Biomass is a very important source for the production of biofuels. During the hydrolysis step of the process for obtaining biofuels
the rate of decomposition of biomass is strictly related to its organic matter content and the operating mode of the facilities. This
paper highlights the effect of different pretreatments on the composition of biomass at the molecular level using Fourier Transform
Infrared Spectroscopy (FTIR) and Principal Component Analysis (PCA). For this experiment, a mixture of vegetable waste as a
potential source of abundant and sustainable feedstock for biofuels was used. Vegetable wastes were subjected to physical and
chemical pretreatment. The physical pretreatment comprised in exposing the wastes at a temperature of 120°C for 20 minutes in
an autoclave. For the chemical pretreatment, Schweizer reagent, sodium hydroxide and urea were used. FTIR analysis shows that
the chemical pretreatment leads to important changes at the molecular structures level, associated with the presence of sucrose,
amide, phospholipids and carboxylic acids. Moreover, results of PCA analyses confirm that the region of C=O and C=C stretching
vibrations (1500-1800 cm-1) are sensitive to NaOH and urea pretreatments on the biomass. For the physical pretreatment, no
substantial changes at the molecular structure level were observed.