Titratable acidity

Question 1

Titratable acidity

Answer 1

The total acid concentration contained within a food sample (total acidity). Is determined by titration of the food and is a good predictor of acid impact on flavor.

Question 2

Food acids are often ______, but can also be _____ and _____.

Answer 2

Organic acids, Phosphoric and carbonic

Question 3

4 effects of acids on food functionality.

Answer 3

Flavor, shelf life/preservation, texture, and food colors

Question 4

titratable acidity and sugar content are used as an indicator of what?

Answer 4

Maturity of fruits

Question 5

Titratable acidity is determined by….

Answer 5

neutralizing the acid present in a know weight or volume of product with a standard base

Question 6

Potentiometric end point

Answer 6

End point of titration is when the titration reaches a target pH.

Question 7

Colorimetric end point

Answer 7

End point is determined by a color change of an added indicator dye.

Question 8

Colorimetric end point

Answer 8

End point is determined by a color change of an added indicator dye.

Question 9

Neutralization reaction

Answer 9

Reaction of an acid with a base to form water and a salt

Question 10

Equivalent weight

Answer 10

The molecular weight divided by the number of equivalents in the reaction.

Question 11

Molarity

Answer 11

The number of moles of solute per liter of solution.

Question 12

Normality

Answer 12

The number of equivalents of solute per liter of solution.

Question 13

Normality

Answer 13

The number of equivalents of solute per liter of solution.

Question 14

Phenolphtalein changes color to _____ between the pHs ___ and ____.

Answer 14

pink, 8-9.6

Question 15

Phenolphtalein changes color to _____ between the pHs ___ and ____.

Answer 15

pink, 8-9.6

Question 16

Stock NaOH

Answer 16

50% NaOH in CO2 free water

Question 17

What is KHP commonly used for?

Answer 17

To standardize the titrant.

Question 18

Titratable acidity is stated in terms of the ________ acid .

Answer 18

Predominant

Question 19

What is the titratable acidity of fresh milk?

Answer 19

0.18-0.23%

Question 20

What is the titratable acidity of fresh milk?

Answer 20

0.18-0.23%

Question 21

Volatile acidity

Answer 21

Is determined using 2 titrations, one before and one after boiling off volatiles on low heat. Volatile acidity = titratable acidity - fixed acidity

Question 22

Volatile acidity

Answer 22

Is determined using 2 titrations, one before and one after boiling off volatiles on low heat. Volatile acidity = titratable acidity - fixed acidity

Question 23

What is the titratable acidity and pH of fresh milk?

Answer 23

0.18-0.23% and 6.4-6.6

Question 24

Volatile acidity

Answer 24

Is determined using 2 titrations, one before and one after boiling off volatiles on low heat. Volatile acidity = titratable acidity - fixed acidity

Question 25

HPLC

Answer 25

High performance liquid chromatography

Question 26

Methods of determining tiratable acidity

Answer 26

Basic titration, automatic titrators, HPLC, Electrochemical methods

Question 27

Methods of determining tiratable acidity

Answer 27

Basic titration, automatic titrators, HPLC, Electrochemical methods

Question 28

pH

Answer 28

Is a measure of the acidity or bacisity of an aqueous solution. Is defined as the negative logarithm of the hydrogen ion concentration.

Question 29

Most foods are in the pH range of ____.

Answer 29

4.6-7

Question 30

Methods for measuring pH.

Answer 30

Litmus paper, pH indicator strips, pH meter/probe

Question 31

Alkaline error

Answer 31

At pH above 10, high con

Question 32

Alkaline error

Answer 32

At pH above 10, high concentrations of ions affect the structure of the electrode, and a lower pH value is measured than it actually is. Alkaline error increases with temperature.

Question 33

Acid error

Answer 33

At pH below 2 the membrane absorbs acid molecules and decreases the activity of the H+ ions, and the pH measurement is higher than it should be.

Question 34

Alkaline error

Answer 34

At pH above 10, high concentrations of ions affect the structure of the electrode, and a lower pH value is measured than it actually is. Alkaline error increases with temperature.

Question 35

Acid error

Answer 35

At pH below 2 the membrane absorbs acid molecules and decreases the activity of the H+ ions, and the pH measurement is higher than it should be.