Detection of adulterant in <i>Aloe barbadensis</i> miller gel using Fourier Transform Infrared Spectroscopy (FTIR) with chemometrics

Abstract Aloe barbadensis Miller , is widely used due to its significant anti-inflammatory properties. Although adulterating aloe vera gel with cheaper substitutes (e.g., maltodextrin) does not raise safety concerns, it presents notable challenges to the product’s quality and efficacy. This study investigates aloe vera gel adulteration using Fourier Transform Infrared Spectroscopy (FTIR) coupled with chemometrics techniques, particularly Principal Component Analysis (PCA), Partial Least Square (PLS), and Partial Least Squares Discriminant Analysis (PLS-DA). The results showed that the PCA model effectively discriminates between pure aloe vera gel, adulterated samples, and retail aloe vera gel. Notably, brand A of the retail aloe vera gel clusters with aloe vera gel adulterated with 2 % maltodextrin. PLS-DA models further revealed that retail aloe vera gel from brand A might be adulterated with low level of maltodextrin, while brands B and C may contain ethanol. The PLS biplot provides insight into the correlation between different aloe vera gels and the Y-variables. It shows that pure aloe vera gel exhibits higher anti-inflammatory activity than the adulterated samples, implying that the presence of maltodextrin may reduce its anti-inflammatory potential. The Partial Least Squares Regression (PLSR) model, based on anti-inflammatory activity as the Y variable, demonstrated high accuracy (R 2 = 0.995) and good predictive ability (RMSEE = 0.0133 and RMSEcv = 0.0995). This approach offers a reliable analytical method for detecting adulterants in aloe vera gel and ensuring product authenticity in the market, thereby safeguarding both its quality and effectiveness.