Learn to be a Food Scientist
- Enhance your employment opportunities
- Start or improve a food supply or service business
- Work in food research, consulting, teaching or the media.
This is a course with relevance to anyone who works in the food industry, both small and large scale operators, for anyone who works with human food - whether production, processing, cooking, marketing or information.
Note that each module in the Qualification - Associate Diploma in Food Science is a short course in its own right, and may be studied separately.
Raw or Processed Foods?
Raw foods have become popular in some places. In fact raw or unprocessed food has always been important in some situations.
People across the world grow vegetables and fruit to harvest and eat straight from the plants; and some indigenous peoples still live a hunter gatherer lifestyle to a large extent (if not at least some extent). These are examples of raw foods; taken from nature and eaten with little or no treatment. There are "health benefit" arguments for choosing to eat raw food; but the benefits of eating processed foods can also be argued.
Most People in Developed Countries will Eat Processed Foods.
Food science is concerned both with the composition of raw foods; and how that composition can be changed through various methods of processing.
Processing is the transformation of raw or fresh foods into other food products. Most food is processed in some way. The heating required for cooking counts as a chemical processing step because chemical processes occur which change the nature of the food.
Food processing also involves preservatives. This is because many food products are expected to last more than a day or two, to increase usefulness and reduce cost. Generally, the higher the level of preservatives in a food product, the longer its shelf life, and the lower its cost. An example of this is canned vegetables, such as peas, carrots, and potatoes.
Preservatives may be used to retain the nutritional value of a food or to limit spoilage. Some preservatives affect taste, some affect nutrition, and some affect both. Awareness of food processing and preservatives is necessary to developing new food products to properly assess consumer needs, cost, and storage.
Processed food is commonly defined as convenience meals and junk food: cakes, potato chips, processed meats, ready-made meals, and more. While these are indeed processed foods, they are not representative of all processed foods from a food industry perspective.
From an industry perspective, food processing means the types of intervention or processing a food undergoes. These include physical processes and chemical processes.
Types of Physical Processing
Physical processing uses physical methods to create change in the food. Sometimes this is simple physical change, like making something smaller. Other times it’s a physical dehydration process, such as high pressure drying.
Physical processing includes:
- High pressure treatment
Foods processed in these ways can usually be classified as minimally processed. This is an important distinction in an increasingly health conscious market.
Mincing – the food is cut into fine, uniform pieces.
Shredding – the food is cut or sliced into shreds, longer than minced pieces.
Macerating – softening or breaking up a food using a liquid, usually an acid.
Slicing – cutting food into slices, larger than shreds.
Milling – grinding into finer particles.
Husking – removing outer layers.
Dehydrating – removing liquid from a food.
High pressure treatment – using pressure to remove liquid from a food.
Types of chemical processing
Chemical processing using chemicals to create chemical change. There are high levels of chemical change and low levels of chemical change. Lower levels of chemical change are things like cooking – tomatoes and herbs are cooked to create pasta sauce. Higher levels of chemical change are usually preserving processes.
Chemical processing involves cooking and preserving processes such as:
Pickling – pickling involves the production of acid from foods via the process of fermentation or involves placing foods into brine (a high salt solution) or into vinegar which is too acidic for microorganisms to grow.
Fermentation – when a food is broken down using microbes like yeast and bacteria. The fermentation process releases heat.
Pasteurisation – the heating of liquids to kill microbes and reduce spoilage.
Canning – canning or bottling involves placing foods into a jar or can and heating foods to a temperature where microbes are destroyed and enzymes are inactivated. Canning food involves removing air from the container to form a vacuum seal.
Cooking – the general process of applying heat to create chemical change. Cooking causes the denaturation or proteins and changes the state of foods involved to improve digestibility, nutrient access, and palatability.
Emulsification – the mixing of different types of liquid to create a product such as mayonnaise.
Liquefaction – generating a liquid from products in a solid or gas form.
Preserving - there are several natural preservatives, many of which are used in food products intended for refrigeration, or which will have shorter shelf lives. There are also several chemical preservatives. Some preservatives are naturally present in foods, while others are added to foods either because they are not naturally present in the food, or because they are only present in small quantities.