Original Article AUTHENTICATION OF GRAPE SEED FACE OIL USING FTIR SPECTROSCOPY COMBINED WITH CHEMOMETRICS TECHNIQUES ANDI PRAYOGA 1 , ANJAR WINDARSIH 2 , WURI APRIYANA 2 , FLORENTINUS DIKA OCTA RISWANTO 3* , ENADE PERDANA ISTYASTONO 1,3 1 Magister of Pharmacy Study Program, Faculty of Pharmacy, Universitas Sanata Dharma, Yogyakarta-55282, Indonesia. 2 Research Center for Food Technology and Processing, National Research and Innovation Agency, Jl. Jogja Wonosari km 31,5, Gunungkidul, Yogyakarta, Indonesia. 3 Research Group of Computer-Aided Drug Design and Discovery of Bioactive Natural Products, Faculty of Pharmacy, Sanata Dharma University, Yogyakarta-55282, Indonesia * Corresponding author: Florentinus Dika Octa Riswanto; * Email: dikaocta@usd.ac.id Received: 21 May 2024, Revised and Accepted: 04 Jul 2024 ABSTRACT Objective: This research aims to authenticate grape seed oil products using FTIR spectroscopy combined with chemometric methods. Methods: In the initial stage, exploratory data analysis was carried out by applying the main components with the Principal Component Analysis (PCA) model. Second derivative spectra resulting from preprocessing of the original spectra are used to create multivariate Principal Component Regression (PCR) and Partial Least Squares (PLS) calibration models. The second derivative spectra of Grape Seed Oil (GO), Olive Oil (OO), and the binary mixture GO+OO are utilized to generate a sparse partial least squares-discriminant analysis (SPLS-DA) model. Results: The PCA model was successfully obtained with visualization that depicted a total of 93.8% in the first and second dimensions. Multivariate calibration produced the best model in PLS with second derivative spectra for both GO and OO. PLS model for GO resulted the value of Rcal 2 , RCV 2 , Rval 2 , RMSEC, RMSECV, and RMSEP of 0.998, 0.992, 0.982, 0.700, 1.557, and 2.331, respectively. The SPLS-DA model was successfully built and discriminated with AUC-ROC values of 1.000, 1.000, and 0.994 for GO, OO, and GO+OO, respectively. Conclusion: Authentication of grape seed face oil can be undertaken using FTIR spectroscopic methods and chemometric techniques, which can produce high sensitivity and specificity values. Keywords: Grape seed oil, Face oil, Adulteration, FTIR spectroscopy, Chemometrics © 2024 The Authors. Published by Innovare Academic Sciences Pvt Ltd. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/) DOI: https://dx.doi.org/10.22159/ijap.2024v16i5.51525 Journal homepage: https://innovareacademics.in/journals/index.php/ijap INTRODUCTION The high demand for cosmetic products for both men and women provides opportunities for the cosmetic industry in Indonesia [1–3]. Modern cosmetics are reported to contain harmful chemicals and have ecological impacts on the environment [4]. With growing awareness, consumers tend to prefer natural products [5–8]. One of the most needed cosmetic products for both teenagers and adults is skincare, especially facial skincare [9]. One type of facial skincare is face oil, aimed at moisturizing and smoothing. One widely used type of face oil is grape seed oil. Grape seed oil contains antioxidants that are beneficial for skin care. The antioxidants contained in it are vitamin E and Oligomeric Proanthocyanidins (OPC) [10]. In the previous research, grape seeds were reported to contain 8-20% oil in the dry state [11]. Grape seed oil has a high vitamin E content, ranging from 1 to 53 mg per 100 g of oil, which is higher than olive oil [10]. Even though grape seed oil has greater economic value than other oils, they appear to share many similar physical characteristics. Currently, research on grape seed oil to detect whether the grape seed extract is adulterated or not is still lacking. Therefore, it is very significant to develop a simple and fast method for the detection of grape seed oil adulteration [12]. In previous related research, analysis of sunflower oil in a ternary mixture with grape seed oil and candlenut oil in a mixed system using FTIR spectroscopy and chemometrics was successfully carried out [13]. However, research that applies the FTIR spectroscopy method combined with chemometric techniques on grape seed face oil has never been carried out. This research aims to authenticate grape seed oil products using FTIR spectroscopy combined with chemometric methods. The undertaken chemometric techniques include Principal Components Analysis (PCA), Partial Least Squares (PLS), and Partial Least Squares Discriminant Analysis (PLS-DA). MATERIALS AND METHODS Materials Grape Seed Oil (GO) and Olive Oil (OO) are obtained from distributors in Indonesia, with a Certificate of Analysis to verify and prove their authenticity. Tools and software In this research, a complete instrument was used with Thermo Nicolet iS10 Thermo Scientific FT-IR spectrophotometer, Socorex® Micropipette with sizes of 20-200 μl and 100-1000 μl and a Globolab measuring cup, the results of the FTIR spectrum data were exported to Excel 2019 software (Microsoft Inc., USA) and saved as a. csv file before being analyzed using statistical software R Version 4.3.2. Methods Methods used in this study were developed according to the previous study from Riswanto et al. (2023) [14] with several modifications. In this research, chemometrics techniques were implemented to authenticate grape seed face oil from olive oil as adulterant. Calibration and validation sample preparation Calibration and validation solution test samples containing grape seed oil and olive oil were made from a mixture of the two ingredients with a concentration range of 0-100% (v/v) to obtain 15 variations of the concentration of the calibration solution and 30 variations of the concentration of the validation solution. Sample preparation for discrimination The solution for PLS-DA analysis is available in three different samples, namely grape seed oil, olive oil, and a binary mixture that contains grape seed oil and olive oil with a range of concentration 0- 100% (v/v). Eight pure grape seed oil solutions, eight pure olive oil International Journal of Applied Pharmaceutics ISSN- 0975-7058 Vol 16, Issue 5, 2024