Food Science

What it’s all about!

Food Science

What is food science?

• Food science is the study of the chemistry, physics and biology of food. • Food technology is the application of knowledge and principles learned from food science to food processing, preservation, distribution and evaluation.

Chemistry Statistics Mathematics Engineering

Food Science

Physics Microbiology Biochemistry Molecular Biology

Common Misconceptions About What Food Science Is

Food Preparation Nutrition • Trained as a chef, or cook, more of an art than a science • Nutritionists try to determine how much and what foods we should eat. Food scientists use this information to design the food products and processes.

Jobs in Food Science

• Product Development • Quality Assurance • Safety Control and Inspection • Research (academia or industry) • Safety or Quality Testing

People will always eat so there will always be jobs in Food Science!!!

• Biology • Chemistry • Physics

Main Areas

• Food Safety • Food Microbiology • Food Chemistry • Food Analysis • Food Processing • Food Packaging

Biology

Food Safety Food Microbiology

Food Microbiology

• The study of bacteria, viruses, yeast and moulds and how they affect food and consumption • Both adverse and beneficial effects: Spoilage and illness vs. fermentation and probiotics

• Food Spoilage

Adverse Microbes

- Changes in texture, colour, taste, or odour during storage. - E.g. Mouldy bread. • Illness - Intoxication or infection caused by microbes or their secretions. - E.g., botulinum toxin or e-coli infection

• Fermen tation

Beneficial Microbes

- Bacteria and yeast ferment carbohydrates in food, this results in alcohol, acid, and gas - E.g. Yeast make alcohol in beer and wine, bacteria make acid in yogurt • Probiotics - Bacteria that are beneficial to health are incorporated into food products - E.g. Bifidus or Casei bacteria are added to yogurt after fermentation

Current Microbiology Research

• Bacteria left on spinach leaf after washing Bacteria • Shows bacteria trapped within leaf contours

Food Safety

• Quality and Safety control to make sure food provided to the consumer is free from contamination by: – microorganisms – foreign bodies – dangerous chemicals

Food Pathogens

www.textbookofbacteriology.net Todar's Online Textbook of Bacteriology

• Microrganisms that cause food borne infection or intoxication:

E.coli

Botulinum Salmonella Listeria Campylobacter Staphylococci

Foreign Bodies

• Any non-edible materials such as: – Glass: No glass is allowed on the production floor of a food manufacturing plant – Plastic: All plastics containing food ingredients are coloured (usually blue or green) to make them easy to see – Metal: Metal detectors are mandatory at the end of all production lines to ensure no metal contaminants in the food – Insect parts: microscopy, inspection

Dangerous Chemicals

• Any chemical agent that can cause adverse, short or long term, health effects: – Cleaning chemicals – Packaging materials – Dangerous additives – Natural toxins

Food Chemistry

Food Chemistry Food Analysis

Food Chemistry

• Foods consist mainly of proteins, carbohydrates, and lipids • Functionality: any property other than nutritional characteristics that contribute to an ingredient’s usefulness in food products

Food Chemistry

Major Functionalities of Proteins: 1) Gelation – proteins interlock and trap water to form a gel Eg. Jello 2) Emulsification – allows for the mixing of oils and water Eg. Egg protein in salad dressing 3) Foaming – Proteins form a network that traps air Eg. Whipped egg meringue 4) Fibre Forming – Simulates meat texture Eg. Soy burgers

Food Chemistry

Major Functionalities of Carbohydrates: 1) Sweeteners – Small chain carbohydrates used as sweetening agents Eg. Sucrose 2) Preservatives Jam – Sugars reduce the availability of water, thus reducing microbial growth Eg. 3) Fermentation – Used by microbes as a food substrate Eg. Yeast in beer produces alcohol 4) Gelation pimentos – Long chains of sugars connect and trap water to form gels Eg. Alginate in olive

Food Chemistry

Major Functionalities of Lipids: 1) Crystalization – Fats crystalize in different ways to give different food textures Eg. Chocolate, ice cream 2) Emulsifiers – Fats like monoglycerides act as emulsifiers 3) Taste – lipids act as flavour carriers, affecting the taste sensation and mouthfeel

Current Food Chemistry Research

• Microfiltration to separate milk proteins • Changing Ice Cream Crystallization • Analysis of Whey proteins and comparison after different heat treatments

Food Analysis

• Principles and techniques for quantitative and qualitative analysis of food composition, sensory properties and safety • Breaking food down into components: – Water – Crude Fat – Crude Protein – Crude Fibre – Nitrogen Free (Starch, Sugar) – Ash (Minerals)

Food Analysis

Scenario

Cheese making: Microbiology – Lactic Acid Bacteria Safety – Listeria, Salmonella, E. Coli O157 Chemistry and physics – Casein Gelation Analysis – Nutritional Labels Processing – Gelation, Cutting, Syneresis, Healing, Cooking, Draining, Moulding, Aging Packaging – Vacuum Packing, Appealing Design

Physics

Physical properties of food Food Engineering and Processing Food Packaging

Physical and Physico-chemical Properties of Foods

• Colours • Colligative properties; freezing point, vapour pressure, water activity • Food dispersions (dispersed particles) such as emulsions • Formation of gels • Food texture and rheology: hardness, elasticity, compressability etc

Food Engineering

• Mass balances; when you make apple juice, where do all the apple components go?

• Energy balances; how can I pasteurize beer with less energy?

• Separation systems; can I use a membrane to remove bacteria from beer, so I don’t have to pasteurize it?

Food Processing

• Methods and technology used to transform agricultural products into food products • These processes include: – Pasteurization – Drying – Canning – Filtration – Freezing

Pasteurization

• The elimination of pathogenic bacteria and reduction in numbers of spoilage bacteria.

• Ensures a safe product and extends shelf life • Often used during production of: – Milk – Honey – Beer – Juices

Drying

• The dehydration of foods • Removing 95%-99% of water from a product by means of various process • Processes include: – Tunnel Drying – vegetables, fruits – Drum Drying – potato flakes – Spray Drying – coffee – Freeze Drying – drinks, instant meals

Canning

• The process of sealing a food in an airtight container and destroying all microorganisms by heating • The sterilization temperature is dependant on pH: pH Temperature 4.6 or greater > 121 °C 4.5 or lower < 100 °C

Filtration

• Separation of parts of a product by size • Used to: – Extract certain ingredients – Remove unwanted particles – Remove microorganisms • Processes include: – Cross Flow Filtration – Milk – Reverse Osmosis – Water Treatment – Charged Carbon Filtration - Brita

Freezing

• The lowering of a products temperature to below approx -10 °C • Decreases rates of chemical change and stops growth and metabolism of microorganisms • Processes include: – Blast Freezing – packaged foods – Fluidized Bed Freezing– Individual Quick Frozen Products – Immersion Freezing – Juices – Scraped Surface Freezing – Ice Cream

Food Packaging

Types of Packages

• MAP – modified atmosphere packages used to store contents in a gas other than air • Biodegradable – packages that will decompose over a relatively short amount of time in a landfill • Recyclable – materials that can be recycled • Permeable – Packages that allow the permeation of air, moisture, or both

Packaging Research

• PLA instead of PET – biodegradable plastic like pop bottles • Modified Atmosphere Packaging • Edible Packaging

Other Resources

•

The Science Behind Our Food

, U of Georgia, Detailed lesson plans on food science for high schools, www.uga.edu/discover/sbof/ • Food Science Ambassador program, Can Inst of Food Science and Technolwww.cifst.ca/default.asp?id=1027 • Institute of Food Technology Teacher Resources, http://members.ift.org/IFT/Education/TeacherResources /

Acknowledgements

• This presentation is based on a slides prepared by undergraduate students, Ben Chan and Michelle Wong, University of Guelph.

• The brochure on food science was prepared by undergraduate student Sara Wong.

• The CIFST Ambassador program is directed by the Scientific and Public Affairs Committee of the Canadian Institute of Food Science and Technology. For more information contact Art Hill, [email protected]