Food and Nutrition Term 1

The food system

  • pathway food travels from “paddock to plate”

  • farm —> food manufacturers —> retailer —> consumer

Distribution

Research

Production

Processing

Consumption

Production

  • agriculture, aquaculture, cropping

  • 90% fresh fruit, vegetables, meat, dairy are fresh

  • 50% Australian production is exported

Processing

  • food is most often cooked / processed to become edible

  • ensures food is accessible and extended life

  • can increase value

  • some aren’t as nutritional after processing due to added fat, sugar, salt or other additives

Distribution

  • includes transport, marketing, merchandising and selling

  • 2 main channels —> retail —> food services

  • FSANZ protect from contamination during transport

  • food industry is dominated by Woolworths and Coles (80%)

Consumption

  • consumers = anyone who buys or uses goods or services

  • influenced by marketing or advertising

Research

  • prepare new food formulations based off sensory properties

  • creating a solution for more food demand

  • essential for innovation and performed by food scientists

Waste management

Protection

Sustainability

Nutrients

  • Carbohydrates

  • Protein

  • Water

  • Fat

  • Vitamins and minerals

Proteins sources

Animal based - meat, eggs, dairy

Plant based - soya beans, legumes, seeds, nuts

Carbohydrates

Simple —> quick release —> sugars

Complex —> slow release —> starch and grains

Fats

Saturated —> Animal and coconut

Unsaturated —> Vegetable

Protein

Complete —> all amino acids

Incomplete —> lack amino acids

Revision questions

  1. What are the building blocks of proteins?

amino acids

  1. What are the chemical elements of amino acids?

carbon, hydrogen, oxygen, nitrogen

  1. Explain the function of proteins

  • maintain and grow muscle

  • secondary protein source

  • support immunity

  • contributes to fullness

  1. Provide 2 examples of both plant and animal protein sources

Animal —> meat, eggs

Plant —> soya beans, nuts

Amino acids

  • proteins are joined by a peptide bond, creating a polypeptide chain

  • the components of amino acids consists of a central carbon, amino group and carboxylic acid group, side chain

  • the shape of protein controls it’s function, elongated or globular

Processing

  • improve palatability and prolong shelf life

Canning

  • safe, inexpensive and convenient

  • heated at steam between 116C and 121C to destroy microorganisms that cause food spoilage

  • sensory qualities of protein foods are altered and become smoother

  • foods are canned at peak freshness

Dehydration

  • removes moisture from food to the point of killing microorganisms

  • prolongs shelf life

  • some meats can be dehydrates with little nutrition change

  • dehydrated meat shrinks in size, the colour darkens and texture hardens

Addition of acid

  • slows down the growth of microorganism - prolongs shelf life

  • vinegar, lemon juice, soda water enhance palatability or extend shelf life

  • marinades also helps enhance flavour and tenderise

Additives

  • food additives maintain the quality and characteristics of food

  • they keep food safe and appealing

Sensory Properties

  • appearance

  • taste

  • texture

  • flavour

  • aroma

Food experiment result

 Sensory analysis

 Cottage cheese

skim milk + vinegar

 Ricotta

whole milk + lemon juice

 Junket

enzyme additive

 Quality of curd

firm

firm , smooth

 soft, smooth

 Texture

soft/ lumpy/ rubbery

smooth 

jelly, watery, jiggly

 Appearance

white/lumpy

white / no discolouration

white, watery

 Flavour

acidic

lemony / acidic

milk

 

Conditions bacteria require to colonise

  • warmth

  • moisture

  • food

Chilling food does not kill bacteria and stop colonization, only slows the process

Heat kills bacteria and stops colonization

Response example

Bacteria colonise on protein based foods and break it down leaving toxins. The amino acids in the chicken are an excellent source of food for bacteria. Salmonella is a common bacteria found in chicken products.

Bacteria require warmth which has been supplied by the oven. It is likely the chicken has got to the danger zone 5-60C and remained there for hours witht the power outage providing time for the bacteria to grow. These chickens are unsafe to consume as they have been in the danger zone for more than a couple of hours, indeed unknown when the power went out.

The exterior of the chicken has been warmed making it an ideal environment for bacteria to colonise.