PARAMETER EXPLANATION

There are 48 parameters determined by C-Cell monochrome.

These same measurements are made on the colour C-Cell along with with additional colour related features.

NOTE: Measurements only applicable to colour instrument marked with *

SLICE DIMENSIONS

External dimensions have an important role in defining product perception. When purchasing a baked product we look for the characteristic indicators specific to the type of bread such as size and shape to indicate product quality, crumb structure and taste assessments take place after the purchase.

Slice dimensions can also be a useful indicator of problems within the baking process such as:

1. Poor quality flour (low level or quality of protein)

2. High ash content

3. Inadequate mixing

4. Reduced yeast activity

5. Reduced elasticity of dough

6. Poor gas retention

7. Inadequate proof

Colour & Brightness*

Colour (Measured using top lit image)

L*a*b* colour space is a commonly used scale found in the food industry to describe a products colour in three dimensions.

L* measures the brightness of a sample. (Darkest black = 0 Brightest white = 100

a* measures the change from red to green. (Negative a* values indicate red component and positive a* values indicate green component)

b* measures the change from yellow to blue (Negative b* values indicate blue component and positive b* indicate the yellow component)

Slice Brightness and contrast (Measured using side lit image)

These measurements are now replaced with L*a*b* in the colour system but still provide a useful measurement representing how crumb structure influences slice brightness. The Monochrome palette uses 256 shades of grey to define the range black (0) to white (256) and correlates with L* values when looking at full colour L*a*b* measurements.

Slice brightness measurement is the average grey level of all of the pixels within the image. Cell walls have higher values and the cells have lower values depending on the level of shadow created within cell, which relates to its volume.

Brightness values are influenced by 2 major factors:

1. Bran content

2. Crumb structure

Cell Contrast is the ratio: (mean cell brightness) / (mean wall brightness)

Higher values indicate shallower cells and hence smaller differences between cell walls and shallow cells

Crust unwrap* (Measured using top lit crust unwrap image)

Crust unwrap is an algorithm that quantifies the colour and thickness of the crust. The border between crust and crumb are identified based on L*a*b* single pixel analysis and once this has been established the crust is “unwrapped and presented on a 2 dimensional display. Data from individual faces of the slice and an average combined figure are recorded.

Shape

Many of today’s breads are characterised by their size and shape, and these qualities are strongly influenced by the properties of the flour, or more precisely its gluten properties.

The Glutenin/Gliadin composition provides the dough with a unique combination of elasticity and extensibility, and this determines dough functionality which can be seen in parameters such as side wall concavity, oven spring and roundness of bottom corners within tinned bread.

Side wall concavity may be caused by:

1. Under scaling forces the dough to cover a larger volume than it is capable off.

2. Overmixing of the dough causing weakening and hence poorer gas retention.

3. Low levels of protein in the flour (or poor protein quality)

Oven spring issues can be related to:

1. Incorrect dough mixing

2. Incorrect water addition - dough too soft/stiff

Cell Information

The Cell Image indicates how cells and cell walls are segmented based on their greyscale shade. The lighter cell walls are colour coded black and the cells are blue. The smallest cell identified have the darkest blue colouration (smallest cell measurable with C-Cell = 0.14mm diameter).

As the cells get larger their shading gets lighter. Cells highlighted with a red border or shaded in yellow indicate possible holes.

A hole is identified by comparing its size to the distribution of cell sizes for that specific sample being tested, By using this approach we can analyse very fine crumb structure as well as more open structured product without any setting changes being required.

The Volume map image depicts the distribution of cell volumes above or below the mean value. The 50% of cells with volumes above the mean value are colour coded red and the remaining 50% of cells with smaller volumes are colour coded blue. The Volume map is translated into a value in the Coarse/Fine Clustering parameter, high values represent clustering of coarse structure and low values indicate a more even distribution of coarse and fine cells. The volume map image is independent of average cell size – red and blue areas are always subdivided equally.

The number, size and shape of cells represent the combined effect of an industrial process using a variable raw material with the end goal being a well-defined characteristic crumb structure.

Although size and shape characterise the external appearance of bread, it is the crumb structure that provide the mechanical structure and mouthfeel that we recognise in its eating properties.

1. Number of cells will range from “hundreds” in open structures such a baguette or laminated products up to tens of thousands in Japanese tinned breads.

2. Average cell diameters will range from 1mm 20mm and above.

3. Cell shape is manipulated is some types of bread by sheeting the dough into a sheet, prior to rolling up and placing in the tin, this causes the cells to elongate along a similar axis.

4. “Holes” are cells with volume larger than typical of the slice.

CELL ELONGATION

The random distribution of air cells produced in a fresh dough are a potential problem to the baker who is trying to produce a fine uniform crumb structured product. By introducing a moulding/ sheeting / rolling step the baker can mechanically manipulate the irregular cell distribution into a regular pattern of aligned cells. This in turn will create a far more reproducible dough resulting in higher yields

The special distribution for each cell is calculated and presented in the cell elongation image and Elongation table

Examples of different cell elongation patterns