Digestive enzymes, dietary fibres, cereals, grains and health drinks as nutraceuticals MCQs With Answer

Introduction:

Digestive enzymes, dietary fibres, cereals, grains and health drinks as nutraceuticals are core topics in Advanced Pharmacognosy for M.Pharm students focusing on plant-based bioactives and functional foods. This set of MCQs is designed to deepen understanding of enzyme classes, zymogen activation, enzyme assays, fibre chemistry and physiological effects, bioactive components in cereals and grains (like β-glucans, γ-oryzanol, avenanthramides), antinutrients, and formulation/standardization principles for health drinks. Questions emphasize mechanistic insight, analytical approaches, and implications for therapeutic use and formulation of nutraceuticals, preparing students for research, quality control, and evidence-based application of botanical-derived dietary supplements.

Q1. Which of the following statements correctly describes zymogen activation in digestive enzymes?

• Zymogens are active enzyme forms that require phosphorylation to become more active
• Zymogens are inactive precursors that undergo proteolytic cleavage to form the active enzyme
• Zymogens become active only after binding to dietary fibres in the gut lumen
• Zymogens are activated by direct reduction of disulfide bonds by bile salts

Correct Answer: Zymogens are inactive precursors that undergo proteolytic cleavage to form the active enzyme

Q2. Which assay is commonly used to quantify amylase activity by measuring reducing sugars released from starch?

• Folin–Ciocalteu assay
• DNS (3,5-dinitrosalicylic acid) assay
• Bradford protein assay
• TBARS lipid peroxidation assay

Correct Answer: DNS (3,5-dinitrosalicylic acid) assay

Q3. Soluble dietary fibre exerts cholesterol-lowering effects primarily through which mechanism?

• Direct inhibition of HMG-CoA reductase in hepatic cells
• Binding bile acids, increasing their excretion and upregulating hepatic cholesterol conversion to bile acids
• Increasing intestinal absorption of dietary cholesterol
• Stimulating pancreatic lipase secretion to degrade cholesterol esters

Correct Answer: Binding bile acids, increasing their excretion and upregulating hepatic cholesterol conversion to bile acids

Q4. Which cereal component is most associated with reducing postprandial glycemic response and improving insulin sensitivity?

• β-glucans from oats and barley
• Phytates in rice bran
• Lectins in legumes
• Saponins from quinoa

Correct Answer: β-glucans from oats and barley

Q5. Resistant starch acts as a prebiotic because it:

• Is fully digested in the small intestine, producing glucose for absorption
• Resists digestion in the small intestine and is fermented by colonic microbiota to short-chain fatty acids
• Directly binds pathogenic bacteria preventing adhesion
• Is absorbed intact and modulates systemic immune responses

Correct Answer: Resists digestion in the small intestine and is fermented by colonic microbiota to short-chain fatty acids

Q6. Which antinutrient commonly found in cereals chelates minerals and can reduce bioavailability of iron and zinc?

• Trypsin inhibitors
• Phytic acid (phytate)
• Oxalic acid
• Lectins

Correct Answer: Phytic acid (phytate)

Q7. In development of health drinks fortified with cereal-derived nutraceuticals, which parameter is most critical to ensure stability of phenolic antioxidants during storage?

• The pH and presence of oxygen/light
• The viscosity of the beverage alone
• The carbohydrate to protein ratio only
• The initial particle size of insoluble fibre exclusively

Correct Answer: The pH and presence of oxygen/light

Q8. Gamma-oryzanol, a bioactive from rice bran, exerts hypolipidemic effects primarily through which proposed mechanisms?

• Direct inhibition of pancreatic amylase in the gut lumen
• Antioxidant activity and modulation of cholesterol metabolism including reduced absorption and altered hepatic enzyme expression
• Binding dietary fibres to form non-absorbable complexes
• Serving as a prebiotic substrate for bifidobacteria

Correct Answer: Antioxidant activity and modulation of cholesterol metabolism including reduced absorption and altered hepatic enzyme expression

Q9. Which analytical technique is most appropriate for quantifying β-glucan content and molecular weight distribution in oat extracts?

• Gas chromatography–mass spectrometry (GC-MS) without derivatization
• Size-exclusion chromatography (SEC) coupled with refractive index or multi-angle light scattering detection
• ELISA specific for gluten proteins
• pH titration method

Correct Answer: Size-exclusion chromatography (SEC) coupled with refractive index or multi-angle light scattering detection

Q10. Which digestive enzyme class primarily hydrolyzes peptide bonds adjacent to aromatic amino acids such as phenylalanine and tryptophan?

• Carboxypeptidases
• Cysteine proteases like papain
• Endopeptidases such as chymotrypsin
• Exopeptidases that remove N-terminal residues

Correct Answer: Endopeptidases such as chymotrypsin

Q11. Which processing method can significantly reduce phytate content in cereals and improve mineral bioavailability?

• High-temperature extrusion without moisture control
• Fermentation and enzymatic phytase treatment
• Micronization to reduce particle size only
• Spray-drying at low temperatures

Correct Answer: Fermentation and enzymatic phytase treatment

Q12. In the context of dietary fibre classification, which descriptor best differentiates soluble from insoluble fibres?

• Soluble fibres are always fermentable; insoluble fibres are always non-fermentable
• Solubility in water and ability to form viscous solutions vs. structural, non-viscous bulking properties
• Soluble fibres are proteins; insoluble fibres are lipids
• Only insoluble fibres affect glycemic index

Correct Answer: Solubility in water and ability to form viscous solutions vs. structural, non-viscous bulking properties

Q13. Which cereal grain is particularly rich in avenanthramides, compounds with anti-inflammatory and antioxidant properties?

• Rice
• Wheat
• Barley
• Oats

Correct Answer: Oats

Q14. When formulating a functional health drink containing probiotic bacteria and cereal-derived prebiotics, what is the primary consideration for maintaining probiotic viability?

• Selecting probiotics based solely on antibiotic resistance profiles
• Ensuring an appropriate prebiotic substrate, protective matrix (e.g., microencapsulation), and suitable pH/osmotic conditions
• Maximizing sugar content to feed probiotics regardless of osmolarity
• Eliminating all dietary fibres to avoid competition

Correct Answer: Ensuring an appropriate prebiotic substrate, protective matrix (e.g., microencapsulation), and suitable pH/osmotic conditions

Q15. Which statement best explains how soluble viscous fibres reduce glycemic response?

• They increase gastric emptying rate, delivering carbohydrates faster to the small intestine
• They form viscous gels that slow gastric emptying and carbohydrate diffusion, reducing glucose absorption rate
• They enzymatically degrade carbohydrates pre-absorption
• They stimulate pancreatic beta cells to release more insulin preprandially

Correct Answer: They form viscous gels that slow gastric emptying and carbohydrate diffusion, reducing glucose absorption rate

Q16. Which parameter is essential for standardization of a cereal-based nutraceutical extract intended as a health drink ingredient?

• Quantification of one or more bioactive marker compounds and assay of total dietary fibre content with validated methods
• Only sensory attributes such as color and mouthfeel
• Measuring just moisture content without bioactive assays
• Counting total bacterial colony forming units in the raw grain only

Correct Answer: Quantification of one or more bioactive marker compounds and assay of total dietary fibre content with validated methods

Q17. Which short-chain fatty acid produced by colonic fermentation of dietary fiber is most strongly associated with colonic epithelial health and anti-inflammatory effects?

• Propionate
• Butyrate
• Acetone
• Ethanol

Correct Answer: Butyrate

Q18. In assessing the impact of heat processing on cereal nutraceuticals, which component is most vulnerable to degradation that could reduce antioxidant capacity?

• Mineral phosphorus bound as phytate
• Heat-sensitive phenolic compounds and certain vitamins
• Insoluble cellulose which becomes more bioavailable
• Stable polysaccharides unaltered by heat

Correct Answer: Heat-sensitive phenolic compounds and certain vitamins

Q19. Which enzyme inhibitor present in some cereals and legumes can interfere with protein digestion and is often reduced by thermal processing?

• α-Amylase inhibitor
• Trypsin inhibitor (protease inhibitor)
• Phytase
• Lipase activator

Correct Answer: Trypsin inhibitor (protease inhibitor)

Q20. For clinical studies evaluating a cereal-derived functional health drink claiming cholesterol reduction, which primary outcome measure is most appropriate?

• Change in fasting serum LDL-cholesterol concentration over a controlled intervention period
• Change in stool consistency only
• Total antioxidant capacity of the beverage measured in vitro alone
• Subjective taste preference scores

Correct Answer: Change in fasting serum LDL-cholesterol concentration over a controlled intervention period

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