Flashcards in Food Analysis Deck (78)

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1

## Which type of HPLC analysis involves the use of a polar stationary phase and a non-polar mobile phase?

### Normal phase HPLC

2

## What types of carrier gases are used to carry samples in a gas chromatograph?

### Helium and Nitrogen

3

## What test is used to detect adulteration of milk with water?

### Freezing point analysis

4

## What symbol is used to express the O/R potential of a system?

### The symbol Eh

5

## What statistic is equal to the square root of the sample variance?

### Standard deviation

6

## What property is the Westphal balance used to measure?

### Specific gravity

7

## What property does a piezometer measure?

### Pressure

8

## What phenomenon occurs when a compound absorbs light and then immediately re-emits energy as light of a longer wavelength?

### Fluourescence

9

## What law describes the relationship between absorbance and concentration?

### Beerâ€™s law

10

## What is the unit of expression of transmittance in spectrophotometry?

### %T

11

## What is the standard method for determining total nitrogen in food?

### Kjeldahl Nitrogen Determination

12

## What is the specific gravity of sulfuric acid used in the Babcock Test for milk?

### 1.82-1.83

13

## What is the scale to measure percent sugar?

### Brix

14

## What is the principle of Atomic Absorption Spectroscopy?

### Determination of elements based on absorption of radiation by the free atoms

15

## What is the official method for determining sulfites in foods?

### Modified Monier-Williams Procedure

16

## What is the most commonly used test for the detection of improperly pasteurized milk?

### Alkaline Phosphatase test

17

## What is the most accurate and sensitive method for quantitative determination of metals and metalloids?

### Atomic Absorption Spectroscopy

18

## What is the Michaelis Menten equation?

### Vo = Vmax[S] / Km + [S]

19

## What is the Henderson Hasselbach equation?

### pH=pKa + log [base]/[acid]

20

## What is the denominator of a t-test?

### Standard error of the mean

21

## What is the common term used to describe -log(H+)?

### pH

22

## What is provitamin A?

### Î²-carotene

23

## What is an Operating Characteristic or OC curve?

### A plot of the probability of acceptance of a lot of material at various levels of defects in the lot at a given AQL (acceptable quality level).

24

## What is a type II error?

### Falsely accepting a null hypotheses

25

## What is a Mojonnier test used for?

### Percentage milk fat

26

## What instrument is used to determine Brix?

### Hydrometer or refractometer

27

## What instrument is used for measuring optical activity of compounds?

### Polarimeter - Dextrorotatory (+), Levorotatory (-)

28

## What does the Schaal Oven test measure?

### Susceptibility of fat to undergo lipid oxidation

29

## What does the phenol sulfuric acid assay measure?

### Reducing sugars

30