Technology and Living | Food Science and Technology Extended Study

Food Science and Technology Extended Study: Your Ultimate Guide!

Hey everyone! Welcome to the extended study of Food Science and Technology. Don't let the name intimidate you! This chapter is all about uncovering the secrets behind our food. We'll explore why ingredients behave the way they do in the kitchen (like why a sauce thickens) and take a peek into how food is made safely on a massive scale in factories.

Understanding this will make you a smarter cook, a more informed consumer, and you'll see the food on your plate in a whole new, exciting way. Let's get started!

Part 1: The Secret Powers of Food Components (Functional Properties)

Ever wonder what makes a cake fluffy or a sauce smooth? It's not magic, it's science! Functional properties are the special jobs that the main components of food—water, carbohydrates, proteins, and fats—do during preparation and cooking.

1.1 Water: The Unsung Hero

Water is more than just for drinking! In food, it's a basic constituent, meaning it's a fundamental part of most foods. It acts as a solvent, dissolving things like salt and sugar, and it's essential for many of the chemical reactions we're about to explore.

1.2 Carbohydrates: More Than Just Energy!

Carbohydrates, especially starch and sugar, have some amazing abilities.

Starch's Amazing Transformations

• Gelatinisation: This is the process where starch thickens a liquid when heated. It's the secret behind a good gravy or a creamy custard!
  How it works, step-by-step:
  1. Starch granules are mixed into a cold liquid (like water or milk).
  2. As you heat the mixture, the starch granules absorb the liquid and start to swell up, like tiny balloons.
  3. At around 60-80°C, they get so full that they burst, releasing long starch molecules.
  4. These molecules tangle together, trapping the water and making the whole mixture thick and viscous.
  Example: Making a white sauce for macaroni and cheese, or thickening a cornstarch slurry for a stir-fry sauce.

• Dextrinisation: This is what happens when starchy foods are cooked with dry heat. It's the reason toast tastes so good!
  How it works:
  The intense dry heat breaks down the long starch chains into shorter sugar units called dextrins. This process causes a brown colour, a crispier texture, and a slightly sweeter, toasty flavour.
  Example: Toasting bread, baking biscuits until golden brown, or the brown crust on a baked potato.

Sugar's Many Jobs

Sugar does a lot more than just make things sweet!

• Sweeteners: The most obvious job!
• Preservatives: In high concentrations, sugar draws water out of microbial cells, killing them or stopping their growth. This is why jam and preserves can last for so long without spoiling.
• Tenderisers: In baking, sugar gets in the way of gluten development and absorbs liquid, which results in a softer, more tender product like a cake or a biscuit.
• Crystallising Agents: When a sugar solution is super-saturated, it can form crystals. Example: Making rock candy or fudge.
• Caramelising Agents: When sugar is heated to a high temperature (without water), it melts and breaks down, creating a beautiful amber colour and a rich, complex flavour. This is caramelisation.
  Example: The hard topping on a crème brûlée, or the sweet flavour of caramel sauce.

We also need to know about hydrolysis, which is simply the process of breaking down a large sugar molecule (like sucrose) into smaller ones (like glucose and fructose) by adding water, often with the help of an acid or an enzyme.

1.3 Proteins: The Shape-Shifters

Proteins are like tiny, perfectly folded pieces of origami. Cooking and preparation can cause them to unfold and change shape, giving us fantastic new textures.

• Denaturation: This is the unfolding of a protein's natural structure. It's usually irreversible. Think of it like un-folding an origami crane—it's very hard to fold it back exactly the same way.
  What causes it? Heat (cooking), acids (lemon juice, vinegar), or mechanical action (whisking, beating).
  Example: The clear egg white turning opaque when you fry it (heat denaturation), marinating meat in lemon juice to make it tender (acid denaturation), or whisking egg whites into a foam (mechanical denaturation).

• Coagulation: This is what happens after denaturation. The unfolded proteins bump into each other and bond together, forming a solid or semi-solid network. They basically tangle up and set.
  Example: A fried egg setting, milk curdling to make cheese, or meat becoming firm when cooked.

• Foaming: Some proteins, when denatured by whisking, are great at trapping air bubbles to create a foam. Egg whites are the star of this!
  How it works: Whisking unfolds the egg white proteins. These proteins then surround the air bubbles you're beating in, forming a stable structure that holds the air in place.
  Example: Making meringue for a lemon meringue pie, or whisking cream into whipped cream.

• Emulsification: An emulsion is a mixture of two liquids that don't normally mix, like oil and water. Some proteins act as emulsifiers, which are like mediators that help oil and water get along and stay mixed together.
  Example: The protein lecithin in egg yolk is a fantastic emulsifier. In mayonnaise, it grabs onto both the oil and the vinegar, creating a stable, creamy sauce that doesn't separate.

1.4 Fats and Lipids: The Smooth Operators

Fats and lipids are also crucial in creating certain textures. Their most important functional property in this context is their role in emulsification. They are the "oil" part of the oil-and-water mixture, held in suspension by an emulsifier to create things like salad dressings, mayonnaise, and creamy sauces.

Quick Review: Key Functional Properties

Gelatinisation: Starch + Heat + Liquid = Thickening
Dextrinisation: Starch + Dry Heat = Browning & Toasting
Caramelisation: Sugar + High Heat = Browning & Rich Flavour
Denaturation: Protein structure unfolds (due to heat, acid, beating).
Coagulation: Unfolded proteins bond and set.
Emulsification: Helping oil and water to mix and stay mixed.

Part 2: From Farm to Factory (Industrial Food Production)

Now let's zoom out from the kitchen to the factory. How is food produced on a large scale for everyone to buy in supermarkets? It involves some clever science and very strict rules.

2.1 The Guiding Principles

Industrial food production follows four main goals:

• Maintain product quality: To make sure every bottle of ketchup or bag of chips tastes and looks the same, batch after batch.
• Enhance flavours and colours: To make food more appealing and tasty.
• Control product consistency: To ensure the texture is always right—crispy chips are always crispy, and creamy yogurt is always creamy.
• Improve nutritive value: To add vitamins and minerals to food to make it healthier (this is called fortification).

2.2 Using Micro-organisms for Good: Fermentation

Don't worry, we're talking about the "good guys"! Fermentation is a process where beneficial micro-organisms (like bacteria and yeast) are used to transform food. This can preserve the food, create unique flavours, and even make it more nutritious.

Types of Fermentation

• Lactic Acid Fermentation: Friendly bacteria consume sugars and produce lactic acid. This acid gives a tangy flavour and acts as a preservative.
  Examples: Yoghurt, sauerkraut, pickles, salami.
• Mould Fermentation: Specific, safe types of mould are used to develop deep, complex flavours.
  Example: The fermentation of soybeans with mould to create traditional soy sauce.
• Acetic Acid Fermentation: Bacteria convert alcohol into acetic acid.
  Example: Turning wine or apple cider into vinegar.

During fermentation, micro-organisms produce different substances. The two most common are alcohol and carbon dioxide. For example, in bread making, yeast ferments sugar, producing carbon dioxide gas that makes the dough rise!

2.3 The Real Deal on Food Additives

Food additives are substances added to food to perform a specific job, like preserving it or improving its taste, texture, or appearance. They are used to achieve the four "guiding principles" we just talked about.

Did you know?

Not all additives are artificial! Many come from natural sources. For example, Vitamin C (ascorbic acid) is often used as an antioxidant, and pectin from fruit is used as a thickener.

Why are additives used?

• To Preserve Product Quality
  - Antimicrobial agents: Stop the growth of bacteria, yeasts, and moulds. Examples: nitrites in cured meats, acids like vinegar.
  - Antioxidants: Prevent food from reacting with oxygen, which can cause fats to go rancid or fruits to brown. Example: citric acid.
• To Enhance Sensory Characteristics
  - Colouring agents: Make food look more attractive. Can be natural (from beetroot) or synthetic.
  - Flavouring agents: Add or restore flavour to food.
• To Control Product Consistency
  - Anti-caking agents: Keep powders like salt flowing freely.
  - Emulsifiers: Help oil and water mix. (We saw this earlier!)
  - Stabilisers and thickeners: Give food a smooth, even texture. Example: in ice cream to prevent ice crystals.
  - pH control agents: Control the acidity or alkalinity of food.
• To Improve or Maintain Nutritive Value (Fortification)
  - Example: Iodine added to salt.
  - Example: Vitamin D added to milk.
  - Example: Iron and B vitamins added to cereal products.
  - Example: Calcium fortified orange juice.

Decoding the Label: The International Numbering System (INS)

On an ingredients list, you'll see additives listed by their name or a code number. The International Numbering System (INS) is a standardized system used worldwide to identify additives. You don't need to memorize the numbers, just understand that it's a code that helps regulate and identify each additive.

2.4 High-Tech Kitchens & Staying Safe

Industrial food production uses advanced technology and rigorous safety systems.

Advanced Food Technologies

• Canning: Food is sealed in an airtight can and then heated to a very high temperature. This kills all micro-organisms and removes oxygen, making the food sterile and allowing it to be stored for years.
• Freeze-drying: This is a gentle way to remove water. First, the food is frozen solid. Then, it's placed in a powerful vacuum, which causes the ice to turn directly into water vapour (a process called sublimation). This preserves the food's structure, flavour, and nutrients much better than regular drying. Think of instant coffee or the food astronauts eat!

HACCP: The Ultimate Safety Plan

Hazard Analysis and Critical Control Point (HACCP) is a systematic, preventive approach to food safety. Instead of just checking the final product for problems, HACCP identifies potential hazards (biological, chemical, or physical) at every single step of the production process and puts in controls to stop them from ever happening.

Analogy: HACCP is like being a detective that predicts and prevents crimes before they happen, rather than a police officer who only shows up after the crime has been committed.

Packaging, Labels, and the Planet

• Food Packaging: Protects food from damage, contamination, and spoilage. It also provides a place for important information.
• Food Labelling: This is a legal requirement. Labels must provide consumers with essential information like the product name, ingredient list, nutritional information, and expiry date.
• Environmental Issues: All that packaging creates waste. The food industry is looking for greener solutions, like using biodegradable plastic bags, which are designed to be broken down by micro-organisms in the environment.

Key Takeaways: Industrial Food Production

Main Goals: Quality, Consistency, Flavour/Colour, Nutrition.
Fermentation: Using good microbes to transform food.
Additives: Substances with specific jobs (preserving, colouring, thickening, etc.).
HACCP: A proactive system to PREVENT food safety hazards.
Technology: Canning and freeze-drying are key preservation methods.
Responsibility: Correct labelling and considering environmental impact are crucial.