https://doi.org/10.17113/ftb.64.02.26.8998

Article in press

Near-Infrared Spectroscopy for Rapid Determination of Physicochemical Properties in Fermented Fish Sauce (‘Nam Pla-Ra’)

Sunee Jungtheerapanich^*, Kraireuk Ngowsuwan and Sumaporn Kasemsumran

Laboratory of Non-Destructive Quality Evaluation of Commodities, Kasetsart Agricultural and Agro-Industrial Product Improvement Institute (KAPI), Kasetsart University, 50 Ngam Wong Wan Road, Bangkok 10900, Thailand

Copyright © 2024 This is a Diamond Open Access article published under CC-BY licence. Copyright remains with the authors, who grant third parties the unrestricted right to use, copy, distribute and reproduce the article as long as the original author(s) and source are acknowledged.

Article history:

Received: 16 December 2024

Accepted: 7 December 2025

Keywords:

fermented fish sauce (nam pla-ra); near infrared spectroscopy; physicochemical values determination; predictive model

Summary:

Research background. Thai community product quality standards have been established for nam pla-ra, which require at least 4 % protein and 12 % salt (sodium chloride). Determining the protein and sodium chloride (NaCl) contents requires the use of chemicals and is time-consuming. In addition to reporting protein and salt content, there are other quality controls that need to be carried out. Thus, the objective of this research was to develop predictive models for the determination of nam pla-ra physicochemical values by using near-infrared spectroscopy (NIRS) for fast and simultaneous multi-parameter prediction.

Experimental approach. The physicochemical values of commercially available fermented fish sauce (‘nam pla-ra’ in Thai) were evaluated to develop predictive models for physicochemical values determination and to develop models to categorize samples. The model was developed and tested based on the seven parameters: total soluble solids (TSS), pH, L*, a*, b*, NaCl, and protein content.

Results and conclusions. The predictive models for pH and color (L*, a*, b*) could be used for screening, based on their coefficients of determination (R²=0.73–0.81; SEP=0.15–0.94); the protein content model could be used for research and general work (R2=0.86; SEP=0.44); and the TSS and NaCl models could be used for all types of work (R²=0.97–0.98; SEP=0.41–0.61). Nam pla-ra physicochemical values could be predicted accurately using TSS, color (L*, a*, b*), NaCl, and protein content. There was no significant (p>0.05) difference between the quality value from the predictive model and the reference method, except for the pH value.

Novelty and scientific contribution. NIRS technique showed a potential for nam pla-ra physicochemical values prediction using TSS, color (L*, a*, b*) with the whole range from 1000–2500 nm, and NaCl and protein contents with the selected range from 1000–1889.64 and 2030.87–2408.48 nm. Furthermore, these findings demonstrate the potential of NIRS as a rapid, non-destructive, environmentally friendly, and reliable analytical tool for nam pla-ra. NIRS can contribute to ensuring product consistency and facilitating standardization in the fermented fish sauce industry. Such applications enhance food safety and consumer confidence.