**5.1.4 Assessment of mechanical damage on apples with image analysis**

The aim of the study was to determine oxidation area and skin colour change at the damaged apples by using image analysis technique. Golden Delicious, Granny Smith and Stark Crimson apple varieties were examined with a special pendulum unit which was developed for the impact test. Plastic and wood materials were used as impact surface, and apples were dropped from different heights to the impact surface. Impact to each apple occurred perpendicular to impact surface from predetermined heights. After the impact test, colour change of damaged regions and oxidation areas of each sample were estimated by using a digital camera. Colour measurements were done with a colourmeter based on L\*, a\*, b\* measurement system. The oxidation areas were evaluated clearly after these processes (Beyaz et al., 2010).

Measurements of the apple physical properties which were used for the tests are given in Table 7. The impact tests applied to the three apple varieties changed colour values. Changes of colour values for each apple varieties for five days are presented in Table 8 (Beyaz et al., 2010).

Repeated ANOVA statistics was used for evaluating colour interaction between other variables. When we look at the results of interactions for each of L\*, a\*, b\* values, interaction between the day and apple varieties was significant (p<0.05) for all values. The interaction values are presented in Tables 9 - 12. Additionally, interaction between the day and surface variety was found to be significant only for b value presented in Table 12 (Beyaz et al., 2010).


L\*: Brightness of colour, a\*: Colour change value from red to green, b\*: Colour change value from yellow to blue.

Table 7. Physical properties of apples which were used for the tests (Beyaz et al., 2010).

As shown in Table 6., the total topping yield loss and image processing measurement values have been evaluated. This results respectively, at the mechanical harvesting machine 3.87% and 3.78%, at the semi-hydraulic machine 4.86% and 4.29%, at the fully hydraulic machine 4.81% and 4.66%. According to IIRB ideal topping quality is group is 4. According to the total topping yield loss values, the best machine is mechanical sugar beet harvesting

The aim of the study was to determine oxidation area and skin colour change at the damaged apples by using image analysis technique. Golden Delicious, Granny Smith and Stark Crimson apple varieties were examined with a special pendulum unit which was developed for the impact test. Plastic and wood materials were used as impact surface, and apples were dropped from different heights to the impact surface. Impact to each apple occurred perpendicular to impact surface from predetermined heights. After the impact test, colour change of damaged regions and oxidation areas of each sample were estimated by using a digital camera. Colour measurements were done with a colourmeter based on L\*, a\*, b\* measurement system. The oxidation areas were evaluated clearly after these processes

Measurements of the apple physical properties which were used for the tests are given in Table 7. The impact tests applied to the three apple varieties changed colour values. Changes of colour values for each apple varieties for five days are presented in Table 8

Repeated ANOVA statistics was used for evaluating colour interaction between other variables. When we look at the results of interactions for each of L\*, a\*, b\* values, interaction between the day and apple varieties was significant (p<0.05) for all values. The interaction values are presented in Tables 9 - 12. Additionally, interaction between the day and surface variety was found to be significant only for b value presented in Table 12

**Delicious** 

**Fruit diameter (mm)** 67.08 + 1.48 69.46 + 2.22 70.38+ 2.91 **Weight (g)** 138.63 + 5.56 201.88 + 5.65 158.63+ 7.68

**Sphericaly (%)** 97.64 + 1.68 96.38 + 2.48 97.36 + 2.94 **Hardness of fruit (kg)** 3.35 + 0.31 7.52 + 0.44 3.97 + 1.01 **L\* colour value** 75.24 + 2.49 64.53 + 3.69 54.01 + 7.82 **a\* colour value** -10.7 + 3.45 -16.83 + 8.24 23.39 + 10.47 **b\* colour value** 45.22 + 2.06 45.01 + 2.28 27.03 + 6.19

**Geometric mean diameter (mm)** 63.74 + 1.33 66.39 + 1.92 66.91 + 2.35

L\*: Brightness of colour, a\*: Colour change value from red to green, b\*: Colour change value from

Table 7. Physical properties of apples which were used for the tests (Beyaz et al., 2010).

**Granny Smith** 

**Stark Crimson** 

**Properties Golden** 

**5.1.4 Assessment of mechanical damage on apples with image analysis** 

machine (Beyaz et al., 2009b).

(Beyaz et al., 2010).

(Beyaz et al., 2010).

(Beyaz et al., 2010).

yellow to blue.


Table 8. Colour value change for each apple varieties (Beyaz et al., 2010).


Table 9. The interaction between the apple varieties and days for L\* value (Beyaz et al., 2010).


Table 10. The interaction between the apple varieties and days for a\* value (Beyaz et al., 2010).


Table 11. The interaction between the apple varieties and days for b\* value (Beyaz et al., 2010).

Machine Vision Measurement Technology and Agricultural Applications 159

The area of damaged surfaces and descriptive statistics for the apple varieties is presented in Table 14. The average plastic surface results of the apple varieties were not observed to be significant statistically. The results of the average impacted surface area of apple varieties for the wood surface are also presented in Table 14. Relations between the Golden Delicious and Stark Crimson varieties had no significant difference, but the Granny Smith variety had

**Surface Varieties Average of Observations (cm2) Std.Error Std. Deviation**  Plastic Golden 20 3.03 A 0.287 1.282 Impact Granny 20 4.957 A 0.447 1.998 Surface Stark 20 4.151 A 0.253 1.131

Wood Golden 20 5.141 A 0.225 1.006 Impact Granny 20 5.005 B 0.239 1.07 Surface Stark 20 6.029 A 0.174 0.777 Table 14. Impacted surface area results for plastic and wood surfaces (Beyaz et al., 2010).

Apple varieties and impact surface interaction were compared and presented in Table 15. The differences between average surface areas were observed significant as indicated in

Table 15. Impacted surface area descriptive statistics for Golden Delicious apple varieties, Granny Smith apple varieties and Stark Crimson apple varieties (Beyaz et al., 2010).

Image analysis of the oxidation areas (bruised area) which were created after impact test is important for designing equipments and machines for classification, packaging, transportation and transmission. The results of these impaction tests indicated that the response to impact bruising was dependent on flesh firmness and on the height of the

When impacted apples were analysed according to Duncan's test, differences between 50, 55 and 60 cm heights were significant but difference between 60 and 65 cm was not significant.

**Average of Observations (cm2)** 

Plastic 20 3.030 B 0.287 1.282

Wood 20 5.141 A 0.225 1.006

Plastic 20 4.957 A 0.447 1.998 Wood 20 5.005 A 0.239 1.07

Plastic 20 4.151 B 0.253 1.131 Wood 20 6.029 A 0.174 0.777

**Std. Error Std.** 

**Deviation** 

Table 15. for Golden Delicious and Stark Crimson apple varieties.

a significant difference from the others.

**Varieties Surface** 

Golden Delicious Apple

Granny Smith Apple

Stark Crimson Apple

impact (Beyaz et al., 2010).


Table 12. The interaction between the days and surface varieties for b\* value (Beyaz et al., 2010).

When the L\*, a\*, b\* values of Granny Smith varieties were reviewed, L\* and a\* values increased while b\* value decreased (Fig.11). For Stark Crimson variety all L\*, a\*, b\* values decreased. The L\*, a\*, b\* values in Golden Delicious varieties revealed that L\* and b\* values decreased while a\* value increased. The L\* value for each Golden Delicious varieties decreased by 65%. The colour value of b\* decreased by 60% for Golden Delicious variety among all varieties. Total colour changes in Golden Delicious varieties were significantly different compared to Granny Smith and Stark Crimson indicated in Table 8 (Beyaz et al., 2010).

According to variance analysis technique, two levels of surfaces (wood and plastic surfaces), four levels of drop heights (50, 55, 60 and 65 cm) as height factor and three apple varieties (Golden Delicious, Granny Smith, Stark Crimson) were analysed. The number of irritation had five subgroups. Duncan's multiple range test was used to determine the mean difference between variety, impact surfaces and drop heights. Impact energy was taken as feature covariant (Beyaz et al., 2010).

Statistical analysis and results of variance analysis showed that height and 'Surface x Variety' interaction were significant at p<0.01 confidence level. All the variance analysis for 'Surface x Variety' interaction was found to be significant statistically (Beyaz et al., 2010).

The descriptive statistics in the variance analysis are given in Table 13. Duncan's test results of the average of damaged apples were significant at 50, 55 and 60 cm heights. The relations between 60 and 65 cm heights were insignificant (Beyaz et al., 2010).


The descriptive statistics for bruised area and drop height.is presented in Table 13.

Table 13. The descriptive statistics for bruised area and drop height (Beyaz et al., 2010).

 **Wood Plastic**  Day 1 30.24+0.93 Aa 28.93+1.18 Aa Day 2 28.02+0.88 Ba 27.32+1.12 Ba Day 3 26.08+1.00 Ca 26.22+1.14 Ca Day 4 25.29+1.09 CDa 25.03+1.23 Da Day 5 24.47+1.16 Da 25.08+1.30 Da

When the L\*, a\*, b\* values of Granny Smith varieties were reviewed, L\* and a\* values increased while b\* value decreased (Fig.11). For Stark Crimson variety all L\*, a\*, b\* values decreased. The L\*, a\*, b\* values in Golden Delicious varieties revealed that L\* and b\* values decreased while a\* value increased. The L\* value for each Golden Delicious varieties decreased by 65%. The colour value of b\* decreased by 60% for Golden Delicious variety among all varieties. Total colour changes in Golden Delicious varieties were significantly different compared to Granny Smith and Stark Crimson indicated in Table 8 (Beyaz et al.,

According to variance analysis technique, two levels of surfaces (wood and plastic surfaces), four levels of drop heights (50, 55, 60 and 65 cm) as height factor and three apple varieties (Golden Delicious, Granny Smith, Stark Crimson) were analysed. The number of irritation had five subgroups. Duncan's multiple range test was used to determine the mean difference between variety, impact surfaces and drop heights. Impact energy was taken as

Statistical analysis and results of variance analysis showed that height and 'Surface x Variety' interaction were significant at p<0.01 confidence level. All the variance analysis for 'Surface x Variety' interaction was found to be significant statistically (Beyaz et al.,

The descriptive statistics in the variance analysis are given in Table 13. Duncan's test results of the average of damaged apples were significant at 50, 55 and 60 cm heights. The relations

**Variable Drop Height (cm) Average (cm2) Std. Error** 

Table 13. The descriptive statistics for bruised area and drop height (Beyaz et al., 2010).

50 5.419 A 0.241 55 4.616 B 0.255 60 4.225 C 0.311 65 4.616 C 0.292

The descriptive statistics for bruised area and drop height.is presented in Table 13.

between 60 and 65 cm heights were insignificant (Beyaz et al., 2010).

**Days Surface** 

Table 12. The interaction between the days and surface varieties for b\* value

(Beyaz et al., 2010).

feature covariant (Beyaz et al., 2010).

2010).

2010).

Impacted Surface Area

The area of damaged surfaces and descriptive statistics for the apple varieties is presented in Table 14. The average plastic surface results of the apple varieties were not observed to be significant statistically. The results of the average impacted surface area of apple varieties for the wood surface are also presented in Table 14. Relations between the Golden Delicious and Stark Crimson varieties had no significant difference, but the Granny Smith variety had a significant difference from the others.


Table 14. Impacted surface area results for plastic and wood surfaces (Beyaz et al., 2010).

Apple varieties and impact surface interaction were compared and presented in Table 15. The differences between average surface areas were observed significant as indicated in Table 15. for Golden Delicious and Stark Crimson apple varieties.


Table 15. Impacted surface area descriptive statistics for Golden Delicious apple varieties, Granny Smith apple varieties and Stark Crimson apple varieties (Beyaz et al., 2010).

Image analysis of the oxidation areas (bruised area) which were created after impact test is important for designing equipments and machines for classification, packaging, transportation and transmission. The results of these impaction tests indicated that the response to impact bruising was dependent on flesh firmness and on the height of the impact (Beyaz et al., 2010).

When impacted apples were analysed according to Duncan's test, differences between 50, 55 and 60 cm heights were significant but difference between 60 and 65 cm was not significant.

Machine Vision Measurement Technology and Agricultural Applications 161

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America

We can conclude that differences between average of impacted surface areas at Golden Delicious and Stark Crimson apples were important but this was not the case for the Granny Smith apples. This result shows us that apple varieties, impact surface and tissue of apple varieties affect average of impacted surface area (Beyaz et al., 2010).

For the surface properties, wood surface creates more impacts on apples than plastic surface because of material properties. According to the results, plastic surface affects in a good way apple surfaces which are harvested or processed for postharvest. In this research we have shown that image analysis technique can easily be used for determining impacted surface areas and changes of colour values of the apples and other agricultural products (Beyaz et al., 2010).
