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Kelep, R.

Publications and source records attributed to Kelep, R..

2 recordsLinked to original sources
bioRxiv2025

Geographical Origin and Variety Differentiation of Kava (Piper methysticum) using Artificial Neural Network with FTIR Spectroscopy: A Novel Method

This study presents a novel method for authenticating the geographical origin and cultivar of kava (Piper methysticum) by combining Fourier Transform Infrared (FTIR) spectroscopy with Artificial Neural Networks (ANN). A spectral database of kava varieties from four (4) countries in the Pacific Island region, namely Vanuatu, Fiji, Papua New Guinea, and Hawaii, was used for regional authentication. For samples collected within Vanuatu, spectral data were obtained from the acetone extract of both fresh and dried kava. The ANN predictive model was trained on geographical origin (countries or islands of origin), quality (noble vs tudei), and between different cultivars. ANN achieved near-perfect performance, with a generalized R-Square of 0.99 (training), 0.84 (validation), and 0.95 (test) for geographical origin prediction. Class-specific accuracy was 100% for Vanuatu, Papua New Guinea, and Hawaii. The model achieved near-perfect internal prediction accuracy (R{superscript 2} = 0.99) under repeated-measure validation. Due to the limited availability of independent Fiji samples, no blind-test validation was performed for that region. Thus, robustness claims apply only to regions with sufficient validation data. Significantly, the model demonstrated perfect classification (100% accuracy) for Malo and Santo Island kava samples, highlighting its ability to authenticate micro-regional origins within Vanuatu. For variety differentiation, ANN achieved 100% accuracy for noble versus tudei cultivars, ensuring compliance with Vanuatus noble-only export policy. ATR-FTIR spectra of fresh and dried kava acetone extracts exhibited visually distinct patterns among kava cultivars at spectral regions of 1750 cm-1 to 1525 cm-1 and 1124 cm-1 to 900 cm-1, indicating potential for direct differentiation. Visual detection of kava adulteration at 1585 cm-1 was feasible at 1% tudei or wichmannii substitution without advanced analysis. These findings position ANN-FTIR as a rapid, non-destructive, and cost-effective solution for food authentication, geographical indication labeling, and export certification, supporting international standards such as Codex Alimentarius and International Standards Organization (ISO) guidelines. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/679113v2_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@171b7eorg.highwire.dtl.DTLVardef@10e218eorg.highwire.dtl.DTLVardef@bd2eb2org.highwire.dtl.DTLVardef@44c952_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗
bioRxiv2024

A simple method for methanol quantification in Spirits using UV Visible Spectroscopy and FTIR

Although standards methods of food safety assessment are important, these methods are expensive and requires intensive work and time. Quality assessment for high alcohol in spirits is still a challenged for industries in developing states due to lack of financial support and technical assistance. Ultra violet visible spectroscopy (UV VIS) and Fourier Transform Infrared Spectroscopy (FTIR) offers the low cost alternative testing methods that are affordable with a short turnaround time for dissemination of results. In this work, methanol content in ethanol was assessed in two approaches using UV VIS and FTIR spectroscopy. For UV VIS method, Potassium dichromate was used as the chromogenic reagent. In FTIR, calibration curve was built by increasing methanol ration from 0 to 40% (m V-1) at the expense of ethanol while keeping deionised water (DO) constant at 5% (m V-1) concentration. This helps gauge the change in methanol concentration relative to ethanol. Results of analysis using UV VIS showed a strong negative correlation for Methanol concentration and absorbance value at UV region from 900 to 1100 cm-1 (r = 98.00, RMSE = 0.023) relative to increasing ethanol concentration. A strong peak was observed for methanol concentration at spectral region of 970 cm -1 which is related to the methanoic acid C-O bond. The FTIR spectra region at 900 to 1050 cm -1 was used for observing methanol concentration with absorbance. A strong correlation was established from spectral region of 1010 cm-1 to 1026 cm-1, enabling quantification of methanol (r= 0.99, RMSEC = 0.55). Methanol peak was observed at 1020 cm-1 region of the spectrum. A set of experimental repetition was made to determine limit of detection (LOD) for UV VIS and FTIR methods which was observed at 0.29 and 0.5 % (m V-1), respectively. The limit of quantification was 0.89 and 1.5 % (m V-1) for UV VIS and FTIR respectively. This study has reaffirmed the utilisation of UV VIS and FTIR as considerable alternative method for quality control of high alcohol in distilled spirits.

biochemistry↗