What is the most indispensable nutrient
Water
What happens to the boiling point of water at higher altitudes?
Boiling point is lower and takes longer to cook food
Define water activity (AW)
The amount of free (available energy) water in foods versus the bound water
What is water hardness determined by?
Presence of mineral salts
TF
Hard water is alkaline
True
Temporarily hard water
VS
Permanently hard water
Temporarily contains bicarbonate salts
—> can be softened by boiling
Permanently contains calcium and magnesium surfaces
—> cannot be softened bc minerals are not precipitated by heat
How to soften permanently hard water?
Exchanges sodium ions for calcium and magnesium
Why is fluoride added to water?
Important in teeth and bone formation
Why is chlorine added to water?
Kills harmful microorganisms
Why is ozone added to water and why is it preferred over chlorine?
Control bacterial growth and doesn’t have the aftertaste that chlorine dies
Why may nitrates be present in water?
From fertilizers, manure and sewage
Why may lead be found it water?
Old lead pipes even though they aren’t permitted anymore
Why may organic chemicals be found in water?
Pesticides contamination
Why may high levels of microorganisms be found in water? What can this result in?
From animal and human waste. Can cause food borne illnesses
6 roles of water in food prep
- Solvent
- Cook medium
- Hydrolysis
- Basic ingredient
- Promotes chemical changes
- Cleaning agent
Did you watch the potato movie on YouTube
Yes
What are the uses of water in making potato chips?
- Washing potatoes
- Rinse the potatoes after peeled
- Rinse potatoes after sliced. Water contains starch which can be dried and sold. Water can be treated and reused
What molecules are contained in carbohydrates?
Carbon
Hydrogen
Oxygen
Carbohydrates are produce from plants during __________.
H2O and CO2 combine to make _______
Photosynthesis
Glucose
T/F scientists can reproduce photosynthesis
False
List carbohydrate foods
Cereal grains and flours Legumes Starchy roots, tubers/stems Fruits Sugars Milk products
List the 4 classifications of carbs
- Monosaccharides (1 unit)
- Disaccharide (2 units)
- Oligosaccharide (3-10 units)
- Polysaccharide (complex sugars)
Monosaccharides are made up of….
6 carbon hexoses and 5 carbon pentoses
Types of monosaccharides
Glucose
Fructose
Galactose
What in glucose found in?
Most abundant sugar
Fruits, plant juices, honey
Glucose in the body
Glucose is in the form of sugar that circulates in the bloodstream.
Broken down to give body 3 products (energy, water, carbon dioxide)
Fructose is found in ….
Fruits, plant juices and honey
Sweetest of all
Very soluble and doesn’t crystallize
Galactose
Not normally found in free firm in foods but firms a bond with glucose to produce lactose
Types of disaccharides (3)
Sucrose (glucose and fructose)
Maltose (glucose and glucose)
Lactose (glucose and galactose)
Sucrose
Glucose and fructose
Table sugar
Extracted from sugar cane and sugar beets
Maltose
Glucose and glucose
Found in germinating grain and corn syrup (product of starch hydrolysis)
Important in production of malted beverages (beer)
Lactose
Glucose and galactose
Milk sugar
Only found naturally in milk and milk products
TF
Oligosaccharides are digested by human intestinal tract
false
cannot be digested
Results in gas formation
Soluble VS insoluble fibre
Can dissolve water VS doesn’t dissolve in water but absorbs water and swells
List the types of fibres
Cellulose Hemicellulose Beta-glucans Pectins Vegetable gums/hydrocolloids
Many glucose molecules linked together by beta bonds to form linear chain
Most abundant type
*plant wall material
Can replace fat in food product
Cellulose
in plant cell walls
Variety of different monosaccharide building blocks
Help in baked goods (improve water binding of flour)
Improve mixing quality, reducing mixing energy, aid incorporation of proteins and loaf volume in bread
hemicellulose
Polysaccharide composer of glucose units that are linked by beta bonds
Less linear, more soluble in water
Rich in oats and barley
Form viscous hydrated mass that traps bile and reduces cholesterol absorbed by body in gastrointestinal tract
Decrease rate of digestion of starch into glucose and rate of glucose absorption
*helps those with diabetes bc controls blood sugar levels
Beta-glucans (homoglucan)
Found in cell walls and space between plant cells
Galacturonic acid is the base building block
Common in fruits and responsible for forming gels in jams jellies and preserves
Pectins
Long chain polysaccharide
Various hexose and pentose sugars are building blocks
Dissolve in water and produce a thickening or texture building block
Can be homo-polysaccharide or hetero-polysaccharide
Either straight or branched
Vegetable gums/hydrocolloids
List 4 types of polysaccharides
Starch
Dextrin
Glycogen
Plant fibres
Plants storage form of glucose
Branched/unbranched
Water insoluble
Provides plant with energy and humans/animals with energy when eaten
Starch
Two kinds of starch molecules
Amylose and amylopectin
Diff between amylose and amylopectin
Amylose - linear chain
Amylopectin- slightly branched
What is gelatinization
When starch granules swell when heated in water
What process is responsible for the thickening that occurs when a starch pudding or sauce is cooked
Gelatinization
Polysaccharide that is derived from starch
Dextrins (homoglucans)
Define dextrinization
Commercial production of starch molecules that are partially broken down by enzymes, acid or dry heat
TF Dextrins can be used as fat replaces?
True
Animal storage of glucose
Chains longer and more branched than starch
Nearly undetectable in meats bc it’s rapidly broken down when the animal in slaughtered
Glycogen
Where is glycogen stored?
Liver and muscles temporarily until hydrolyzed to help maintain blood glucose levels or used as fuel by muscles
A complex mixture of cellulose, hemicellulose, beta-glycine, pectins and gums
Polysaccharide
Plant fibres
Which fibre can help retain water, reduce evaporation rates and modify ice crystals formation
Also is widely used in the food industry as fat replacers in ice cream, low cal salad dressing, and low fat foods
Vegetable gums/hydrocolloids
Provide examples of gums/hydrocolloids
Seaweed extracts Plant seed gums Plant exudates Microbial gums Modified cellulose
___% of the wheat produced worldwide is used to produce flour
75%
What is Durum wheat
Wheat milled to form “semolina” and used to make pasta
Define prebiotics
Indigestible dietary carbohydrates which are able to stimulate the growth of potentially beneficial bacteria/probiotics
Define Fructose-oligosaccharides (FOS)
Naturally occurring sugars found in a variety of plant foods and honey and brown sugar
FOS is used as “food” by the following beneficial bacteria
1 Faecium
2 Acidophilus
3 Bifidus
- not able to feed harmful bacteria
Benefits of FOS
Lower cholesterol and triglyceride levels
Reduce pH of feces
Reduce CHO and lipid absorption
Reduce toxic metabolites
Define Inulin
Natural plant extract composed of linear fructose chains with mostly one terminal glucose unit.
Where is Inulin digested
Undergoes completed anaerobic fermentation by bacteria in the Lg intestine
List 5 health benefits of Inulin
Increase bioavailability of minerals (calcium, magnesium, iron)
Reduce risk of colon cancer
Reduction in cholesterol and blood lipids
Prevention of gastrointestinal tract infections
Increase bifidobacteria
How is Inulin used in low fat foods?
Modifies texture to provide a creamy mouthfeel
Used in yogurt, cheese, whipped cream, frozen desserts, baked goods and processed meats