Food safety hurdles — Using a combination of low NaCl, NaNO3 (curing salts), and slightly acidic pH most effectively prevents multiplication and toxin formation of which pathogen?

Introduction / Context:
Hurdle technology combines multiple sublethal stresses to inhibit pathogens in foods. In cured meats and similar products, salt (NaCl), nitrite/nitrate (often denoted as NaNO2/NaNO3, collectively curing salts), and slightly acidic pH are classic hurdles. Identifying which organism is most specifically targeted by this combination is central to safe product design.

Given Data / Assumptions:

• NaNO3 (and its reduced form NaNO2) act as curing agents with antimicrobial effects.
• NaCl reduces water activity, stressing many microbes.
• Slightly acidic pH (for example, pH ~5.2–6.0) enhances inhibitory action.

Concept / Approach:
Clostridium botulinum is an obligate anaerobe capable of producing botulinum neurotoxin in low-acid, anaerobic, moist foods. Curing salts specifically inhibit spore germination and outgrowth, while salt and acidity further reduce risk. Although Salmonella and Staphylococcus aureus are affected by salt and acid to varying degrees, the targeted, long-established purpose of nitrite/nitrate in cured meats is to prevent C. botulinum toxin formation under anaerobic storage.

Step-by-Step Solution:

Verification / Alternative check:
Regulatory guidance for cured meats specifies minimum nitrite concentrations and pH/salt combinations as control measures against botulism, confirming the primary target organism.

Why Other Options Are Wrong:

• Salmonella: sensitive to hurdles, but nitrite use is not chiefly aimed at this pathogen.
• S. aureus: relatively salt tolerant; toxin production control relies on temperature/aw limits rather than nitrite alone.
• All of these: too broad; the combination is designed principally to prevent botulinal toxin.

Common Pitfalls:
Assuming “more salt” alone ensures safety; the synergy of nitrite/nitrate, salt, pH, and temperature is essential for anti-botulinal protection.

Final Answer:
C. botulinum