Australian Export Grains Innovation Centre

AEGIC is an initiative of the Western Australian State Government and Australia’s Grains Research and Development Corporation

Department ofAgriculture and Food

Digital laser topography volume analyser— improved evaluation of bread volume

J. Ng1 and L. Cato1 1Australian Export Grains Innovation Centre (AEGIC), Perth, WA, 6151, Australia

1. INTRODUCTION 4. RESULTS

3. MATERIALS AND METHODS

2. AIMS

5. CONCLUSIONS

Bread in its many forms is a staple food consumed worldwide. The term ‘bread’ is widely used to describe a range of products of different shapes, sizes, textures etc. In this study, references to bread means test baked pan bread.

A range of quality parameters are considered when it comes to bread and baking quality. However, possibly the most commonly assessed quality trait of bread is loaf volume. Traditionally, in a test baking context bread volume is measured using a suitable seed displacement method (Fig. 2). More recently infrared scanning of products has been introduced as a means of assessing product volume, for example the Stable Micro Systems (Volscan) and the TexVol instrumentation (BVM-L

All flour samples were baked using an AEGIC method (modified long fermentation method, AACC 10–09 and 10–10B approved methods). The method was modified to reflect commercial baking practices in South East Asia. The basic steps used in the test baking are shown in Fig. 1.

• To evaluate results (Baked Specific Volume) from a seed displacement (SD) volume meter and TexVol BVM analyser.

• To define the relationship between loaf volume (BSV) and slice height and slice per unit area (C-Cell).

• When comparing BVM and SD meter, a R2 of 0.817 was obtained in this study (Fig. 4).

• Complementary data to bread volume or bread specific volume can be obtained by C-Cell (image analyser) outputs like slice area / mm2 (Figs. 5a and b) and total number of cells per unit area (data not shown).

• R2 = 0.870 was obtained for bread volume as measured by BVM and slice area / mm2 (C-Cell), while an R2 = 0.719 was achieved between the same measurements using the seed displacement unit (Figs. 5a and b).

• Variations in test baking (CoE) of 3.0% and 1.3% were obtained for control samples when measured by SD and BVM, respectively (Figs. 6a and b).

References• American Association of Cereal Chemists International (AACCI). Approved

Methods Committee. (2011). Approved methods of the American Association of Cereal Chemists (11th ed.). St. Paul, Minn.: AACCI.

• Cauvain, S. P. (2009). The Relevance to the Manufacture of Bread and Fermented Products, In The ICC Handbook of Cereal, Flour, Dough & Product Testing, Methods and Applications (ed: Cauvain and Young), DEStech Publications Inc. Lancaster, USA, pp. 125–156.

FIGURE 4 Comparison of two assessment methods — BVM and seed displacement volume meter (n=505)

FIGURE 5 Two bread volume assessment methods compared to slice per unit area (C-Cell)

FIGURE 6 Test baking variation (control samples) and assessment of bread volume using the two assessment methods

(a) Slice area vs BVM (C-Cell)

(a) Test baking control BSV measured by BVM

(b) Slice area vs SD (C-Cell)

(b) Test baking control BSV measured by SD

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aegic.org.au

Step 1. Step 2. Step 3.

Step 4.

Mixing Moulding Resting

Proofing and baking

FIGURE 1 Test baking steps — mixing; moulding; resting; proofing and baking

FIGURE 2 Bread volume measurement (BVM and SD)

FIGURE 3 Bread crumb structure assessment (C-Cell)

series) (Cauvain 2009). In this study, the TexVol has been used to evaluate tests of bread volume using seed displacement methods and infrared scanning (Figs. 2 and 3).

Previous methods for calculating loaf volume of bakery products include seed displacement, in which the amount of rape seed or canola seed around the loaf in a standard container is measured. This method is time consuming and unreliable due to seed clumping, moisture absorption and potential crushing of the product (Cauvain 2009). The TexVol offers non-contact evaluation, the results of which can be obtained rapidly and accurately.

• To evaluate the potential of BVM use for test-baked loaf volume assessment.

• The correlations between BSV and C-Cell slice height were poorer (data not shown), due to the shape profile of the slice and the tendency for the shape of the loaves to have a bulbous head.

• Laser methodology offers non-contact evaluations, rapid and accurate volume measurement. In addition, the shape of bread loaves are more likely to affect the packing of the seeds than the measurements by the laser.