Bromelain is a proteolytic enzyme complex derived primarily from the stem and fruit of Ananas comosus (pineapple). It includes cysteine proteases with molecular isoforms that show optimum activity around neutral pH and moderate temperatures. Bromelain extraction and preparation involve homogenization, centrifugation, ammonium sulfate precipitation, dialysis and chromatographic purification, while evaluation uses activity assays (casein/azocasein), SDS-PAGE and zymography. Preservation and storage rely on lyophilization, stabilizers and low-temperature conditions to maintain activity. Therapeutic uses include anti-inflammatory, anti-edematous, fibrinolytic and digestive applications; commercial utility spans pharmaceuticals, nutraceuticals, food processing and cosmetics. Now let’s test your knowledge with 30 MCQs on this topic.
Q1. What is the primary botanical source of commercially produced bromelain?
- Papaya (Carica papaya)
- Ginger (Zingiber officinale)
- Pineapple (Ananas comosus)
- Fig (Ficus carica)
Correct Answer: Pineapple (Ananas comosus)
Q2. Bromelain is classified mainly as which type of protease?
- Serine protease
- Cysteine protease
- Aspartic protease
- Metalloprotease
Correct Answer: Cysteine protease
Q3. Which plant part yields the highest commercial bromelain activity?
- Leaves
- Fruit pulp
- Stem
- Seeds
Correct Answer: Stem
Q4. A common first step in bromelain purification after extraction is:
- High-performance liquid chromatography (HPLC)
- Ammonium sulfate precipitation
- Supercritical CO2 extraction
- Gel electrophoresis
Correct Answer: Ammonium sulfate precipitation
Q5. Which assay is commonly used to quantify bromelain proteolytic activity?
- Casein digestion assay
- Glucose oxidase assay
- Bradford protein assay only
- Ortho-phthalaldehyde (OPA) for lipids
Correct Answer: Casein digestion assay
Q6. Which inhibitor would most likely inhibit bromelain activity?
- PMSF (phenylmethylsulfonyl fluoride)
- EDTA
- E-64 (trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane)
- Bestatin
Correct Answer: E-64 (trans-epoxysuccinyl-L-leucylamido(4-guanidino)butane)
Q7. The typical molecular weight range reported for bromelain isoenzymes is approximately:
- 5–10 kDa
- 20–40 kDa
- 70–100 kDa
- 150–200 kDa
Correct Answer: 20–40 kDa
Q8. Optimum pH for many bromelain isoforms is generally around:
- pH 2–3
- pH 4–5
- pH 6–7
- pH 9–10
Correct Answer: pH 6–7
Q9. Which chromatographic method is commonly used for final polishing of bromelain preparations?
- Ion-exchange chromatography
- Thin-layer chromatography (TLC)
- Gas chromatography
- Size-exclusion chromatography
Correct Answer: Ion-exchange chromatography
Q10. A suitable long-term storage condition for purified bromelain to retain activity is:
- Room temperature in solution
- Lyophilized at -20°C under desiccation
- In aqueous buffer at 37°C
- Exposed to sunlight in a sealed vial
Correct Answer: Lyophilized at -20°C under desiccation
Q11. Which stabilizer is often used during lyophilization to preserve bromelain activity?
- Sodium lauryl sulfate
- Trehalose or maltodextrin
- Hydrochloric acid
- Hexane
Correct Answer: Trehalose or maltodextrin
Q12. Zymography is used to assess bromelain by:
- Measuring UV absorbance at 280 nm
- Detecting proteolytic activity in gels
- Quantifying carbohydrate content
- Analyzing volatile impurities
Correct Answer: Detecting proteolytic activity in gels
Q13. A key therapeutic application of bromelain is:
- Antihypertensive therapy
- Anti-inflammatory and anti-edematous treatment
- Insulin replacement
- Antiviral monotherapy for HIV
Correct Answer: Anti-inflammatory and anti-edematous treatment
Q14. In pharmaceutical formulations, topical bromelain is clinically used for:
- Wound debridement and eschar removal
- Systemic chemotherapy
- Long-term antibiotic therapy
- Hormone replacement therapy
Correct Answer: Wound debridement and eschar removal
Q15. Which analytical technique is used to estimate purity and molecular weight of bromelain?
- Gas chromatography–mass spectrometry (GC-MS)
- SDS-PAGE electrophoresis
- UV-Vis colorimetry for lipids
- Thin-layer chromatography for sugars
Correct Answer: SDS-PAGE electrophoresis
Q16. Which of the following is a potential adverse effect or contraindication when using bromelain orally?
- Increased bleeding risk with anticoagulants
- Severe hyperglycemia
- Permanent hair loss
- Renal cyst formation
Correct Answer: Increased bleeding risk with anticoagulants
Q17. Spray-drying bromelain for commercial powders requires consideration of:
- High inlet temperatures that may denature the enzyme
- Use of organic solvents to increase yield
- Adding proteases to enhance activity
- Exposing product to ultraviolet light to sterilize
Correct Answer: High inlet temperatures that may denature the enzyme
Q18. Which parameter defines specific activity of bromelain?
- Total protein per mg of formulation
- Enzyme activity units per mg protein
- Volume per unit weight
- pH per mg of enzyme
Correct Answer: Enzyme activity units per mg protein
Q19. A common quality control microbial limit test for bromelain preparations is intended to detect:
- Total bacterial count and absence of pathogens
- Presence of heavy metals only
- Yield of ammonium sulfate precipitation
- Optical rotation of the product
Correct Answer: Total bacterial count and absence of pathogens
Q20. Which buffer condition would likely help maintain bromelain stability during short-term storage?
- Acidic buffer at pH 2
- Neutral buffer around pH 6–7 with low ionic strength
- Highly alkaline buffer at pH 11
- Pure distilled water at 60°C
Correct Answer: Neutral buffer around pH 6–7 with low ionic strength
Q21. In downstream processing, dialysis of bromelain is primarily used to:
- Sterilize the enzyme by filtration
- Remove small salts and exchange buffer
- Increase molecular weight
- Denature contaminating proteins
Correct Answer: Remove small salts and exchange buffer
Q22. Which of the following commercial applications utilizes bromelain’s proteolytic activity?
- Meat tenderization in food processing
- Polymer cross-linking in plastics
- As a primary source of dietary iron
- As a UV-protectant in sunscreens
Correct Answer: Meat tenderization in food processing
Q23. When measuring bromelain activity using azocasein, the assay endpoint reflects:
- Release of colored peptide fragments from substrate
- Formation of gas bubbles
- pH increase above 10
- Reduction of nitrate to nitrite
Correct Answer: Release of colored peptide fragments from substrate
Q24. Which regulatory consideration is important for bromelain as a pharmaceutical excipient or API?
- Confirmation of enzymatic potency, purity, and microbial safety
- Only color and odor testing
- No testing needed for plant-derived enzymes
- Approval as a pesticide before human use
Correct Answer: Confirmation of enzymatic potency, purity, and microbial safety
Q25. Encapsulation of bromelain in enteric-coated capsules is done to:
- Promote release in the stomach
- Protect the enzyme from gastric acid and deliver to intestine
- Convert bromelain into a lipid-soluble form
- Increase enzyme denaturation
Correct Answer: Protect the enzyme from gastric acid and deliver to intestine
Q26. Which downstream technique separates proteins primarily by size and helps in bromelain fractionation?
- Ion-exchange chromatography
- Size-exclusion (gel filtration) chromatography
- Reverse-phase HPLC with organic solvents
- Affinity precipitation with polyethyleneimine
Correct Answer: Size-exclusion (gel filtration) chromatography
Q27. An important physicochemical property influencing bromelain formulation is:
- High volatility
- Thermal sensitivity and denaturation temperature
- Intrinsic radioactivity
- pH-independent activity under all conditions
Correct Answer: Thermal sensitivity and denaturation temperature
Q28. Combining bromelain with which class of drugs requires caution due to potential additive effects on bleeding?
- Antihistamines
- Anticoagulants and antiplatelet agents
- Proton pump inhibitors
- Topical emollients
Correct Answer: Anticoagulants and antiplatelet agents
Q29. Which biochemical feature often contributes to bromelain’s susceptibility to oxidation and inactivation?
- Presence of a catalytic cysteine residue
- High content of disulfide-free lipids
- Metal ion cofactors only
- Extensive glycosylation that prevents oxidation
Correct Answer: Presence of a catalytic cysteine residue
Q30. In commercial quality control, “unit activity” of bromelain typically refers to:
- Weight in milligrams per capsule
- Standardized enzyme activity measured under defined assay conditions
- pH per defined volume
- Number of microbial colonies allowed
Correct Answer: Standardized enzyme activity measured under defined assay conditions
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.
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