Measuring the Texture of Marzipan and Icing

Dr. Jeanette Purhagen,
Perten Instruments AB, Strandbadsvägen 19A, 252 29 Helsingborg, Sweden
jpurhagen@perten.com

Introduction 

There is a need for new and objective equipment to measure food texture. Many companies still control texture manually, i.e. the process operators touch or taste the products online, or use old instruments that are no longer produced or supported. This makes the production process vulnerable. The aims of this study were to investigate the texture of various marzipans and icings, to develop a TVT method that correlates with legacy drop cone penetrometer values, and to provide additional information about the texture of the samples.


Materials and Methods

Materials

Four types of marzipan and two types of icing (Table 1) with known penetrometer values were tested. The penetrometer values (distance values) were received from the producer, taken 5 days after production at 20°C. Penetrometer measurements were performed using a cone probe and the penetrometer distances were taken after 10s for all samples, but for soft marzipan the distance was read after 5s.

Table 1. Sample description and penetrometer distances
Table 1. Sample description and penetrometer distances
Texture Analysis

Texture measurements were performed using a TVT-XP (Perten Instruments AB) equipped with a 7kg load cell and three different probes and settings (Table 2).

Table 2. TVT settings and probes 
Table 2. TVT settings and probes

Statistical Analysis

Mean values and standard deviations were calculated from 6–9 replicates for green and white icing, and 10–28 replicates for the marzipans. The significances were determined by using Anova and T-test.

Results and Discussion

3mm Cylinder Probe Penetration

 

 

 

 

 

 

 

Figure 1. Penetration curves using 3mm cylinder probe

 

The 3mm cylinder probe penetration method could distinguish between the different samples. Firmness, adhesiveness and area+ (Figure 2) were measured and are displayed in Table 3.

 

 

 

 

 

 

 

 


Figure 2. Parameters analyzed for 3mm cylinder probe penetration method

Table 3. Penetration with 3mm cylinder probe, mean values and std. dev.1
Table 3. Penetration with 3mm cylinder probe, mean values and std. dev.1
1 Values within a column not containing the same letter (a-f) are significantly different (P <0.05)

All samples were significantly different in terms of firmness, while for adhesiveness the two icings and the cover marzipan were similar. These three samples were also firmer than the marzipans used only for cookies and soft decorations. The extra white marzipan was the third-softest marzipan but was significantly the most adhesive.

Power-fit correlations between the penetrometer values and the firmness and area+ were found and can be seen in Figures 3 and 4. The firmness gave higher correlation factor (0.9756) than the area+ (0.8806) when compared to the penetrometer values. As expected, no correlation was found between the penetrometer values and the adhesiveness.

Figure 3. Power-fit correlation between penetrometer values at 10s and firmness for 3mm cylinder penetration method
Figure 3. Power-fit correlation between penetrometer values at 10s and firmness for 3mm cylinder penetration method

Figure 4. Power-fit correlation between penetrometer values at 10s and area for 3mm cylinder penetration method
Figure 4. Power-fit correlation between penetrometer values at 10s and area for 3mm cylinder penetration method

45° Cone Probe Penetration

When penetrating the samples using a 45° cone probe, all samples gave the same curve pattern but to different force levels (Figure 5).

Figure 5. Penetration curves using 45° cone probe
Figure 5. Penetration curves using 45° cone probe

The 45° cone probe penetration method could distinguish between different samples, with the results and their significant differences displayed in Table 4.

Table 4. Penetration with 45° cone probe, mean values and std. dev.1
Table 4. Penetration with 45° cone probe, mean values and std. dev.1
Values within a column not containing the same letter (a-f) are significantly different (P <0.05)

All marzipan products were significantly different in terms of firmness, adhesiveness and penetration area when using the 45° cone probe. The extra white marzipan was still the most adhesive product. The penetration distances were slightly different, however, the final order in terms of firmness and area was reached after less than 5s (<10 mm).

The penetrometer values were correlated with both the firmness and the area+ and can be seen in Figures 6 and 7. The correlation factors were R2=0.8582 and R2=0.8132 respectively.

Figure 6. Power-fit correlation between penetrometer values at 10s and firmness for 45° cone penetration method

Figure 7. Power-fit correlation between penetrometer values at 10s and area for 45° cone penetration method
Figure 7. Power-fit correlation between penetrometer values at 10s and area for 45° cone penetration method

Wire cutting method

When cutting the samples using a wire probe, most samples displayed a clear difference between the surface and the internal mass of the marzipan (Figure 8). The firmer the sample, the greater the difference between the surface firmness and the internal mass firmness (plateau firmness) (Figure 8, Table 5). When comparing the two icings, only the surface distances differed significantly.

Figure 8. Cutting using wire probe
Figure 8. Cutting using wire probe

Table 5. Cutting with wire probe, mean values and std. dev.1
Table 5. Cutting with wire probe, mean values and std. dev.1
1 Values within a column not containing the same letter (a-d) are significantly different (P <0.05)

Conclusions

Both the 3mm cylinder probe method and the 45° cone probe method gave good power-fit correlations to the given penetrometer values for both firmness and area+. The correlation, R2 factor, would have been even higher if the soft marzipan had been included in the correlation. However, this sample was excluded in the fitting due to the shorter penetrometer reading time. All three methods gave additional information regarding the texture of the marzipans compared to a normal penetrometer measurement. Differences between the surface and internal mass were clearly seen when using the 3mm cylinder penetration method and the wire cutting method and could be useful as a measurement of drying of the surface in open air.