lecture 1 Flashcards
(18 cards)
What are the essential food components?
- Carbohydrates
- Fats
- Proteins
- Minerals
- Vitamins
- Fibre
- Water (H2O)
describe physio-chemical analysis
Analyses
. pH
. water content
. moisture content
. Protein, fat and carbohydrate content
.rheology and viscosity of foods.
Microbiological Analysis
analyses growth of bacteria, yeasts, and moulds
What is pH
potential hydrogen
* ph is determined with a ph meter or paper.
how could you measure the moisture content of a food?
By drying it, subtracting the initial mass from the final mass, using an oven (slow) or infrared drying (fast),
What does water activity (a_w) influence?
- Microbial growth
- Enzyme and vitamin decomposition
- Stability of color, taste, and flavor
What does a water activity of 0 mean?
absolute dryness
What does a water activity of 1 mean?
condensed humidity
How is protein content measured?
Protien has an amine group that is compriesed of a nitrogen and 2 hydrogens(NH2–C–COOH).
K-JEL-DAHL method determines protein content by measuring the nitrogen content.
What is the purpose of the Soxhlet method?
To determine fat content in food.
What is the formula for calculating carbohydrate content?
Carbohydrate (%) = 100% - (H2O + ash + fat + protein)
What does ash content represent?
The minerals left after burning it (ignition) or after oxidation of organic matter.
Name two methods of analysing microbiological activity.
- ATP-meter
- plate reading
define what a food is
a substance that provides at least one nutrient when eaten, digested and absorbed.
define what a nutrient is
A substance that promotes body functions.
(when digested and absorbed)
define nutrition
A process by which living organisms receive material and use it to promote their
vital activities
Define what a food is
a substance that provides at least one nutrient when eaten, digested and absorbed.
How are oils, fats and lipid content measured
SO-XH-LET
