Intro to analysis Flashcards
Why do we analyze food?
- Compliance with legal and labeling requirements, 2. Assessment of product quality, 3. Determination of nutritive value, 4. Detection of adulteration, 5. Research and development
What are the types of samples analyzed?
- Raw materials, 2. process control samples, 3. Finished product, 4. competitor’s sample, 5. Complaint sample
Properties of food analyzed
- Composition, 2. structure, 3. physiochemical properties, 4. sensory attributes
Molecular structure
1-100nm, type of molecules present, their 3D structures, and their interactions with each other.
Microscopic structure
10nm-100microm, Regions in a material where the molecules associate to form discrete phases (ex. emulsion droplets, fat crystals, protein aggregates, small air cells)
Macroscopic structure
> 100microm, can be observes by the unaided human eye (ex. sugar granules, large air cells, raisins, chocolate chips)
Physiochemical properties determine…
- perceived quality, 2. sensory attributes, 3. behavior during production, storage, and consumption
Optical properties
Determined by the way foods interact with electromagnetic radiation in the visible region of the spectrum.
Rheological properties
Determined by the way that the shape of the food changes, or the way that the food flows, in response to some applied force
Stability
The ability to resist changes in its properties over time
Examples of chemical stability
fat rancidity, non-enzymatic browning, pigment formation
chemical stability
A change in the type if molecules present
Physical stability
A change in the spatial distribution of molecules
Examples of physical stability
Creaming in milk, emulsions
Biological stability
A change in the number of microorganisms present in a food with time
Perceived flavor depends on….
The type and concentration of flavor constituents, the nature of the food matrix, and how quickly the flavor molecules can move from the food to the sensors in the mouth and nose
Flavor is determined by…
the way that certain molecules in the food interact with receptors in the mouth and nose
How is flavor characterized?
By measuring the concentration of flavor molecules within a food or in the headspace above the food.
AOAC
Association of the Official Analytical Chemists
AOCS
American Oil Chemists Society
ADSA
American Dairy Science Association
