Food Analysis Quiz

Among the three types of water occurring in food which influence water activity?

• bound water

• free water

• adsorbed water

• all types of water

Five (5.0) g food sample was taken from a thoroughly mixed food X and subjected to moisture content determination using the oven drying method. After 8 hours, 2.000 g constant weight was obtained. The moisture content of food X is ______.

• 60%, wet basis

• 40%, wet basis

• 40%, dry basis

• no correct answer

Five (5.0) g food sample was taken from a thoroughly mixed food X and subjected to moisture content determination using the oven drying method. After 8 hours, 2.000 g constant weight was obtained. The Total solids in food X is ______.

• 60%, wet basis

• 7.5%, wet basis

• 75%, wet basis

• no correct answer

The protein content of beef patties was determined using the Kjeldahl method. After titration the %N calculated/computed was 2.48%. The corresponding protein content is

• 15.5%

• 2.48%

• 6.25%

• 4.96%

Which of the amino acid residues in the proteins serve as the basis of the principle(s) behind the Lowry method and the UV absorption method of protein content determination?

• aromatic amino acids such as tryptophan & tyrosine

• aliphatic amino acids such as alanine & valine

• neutral amino acids

• all amino acids composing the protein

To identify and possibly quantify the flavor compounds in food, which of the following analytical instrumental methods is most appropriate in conducting the analysis?

• Size exclusion chromatography

• Spectrometry

• Gas chromatography

• Electrophoresis

Spectrophotometers are commonly/widely used in the food industry for various analyses. Which of the following is/are true?

• Spectrophotometers are used to determine concentration of solutes in the UV and visible range.

• UV range is from 185 - 400 nm and visible range from 400 - 700 nm

• Spectrophotometers can be used for qualitative analysis

• All given are true.

Ash analysis is needed for nutritional assessment of food. It is also an initial step in the preparation of food for analysis of specific minerals such as the determination of specific metals through Atomic Absorption Spectroscopy (AAS). Which of the following analytical methods is recommended as a preparatory step for analysis of specific minerals in food without loss or volatilization of some minerals?

• dry ashing

• wet ashing

• low-temperature plasma ashing

• instrumentation: microwave ashing

The nutritive value of proteins in food can be evaluated in terms of the following, except:

• Protein digestibility

• Protein efficiency ratio (PER)

• Nitrogen balance

• No correct answer

To measure quantitatively fat in fresh milk, which of the following methods is most appropriate?

• Soxhlet method

• Goldfish method

• Babcock method

• Refractive index method