Food additives Flashcards
(36 cards)
What are food additives?
Substances/chemicals added to food to make them either part of the food or to influence its structural/functional properties
- may be added intentionally/directly or unintentional/indirectly
What are food components that are NOT food additives? (12)
why?
- vitamins, minerals, amino acids
- salt, sugar, starch, spices, seasoning, flavorings
- agricultural chemicals and veterinary drugs
- food packaging materials
- salt, sugar are used from time immemorial so not a food additive
- starch: cannot say its a food additive for potato bc its all starch VS adding starch as a thickener = a food additive
difference between direct and indirect additives?
DIRECT:
- added to achieve structural and functional changes in food product
INDIRECT:
- added as a result of various domestic (ie spray cabinets with bug spray: residue can stay in cabinets), industrial (wood smoke, wild fire residues can be added to food materials) and agricultural practices (add pesticides)
3 main groups of direct additives? + functions
- food processing aids/functional additives: used in preparation of production of foods into desired finished forms
- food preservatives: help extend shelf-life of food material
- food quality enhancers: improve quality in terms of particular attributes
what are 2 broad categories of food processing aids? + subtypes?
FOOD TEXTURE IMPROVERS:
1. emulsifiers
2. thickeners
WATER BINDING AGENTS:
1. humectants
2. anti-caking agents
difference between emulsifiers and thickeners/stabilizers?
- give examples
EMULSIFIERS:
- ie: lecithin, mono and diglycerides
- emulsifiers are amphiphatic: have both polar and nonpolar ends –> added to 2 immiscible solvents (ie oil and vinegar) –> polar end binds to vinegar and non-polar binds to oil to form a stable product
- basis for making products like salad dressing and mayonnaise
THICKENERS/STABILIZERS:
- ie starch, gums, pectin, carboxymethylcellulose (CMC)
- can imbibe moisture –> when added to foods, they absorb moisture and swell to thicken the food
humectants vs anti-caking agents
- give examples
HUMECTANTS:
- bind and retain moisture in food to make them juicy/succulent
- ie polyhydric alcohols like sorbitol and glycerol, phosphates, polyphosphates
ANTI-CAKING AGENTS:
- absorb/withdraw water from food product to prevent clumping and to keep food material dry
- ie silicates, cornstarch
- ie: add rice in salt and sugar to keep them dry
what is sometimes added to scallops to make them swell so they appear bigger at supermarket?
polyphosphates!
- a humectant which is a water binding agent which is a food processing aid
Food processing aids:
ENZYMES:
- function
- 4 application examples
- 3 enzymes for _____ __________
- 2 enzymes for _______ ___ _______ _____
ENZYMES:
- transform raw materials into finished products
- ie: use invertase on sucrose to make invert sugar, glucose isomerase to make HFCS, rennin & proteases to make cheese, LOX for bleaching flour
- bromelain, papain and ficin as meat tenderizers
- amylases and pectinases for clarification of fruit juices
Food processing agents:
FOAMING VS ANTI-FOAMING AGENTS
- function
- uses what?
- used in which food products
FOAMING:
- enhances foam formation in food products to make them fluffy and airy
- proteins and peptides (egg white/albumin, milk powder) –> make bubbles + air gets trapped inside
- ice cream, frozen desserts
ANTI-FOAMING AGENTS:
- prevent foaming in food products
- octanol, parafins, oleic acid, silicone oil
- chicken nuggets, french fries, potato chips
Food processing aids:
ACIDS vs ALKALIS
ACIDS:
- provide sour flour + inhibit growth of bacteria/enzyme activity by decrease pH –> makes food milieu not conductive to proliferation of microorgs
- acetic acid, citric acid, phosphoric acid, lactic acid, malic acid, benzoic acid, sorbic acid
ALKALIS:
- leavening agents bc can release CO2 and increase volume of foods
- Na2CO3, NaHCO3, K2CO3, NH4HCO3, carbonates and bicarbonates
benzoic acid and sorbic acid
- function?
- what category of food additive?
- used in salt or acid form?
- inhibit microbial growth
- acids! as a food processing aid
- GOOGLE ANSWER
Food processing aids:
BUFFERS
- function
- examples
- specific example for salt
- criteria for selecting a buffering agent (3)
- precent acidic and alkaline changes in food products –> maintain pH to add/preserve food flavors AND oto stabilize food product
- phosphates, citrates, calcium hydroxide, borates, lactate, glycine
- KI added to salts to prevent goiter –> Ca(OH)2 added to iodized salts to maintain pH stable to prevent KI from breaking down to I2 which will impart a brownish/orange color to the salt
1. must not alter their characteristics traditionally associated with food material
2. must be readily available
3. not too expansive
2 main functions of food preservatives + subtypes
CONTROL MICROBIAL GROWTH
1. fermentation
2. humectants
3. acids
FOOD STORAGE EXTENDERS:
1. antioxidants
2. enzyme inhibitors
3. antimicrobial agents
4. modified atmosphere packaging (MAP)
5. additives that can be added to food packaging materials
3 ways to control microbial growth? + process/examples
FERMENTATION:
- produces intermediates/produces like acetic acid, proprionic acid, lactic acid, ethanol that can prevent spoilage by inactivating or destroying microorganisms
HUMECTANTS:
- lower water activity to make food milieu non conductive to growth and proliferation of microorgs
- ex. sugars, salts, alcohols
ACIDS:
- decrease pH to render the milieu non conductive to both enzymes and microorgs –> the 2 causative agents of food spoilage
- phosphoric acid, citrate, lactate, acetate, benzoate, sorbate
5 ways to extend food storage of foods
- what category of food additives?
- function + examples
- food preservatives!
1. ANTIOXIDANTS - prevents rancidity and discoloration potentiated by enzymes
- vit E, vit C, EDTA, citrate, propyl gallate, SO2
2. ENZYME INHIBITORS - prevent deleterious effects in foods
- nitrites, sulfites
3. ANTIMICROBIAL AGENTS - destroy microors to protect food from spoilage
4. MODIFIED ATMOSPHERE PACKAGING (MAP)/ SHRINK WRAPPING: - create vaccuum conditions in food materials OR exclude O2 to prevent undesirable oxidations in foods
5. ADDITIVES THAT CAN BE ADDED TO FOOD PACKAGING MATERIALS - ie plasticizers to make plastic packaging stretchable
- microbial agents to prevent microorgs from gaining access to food material
what can be added to plastic films made from crab shells or starch or milk to extend shelf life? (2)
- plasticizers to make it more stretchable
- antimicrobial agents to prevent spoilage
what are 3 food preservatives that are not in the categories to control microbial growth and to extend food storage?
- function + examples
- GAS STERILANTS
- used to clean/sterilize processing equipment –> NOT added to foods!
- iodophor chlorine, methyl bromide - SYNTHETIC METABOLIC INHIBITORS
- often added to food packaging materials
- parabens - INORGANIC COMPOUNDS
- ie sulfites and nitrites
- ie for curing of meats + used as enzyme inhibitors to extend food storage
What are the 3 categories of food quality enhancers?
- FLAVORING AGENTS
- ORGANIC FLAVORS
- NUTRITIONAL ADDITIVES –> improve health benefits, increase nutrient content
- describe flavoring agents –> 2 types
- describe organic flavors –> 3 ways to get them
FLAVORING AGENTS
- natural types (sugars (honey, maple syrup), salts, spices, protein hydrolysates)
- artificial types (aspartame, sugar alcohols, acesulfame K)
ORGANIC FLAVORS:
- by extraction of natural flavors using solvents (ie water, ethanol) (cocoa, tea, coffee flavors)
- by fermentation (production of MSG, of acids (lactic acids))
- by chemical synthesis (ie vanilla)
what are the 3 types of nutritional additives?
- RESTORATION
- nutrients added back to food to replace losses during processing (ie loss of heat-labile vit C in fruit juices in processing)
- ie adding vit C to canned tomato juice or dehydrated mashed potatoes - ENRICHMENT:
- nutrients are added in food products that are naturally deficient/limited in particular nutrients –> you want to add more
- addition of Fe and vit B1, B2 and niacin to flour/cereals - FORTIFICATION:
- nutrients are added deliberately to a food product to address a health need
- ie add vit A to rice to reduce eye defects, add vit A and D to margarine and skimmed milk
palm oil has many __________ pigments –> decrease palm oil because too much _________ oil but increase in what disease?
- solution?
- carotenoid pigments –> vit A!
- saturated oil
- increase night blindness
- solution: add vit A to rice
3 criterias used for use of food additives (you can’t just add stuff to food just because you want to)
- must be safe for continuous use
- ie some salts (lead acetate) are not safe to use –> not used as additive - must not be used to deceive the consumer
- during storage, food loses quality –> we shouldn’t treat it in a way to make consumers think it’s fresh - must be used to the consumer’s advantage
- must benefit consumer
how to check if the food additive is safe for continuous use?
by feeding the chemical additive to at least 2 experimental animals (mice, rabbits, fruit flies, guinea pigs!!)
- guinea pigs = most common one
- both parents and offsprings are monitored for short and long term effects
