Food Preservation Quiz 13.2

What are the main causes of food deterioration and spoilage?

• Microbial growth, enzymatic activity, chemical reactions, and physical damage

• Only microbial growth and enzymatic activity

• Only chemical reactions and physical damage

• None of the above

Answer explanation

The main causes of food deterioration and spoilage include microbial growth, enzymatic activity, chemical reactions, and physical damage. All these factors contribute to the degradation of food quality, making this the correct choice.

What is required for microbial growth to occur in food?

• Nutrients, water activity, and time in the danger zone

• Only nutrients and water activity

• Only time in the danger zone

• None of the above

Answer explanation

Microbial growth in food requires nutrients for energy, sufficient water activity for metabolic processes, and time spent in the danger zone (40-140°F) where bacteria can multiply rapidly. Thus, the correct answer is nutrients, water activity, and time in the danger zone.

What type of equipment is used in pasteurisation?

• Tubular exchanger

• Plate exchanger, vats

• Aseptic systems

• Vacuum chambers

Answer explanation

Plate exchangers and vats are commonly used in pasteurisation to heat liquids efficiently. They allow for rapid heating and cooling, ensuring that the product is pasteurised effectively while maintaining quality.

What is an example of a chemical reaction in food?

• Oxidation of unsaturated fats in peanuts

• Polyphenol oxidase in a cut apple

• Lactobacillus bacteria fermenting milk

• None of the above

Answer explanation

The oxidation of unsaturated fats in peanuts is a chemical reaction that can lead to rancidity, affecting flavor and nutritional quality. This process exemplifies how chemical changes occur in food.

What is a key factor in the preservation needs of milk according to the syllabus?

• Color of the milk

• Microbial load and moisture

• Price of the milk

• Brand of the milk

Answer explanation

The preservation needs of milk are primarily influenced by its microbial load and moisture content. High microbial load can lead to spoilage, while moisture levels affect the growth of bacteria, making this the key factor.

What is the temperature range for UHT treatment?

• 63–72°C

• 100–110°C

• 135–150°C

• 160–180°C

Answer explanation

UHT (Ultra High Temperature) treatment typically occurs at temperatures between 135–150°C. This range effectively sterilizes the product while preserving its quality, making it the correct choice.

What does the acronym FAT-TOM stand for in microbial growth requirements?

• Food, Acidity, Temperature, Time, Oxygen, Moisture

• Fat, Acidity, Temperature, Time, Oxygen, Minerals

• Food, Alkalinity, Temperature, Time, Oxygen, Moisture

• Fat, Alkalinity, Temperature, Time, Oxygen, Minerals

Answer explanation

FAT-TOM stands for Food, Acidity, Temperature, Time, Oxygen, Moisture, which are essential factors for microbial growth. The correct choice highlights these key elements necessary for understanding microbial needs.

What does UHT treatment sacrifice for sterility and shelf stability?

• Nutrient content

• Sensory attributes

• Packaging cost

• Processing time

Answer explanation

UHT treatment sacrifices sensory attributes, such as taste and texture, to achieve sterility and shelf stability. This process can alter the flavor and overall quality of the product, despite ensuring safety and longevity.

What does the term "aseptic" refer to in the context of UHT milk packaging?

• Flavor enhancement

• Sterility and protection from contamination

• Increased fat content

• Added preservatives

Answer explanation

The term 'aseptic' in UHT milk packaging refers to sterility and protection from contamination, ensuring that the milk remains safe and shelf-stable without the need for preservatives.

What impact do chemical reactions have on food?

• Makes food unpalatable and reduces shelf life

• Improves nutritional content

• Enhances flavor

• None of the above

Answer explanation

Chemical reactions can lead to spoilage, making food unpalatable and reducing its shelf life. This is particularly true for reactions like oxidation and microbial growth, which negatively affect food quality.