DOI: https://doi.org/10.55373/mjchem.v28i1.161

Keywords: Halal authentication, Pig bristles, SPME-GC-MS, Chemometrics

Abstract

Pig bristles are prohibited by Islamic law. They pose a serious halal compliance risk when used in cosmetic brushes, filters, and food processing equipment. Animal-derived processed materials, such as pig bristles, are often used in traditional deoxyribonucleic acid (DNA) tests or protein-based species identification techniques, which can be expensive and time-consuming. Hence, new strategies for halal certification must be developed. This paper outlines a detailed methodology for the chemical characterization of pig bristles utilizing solid-phase microextraction (SPME) in conjunction with gas chromatography-mass spectrometry (GC-MS), augmented by sophisticated chemometric analysis. This research presents the first integrated SPME-GC-MS chemometric pipeline tailored for halal authentication of pig bristles, delivering a robust, processing-resilient chemical signature. Volatile organic compounds (VOCs) were extracted from pig bristles via a divinylbenzene (DVB)/Carboxen (CAR)/polydimethylsiloxane (PDMS) SPME fiber at optimized headspace conditions. The extracted volatiles were subsequently analyzed using GC-MS, revealing a diverse array of chemical markers, including phenols, alkanes, and alkyl-substituted hydrocarbons. Chemometric approaches, such as Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), demonstrated strong clustering and discrimination of pig-derived samples from non-pig equivalents. Variable Importance in Projection (VIP) scores identified the most important chemicals responsible for class separation. A total of 15 high-VIP compounds were visualized in a heatmap, and PCA loadings validated their role in explaining sample variance. A compound classification table was developed to categorize detected volatiles into chemical groups, including alkenes, esters, alcohols, and phenols. The findings of this study support the viability of SPME-GC-MS, combined with multivariate statistical modeling, as a rapid, non-destructive, and highly selective approach for certifying pig-derived products. The validated marker panel and workflow can be utilized for certification laboratories and for manufacturing screening bristles, routine inspections of brushes, and verification of materials tainted by non-halal sources.