food studies Flashcards
define food matrix
the nutrient and non-nutrient components of foods and their molecular relationships
name the 5 sections of the eat well guide and what % they make up
fruit and veg - 40% protein - 12% dairy and alternatives - 8% Carbohydrates - 38% oils and spread - 1%
energy in carbohydrates (kcal/g)
3.75
energy in protein (kcal/g)
4.0
energy in fat (kcal/g)
9
energy in alcohol (kcal/g)
7
does the eat well guide apply to everyone?
not under 2 years old
what is a portion of fruit and veg?
80g fresh, 30g dried, 150ml fruit juice
cereals are low in …. and are a good source of …
potassium, zinc
which part of the grain contains all of the micro and macro nutrients of the grain?
bran and aleurone
which part of the grain contains the new plant
embryo
what is the composition of carbs and protein in cereals
75% carbs, 6-15% protein
what are phytochemical
chemical compounds produced by plants to protect against herbivores, to resist fungi, bacteria and plant viruses
what % of adults in the UK were eating the recommended 5/day in 2017
29%
what sugar is common granulated sugar
sucrose
what foods are glucose found in
honey, sugar, fruit and veg
what foods are fructose found in
honey, sugar, fruit and veg, processed food and drinks
what food is galactose found in
milk
what sugar components are found in sucrose
what foods contain sucrose
glucose + fructose
table sugar, golden syrup, honey, fruit, veg
what sugar components are found in lactose
what foods contain lactose
glucose + galactose
milk products
what sugar components are found in maltose
what foods contain maltose
glucose + glucose
alcohol
what are free sugars
all mono and disaccharides added to foods and drinks
what is the RDI for free sugars
less than 5%
what are intrinsic and extrinsic sugars
intrinsic - contains within the plant cell
extrinsic - free sugars
how is alcohol produced
fermentation - yeast grow by feeding on the sugars and produce alcohol and CO2
what is 1 unit of alcohol
10ml (8g)
what is fresh meat?
meat that has not undergone any preserving process other than chilling, freezing or quick-freezing
which proteins are in cells
actin and myosin
which protein undergoes major change when cooked
myo-fibrillar proteins
which proteins make up the connective tissue
collagen and elastin
does age affect muscle fibres?
yes, younger animals or less active animals have finer muscle fibres (tender). older animals or those who do more work have thick muscle fibres (tougher meat)
what makes meat red
myoglobin
why does meat turn bright red20 minutes after being cut
myoglobin changes to oxymyoglobin
how many grams of protein is in raw red meat/ (/100g)
20-25g
how many grams of protein are in cooked meat (/100g)
28-36g
what are processed meats
cured, smoked or has had salt or chemical preservatives added
what 4 things are added to processed meats
salt - flavour enhancement
phosphates - retains moisture
sugar - counteracts saltiness
nitrates (and nitrite) - preserves meat
name some shellfish
crustaceans - crab, crayfish, lobster, shrimp
mollusks - bivalve (clam, mussel, oyster, scallop), univalve (snail), cephalopod (octopus, squid)
does fish have shorter or longer muscle fibres than meat?
shorter
does fish have more or less connective tissue than meat?
much less
- muscle cells run parallel connecting to sheaths of connective tissue
what vitamins does fish oil contain
fat soluble A and D and PUFA
what are the three main omega-3 fatty acids in oily fish
short chain - ALA (alpha-linolenic acid)
required to make…
long chain - EPA
long chain - DHA
what are the recommendations for fish intake
2 portions a week - 1 oily
what types of fish should pregnant women avoid?
shark, swordfish and marlin - high mercury risk
raw shell fish - food poisoning risk
define fats and oils
long hydrocarbon chain with a terminal carboxyl group
what are saturated fats
solid fats, straight chain fatty acids
what are unsaturated fats
liquid, kinked chain fatty acid because of C=C bonds
name some foods high in saturated fats
animal fat, coconut oil
name some foods high in monounsaturated fats
olive oil, nuts, avocado
name some foods high in polyunsaturated fats
plant oils, oily fish, nuts, seeds
name some potential effects on health of overconsumption of fats
CVD, stroke, cancer
what processed cause oxidation (rancidity) of fats
oxidation, hydrolysis
what is the effect of rancidity on lipids
causes them to bee un-palatable, bad odour, unhealthy to digest
are saturated or unsaturated fats more susceptible to oxidation
Unsaturated
2 things that contribute to oxidation
oxygen, UV light
2 primary products of oxidation
peroxides (ROO) and hydroperoxides (ROOH)
what proteins are in milk
caseins and whey
what vitamins are in milk
fat soluble vitamins A,D,E and K
what is a portion of dairy?
200ml glass milk, 150g pot of yogurt or 30g cheese
