Cocoa Sample Sensory Evaluation

This assignment involves evaluating the sensory attributes of four different cocoa samples. Assessors evaluate characteristics like shine, lightness, cocoa odour, bitterness, sweetness, firmness, and melting. The analysis delves into statistically significant differences in scores across samples and assessors, revealing variations in sensory perception. The findings contribute to understanding consumer preferences and product quality.

Running head: FOOD CHARACTERISATION
Food Characterization
Name of the student
Name of the university
Author’s note

1FOOD CHARACTERISATION
Abstract
Four different samples of Cocoa were analysed for its properties. Six assessors tasted the
Cocoa samples and provided scores for their Shine, Lightness, Cocoa odour, Bitterness,
Sweetness, Firmness and Melting. The analysis found that there are differnces in the scores of
four cocoa samples. However the analysis found that there are no differences in the scores as
given by the assessors. The analysis further found that there are no differences in the interaction
scores of the assessors and samples for the variables of interest.

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Table of Contents
Results and Discussions...................................................................................................................3
Lab 2............................................................................................................................................3
Lab 3............................................................................................................................................6
Conclusion.......................................................................................................................................0

3FOOD CHARACTERISATION
Results and Discussions
Lab 2
Six panelists were provided with three opportunities to taste and provide scores to the 4
cocoa samples. From the scores given by the panelists of the cocoa samples it is seen that for
each trail of the same cocoa samples the scores are different.
There is a wide variation in the scores of the samples given by the panelists.
Tests for Normality
Table : Tests of Normalitya
Kolmogorov-Smirnovb Shapiro-Wilk
Statistic df Sig. Statistic df Sig.
Firmness .109 24 .200* .942 24 .180
Melting .150 24 .176 .954 24 .327
*. This is a lower bound of the true significance.
a. Trial = 1.00
b. Lilliefors Significance Correction
Tests of Normalitya
Kolmogorov-Smirnovb Shapiro-Wilk
Statistic df Sig. Statistic df Sig.
Firmness .198 24 .015 .908 24 .032
Melting .124 24 .200* .966 24 .579
*. This is a lower bound of the true significance.
a. Trial = 2.00
b. Lilliefors Significance Correction
Tests of Normalitya
Kolmogorov-Smirnovb Shapiro-Wilk
Statistic df Sig. Statistic df Sig.
Firmness .177 24 .050 .936 24 .133
Melting .089 24 .200* .967 24 .589
*. This is a lower bound of the true significance.

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a. Trial = 3.00
b. Lilliefors Significance Correction
The above table presents the tests for Normality for the three trails. The Attributes of Firmness
and Melting were tested for Normality. From the Shapiro-Wilks test we find that the data for
Firmness and Melting are normally distributed for trial 1 and 3, Sig > 0.05. For trial 2 the Scores
of Firmness of the samples was not normally distributed, Sig < 0.05.

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The above figures show the scores of Firmness and Melting for each sample plotted
against the assessors. From the above figures it can be seen that there is a wide variation in the
scores of the samples.
Attribute
Sample 315
Trial 1 Trial 2 Trial 3
Mean Stdev Mean Stdev Mean Stdev
Shine 6.5 0.6 6.1 1.9 5.9 0.5
Lightness 2.4 0.3 2.7 1.2 2.2 0.5
Cocoa odour 6.0 0.8 6.1 2.1 5.8 0.3
Bitterness 5.5 0.6 6.5 1.3 7.4 0.9
Sweetness 2.9 0.5 3.9 1.6 3.6 0.4
Firmness 5.1 1.6 6.9 1.0 6.4 0.3
Melting 3.7 0.6 5.0 1.4 5.5 0.9

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There are variations in the standard deviations between trials. There seems to be
discrimination in the scores of the assessors for the attributes for different trials.
Lab 3
Shine
Lightness
Cocoa odour
BitternessSweetness
Firmness
Melting
0.0
5.0
Sample 137
Figure 1: Radar Plot for Sample 137
Shine
Lightness
Cocoa odour
BitternessSweetness
Firmness
Melting
0.0
5.0
10.0
Sample 315
Figure 2: Radar Plot for Sample 315

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Shine
Lightness
Cocoa odour
BitternessSweetness
Firmness
Melting
0.0
5.0
10.0
Sample 486
Figure 3: Radar Plot for Sample 486
Shine
Lightness
Cocoa odour
BitternessSweetness
Firmness
Melting
0.0
5.0
10.0
Sample 769
Figure 4: Radar Plot for Sample 769

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Shine
Lightness
Cocoa odour
BitternessSweetness
Firmness
Melting
0
5
10
137
315
486
769
Figure 5: Comparision of Properties
From the above plot we find that Cocoa sample No. 769 has a higher Melting Score than
other samples. Sample 769 is also light and has more sweetness as compared to other samples of
Cooca. Both sample 315 and 486 have equal Firmness. Sample 315 scores high on Shine,
Bitterness and Cocoa Odour as compared to other samples.Sample 137 is found to have
moderate scores for all the seven attributes. Sample 769 has the least Firmness score, is less
bitter, low Cocoa odour and has least shine.
Table Summary table of Analysis of Variance (ANOVA) for each attribute
Attributes
Significance level (p value)
R squaredSample Panellist Sample *
Panellist
Shine 0.000 0.990 0.521 0.662
Lightness 0.000 0.710 0.998 0.528
Cocoa Odour 0.000 0.929 0.887 0.551
Bitterness 0.000 0.718 0.889 0.743
Sweetness 0.000 0.733 0.964 0.523
Firmness 0.000 0.636 0.813 0.637
Melting 0.000 0.607 0.997 0.473
The univariate analysis of variance shows that there are statistically significant
differences in attributes of the 4 Cocoa samples at 0.05 level of significance. However there
exists statistically no significant differences in the scores given to the samples by the analysts. In

9FOOD CHARACTERISATION
addition there are exists statistically no significant differences in the interaction scores of
Panelists and Samples.

Running head: FOOD CHARACTERISATION
Table 6 Summary table of multiple pair comparison (Tukey’s HSD) for each sample Cocoa 50%
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Cocoa
50%
62% Cocoa -2.360.000 1.530.063 -1.710.035 -3.890.000 0.610.765 -2.330.001 -0.360.947
72% Cocoa -1.500.030 1.960.010 -0.980.386 -3.300.000 2.070.10 -2.330.001 1.860.035
33% Cocoa 1.980.002 -1.740.027 2.300.002 1.480.054 -2.010.013 1.870.014 -2.060.016
X = superscript to show significant differences if any.
Summary table of multiple pair comparison (Tukey’s HSD) for each sample Cocoa 62%
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Cocoa
62%
50%
Cocoa
2.360.000 -1.530.063 1.710.035 3.890.000 -0.610.765 2.330.001 0.360.947
72%
Cocoa
0.860.362 0.430.891 0.730.628 0.590.722 1.460.108 0.0001.000 2.220.008
33%
Cocoa
4.340.000 -3.280.000 4.010.000 5.370.000 -2.620.001 4.200.000 -1.700.061
X = superscript to show significant differences if any.

1FOOD CHARACTERISATION
Summary table of multiple pair comparison (Tukey’s HSD) for each sample Cocoa 72%
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Cocoa
72%
50%
Cocoa
1.500.030 -1.960.010 0.980.386 3.300.000 -2.070.010 2.330.001 -1.860.035
62%
Cocoa
-0.860.362 -0.430.891 -0.730.628 -0.590.722 -1.460.108 0.0001.000 -2.220.008
33%
Cocoa
3.480.000 -3.710.000 3.280.000 4.780.000 -4.070.000 4.200.000 -3.920.000
X = superscript to show significant differences if any.
Summary table of multiple pair comparison (Tukey’s HSD) for each sample Cocoa 33%
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Cocoa
33%
50%
Cocoa
-1.980.002 1.740.027 -2.300.002 -1.480.054 2.010.013 -1.870.014 2.060.016
62%
Cocoa
-4.340.000 3.280.000 -4.010.000 -5.370.000 2.620.001 -4.200.000 1.700.061
72%
Cocoa
-3.480.000 3.710.000 -3.280.000 -4.780.000 4.070.000 -4.200.000 3.920.000
X = superscript to show significant differences if any.

2FOOD CHARACTERISATION
Summary table of multiple pair comparison (Tukey’s HSD) for Gretel
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Gretel
Neha -0.210.999 -0.760.904 0.061.000 0.0001.000 -0.930.828 1.050.697 0.181.000
Diane 0.121.000 -0.710.926 -0.240.999 0.470.983 0.211.000 1.180.581 -0.580.978
Leona -0.151.000 -0.630.956 -0.360.997 -0.520.974 -0.530.983 0.580.965 -0.211.000
Helen 0.181.000 -1.170.608 0.420.993 -0.111.000 -0.420.994 0.650.945 0.251.000
John 0.031.000 -0.970.773 0.091.000 -0.510.976 -0.460.991 0.910.808 0.870.890
Summary table of multiple pair comparison (Tukey’s HSD) for Neha
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Neha
Grete
l
0.210.999 0.760.904 -0.061.000 0.001.000 0.930.828 -1.050.697 -0.181.000
Diane 0.3300.996 0.051.000 -0.300.999 0.470.983 1.140.675 0.131.000 -0.760.935
Leon
a
0.061.000 0.131.000 -0.420.993 -0.520.974 0.410.995 -0.470.987 -0.380.997
Helen 0.380.991 -0.410.993 0.360.997 -0.111.000 0.520.984 -0.400.994 0.081.000
John 0.230.999 -0.211.000 0.031.000 -0.510.976 0.480.989 -0.141.000 0.690.955
Summary table of multiple pair comparison (Tukey’s HSD) for Diane
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Diane
Gretel -0.121.000 0.710.926 0.240.999 -0.470.983 -0.211.000 -1.180.581 0.580.978
Neha -0.330.996 -0.051.000 0.300.999 -0.470.983 -1.140.675 -0.131.000 0.760.935
Leona -0.270.998 0.0831.000 -0.121.000 0.980.709 -0.730.930 -0.600.961 0.380.997
Helen 0.061.000 -0.460.989 0.660.949 -0.580.959 -0.630.964 -0.530.976 0.830.905
John -0.091.000 -0.260.999 0.330.998 -0.980.716 -0.670.952 -0.280.999 1.450.479

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Summary table of multiple pair comparison (Tukey’s HSD) for Leona
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Leona
Gretel 0.151.000 0.630.956 0.360.997 0.520.974 0.530.983 -0.580.965 0.211.000
Neha -0.061.000 -0.131.000 0.420.993 0.520.974 -0.410.995 0.470.987 0.380.997
Diane 0.270.998 -0.081.000 0.121.000 0.980.709 0.730.930 0.600.961 -0.380.997
Helen 0.330.996 -0.540.976 0.780.903 0.410.991 0.071.000 0.071.000 0.460.993
John 0.181.000 -0.340.997 0.450.990 0.011.000 0.330.998 0.330.998 1.080.767
Summary table of multiple pair comparison (Tukey’s HSD) for Helen
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
Helen
Gretel -0.181.000 1.170.608 -0.420.993 0.111.000 0.420.994 -0.650.945 -0.251.000
Neha -0.380.991 0.410.993 -0.360.997 0.111.000 -0.520.984 0.400.994 -0.081.000
Diane 0.061.000 0.460.989 -0.660.949 0.580.959 0.630.964 0.530.976 -0.830.905
Leona -0.330.996 0.540.976 -0.780.903 -0.410.991 -0.071.000 -0.071.000 -0.460.993
John -0.151.000 0.201.000 -0.330.998 -0.400.992 -0.041.000 0.260.999 0.620.972
Summary table of multiple pair comparison (Tukey’s HSD) for John
Shine Lightness Cocoa Odour Bitterness Sweetness Firmness Melting
John
Gretel -0.031.000 0.970.773 -0.091.000 0.510.976 0.460.991 -0.910.808 -0.870.890
Neha -0.230.999 0.211.000 -0.031.000 0.510.976 -0.480.989 0.141.000 -0.690.955
Diane 0.091.000 0.260.999 -0.330.998 0.980.716 0.670.952 0.280.999 -1.450.479
Leona -0.181.000 0.340.997 -0.450.990 -0.011.000 -0.330.998 -0.330.998 -1.080.767
Helen 0.151.000 -0.201.000 0.330.998 0.400.992 0.041.000 -0.260.999 -0.620.972

4FOOD CHARACTERISATION

Running head: FOOD CHARACTERISATION
The Summary table of multiple pair comparison provides the differences of the scores for the
samples and assessors. From the tables it is seen that there exists statistically significant
differences in some of the attributes of the samples. Similarly there also exists statistically
significant differences in the scores given by the Assessors.
Discussion
The analysis of the data shows that there are significant differences in the scores of the attributes
based on trials. However the scores of the attributes seems to be normally distributed. There is a
wide variation in the scores of the samples for Firmness and Melting as given by the Assessors.
There is also variation in the average attributes of the samples. While sample 769 has a higher
score for Seetness, Lightness and Melting, sample 315 has a higher score for Bitterness, Cocoa
odour and Shine. The Firmness score for sample 315 and 486 are both similar.
Moreover it is found that there are significant differences in the scores of the samples. on the
other hand there are no differences in the scores given to the attributes by the panelists. In
addition when the samples and attributes both are taken together there are no differences.
Conclusion
The above analysis shows that there are statistically significant differences in the scores
of Shine, Lightness, Cocoa odour, Bitterness, Sweetness, Firmness and Melting for the four
cocoa samples. On the other hand there are statistically no significant differences in the scores of
the variables based on the assessors. In addition, there are no differences in the scores of the
samples as provided by the assessors. Hence, there are no differences in the four cocoa samples
on the basis of Shine, Lightness, Cocoa odour, Bitterness, Sweetness, Firmness and Melting