable free radicals in the body by donating an e- to them
What are the 5 kinds of plant pigments and what colour do they produce?
Chlorophyll-Green Carotenoids- Yellow/Orange Anthocyanins- Red/Purple/Blue Betalains- Rurple/Red Anthoxanthins- White or colourless
What is the flow chart of phytochemical?
Phyto -Caotenoids Lycopeene Beta Carotene Lutein -Polyphenols Lignans Phenolic Acid Flavanoid **Anthoxanthin **Anthocyanin **Isoflavin (soy)
What does phenolic acid do?
Gives a bitter taste to food, normally found in immature fruit
What do Lycopeene Beta Carotene Lutein do?
Lycopeene- Helpful for males to prevent prostate cancer. In tomatoes
Beta Carotene- Good for eyes. Found in orange fruits and veggies
Lutein-good for ever. found in dark leafy green veggies
What is the flavour of something contributed by?
Aromatic compounds
Organic Acids
Essential oils (in Skin)
Phenolic Compounds
What is an aromatic compounds?
Esters, aldehydes and alcohols
-can be synthesized in the lab
What is an organic acid?
Malic (Apples) Citric (Oranges) Tartaric (Grapes) Benzoic (Plums) Oxalic Acid (rhubarb)
What are phenolic compounds?
When unripe fruit are consumed, and have a bitter or pucker taste
What is a cell wall composed of?
Cellulose and hemi cellulose
How are individual cells held together?
Pectin substances
-act as glue
What is the process of ripening?
Protopectin>protopectinase>Pectin (Pectinic acid> Pectin Methyl Esterase> Pectic acid
What are the purposes of the enzymes in the ripening of fruit?
Help speed up the conversion of the steps required to get protopectin to pectic acid
What is pectin?
Found naturally in fruit
Helps with gelling
-composed of units of galacturonic acid (derivatives of galactose)
What does pectic acid cause?
Causes soft mushy and mealy texture
-doesnt form a Gell when food is over ripe
What are the 4 changes we see during ripening?
- Colour
- Flesh becomes softened
- Development of flavours
- Changes in soluble solids (organic acids and sugars)
What is ethylene gas?
Ripening hormone, without it the fruit will not ripen
-naturally found in tomatoes and apples
Is there a difference in nutritions when a fruit ripens naturally vs with ethylene gas?
No different in composition of nutritions
What is the colour change of ripened fruit related too?
Related to the synthesis of new pigments and breakdown of the green pigment chlorophyll
In terms of softening food, what helps food soften faster?
Soften faster when the temp of surrounding air has increased
What are things to consider about how fruit can be impacted when purchasing it?
Overall quality
Seasonality
Cost
Organic vs conventional
What is happening to the Cavendish banana?
Panama disease is affecting it
- disease has been around since the 1980’s
- though this type of banana would replace the previous kind because it was less resistant to the fungus
What are the ways in which fruit can be purchased?
Fresh Frozen Dried Canned Juice
What vitamin do fruit juices contain?
Vitamin C which is retained in the citrus juices but it added to other juices
Why is vitamin C added to other juices?
- Increase nutrient value
- Improve appearance
- Improve Flavour
- Improve Stability during storage
What do we add vitamin C too?
To non citrus juices
-this type of vitamin C is less stable because it is more susceptible to heat, air and light degradation
What are the kinds of juice processing?
Orange juice
Non citrus juice
Cloud or haze
Pasturizaton
Is vitamin C lost in juice production?
Loss of vitamin C is minimized in the processing and preparation of citrus juices
Does freezing juice damage vitamin c?
Freezing and storage of orange juice does not cause a significant loss in vitamin C
Does non citrus juice contain vitamin C?
Contain minimal amounts of vitamin C unless fortified
What is the difference between fruit juice and fruit drink/beverage/cocktail?
Juice= 100%
Drink/beverage/cocktail= <100%
What is a haze/cloudy juice due to?
Mix of cellular organelle, colour bodies, oil droplets flavonoids, pectic substances, cellulose and meicellulose
Why do you want a haze?
Appearance is desirable in citrus juice but not others
How do you stabilize citrus juices?
Cloudiness is stabilized by flash heating to a temp higher than usual pasteurization to destroy pectin esterase
What happens to clarified juice?
Occurs when pectin-degrading enzyme (pectinate) are added so that the juice is less viscous and can be easily filtered
What is juice from concentrate?
Heated to a higher extent which results in the removal of water and then water is readied before it is sold
-volume reduced which reduces shipping costs
What is dried fruit?
When water content has been reduced to 30% or less
In vacuum drying what does the water content need to be at?
- 5-5%
- makes it more resistant to microbial growth
What are pros and cons to dried fruit?
Pro
- Resistant to microbial spoilage
- Preserves Vit A and C (with sulphur)
Cons:
- Highly concentrated in calories and sugar
- Need to add austere to preserve vitamins
What are the methods of fruit drying?
Sun dried
-Using sun and that heat to remove water
Artificial Heat
-Dehydration under well controlled humidity, temperature and air circulation
Vacuum-Drying
-low moisture because water evaporates at a lower temp
Freeze-Drying
-Freezing produce and placing it in vacuum chamber
Why is freezer drying really good?
Allows product to be more flavourful and fresher because it doesn’t become hot in the frying process
What are sulphites?
Found naturally and added to some foods
-They have no nutritional value but preserve Vitamin A and C and used to preserve colour
What is canned fruit?
Cooked fruit that has been canned in either heavy/light syrup or fruit juices
What are the disadvantages for canned fruit?
Vitamin content may be slightly reduced
Texture and flavour may be altered
-Pro: Lose less nutritions when stored at relatively low temperatures
What are characteristics of frozen fruit?
Can be frozen as is or in a sugar syrup
Not heated during processing
Adding Vitamin C to delay browning
Partial thawing and refereeing decreases quality
What are the 3 ways in which to extends storage of fresh fruits?
- Controlled atmosphere
- Modified atmosphere packaging
- Irradiation
What is controlled atmosphere?
The O2 within the atmosphere is reduced below 21% to as low as 2-3%
What is modified atmosphere packaging?
Modification to the O2, CO2 and water vapour levels in the air surrounding the product within a package. Requires low storage temp
-uses semipermeable film to allow natural respiration of fruit to reduce the O2 and increase CO2 of the atmosphere around the fruit
What is irradiation?
Use of electron beams to reduce mold growth, extends held life, kill insects, and can be used in combination with modified atmosphere packaging
-can help delay biological aging/deterioration
What is AP vs EP
As purchased
Edible portion (usually less)
What is enzymatic browning?
Occurs when polyphenoloxidase (PPO) or other enzymes cause oxidation of phenols in the fruit to form compounds called quinones
What is the pro and con for enzymatic browning?
Pro: colour and flavour develop
Con: detrimental when fruits become discoloured
How do you inactivate PPO?
With heat
What are quinones?
Responsible for forming melanin
What reacts with quinones to become inactive?
Sulphites react with quinones and no colour pigment is formed
How do you prevent enzymatic browning?
- Add an acid
- ascorbic acid - Reduce O2
- using sugar or salt
- honey - Heat Treatment (blanching)
- denature enzymes that cause browning - Use of Sulphites
- react with quinones to preserve colour
What is osmosis?
Solvent moves from a less concentrated solution to a more concentrated one
Ex: cooking fruit without sugar = mushy/soft
What is diffusion?
Opposite of osmosis where a substance moves from an area of high concentration to a lower one
Ex: cooking fruit in sugar= retains shape
