food flavors

Question 1

what are the three components to flavors?

Answer 1

smell taste mouthfeel

Question 2

Define food flavor

Answer 2

the sensation produced by food in the mouth and nose

Question 3

to what is due the sweet taste?

Answer 3

due to electromagnetic elements of organic molecules (like nitrogen and oxygen).

Question 4

which optical isomer of the amino acid is sweet ? the D or L?

Answer 4

D isomer is sweet while L is bitter

Question 5

how are the high fructose corn syrup are made

Answer 5

HFCS : the amylase are used to break the starch into mixture of monosaccharides abd then the enzyme glucose isomerase is used to convert the glucose into fructose.

Question 6

what is maltodextrin?

Answer 6

it is the breakdown products of carbohydrates

Question 7

what are the criteria for selecting alternate sweetners?

Answer 7

1. cariogenicity 2. sweetness equivalent 3. solubility and viscosity 4. hygroscopicity 5. heat of solution 6. laxative effect 7. cost

Question 8

what are the only two polyol that are not hygroscopic?

Answer 8

mannitol and isomalt

Question 9

why polyol produces the higest cooling effect

Answer 9

xylitol

Question 10

explain the cooling effect observed with certain polyols

Answer 10

The sweetners will need heat energy (from the saliva) to be able to be dissolved. When they absorb the heat, they can leave a cooling sensation in the mouth and so it gives a cooling effet that is not desirable. It could be desirable is some kind of products.

Question 11

___ and __have laxative effect – because they are incompletely digested and slowly absorbed

Answer 11

Polyols and polydextrose

Question 12

Rate these polyol in relative sweetness order : maltitol mannitol polydextrose isomalt sorbitol xylitol

Answer 12

xylitol > maltitol > mannitol > sorbitol > isomalt > polydextrose (xylophone monopolise mon super incroyable passetemps)

Question 13

T or F : xylitol is as sweet as sugar

Answer 13

true

Question 14

Does xylitol have an after taste

Answer 14

no

Question 15

what are the technical characteristics of xylitol?

Answer 15

-high thermal stability; -high microbiological stability; -inhibits many food-spoilage organisms; -does not react with amino acids; -moderate hygroscopicity

Question 16

In general, the ___-amino acids tend to be sweet & the ___-isomers are bitter; some exceptions are ___ which has an insipid taste and ___ which is sweet and the amino acid ___

Answer 16

D L D-Ala L-Ala glycine (no D and L)

Question 17

To what sugar do we compare the others on the relative sweetness scale

Answer 17

compare to sucrose

Question 18

What is the relative sweetness scale?

Answer 18

Relative sweetness. is defined as “the ratio of concentrations of substances. matching in sweetness” (12), and it is used to calculate the. concentration of an alternative sweetener that produces. sweetness equivalent to that of sucrose.

Question 19

name the natural sweeteners seen in class (3)

Answer 19

1. miraculin 2. thaumatin 3. stevia

Question 20

name the alternate sweetener : a glycoprotein from berries found in West Africa. The fruit of this plant is commonly referred to as the miracle fruit. Has the unusual property of tasting intensely sweet only in the presence of acids.

Answer 20

miraculin

Question 21

name the alternate sweetener : a mixture of sweet-tasting proteins found in the African fruit known as katemfe. It is about 1,500-2,500x sweeter than sucrose.

Answer 21

thaumatin

Question 22

name the alternate sweetener : a shrub found in the tropical and sub-tropical zones of the Americas. Active compound is steviol glycoside

Answer 22

stevia

Question 23

name the alternate sweetener : the methyl ester of the dipeptide, L-aspartyl-L-phenylalanine; about 200x sweeter than sugar; approved in early 1980’s for use as table-top sweetener, in dry beverage mixes, and in foods that are not heat processed;

Answer 23

aspartame

Question 24

name the alternate sweetener : - It is K-salt of methyl-oxathiazine-dioxide; about 200x sweeter than sugar; more stable than other synthetic sweeteners; and sweet taste is clean and does not linger;

Answer 24

acesulfame K

Question 25

name the alternate sweetener : trichloro derivative of glucose-fructose; ~600x sweeter than sucrose. More stable than sugar, and appears to be very suitable for several

Answer 25

sucralose

Question 26

T or F : aspartame can be used in baked goods

Answer 26

false it is heat labile

Question 27

T or F : the acesulfame K can be used in hot beverages

Answer 27

true

Question 28

what is the general structure of sucralose

Answer 28

trichloro derviative of sucrose

Question 29

Which alternate sugar is this

Answer 29

aspartame

Question 30

which alternate sugar is this

Answer 30

Question 31

which alternate sugar is this

Answer 31

sucralose (3 cl on the sucrose molecule)

Question 32

name the alternate sweetener : :- a derivative of the dipeptide L-a-aspartyl-alaninamide. It is about 2,000-3,000x sweeter than sucrose

Answer 32

alitame

Question 33

which alternate sugar is this?

Answer 33

alitame

Question 34

is alitame stable to heat?

Answer 34

yes ( it is the advantage over aspartame in food application)

Question 35

which alternate sweetener is this ? : (Na or Ca salts - ~200-400x sweeter than sucrose);

Answer 35

saccharin

Question 36

cyclamate : intestinal bacteria can convert them in \_\_\_\_

Answer 36

cyclohexyl amine

Question 37

why is there a controversy around the cyclamates

Answer 37

because intestinal bacteria can convert it into cyclohexylamine which is a carcinogen

Question 38

To what is due the sour taste?

Answer 38

due to the H+ ions from acids.

Question 39

[H+] determines \_\_\_\_\_, not the \_\_\_\_

Answer 39

degree of sourness total acidity

Question 40

what are the factors that will influence the sour taste of a food

Answer 40

1. the nature of acid (strong / weak) 2. buffering capacity 3. presence of other compounds

Question 41

\_\_\_ acid will give a more sour taste

Answer 41

stronger, since they will ionize into H+ more extensibily.

Question 42

t or f : the total acidity influences the sourness

Answer 42

false, the sourness is due to the H+ ions and not the total acidity

Question 43

t or f : acids enhance the action of natural anti-oxidants

Answer 43

true

Question 44

what is the salty taste due to ?

Answer 44

salt ions like Na+, K+, Cl- etc

Question 45

The salty taste depends on \_\_

Answer 45

the size of the ions

Question 46

small ions taste ___ salty

Answer 46

more

Question 47

large ions will taste \_\_\_

Answer 47

bitter

Question 48

true of false ; all ions will give a salty taste

Answer 48

false, larger ions have a bitter taste

Question 49

what are the function of salt (NaCl)

Answer 49

1. reduce Aw (microbial activity) 2. impart flavors and bost food consumption 3. digestive stimulant

Question 50

to what is due the bitter taste in foods ?

Answer 50

to the various organic and inorganic compounds

Question 51

what are the three classes of bitter compounds?

Answer 51

1. alklaoids 2. glycoides 3. amino acids peptides

Question 52

define alkaloids

Answer 52

a class of compounds that yields a bitter taste because of their nitrogenous composition.

Question 53

quinine, caffeine and theobromine are exmaple of ___ compounds

Answer 53

alkaloids

Question 54

what is the difference in structure between theobromide and caffeine

Answer 54

theobromide has 2 methyl groups attached to 2 of the 4 nitrogen while in cafeine there is three methyl group attached to 4 of the nitrogen.

Question 55

What are glycosides?

Answer 55

aglycones esterifed with various sugars, e.g., are naringin, hesperidin, coniferin, and sinigrin.

Question 56

which glycoside are we refering to : ofound predominantly in grapefruit and bitter orange; it is one of the most bitter substances known;

Answer 56

naringin

Question 57

name the glycoside we are refering to : Found in sweet orange and several other citrus fruits; yields rutinose and the aglycone hesperetin on hydrolysis.

Answer 57

hesperidin

Question 58

Which glycoside are we refering to : in conifer wood, it produces glucose and coniferyl alcohol on hydrolysis - which may subsequently be oxidized to vanillin;

Answer 58

coniferin

Question 59

which glycoside are we referring to : in black mustard seed, it yields glucose and allyl isothiocyanate on hydrolysis

Answer 59

sinigrin

Question 60

what is the aglycone of hesperidin nad the sugar

Answer 60

sugar : glucose aglycone : hesperetin

Question 61

what is the sugar part and the aglycone part of sinigrin?

Answer 61

sugar : glucose Aglycone : isothiocyanate

Question 62

what is the sugar part and the aglycone part of coniferin?

Answer 62

aglycone : conniferryl alcohol sugar : glucose

Question 63

what are the bitter glycoside we saw in class ?

Answer 63

1. naringin 2. hesperidin 3. coniferin 4. sinigrin

Question 64

Sub-threshold levels of\_\_ reduces sourness in foods

Answer 64

salt

Question 65

Sub-threshold levels of \_\_\_\_enhances saltiness in foods

Answer 65

acid

Question 66

oSub-threshold levels of ___ reduces saltiness in foods.

Answer 66

sugars

Question 67

name the flavor enhancer we saw in class

Answer 67

1. MSG 2. Nucleotides 3. Maltol

Question 68

What are the flavor enhancer that we have seen in class?

Answer 68

MSG Nucleotides (IMP and GMP) Maltol

Question 69

What are the three componennts of mouthfeel?

Answer 69

1. Pain 2. Temperature 3. Tactile sensations

Question 70

what are the two methods of sensory evaluation of foods?

Answer 70

1. peference testing 2. difference testing

Question 71

what are the three methods comonly used in the preference testing?

Answer 71

1. paired comparison test 2. hedonic scale 3. ranking test

Question 72

name the test : the panelist are presented with two products and they need to pick the one that they prefer. Simple paired comparision test.

Answer 72

simple paired comparision test

Question 73

name the test : test this is an extension of the simple paired comparison test in the sense that the panel is able to quantify the degree of difference – ex A is 20 % sweeter then B and so on. So you don’t only say the number 1 is preferred by me.

Answer 73

Scheffé paired comparision

Question 74

name this test : In this approach, 3 or more products are compared with each other for particular attributes. Ex for A B and C, you would compare A-B, A-C and B-C and you say the one that is your preferred product..

Answer 74

multiple paired comparison test

Question 75

name this test : you are ask to select the odd one from a set of 3 products in which two are the same.

Answer 75

triangle test

Question 76

name this test : a variation of the triangle test. There is 3 items, and there is one of the three that is a reference, and you need to select the one that is similar to the reference. So 2 of the 3 items are identical and you need to state the one that is 1- identifical and 2 – different

Answer 76

duo trio test

Question 77

what are the different test we use in difference testing?

Answer 77

simple paired comparison test scheffé paired comparison multiple comparison triangle test duo-trio test ranking test

Question 78

Solubility can influence \_\_\_, ___ and ____ of the product;

Answer 78

mouthfeel, texture & onset of sweetness perception