02 Introduction to Food Processing

According to Dennis R. Heldman, food processing is the conversion of raw materials or ingredients intro a consumer __.

food product

According to Connor (1988), food processing is the branch of __ that starts with raw materials and transforms then into _ or edible products through the application of _.

• manufacturing

• intermediate foodstuffs

• labor, machinery, energy, scientific knowledge

What is food processing?

the summation of all processes undergone by foods from producers to consumers (farm to table)

What is the ultimate goal of food processing?

Food preservation to extend shelf life

What are the goals of the food industry through food processing?

• extend shelf-life

• provide nutrients required for health

• increase variety in the diet

• generate income

What are the different methods of food preservation?

• physical

• chemical

• biological

What are the two types of physical method of food preservation? What are their differences?

• Conventional: The product is placed in the packaging first, and then the entire unit (product + pack) is sterilized together.

• Aseptic: The product and the packaging are sterilized separately and then brought together to be hermetically sealed in a sterile environment.

What are the different physical methods of food preservation?

• asepsis

• increase in temp

• decrease in temp

• lowering Aw

What is Asepsis and what some natural examples?

• The absence of microorganisms by keeping them out at the start of the process.

• egg shells and apple peels.

This physical method of preservation aims to kill or destroy microorganisms and inactivate enzymes present in food.

increasing temperature

What are the two primary goals of increasing temperature in food?

• To kill/destroy microorganisms.

• To inactivate enzymes naturally present in the food.

Compare Pasteurization versus Sterilization.

• Pasteurization: Processed at <100°C; product must be stored in the refrigerator.

• Sterilization: Processed at >100°C; product can be stored at room temperature.

What is the definition of Commercial Sterility?

The destruction of all viable microorganisms that are of public health significance.

How does decreasing temperature preserve food?

• It slows down degradation reactions in the food.

• It retards the growth of microorganisms.

Contrast Refrigeration and Freezing

• Refrigeration (4-7°C): Preserves food only for days or weeks.

• Freezing (<-18°C): Preserves food for months or even years.

Compare quick freezing vs slow freezing. Which is better for food quality?

• Quick Freezing: Fast nucleation leads to small ice crystals, maintaining better quality.

• Slow Freezing: Slow nucleation leads to large ice crystals, which can damage food structure.

What are three physical methods used to lower Water Activity (Aw)?

• Addition of solutes (humectants like sugar and salt) to bind water.

• Dehydration.

• Freeze concentration.

What is Freeze Concentration?

The removal of water from liquid foods by freezing it into pure ice crystals and then separating them.

At what pH is Benzoate effective and where is it commonly used?

pH 2.5-4.0; typically used in beverages and added at 0.1% concentration

This chemical is effective at an acidic pH (2.5–4.0); typically used in beverages and added at 0.1% concentration.

benzoate

What is the effective pH for Sulfite, and what is the role of metabisulfite?

pH >4.5; metabisulfite is specifically used to control browning

What is the primary function of Nitrates and Nitrites in processed meat?

They inhibit the growth of Cbot.

Why is Vitamin C added as a preservative?

It acts as an antioxidant to prevent lipid oxidation.

This chemical is effective at pH > 4.5, specifically __ is used to control browning.

sulfite; metabisulfite

These chemicals are used to inhibit the growth of C. bot (Clostridium botulinum) in processed meat.

nitrates and nitrites

This chemical acts as an antioxidant to prevent lipid oxidation.

Vitamin C

What are the different chemicals used in food preservation?

• benzoate

• sulfite

• nitrate/nitrite

• vitamin C

What is the main principle of biological food preservation?

The use of natural antimicrobials and microorganisms to increase the shelf-life of food.

What is a primary example of a microorganism and its byproducts used in biological method?

LAB (Lactic Acid Bacteria) and its metabolites.

What are Bacteriocins in the context of food preservation?

secondary metabolites produced during the proliferation of microorganisms like LAB

What is the definition of Hurdle Technology?

The intelligent combination of different preservation techniques to achieve multi-target and mild but reliable preservation effects.

What are four common examples of "hurdles" used in food preservation?

• temp

• Aw

• Acidity

• Preservatives

What is Homeostasis in the context of food science?

An organism’s automatic, self-regulating process of maintaining a stable, balanced internal environment despite changing external conditions.

What will happen if you fail to disturb the homeostasis of microorgs in foods consumed by humans?

• Food poisoning: general category for all food-borne illness

• Food intoxication: ingestion of toxins already present in the food (produced by bacteria or fungi)

• Food infection: ingestion of live, harmful microorgs