Firmness measurement of baked goods

APPLICATION

To establish a standard compression test method for evaluating the firmness of baked goods.

OBJECTIVE

FROM THE TEST Firmness is accepted as a measure of freshness and quality. This method is useful for measuring freshness and quality in product development and quality control.

PRINCIPLE

OF THE TEST Quantitatively measure the force necessary to compress the sample of bread.

CONTEXT

The American Association of Cereal Chemists (AACC) has developed a standard method for the evaluation of bread samples by straining. The compressive force of a bread sample over a specific distance simulates a slight pressure by the consumer when selecting his bread at the supermarket.

METHOD

A 25mm thick slice of bread or two slices (each 12.5mm thick) can be used. The slices can be cut mechanically or by hand as long as the last three slices are discarded and the crusts are not removed. A Ø 38.1 mm probe (TA4 / 1000) at a test speed of 2 mm / s. The test location is the center of the bread slice (s), avoiding unrepresentative crumb areas. The sample is subjected to a deformation of 40 % and a compression load of 25 % deformation is recorded in Newton or in g. Test a load of three samples per bar.

Settings:

Fashion: Normal

Speed: 2 mm / s

Distance: 10 mm

Trigger: 5g

RESULTS

The following is a result graph (using TexturePro CT software)

EMPIRICAL FACTORS

Test conditions that will affect the generated results:

1.Sample size

2.Age of sample

3.Test probe used

4.Position and consistency of sample location

Sample conditions that will affect the generated results:

1.Formulation and composition

2.Cooking or processing treatments

3. Storage conditions imposed on bread

Example description

RELATED TESTS

TPA type evaluation of the bread sample

Measurement of resistance and stretchability of bread

Stress relaxation as an indicator of bread stale

DISCUSSION

The structure of the bread can be defined as a solid colloid foam with multiple pockets of carbon dioxide distributed evenly throughout its mass. Gluten forms the interconnected network that supports carbon dioxide in small pockets. The end result, when baked, is the characteristic airy honeycomb texture of bread.

Texture analysis is a valuable tool to better understand the quality of bread. The method applied in this study clearly quantified the effect of "stale" on the strength of the gluten matrix.

CONCLUSION

The texture measurement described was found to quantify the physical characteristics of a range of breads in the early stages of their life. The simple compression test is ideally suited for production or development environments where it can give an indication of stale or formulation of the product with respect to enhancers, flour quality or the use of additives such as alpha-amalayse.