Food Additives: Analysis of preservatives, antioxidants, sweeteners and stabilizers MCQs With Answer

Food Additives: Analysis of preservatives, antioxidants, sweeteners and stabilizers MCQs With Answer

This quiz set is designed for M. Pharm students studying MPA 104T Food Analysis. It focuses on analytical principles and practical methods used to detect and quantify common food additives — preservatives, antioxidants, sweeteners and stabilizers. Questions probe mechanisms of action, sample preparation, instrumental techniques (HPLC, GC-MS, ion chromatography, spectrophotometry), regulatory considerations and interpretation of results. The content emphasizes critical thinking about matrix effects, specificity, limits of detection, and common interferences encountered in real food samples. Use these MCQs to test knowledge, prepare for exams and reinforce analytical strategies essential for ensuring additive safety and compliance.

Q1. Which analytical technique is most commonly used for simultaneous quantification of synthetic antioxidants like BHA and BHT in fatty food matrices?

• Gas chromatography with flame ionization detection after derivatization
• High performance liquid chromatography with UV detection
• Ion chromatography with conductivity detection
• Atomic absorption spectroscopy

Correct Answer: High performance liquid chromatography with UV detection

Q2. Benzoic acid and its salts (benzoates) are most effective as preservatives at which pH range due to their mode of action?

• pH 7.0–8.5
• pH 5.5–7.0
• pH 3.0–4.5
• pH 8.5–10.0

Correct Answer: pH 3.0–4.5

Q3. Which assay is widely used as a rapid screening method to estimate total antioxidant capacity of food extracts?

• DPPH radical scavenging assay
• Monier-Williams sulfite determination
• Kjeldahl nitrogen analysis
• Peroxide value titration

Correct Answer: DPPH radical scavenging assay

Q4. For quantitative determination of sulfite (SO2) residues in wine, which classical method is commonly applied in regulatory labs?

• Monier-Williams distillation followed by titration
• Enzyme-linked immunosorbent assay (ELISA)
• Atomic fluorescence spectroscopy
• Gel permeation chromatography

Correct Answer: Monier-Williams distillation followed by titration

Q5. Which preservative acts primarily by inhibiting microbial enzymes through interaction with sulfhydryl groups and is used for dried fruits and wines?

• Potassium sorbate
• Sodium nitrite
• Sulfites (e.g., sodium metabisulfite)
• Propionic acid

Correct Answer: Sulfites (e.g., sodium metabisulfite)

Q6. Aspartame analysis in soft drinks is best performed by which analytical technique given its low concentration and need for specificity?

• Refractive index HPLC without sample cleanup
• HPLC with UV detection or LC-MS after solid-phase extraction
• Infrared spectroscopy on neat samples
• Flame photometry

Correct Answer: HPLC with UV detection or LC-MS after solid-phase extraction

Q7. Which statement about potassium sorbate (sorbic acid) is correct regarding its antimicrobial spectrum?

• It is most effective against Gram-negative bacteria and spores
• It is mainly effective against molds and yeasts at acidic pH
• It acts as a strong reducing agent to prevent oxidation
• It is only active at pH above 8

Correct Answer: It is mainly effective against molds and yeasts at acidic pH

Q8. The Monier-Williams method for sulfite determination can give false high results if which interfering compound is present in the sample?

• Ascorbic acid (vitamin C)
• Pectin
• Sucrose
• Calcium chloride

Correct Answer: Ascorbic acid (vitamin C)

Q9. Which antioxidant is a primary phenolic antioxidant used in fats and oils and is commonly analyzed by HPLC after liquid–liquid extraction?

• Ascorbic acid
• Alpha-tocopherol
• Calcium propionate
• Benzoic acid

Correct Answer: Alpha-tocopherol

Q10. Which analytical approach is most appropriate to separate and quantify multiple high-intensity sweeteners (e.g., sucralose, saccharin, cyclamate) in a complex beverage matrix?

• Thin layer chromatography with visual inspection
• HPLC with photodiode array or MS detection after SPE cleanup
• Rheological measurement
• pH meter titration

Correct Answer: HPLC with photodiode array or MS detection after SPE cleanup

Q11. Which stabilizer’s characterization commonly uses determination of degree of esterification and gel strength as critical analytical parameters?

• Xanthan gum
• Pectin
• Sodium chloride
• Monosodium glutamate

Correct Answer: Pectin

Q12. Which preservative is often monitored by GC-MS as its methyl or propyl esters after derivatization when analyzing complex fatty food matrices?

• Sodium benzoate
• Parabens (e.g., methylparaben, propylparaben)
• Sodium nitrite
• EDTA

Correct Answer: Parabens (e.g., methylparaben, propylparaben)

Q13. Sucralose is notable among artificial sweeteners because it is:

• Metabolized to phenylalanine and unsafe in PKU
• Heat-stable and not significantly metabolized by humans
• A sugar alcohol with laxative effects
• Identical chemically to sucrose

Correct Answer: Heat-stable and not significantly metabolized by humans

Q14. Which method provides a direct measure of oxidative rancidity in fats and oils and is used to evaluate antioxidant efficacy?

• Peroxide value titration
• Phenolic content by Folin-Ciocalteu only
• pH measurement
• Kjeldahl nitrogen

Correct Answer: Peroxide value titration

Q15. When analyzing trace levels of nitrite and nitrate in processed meats, which technique is preferred for sensitivity and separation?

• Ion chromatography with UV or conductivity detection
• Ultraviolet-visible spectrophotometry without separation
• Simple gravimetric analysis
• Flame photometry

Correct Answer: Ion chromatography with UV or conductivity detection

Q16. Which stabilizer or thickener is often analyzed by rheological methods (viscosity, shear stress) to assess functional performance in formulations?

• Sodium nitrite
• Xanthan gum
• Ascorbic acid
• Sodium benzoate

Correct Answer: Xanthan gum

Q17. A common enzymatic kit used for rapid measurement of total sugar content in beverages is based on which principle?

• Oxidation of sugars followed by oxygen electrode measurement
• Specific enzymes converting sugars to NADH/NADPH measured spectrophotometrically
• Direct weight measurement after evaporation
• Gas evolution proportional to sugar concentration

Correct Answer: Specific enzymes converting sugars to NADH/NADPH measured spectrophotometrically

Q18. Which regulatory concept defines the maximum amount of an additive that can be ingested daily over a lifetime without appreciable risk?

• Maximum Residue Limit (MRL)
• Acceptable Daily Intake (ADI)
• Minimum Effective Dose (MED)
• Threshold of Toxicological Concern (TTC)

Correct Answer: Acceptable Daily Intake (ADI)

Q19. When validating an HPLC method for preservative quantification in jam, which parameter specifically assesses matrix effects during extraction and analysis?

• System suitability only
• Matrix-matched calibration or recovery studies
• Theoretical plate count alone
• Mobile phase pH measurement

Correct Answer: Matrix-matched calibration or recovery studies

Q20. Which sweetener is contraindicated for individuals with phenylketonuria (PKU) due to its metabolic breakdown products?

• Saccharin
• Aspartame
• Sucralose
• Steviol glycosides (stevia)

Correct Answer: Aspartame

Download