Volume Measurements of Frozen and Baked Pizza

Introduction

Pizza is a popular food which is consumed all over the world and can be bought in several different formats and states. The consumption of frozen pizzas increases and thus also the need for production and quality controls.

Volume measurement is one of the quality controls which has received increased attention recently, partly due to the fact that there is now a practical and standardized method available –the AACC approval of the BVM-method (method 10-14.01) (AACC International, 2014). It uses laser topography to measure the volume of the product, enabling non-contact measurement of sticky, crispy and soft products. Traditional methods for volume measurement are all based on the displacement principle which does not work for this type of products due to the physical contact between the displacement material and the product.

The aim of this study was to see how well the AACC standard method for volume measurements would work on frozen and baked pizza.

Material and Volume Measurements

Commercial frozen pizzas were bought in a supermarket and baked according to the instructions on the package, Figure 1. The same pizza was measured both frozen and baked. The volumes were measured using a BVM-370 (Perten Instruments AB, Sweden) equipped with a flat circular support with a diameter of 100 mm (FSPC100). The test duration time was set to be 60 seconds, the object shape flat horizontal and the filtering function activated. Four measurements were performed. The test set-up can be seen in Figure 2.


Figure 1: A – Frozen pizza and B – Baked pizza


Figure 2: Attachment and sample setup

Results

The mean values and standard deviation for both frozen and baked pizza are displayed in Table 1. The 3-D image from the software of the frozen and baked pizza can be seen in Figure 3 and 4.

Table 1: BVM results for 4 measurements.

Batch Volume
(mL) 
Area
(cm2)
Depth
(mm)
Width
(mm)
Height
(mm)
Max Diameter
(mm)
Shape Ratio
(height/width)
Frozen 820±3.2 1050±2.5 247±0.0 249±0.0 41.5±0.6 251±1.3 0.17±0.005
Baked 654±0.6 985±3.0 237±0.0 239±0.0 25.0±0.0 239±0.0 0.11±0.000


Figure 3:
3-D pictures of A-Frozen and B-Baked pizza, from the side

Figure 4: 3-D pictures of A-Frozen and B-Baked pizza, from above

There is a clear decrease in volume and size dimensions when the pizza is baked compared to its frozen state. This is expected since the filling hinders the frozen dough to increase and at the same time the cheese etc. melts. Furthermore, no structural differences can be noticed in the 3-D pictures seen from the side of the pizzas. However, the 3-D pictures seen from above reveal that there is a structural difference between the frozen and baked state even though no clear details can be seen in the pictures, which was expected.

Conclusions

The Perten BVM volume meter is highly suitable for volume measurement of pizzas and gives good results for both frozen and baked products. The frozen pizzas decreased in volume when baked.

References

AACC International. Approved Methods of Analysis, 2014, Method 10-14.01. Determination of Bread Volume by Laser Topography: BVM Method. Approved October 2014. AACC International, St. Paul, MN, U.S.A.