# Investigation of Oil Extracted from Roasted and Unroasted Oats with Use of Chemometrics
## 4 Conclusions  
The conclusions drawn in the current investigation are based on a thorough research process involving determining oxidative induction time using a PDSC, acid values by titration, calorific value using a calorimetric bomb, and fatty acid compositions using gas chromatography. The oxidative stability of the oil increased after the roasting of oat grains. Oil from roasted oat grains is characterised by lower acid and peroxide values than oil from grains that have not been thermally treated. The longer the roasting time, the less acidic and peroxide value there is, thus providing better hydrolytic and oxidative quality of the oil. Roasting does not cause significant changes in the composition of fatty acids. Many factors can influence oxidative stability. The more unsaturated acids the oil contains, the faster it will oxidise. However, in addition to the composition of fatty acids, the content of free fatty acids and the content of substances with pro- and antioxidant activity may influence the oxidative stability and the content of primary oxidation products. During roasting, such substances may decompose or be formed. Therefore, the change in stability does not always correlate with the change in the composition of fatty acids. Determination of every recorded value in the current investigation is laborious and requires the use of chemicals, except the spectral method. The chemical changes reported above were described using statistical models, and characteristic parameters are summarised in Table 2.  
The potential scientific applications of FT-IR spectroscopy for the rapid and comprehensive characterization of oils extracted from roasted oats are listed below. To determine every listed characteristic, it is necessary to construct a statistical model, which might be time-consuming. However, determination of a given characteristic is relatively straightforward. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Name**} & \multirow{2}{*}{**Type**} & \multirow{2}{*}{**Spectral Regions Used**} & \multicolumn{2}{c}{**Correlation Coefficient**} & \multicolumn{2}{c}{**RMSE**} \\ \cline{3-6}  & & & **Calibration** & **Prediction** & **Calibration** & **Prediction** \\ \hline MODEL 1 & Discriminant & 4000–400 cm\({}^{-1}\) & & & & \\ MODEL 2 & & 3636–3173 cm\({}^{-1}\) & & & & \\ MODEL 3 & Relative & 3699–435 cm\({}^{-1}\) & 0.9635 & 0.9022 & 0.649 & 1.510 \\ MODEL 4 & & 3636–3145 cm\({}^{-1}\) & & 0.9440 & 0.9191 & 1.690 & 2.640 \\ MODEL 5 & & 1852–1685 cm\({}^{-1}\) & 0.9672 & 0.8186 & 0.388 & 0.998 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Fatty acid composition is present in unroasted and roasted oat oil. Figure 11: Calculated (model predicted) versus actual values of PV determined experimentally. ward once the model has been constructed. It has been concluded that IR spectroscopy can be applied for the following:  
1. Discrimination of oil extracted from roasted and fresh oat grains;
2. Determination of acid value;
3. Determination of peroxide value;
4. Time of thermal processing;
5. Oxidation induction time. Results obtained within the current investigation show that barely one method, FT-IR spectroscopy, can be used for versatile qualitative and quantitative evaluation of oat oil if statistical models are previously constructed, calibrated, and validated. Conceptualization, B.K.P., J.B. and P.K. ; methodology, B.K.P., J.B., E.G.-S. and P.K. ; formal analysis, B.K.P., M.S. and S.M. ; investigation, B.K.P., M.S. and S.M. ; data curation, B.K.P., J.B., E.G.-S. and P.K. ; writing--original draft preparation B.K.P., J.B. and P.K. ; writing--review and editing, J.B., E.G.-S. and P.K. ; supervision, P.K. and J.B. All authors have read and agreed to the published version of the manuscript.