Food Microstructure

Question 1

What is raman microscopy?

Answer 1

It is using vibrational energy to assign chemical signatures to the composition of your sample, paired with confocal laser scanning you can create an accurate representation of particle distribution. we can relate these signatures and distribution to things such as texture.

Question 2

What is micro computer tomography

Answer 2

This is essentially a scan of the food structure, by taking scans of different angles and heights you can create a 3d representation of an entire structure. The benefits include very simple sample prep allowing for liquids and solids to be measure.

Question 3

What is bright-field microscopy?

Answer 3

This is optical microscopy that transmits light directly into sample,.

Question 4

What are the advantages of bright field microscopy?

Answer 4

It is cheap and easy, our detectors are our eyes and you get significant magnification over the eye

Question 5

What are the disadvantages to brightfield microscopy?

Answer 5

It is the worst of magnification, it can be in focus and out of focus for mutliple particles in one shot. to see transparent particles you would need to use staining.

Question 6

What is dark-field microscopy?

Answer 6

It is when you block out the light and only allow it to enter from the sides. this provides reflectance of particles.

Question 7

What are the advantages for dark-field microscopy?

Answer 7

It is still cheap, you can see transparent particle edges, it is good for external structures.

Question 8

What are the disadvantages for dark-field?

Answer 8

It is prone to inaccuracies and degradation.

Question 9

What is phase contrast microscopy?

Answer 9

It is when the light is converted into a hollow cone that is transmitted into the sample.

Question 10

What are the advantages of phase contrast microscopy?

Answer 10

It allows you to see the internal structure of a thin sample, it provides high resolution.

Question 11

What are the disadvantaged of phase contrast microscopy?

Answer 11

You can get distorted results if it is too thick, and bad edge effects.

Question 12

What is Differential Interference contrast microscopy?

Answer 12

It is when you split beams using prisms to pass a beam through the surrounding and through the sample, this creates a very large contrast between background and

Question 13

What are the advantages of DIC?

Answer 13

no edge effects - very clear

Question 14

What are the disadvantages?

Answer 14

Expensive and prone to distortion

Question 15

What is confocal laser scanning?

Answer 15

this works of excitation and emission of a sample, and it can do this on a z-stack.

Question 16

what are the advantages of Confocal laser scanning?

Answer 16

This gives us a really good 3D representation of a thick sample, high resolution

Question 17

What are the disadvantages of confocal laser scanning?

Answer 17

It is super expensive in comparison to flourescent microscopy.

Question 18

What is SEM

Answer 18

it is scanning electron microscopy it detects the reflection of of electrons from the topography of the sample

Question 19

What are the advantages of SEM

Answer 19

it is super easy to do, and sample prep is very quick.

Question 20

What are the disadvantages of SEM

Answer 20

It is limited to dry samples as it is in a vacuum, it is super expensive and you need high training

Question 21

What is TEM?

Answer 21

It is the transmission electron microscope. This measures the intensity of electrons from incident to detector. It can provide good information of super thin samples

Question 22

What are the advantages of TEM?

Answer 22

It is very clear and resolved, it has a wide range of applications.

Question 23

What are the disadvantages of TEM?

Answer 23

It can only be done on thin samples that are electron transparent, it is super expensive and very laborious to prepare.