Food Preservation and HACCP Principles in Food Microbiology

What is the primary goal of food preservation?

To prevent spoilage, contamination, and deterioration, extending shelf life while maintaining quality and safety.

What are the three main categories of food preservation methods?

Thermal methods, non-thermal methods, and chemical methods.

What causes microbial spoilage in food?

Bacteria, yeasts, molds, and enzymes, with examples including Salmonella, Listeria monocytogenes, and Clostridium botulinum.

What is thermal preservation?

A method that uses heat to destroy microbes and enzymes, including processes like pasteurization, sterilization, and blanching.

What is pasteurization?

A thermal preservation method using mild heat (60-85°C for seconds/minutes) to destroy pathogens while preserving flavor, such as heating milk to 72°C for 15 seconds.

What is the purpose of sterilization and canning?

To achieve commercial sterility by using high heat (≥121°C for 15 minutes), preventing the growth of Clostridium botulinum.

What is blanching?

A short heating process (90-100°C for 1-5 minutes) that inactivates enzymes and maintains color and flavor, commonly used before freezing vegetables.

What is the aim of non-thermal food preservation methods?

To preserve nutrients, flavor, and texture without the use of heat.

What is High Pressure Processing (HPP)?

A non-thermal method that uses 100-600 MPa pressure to disrupt microbes while maintaining freshness, often used in juices and meats.

How does Pulsed Electric Field (PEF) technology work?

It uses high-voltage pulses to damage microbial cell membranes, suitable for liquid foods while retaining nutrients.

What is the function of UV-C light in food preservation?

It damages microbial DNA using wavelengths of 200-280 nm, commonly applied to produce, water, and packaging.

What is food irradiation?

A method that uses gamma rays, X-rays, or electron beams to kill insects, parasites, and pathogens, applied to spices, dried herbs, and meats.

What are common chemical preservatives?

Organic acids (like benzoic and sorbic acid), nitrites (sodium nitrite), sulfites, and antioxidants (BHA, BHT, Vitamin E) that inhibit spoilage.

What is Hurdle Technology in food preservation?

A method that combines multiple mild preservation techniques to enhance shelf life and safety.

What are the advantages and limitations of thermal preservation?

Advantages: Effective and simple. Limitations: Causes nutrient loss.

What are the advantages and limitations of non-thermal preservation?

Advantages: Retains quality. Limitations: Requires costly equipment.

What is HACCP?

Hazard Analysis and Critical Control Points, a systematic preventive approach to food safety that identifies and controls potential hazards.

What are the seven principles of HACCP?

1. Hazard Analysis, 2. Identify Critical Control Points, 3. Establish Critical Limits, 4. Monitor CCPs, 5. Establish Corrective Actions, 6. Record Keeping, 7. Verification.

What is the first principle of HACCP?

Hazard Analysis: Identifying significant hazards in the food production process and determining control measures.

What defines a Critical Control Point (CCP)?

A step in the food production process where control can be applied to prevent, eliminate, or reduce food safety hazards.

What is a Critical Limit (CL) in HACCP?

The maximum or minimum value to which a biological, chemical, or physical parameter must be controlled at a CCP to ensure safety.

What is the purpose of monitoring CCPs?

To ensure they remain within established critical limits through regular checks and measurements.

What are corrective actions in HACCP?

Procedures followed when a deviation in a critical limit occurs, aimed at preventing hazardous food from entering the food chain.

Why is record keeping important in HACCP?

It validates the HACCP plan and ensures the system operates according to the plan, crucial for audits and traceability.

What is the importance of HACCP in food microbiology?

It helps control microbial hazards, reducing the likelihood of contamination and ensuring compliance with food safety regulations.