NIR Technology Australia
Suite 103 / 56 Kitchener
Pde Bankstown NSW 2200 Tel: +61 2 9790 6450 Fax: +61 2 9790 1552
Application Note 59: Comparison of NIT-38 Olive Analyser with other NIR analysers.
April 2005.
Introduction:
NIR analysers are widely used in the measurement of oil and moisture levels in olives through out Europe. More recently the Australia Olive Industry has begun to take up NIR for this analysis. The NIT-38 Olive Analyser was developed in Australia for use in the Spanish Olive Industry. A number of Calibrations have been developed for measuring oil and water content in olives and orjuha, as well as free fatty acids in virgin olive oils.
The purpose of this study is to demonstrate the ability to transfer a calibration for oil and water in olives from Spain to Australia and to compare the performance of the NIT-38 Olive Analyser with reference laboratory data and 7 other NIR analysers in use within Australia.
Procedure:
The Spanish calibration was loaded into the NIT-38 Olive Analyser. Olives were macerated using a Retsch hammer mill to form a semi-homogeneous paste which was loaded into a Squeeze Cell with a 10mm pathlength. The sample was compressed between two glass windows to form a consistent 10mm thick layer. The cell was inspected for holes in the meat sample and for even spread across the cell. The cell was loaded into the NIT-38 Olive Analyser which moves the cell up and down in front of the light beam to collect five spectra for each sample across the wavelength range of 720nm to 1100nm. The averaged results were recorded for the fourteen samples.
Data was provided form a round robin analysis of the fourteen samples by seven other near infrared analysers. The data obtained from each NIR analyser were compared to the laboratory reference values for the fourteen samples.
Results:
The readings for all NIR systems tested are plotted on the charts below for the Oil and Moisture values. The full list of data can be found in the tables in appendix 1.
Chart 1: Oil values as given by systems and the reference values.
Chart 2: Moisture values as given by systems and reference values
The differences between the reference values and the values generated by each of the analysers were calculated with the resultant error values displayed in the tables below. The full list of data values can be found in appendix 2.
Chart 3: Error values for oil measurements.
Chart 4: Error values for moisture measurements.
Conclusion:
As can be seen in the above results the measurement of Oil and Moisture in olives is reasonably consistent for all analysers. With differences between the reference values and the analysers in most cases being within acceptable ranges.
As illustrated in the above results the NIT-38 Olive Analyser compares favourably to all systems currently in use by the Australian Olive industry. In most cases the NIT-38 out performs it’s contemporaries.
Appendix 1:
Below are the tables of actual resultant measurements.
|
Samples/NIR
equipment |
1 |
2 |
3 |
4 |
5 |
6 |
NIT-38 |
8 |
Reference |
Average |
|
Frantoio
FROC |
15.63% |
13.33% |
15.50% |
16.07% |
14.03% |
21.53% |
17.03% |
15.60% |
15.76% |
16.09% |
|
Leccino
FROC |
11.87% |
8.22% |
11.90% |
12.87% |
11.20% |
13.26% |
13.50% |
11.77% |
10.79% |
11.82% |
|
Frantoio
IOPL |
19.17% |
18.10% |
17.90% |
17.10% |
17.50% |
25.23% |
19.50% |
17.87% |
17.51% |
19.05% |
|
Manzanillo
IOPL |
14.07% |
13.26% |
13.20% |
14.50% |
15.90% |
18.37% |
17.10% |
12.97% |
15.81% |
14.92% |
|
Arbequina
MO |
6.93% |
6.82% |
8.30% |
10.93% |
9.73% |
10.36% |
9.67% |
9.00% |
7.03% |
8.97% |
|
Picual
MO |
3.87% |
4.74% |
7.10% |
10.17% |
8.50% |
6.93% |
10.90% |
7.87% |
5.62% |
7.51% |
|
Frantoio
OW |
20.83% |
17.77% |
17.80% |
18.33% |
17.83% |
27.20% |
18.60% |
19.60% |
18.83% |
19.75% |
|
Manzanillo
OW |
16.70% |
12.82% |
13.00% |
16.27% |
15.97% |
20.70% |
17.17% |
15.37% |
17.19% |
16.00% |
|
Barnea
TIM |
9.37% |
9.58% |
10.50% |
13.03% |
11.97% |
11.93% |
12.70% |
10.60% |
10.43% |
11.21% |
|
Frantoio
TIM |
13.97% |
11.86% |
13.00% |
13.93% |
13.67% |
17.06% |
14.43% |
12.17% |
12.03% |
13.76% |
|
Frantoio
TOP |
15.13% |
13.10% |
12.40% |
14.03% |
14.47% |
18.80% |
16.03% |
14.07% |
14.73% |
14.75% |
|
Manzanillo
TOP |
10.33% |
8.93% |
9.50% |
12.63% |
11.60% |
12.06% |
13.83% |
11.37% |
10.90% |
11.28% |
|
Barnea
VOOP |
12.97% |
11.11% |
11.70% |
13.77% |
12.33% |
15.10% |
13.93% |
13.83% |
13.14% |
13.09% |
|
Picual
VOOP |
8.97% |
7.36% |
9.10% |
11.70% |
10.10% |
9.87% |
12.57% |
9.57% |
10.72% |
9.91% |
|
|
|
|
|
|
|
|
|
|
|
|
|
Correlation |
96.72% |
94.11% |
90.72% |
96.05% |
95.80% |
94.86% |
96.60% |
94.22% |
100.00% |
96.59% |
Appendix Table 1: Oil values as given by systems against reference values
|
Samples/NIR
equipment |
1 |
2 |
3 |
4 |
5 |
6 |
NIT-38 |
8 |
Reference |
Average |
|
Frantoio
FROC |
50.10% |
64.34% |
50.20% |
51.73% |
53.33% |
45.06% |
55.57% |
54.37% |
49.80% |
53.09% |
|
Leccino
FROC |
54.40% |
68.60% |
55.10% |
53.10% |
54.77% |
51.80% |
56.87% |
57.73% |
54.40% |
56.55% |
|
Frantoio
IOPL |
54.47% |
65.81% |
52.50% |
54.73% |
54.27% |
51.57% |
55.77% |
58.67% |
51.70% |
55.97% |
|
Manzanillo
IOPL |
59.87% |
68.80% |
57.30% |
57.93% |
58.33% |
59.03% |
59.47% |
63.60% |
60.00% |
60.54% |
|
Arbequina
MO |
64.73% |
74.70% |
62.90% |
60.23% |
62.63% |
65.67% |
59.00% |