Short path evaporation for methyl chavicol enrichment from basil essential oil

Antioxidant activity of rosemary essential oil fractions obtained by molecular distillation and their effect on oxidative stability of sunflower oil

The objective of this study was to evaluate the antioxidant activity of rosemary essential oil fractions obtained by molecular distillation (MD) and investigate their effect on the oxidative stability of sunflower oil. MD fractions were prepared in a series of low-pressure stages where rosemary essential oil was the first feed. Subsequently, a distillate (D1) and residue (R1) were obtained and the residue fraction from the previous stage used as the feed for the next. The residue fractions had the largest capacity to capture free radicals, and the lowest peroxide values, conjugated dienes and conjugated trienes. The antioxidant activity of the fractions was due to oxygenated monoterpenes, specifically α-terpineol and cis-sabinene hydrate. Oxidative stability results showed the residues (R1 and R4) and butylated hydroxytoluene had greater antioxidant activity than either the distillate fractions or original rosemary essential oil. The residue fractions obtained by short path MD of rosemary essential oil could be used as a natural antioxidants by the food industry.

Evaluation of the chemical composition, antioxidant and anti-inflammatory activities of distillate and residue fractions of sweet basil essential oil

In this study, the chemical composition and antioxidant and anti-inflammatory activities of sweet basil (Ocimum basilicum L. Lamiaceae family) were evaluated. Sweet basil is a food-related plant that is widely used in traditional Chinese medicine. Sweet basil crude oil was processed via molecular distillation and further characterized using gas chromatography-mass spectrometry (GC-MS) to screen for new compounds. The GC-MS analysis identified thirty-eight compounds. The major constituents of the residue fraction were estragole (17.06%), methyl eugenol (11.35%) and linoleic acid (11.40%), while the distillate fraction primarily contained methyl eugenol (16.96%), α-cadinol (16.24%) and α-bergamotene (11.92%). The antioxidant (DPPH and ABTS assays) and anti-inflammatory (in Raw264.7 cells) activities were evaluated. The residue fraction markedly scavenged the DPPH (IC₅₀ = 1.092 ± 0.066 mg/mL) and ABTS (IC₅₀ = 0.707 ± 0.042 mg/mL) radicals. Meanwhile, the distillate fraction distinctly suppressed the production of cytokines (TNF-α, IL-β, IL-6) and their gene expression in LPS-induced Raw264.7 cells and suppressed NO and iNOS in an in vitro model when compared with the crude oil. In conclusion, the fractions obtained from sweet basil crude oil showed different antioxidant and anti-inflammatory properties, and they could be used as an effective source of natural antioxidant and anti-inflammatory agents after molecular distillation. Thus, the properties of essential oils in natural herbal medicines may be maximized to provide a valuable therapeutic strategy for treating various disorders caused by extreme oxidative stress.

Study of Lactic Acid Thermal Behavior Using Thermoanalytical Techniques

Actually, there is a growing interest in the biotechnological production of lactic acid by fermentation aiming to substitute fossil fuel routes. The development of an efficient method for its separation and purification from fermentation broth is very important to assure the economic viability of production. Due to its high reactivity and tendency to decompose at high temperatures, the study of lactic acid thermal behavior is essential for its separation processes and potential application. In the present study, differential scanning calorimetry (DSC) analyses showed endothermic peaks related to the process of evaporation. Data of thermogravimetry (TG/DTG) were correlated to Arrhenius and Kissinger equations to provide the evaporation kinetic parameters and used to determine the vaporization enthalpy. Activation energies were 51.08 and 48.37 kJ·mol−1 and frequency values were 859.97 and 968.81 s−1 obtained by Arrhenius and Kissinger equations, respectively. Thermogravimetry, coupled with mass spectroscopy (TG-MS), provided useful information about decomposition products when lactic acid was heated at 573 K for approximately 30 min.