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Food Chemistry > 13 Food Additives > Flashcards

13 Food Additives Flashcards

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1
Q

2 types of food additives?

A

intentional additives and incidental additives

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2
Q

3 classes of intentional additives recognized

A
  1. Additives generally recognized as safe (GRAS)
  2. Additives with prior approval
  3. Food additives
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3
Q

the ratio between effective dose and toxic dose of many compound is…

A

the order of 1-100

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4
Q

what are the types of food additives?

A
  1. complex substances: proteins, starches that are extracted from other foods, i.e. use of caseinate in sausages
  2. naturally occurring, well-defined chemical compounds, i.e. salts, phosphates, acetic acid, ascorbic acid
  3. substances produced by synthesis, which may or may not occur in nature, i.e, coal tar dyes, antioxidants, preservatives, emulsifier, synthetic b-carotene
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5
Q

benzoic acid can be used as?

A

benzoic acid or as benzoate

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6
Q

kenapa benzoic acid harus in low pH?

A

because benzoate is active in low pH, which is in benzoic acid form

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7
Q

what’s the most effective antimicrobial agent? at what pKa and pH are it most effective?

A

undissociated form of benzoic acid. pKa 4.2 and pH 2.5-5

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8
Q

what are the applications of benzoic acid?

A

high-acid foods, cider, carbonated beverages, pickles, margarines, salad dressings, soy sauce, jams

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9
Q

what’s paraben?

A

alkyl esters of p-hydroxybenzoic acid

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10
Q

what alkyl groups can be used in parabens?

A

methyl, ethyl, propyl, butyl, heptyl

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11
Q

what are the traits of paraben?

A

colorless, tasteless, odorless, nonvolatile, nonhygroscopic

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12
Q

which type of paraben isn’t colorless, tasteless, and odorless?

A

methyl paraben

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13
Q

explain the correlation between solubility and antimicrobial activity of paraben!

A

solubility in water depends on the nature of alkyl group -> the longer the alkyl chain length, the lower the solubility. it has antimicrobial activity in acid and alkaline pH regions. antimicrobial activity of parabens in proportional to chain of alkyl group

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14
Q

what’s paraben most effective for?

A

to inhibit molds and yeasts than bacteria (more effective in gram + than gram -)

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15
Q

what’s the difference between toxicity and hazard?

A

toxicty: capacity of a substance to produce injury while hazard means the probability that injury will result from the intended use of substance

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16
Q

application of paraben? ada lanjutan di card lain)

A

fruit cakes, pastries, fruit fillings

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17
Q

methyl and propyl parabenes is used for

A

soft drinks

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18
Q

combination of several parabens is used for?

A

fish products, flavor extracts, salad dressings

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19
Q

what’s a sorbic acid?

A

straight-chain, trans-trans unsaturated fatty acid, 2-4-hexanedioic acid. low stability in water, rtp

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20
Q

what form is sorbate most stable in?

A

dry form bc it decomposes through oxidation in aqueous form. oxidation rate is affected by low pH, high temperature, and light exposure

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21
Q

what is sorbic acid most effective in tackling at?

A

yeasts and molds (sorbic acid and sorbate)

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22
Q

sorbate inhibits…

A

yeast growth in wine, fruit juice, dried fruit, cottage cheese, meat, fish products

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23
Q

sorbic acid is most effective in what condition and level?

A

low pH such as in salad dressings, tomato products, carbonated beverages.it’s effective between the range of 0.5-0.30%

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24
Q

what’s the general function of sorbate?

A

used in sweetened wines or wines that contain sugars to prevent refermentation, doesn’t affect food flavor

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25
Q

explain the mechanism of sorbate degradation

A

molds metabolize sorbate to produce 1,3-pentadiene which is a volatile compound with odor like kerosene. high level of mo results in degradation of sorbate in wine causing off-flavor (geradium off-odor)

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26
Q

what are the responsible compounds for the flavor defect?

A

ethyl sorbate, 4-hexenoic acid, 1-ethoxy-hexa-2,4-diene, and 2-ethoxyhexa-3,5-diene

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27
Q

ngasitau aja ngab,

sulfur dioxide and sulfites are used as antimicrobial substance and antioxidant

A
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28
Q

what’s sulfur dioxide?

A

gas that can be used in compressed form in cylinders, liquid under pressure of 3.4 atm, can be injected directly in liquids, also used to prepare solutions in ice cold water and dissolves to form sulfurous acid

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29
Q

sulfites yield active SO2 when dissolved in water

A
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30
Q

what’s the most widely used sulfite?

A

potassium metabisulfite

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31
Q

sulfurous acid inhibits?

A

molds and bacteria to a lesser extent yeasts

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32
Q

SO2 can be used to control?

A

bacteria and wild yeast in fermentations without affecting the SO2- tolerant cultured yeasts

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33
Q

what’s the maximum amount of SO2 to be added in foods?

A

200-500 ppm: develop unpleasant flavor
- ADI: 1.5 mg/kg body weight

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34
Q

why is addition of SO2 not permitted in foods containing significant amount of thiamine?

A

SO2 is destroyed by thiamine

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35
Q

application of sulfites?

A

wine, meat products, dried vegetables, dried potato products

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36
Q

nitrate and nitrite are usually contained in?

A

curing salts (e.g. bacon and ham)

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37
Q

nitrate and nitrite offer antimicrobial action.

A
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38
Q

nitrate is used in the production of gouda cheese to…

A

prevent gas formation by butyric acid-forming bacteria

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39
Q

nitrite is involved in the inhibition of?

A

toxin formation by C. botulinum.

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40
Q

why is the usage of nitrite concerning?

A

secondary amines in foods may react to form nitrosamines (R-NNO-R)

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41
Q

why is nitrosamine harmful?

A

powerful carcinogens, can be mutagenic and teratogenic. can be formed in cured meet products, volatile and non-volatile. present in foods as the result of processing methods. ADI of nitrite: 60 mg/day

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42
Q

what are the structures of nitrosamines?

A

NDMA, NPYR, NDEA, NDIPA

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43
Q

what are the functions of hydrogen peroxide?

A

strong oxidizing agent, bleaching agent, antimicrobial action in cheese and milk

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44
Q

explain the mechanism of hydrogen peroxide usage?

A

it decomposes slowly into water and oxygen. process is accelerated by increased temperature and presence of catalysts (catalase, lacto-peroxidase, and heavy metals). its microbial action increases with temperature. can be used for sterilizing food processing equipment and for sterilizing packaging material used in aseptic food packaging system

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45
Q

what’s the main function of sodium chloride?

A

prevent spoilage of foods and used in combination with other processing methods. Antimicrobial activity is related to Aw.

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46
Q

what are the characters of sodium chloride?

A
  • produces osmotic effect
  • limits oxygen solubility
  • changes pH
  • sodium and chloride ions are toxic
  • salt contributes to loss of magnesium ions
47
Q

what’s nisin?

A

antibacterial polypeptide produced by some strains of lactococcus lactis. nisin-like substances are widely produces by LAB. it’s a polypeptide with a molecular weight of 3500 (dimer of MW 7000)

48
Q

Inhibitory substances are also known as?

A

bacteriocins

49
Q

nisin-producing organisms occur in

A

milk

50
Q

nisin can be used as a processing aid against

A

gram-positive organisms

51
Q

what are the properties of nisin?

A
  • contain unusual sulfur-AA, lanthionine, and b-methyl lanthionine
  • contains no aromatic AA
  • Stable to heat
52
Q

natamycin is identical to pimaricin

A
53
Q

what’s the usage of natamycin?

A

controls growth of fungi, but has no effect on bacteria/viruses

54
Q

application of nisin

A

processed cheese, heat treatment of nonacid foods and in extending the shelf life of sterilized milk

55
Q

acids have dual purposes

A

acidulants and as preservatives

56
Q

phosphoric acid is used in

A

cola soft drinks to reduce pH

57
Q

acetic acid is used to

A

provide tartness in mayonnaise and salad dressings

58
Q

several notable similar acid functions: citric, tartaric, malic, lactic, succinic, adipic, fumaric

A
59
Q

propionic acid is mainly used for

A

antifungal properties, higher at pH 4 than pH 5. sodium salts of propionic acid also have antimicrobial properties

60
Q

what acids are used for their antimicrobial properties?

A

straight-chain carboxylic acids, propionic and sorbic acids

61
Q

what’s antioxidant?

A

substances that have some effect on preventing or retarding oxidative deterioration in food

62
Q

primary antioxidants terminate?

A

free radical chains and donors electron

63
Q

mention examples of antioxidants

A

phenolic antioxidants, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butyl hydroquinone (TBHQ), alkylgalates, propylgallate (PG), natural & synthetic tocopherols and tocotrienols

64
Q

can oxygen scavengers remove o2 in a closed system?

A

yes. e.g. vit c and related substance, ascorbyl palmitate, erythorbic acid

65
Q

antioxidants as chelating agent or sequestrants remove?…

A

metallic ions (Cu, Fe are powerdul prooxidants): citric acid, amino acids, EDTA

66
Q

superoxide dismutase

A

enzymatic antioxidants remove dissolved or head space oxygen

67
Q

natural oxidants:

A

spices, herbs; e.g. rosemary (carnosic acid and carnosol), sage

68
Q

maximum amount of antioxidants in food?

A

50 ppm

68
Q

maximum amount of antioxidants in food?

A

50 ppm

69
Q

natural emulsifiers?

A

lecithin. other than that, all are synthetic and derivatife of fatty acids

70
Q

characteristic of emulsifier?

A

ionic or nonionic

hydrophile/lipophile balance (HLB)

71
Q

what’s lecithin?

A
  • commercial name of a mixture of phospholipids obtained as a byproduct of refining soybean oil
  • phosphatidylcholine
72
Q

crude soybean lecithin?

A

dark, bleached with h2o2 or benzoyl peroxide

73
Q

hydroxylated lecithin?

A

treatment with h2o2 and lactic or acetic acid

74
Q

more hydrophilic lecithin makes it a better o/w emulsifier

A
75
Q

Monoglycerides is produced by…

A

transesterification of glycerol with triglyceride, high temperature, under vacuum, in alkaline catalyst

76
Q

commercial MG:

A

mixture about 40% MG and DG (diglyceride) and TG (triglyceride)

77
Q

emulsifying properties (HLB) are determined by…

A

chained length and unsaturation of the fatty acid chain

78
Q

hydrocarboxylic and fatty acid esters are produced by..

A

esterifying organic acids to monoglycerides, increasing their hydrophilic properties

79
Q

examples of hydroxycarboxylic acid and fatty acid esters:

A

acetic, citric, fumaric, lactic, succinic, or tartaric acid

80
Q

flavors include a wide variety of spices, oleoresins, essential oils and natural extractives

A
81
Q

categories of flavor compounds?

A
  • natural flavor and flavoring substances:
    preparations or single substances obtained exclusively by physical process from raw material in natural state or processed for human consumption
  • nature-identical flavors
    produced by chemical synthesis or from aromatic raw materials. chemically identical to natural product
    ?????? kepotong gambar
  • artificial flavors
    not present in natural products
82
Q

flavor enhancers are substances that carry the property of umami and comprise of…

A

glutamates and nucleotides

83
Q

glutamic acid consists of

A

amino acid (AA)
free glutamic acid

84
Q

high levels of free glutamate in many vegetables such as

A

mushrooms, peas, and tomatoes

85
Q

what is glutamate?

A

element of natural ripening process that results in fullness of taste

86
Q

nucleotides examples

A
  • Disodium 5-inosinate (IMP): in meat, poultry, and fish
  • Adenosine monophosphate (AMP): in vegetables, crustaceans, mollusks
    -Disodium 5-guanylate (GMP): in mushrooms (shiitake)
    -Disodium xanthylate (XMP)
87
Q

Monosodium glutamate properties:

A
  • similar taste properties in the L-forms of a-amino dicarboxylates with four to seven carbon atoms
  • intensity of flavor is related to chemical structure of these compounds

-other amino acid with similar taste properties: salts of ibotenic acid, thricholomic acid, L-theanine

87
Q

Monosodium glutamate properties:

A
  • similar taste properties in the L-forms of a-amino dicarboxylates with four to seven carbon atoms
  • intensity of flavor is related to chemical structure of these compounds

-other amino acid with similar taste properties: salts of ibotenic acid, thricholomic acid, L-theanine

88
Q

tasteless MSG?

A

nucleotides with ester group in 2 or 3 position

89
Q

enzyme that cause taste activity loss?

A

phosphomonoesterases cause removal of ester group. it’s important to inactivate such enzymes in foods before adding 5’-nucleotide flavors enhancers

90
Q

taste intensity of MSG is linear to the concentration

A
91
Q

threshold of MSG, NaCl and sucrose

A

in g/100 mL

MSG: 0.012
NaCl: 0.0037
Sucrose: 0.086

92
Q

strong synergistic effect between MSG and IMP: taste intensity 16x stronger than same amount of MSG

A
93
Q

benefit of using flavor enhancers in food?

A

reduce salt level w/o affecting palability

94
Q

2 groups of sweeteners

A
  1. Non-nutritive sweeteners
    Saccharine, cyclamate, aspartame, acesulfame K, sucralose
  2. Nutritive sweeteners
    sucrose, glucose, fructose, invert sugar, variety of polyols (sorbitol, mannitol, maltitol, lactitol, xylitol, hydrogenated glucose syrup
95
Q

saccharine is available as sodium/calcium salt of orthobenzosulfimide

A
96
Q

cyclamate is the sodium or calcium salts of cyclohexane sulfamic acid or the acid itself

A
97
Q

cyclamate is 30-40 times sweeter than sucrose, 300 times sweeter than saccharine

A
98
Q

cyclamate can be converted by intestinal flora in certain individuals into cyclohexamine, a carcinogen. some population are nonconverters

A
99
Q

at higher concentrations, the sweetness intensity of the synthetic sweeteners increases at lower rate than which occurs with sugar.

bitterness and strong aftertaste that appears at these relatively high concentrations

A
100
Q

what’s aspartame?

A

dipeptide derivative -> L-aspartyl-L-phenylalanine methyl ester

101
Q

aspartame is used for?

A

tabletop sweetener, dry beverage mixes, foods that are not heat processed

102
Q

what’s the limiting factor of aspartame?

A

lacks heat stability

103
Q

aspartame is metabolized in body to form phenylalanine, aspartic acid, and methanol. it’s not harmful

A
104
Q

acesulfame K is the potassium salt of 6-methyl-1,2,3-oxathiozine-4(3H)-one-2,2-dioxide

A
105
Q

properties of acesulfame K?

A
  • crystalline powder, 200 times sweeter than sugar
  • sweetening powder depends to a certain degree on the acidity of the food it is used in
  • more stable than the other sweeteners
  • clean sweet taste, doesn’t linger
106
Q

phosphates are widely used in the form of:

A
  • phosphoric acid-acidulant
  • monophosphates
  • polyphosphates
107
Q

phosphates are used as…

A
  • buffering agent in dairy, meat, fish products
  • anticaking agents in salts
  • firming agents in fruits and vegetables
  • yeast food in bakery and alcoholic beverage
  • melting salts in cheese processing
108
Q

orthophosphates is the largest group of phosphates and the most important in the food industry. phosphates examples are: orthophosphates, polyphosphates, metaphosphates

A
109
Q

orthophosphates have 3 replaceable hydrogen which give 3 possible sodium orthophosphates which are

A
  • Monosodium
  • Disodium
  • Trisodium phosphate
110
Q

phosphates affect the absorption of calcium and other elements. the absorption of inorganic phosporus depends on…

A

amount of Ca, Fe, Sr, and Al present

111
Q

what danger may arise when raising phosphorus level?

A

Ca becomes available

Food Chemistry (5 decks)

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