Sample collection and analysis is important in calibrating near infrared transmitters and lab analyzers for snack food moisture, oil and other measurements. Specific practices must be outlined for standardized measurements. Sealed collection containers with limited head space is required. Drying temperature and times for moisture and standard practice for other measurements must be determined.

1. Best Practices for Using Near Infrared for Snack Quality

2. Best Practices for Using Near
Infrared for Snack Quality
Presented by: Greg Brown, Project
Manager
Process Sensors Corp.
Milford, MA USA

3. Best Practices for Using Near Infrared for Snack Quality-- Overview
• Sample collection and analysis is important in
calibrating near infrared transmitters and lab analyzers
for snack food moisture, oil and other measurements
• Specific practices must be outlined for standardized
measurements
• Sealed collection containers with limited head space is
required
• Drying temperature and times for moisture and
standard practice for other measurements must be
determined

4. Near Infrared (NIR) Measurements for Snack Foods for Lab & Process Photometers
• Moisture
• Oil
• Flavorings
• Protein
• Sugar

5. Light Wavelength Frequencies

6. NIR Functional Groups

7. NIR Photometer

8. NIR Measurements for Snack Foods
• Moisture
• Oil
• Protein
• Flavorings
• Color (Vis/NNIR)

9. Moisture Measurement Critical
• Moisture impacts taste, texture and shelf life
• Especially important for corn, potato-based and
other products that are extremely hydroscopic
and absorb moisture from the surrounding air
• Moisture can adversely impact shelf life by over
45%

10. Sample Collection and Location
• Sample should be collected after the unit
operation while allowing sufficient
time/distance for flashing to occur, so as to
collect a representative sample of finished
product prior to packaging

11. Sample Collection
• Open containers not suitable for sample
collection
• Ziplock freezer bags or other sample bags
with moisture barrier coatings with excess
air squeezed out
• Closed containers with minimum air space
acceptable

12. Importance of Sample Collection Containers/Bags
• Higher cost of sample collection
containers/bags negligible
• Better moisture measurement reduces cost
related to customer satisfaction and shelf life

13. Open Containers or Varying Air Space in Collection Containers
• Subject to ambient humidity
• Time to deliver to lab, chat on trip to lab
• Turn around time for lab analysis

14. Comparison of Duplicate Double-Blind Samples
Between Open and Sealed Collection
Sample # Chips Unsealed Sample Sealed Sample
1A 1.45 1.42
1B 1.71 1.42
2A 1.63 1.59
2B 2.1 1.58
3A 2.21 1.82
3B 2.78 1.82

15. Weigh Dry Weigh
• Automatic extrapolated weigh dry weigh okay
for quick check not calibration due to variability
• Extended weigh dry weigh oven dry best for
calibration

16. Time for Sample Oven Dry Product Dependent
• Each company has their own practice for each
product
• 105⁰ C and 120⁰ C are most common
• Two hours dry time usually sufficient, and three
hours or 24 hours usually offers minimum benefit

17. Double-Blind Samples for Lab Analysis With Sealed Containers
During Calibration Critical For Success
Sample # Chips
One Hour Sample at
120'C
Two Hour Sample at
120' C
Extrapolated WDW
Sample Analysis
1A 1.45 1.42 1.38
1B 1.39 1.42 1.26
2A 1.61 1.59 1.63
2B 1.65 1.58 1.71
3A 1.88 1.82 1.91
3B 1.83 1.82 2.11

18. Grinding Samples
• Better results usually achieved with grinding
samples
• Grinding required for nuts, hulled shells and
skin products

19. Raw Material Samples
• Raw materials require multiple sample points
• Must be well mixed
• Sampled by batch

20. Process Moisture Measurement is Often More Accurate Due to
Sample Collection Methods
Lab Moisture Measurement NIR Transmitter Measurement
1.42 1.26
1.59 1.49
1.82 1.96
2.24 2.38
2.42 2.53
Standard Error 0.073185818

21. Lab vs. NIR Transmitter Trend
0
0.5
1
1.5
2
2.5
3
1 2 3 4 5
Chart Title
Lab Moisture Measurement NIR Transmitter Measurement

22. Lab vs. NIR Measurement
0
0.5
1
1.5
2
2.5
3
0 0.5 1 1.5 2 2.5 3
LabMoisture
NIR Transmitter
NIR Transmitter Measurement

23. NIR Lab & At-Line Measurement

24. Oil/Fat Measurements
• Press method accuracy dependent on sample
presentation and method
• Soxhlet extraction expensive and time
consuming
• NIR supplies quick accurate measurements

25. Protein Measurements
• Photometers can provide trends at best
• Spectrophotometers can measure quickly in lab
• Kjeldahl is accurate, expensive and time
consuming

26. NIR Methodology
• NIR photometers moisture and oil measurements
are based on linear measurements (y=mx + B) and
non-linear segmentation
• Spectrophotometers typically use chemometrics
or eigen vector analysis such as PCR, PLS1, PLS2
or other

27. Conclusions
• Sample collection is important to insure accurate
analysis of process samples
• Air space for samples collected must be minimized
• Samples must be analyzed in a timely manner

28. Best Practices for Using Near Infrared for Snack Quality
• Presented by: Greg Brown, Project Manager
• Process Sensors Corp.
113 Cedar Street
Milford, MA 01757 USA
508.473-9901
www.processsensors.com
gbrown@processsensors.com