Volatile oils – Coriander MCQs With Answer

Volatile oils – Coriander MCQs With Answer

Coriander (Coriandrum sativum) volatile oils are concentrated, aromatic mixtures of terpenoids and oxygenated compounds, with linalool as the dominant constituent in seed oil. B.Pharm students should understand their phytochemistry, extraction (steam distillation/hydrodistillation), analytical profiling by GC‑MS/GC‑FID, and quality control parameters such as refractive index, specific gravity and sensory evaluation. Coriander oil exhibits antimicrobial, antioxidant and carminative properties and is used in formulations for flavoring and therapeutic purposes. Knowledge of adulteration detection, proper storage, and safety (skin sensitization) is essential for pharmacists working with essential oils. Now let’s test your knowledge with 30 MCQs on this topic.

Q1. What is the botanical name of the plant commonly called coriander?

• Coriandrum sativum
• Mentha piperita
• Foeniculum vulgare
• Ocimum basilicum

Correct Answer: Coriandrum sativum

Q2. Most commercial coriander volatile oil is obtained from which part of the plant?

• Leaves (foliage)
• Roots
• Seeds
• Flowers

Correct Answer: Seeds

Q3. Which compound is the major constituent of coriander seed oil?

• Eugenol
• Linalool
• Menthol
• Carvacrol

Correct Answer: Linalool

Q4. Which extraction method is most commonly used for obtaining coriander volatile oil at commercial scale?

• Cold maceration
• Steam distillation / Hydrodistillation
• Soxhlet extraction with water
• Supercritical CO2 at room temperature without pressure

Correct Answer: Steam distillation / Hydrodistillation

Q5. Which technique is NOT suitable for extracting volatile oils due to loss of aroma compounds?

• Steam distillation
• Hydrodistillation
• Cold maceration in water
• Solvent extraction with volatile organic solvents

Correct Answer: Cold maceration in water

Q6. Which analytical technique is the preferred method for qualitative and quantitative profiling of coriander volatile oil?

• UV–Vis spectrophotometry
• Gas chromatography–mass spectrometry (GC‑MS)
• Gravimetric analysis
• Direct visual inspection

Correct Answer: Gas chromatography–mass spectrometry (GC‑MS)

Q7. Which constituent is primarily responsible for the floral‑sweet aroma of coriander seed oil?

• Geraniol
• Linalool
• Borneol
• Thymol

Correct Answer: Linalool

Q8. Coriander volatile oils are rich in which class of natural products?

• Alkaloids
• Terpenoids (monoterpenes/oxygenated terpenes)
• Saponins
• Polysaccharides

Correct Answer: Terpenoids (monoterpenes/oxygenated terpenes)

Q9. The antimicrobial activity of coriander oil is largely attributed to which molecule?

• Linalool
• Sucrose
• Cellulose
• Ascorbic acid

Correct Answer: Linalool

Q10. Which statement best describes the solubility of coriander volatile oil?

• Miscible with water and insoluble in organic solvents
• Soluble in polar organic solvents (ethanol, ether) and insoluble in water
• Only soluble in saline solutions
• Completely insoluble in both water and alcohol

Correct Answer: Soluble in polar organic solvents (ethanol, ether) and insoluble in water

Q11. What is the recommended storage condition for coriander volatile oil to preserve quality?

• Clear glass bottle exposed to light
• Amber glass container, cool and airtight
• Plastic bottle at high temperature
• Open container at room temperature

Correct Answer: Amber glass container, cool and airtight

Q12. Which physicochemical parameter is commonly used to detect adulteration of essential oils including coriander oil?

• Refractive index
• pH of pure oil
• Boiling point of water
• Melting point

Correct Answer: Refractive index

Q13. What is the typical color appearance of pure coriander seed oil?

• Dark brown to black
• Pale yellow to greenish‑yellow
• Bright red
• Opaque white

Correct Answer: Pale yellow to greenish‑yellow

Q14. In pharmaceutical formulations, coriander volatile oil is primarily used as a:

• Bulk laxative
• Flavoring and carminative agent
• Systemic antibiotic
• Parenteral solvent

Correct Answer: Flavoring and carminative agent

Q15. Which analytical method is routinely used for quantifying linalool content in coriander oil?

• High performance liquid chromatography with UV detection (HPLC‑UV)
• Gas chromatography with flame ionization detection (GC‑FID) or GC‑MS
• Colorimetric titration with iodine
• Gravimetric determination after evaporation

Correct Answer: Gas chromatography with flame ionization detection (GC‑FID) or GC‑MS

Q16. Which physical property most directly influences the volatility and evaporation rate of coriander oil constituents?

• Optical rotation
• Boiling point
• Colour
• Water content

Correct Answer: Boiling point

Q17. Which constituent is typically higher in coriander leaf (foliar) oil compared with seed oil?

• Linalool
• Geranyl acetate
• Menthol
• Ocimene

Correct Answer: Geranyl acetate

Q18. Which technique provides a chemical fingerprint for quality control of coriander volatile oil?

• Thin layer chromatography without standards
• Gas chromatography with retention index comparison (GC fingerprinting)
• Simple olfactory assessment only
• Paper chromatography in water

Correct Answer: Gas chromatography with retention index comparison (GC fingerprinting)

Q19. Linalool is classified chemically as a:

• Monoterpene alcohol
• Phenolic acid
• Alkaloid
• Polypeptide

Correct Answer: Monoterpene alcohol

Q20. Which pharmacological effect is commonly associated with coriander volatile oil in gastroenteric use?

• Carminative / antispasmodic effect
• Hypoglycemic shock
• Central nervous system stimulation causing seizures
• Renal diuresis leading to dehydration

Correct Answer: Carminative / antispasmodic effect

Q21. Which factor would most likely decrease the oil yield from coriander seeds?

• Mature, well‑dried seeds
• Immature seeds harvested early
• Optimal agronomic practices
• Proper post‑harvest drying

Correct Answer: Immature seeds harvested early

Q22. Volatile oils are also commonly referred to as which of the following?

• Fixed oils
• Essential oils
• Fatty acids
• Proteins

Correct Answer: Essential oils

Q23. Which characteristic is NOT typical of volatile (essential) oils?

• Complex mixtures of low molecular weight compounds
• Generally volatile at ambient temperatures
• Highly water‑soluble
• Soluble in organic solvents

Correct Answer: Highly water‑soluble

Q24. What is the main safety concern when using undiluted coriander volatile oil topically?

• Severe hepatotoxicity after single use
• Skin sensitization / irritation
• Immediate nephrotoxicity
• High risk of inhalation pneumonia

Correct Answer: Skin sensitization / irritation

Q25. For long‑term storage of coriander volatile oil in a pharmacy, which condition is best?

• Open bottle in direct sunlight
• Cool, dark place in amber glass
• Warm shelf near heating source
• Sealed plastic container exposed to heat

Correct Answer: Cool, dark place in amber glass

Q26. Which sign typically indicates oxidative deterioration of an essential oil sample?

• Stronger, fresher floral aroma
• Development of rancid or off‑odour
• Complete disappearance of color under UV
• Increase in freezing point

Correct Answer: Development of rancid or off‑odour

Q27. Which additive is commonly used as an antioxidant to retard oxidation of essential oils?

• Sucrose
• Tocopherol (vitamin E)
• Sodium chloride
• Hydrochloric acid

Correct Answer: Tocopherol (vitamin E)

Q28. Relative to water, the specific gravity of coriander volatile oil is typically:

• Greater than 1 (sinks in water)
• Less than 1 (floats on water)
• Exactly 1
• Variable and always equal to glycerol

Correct Answer: Less than 1 (floats on water)

Q29. Which chromatographic technique is best suited for separating and analyzing the volatile constituents of coriander oil?

• Gas chromatography (GC)
• Ion exchange chromatography
• Size exclusion chromatography
• Paper chromatography with water solvent

Correct Answer: Gas chromatography (GC)

Q30. Volatile oils such as coriander oil are biosynthetically classified under which group of secondary metabolites?

• Alkaloids
• Terpenoids
• Glycosides
• Tannins

Correct Answer: Terpenoids

G S Sachin

I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.

Mail- Sachin@pharmacyfreak.com