Chemical profiling of liposoluble liquid smokes obtained from Eucalyptus wood tar: confirmation of absence of polycyclic aromatic hydrocarbons.

Liposoluble liquid smoke (LS) preparations are versatile food additives used worldwide. The objective of the present work was to characterise the chemical composition of four types of industrial liposoluble LS currently used as the basis for the production of commercial smoke flavourings. The LS was obtained by vacuum fractional distillation from a raw pyrolysis oil (raw LS) obtained primarily from eucalyptus wood tar. The raw LS and the four LS flavourings obtained therefrom were analysed by gas chromatography/mass spectrometry (GC/MS) to characterise the main groups of components. Additional analyses were carried out to evaluate the occurrence of PAHs (polycyclic aromatic hydrocarbons) in the samples, as the producer claimed that these samples are free of PAHs. The main chemical components characterised in the LS were organic acids, aldehydes, esters, furans, pyrans and phenols, with phenolic compounds being the major chemical group. For the four LS tested samples, no PAHs could be detected with the method employed, which could indicate that the industrial processing was able to effectively remove this harmful class of compounds, or at least decrease its concentrations to levels below the limits of detection of the method of analysis.

NMR techniques for determination of lipid content in microalgal biomass and their use in monitoring the cultivation with biodiesel potential.

In the present investigation, the application of NMR spectroscopic techniques was extensively used with an objective to explore the biodiesel potential of biomass cultivated on a lab scale using strains of Chlorella vulgaris and Scenedesmus ecornis. The effect of variation in the composition of culturing medium on the neutral and polar lipids productivity, and fatty acid profile of solvent extracts of microalgae biomass was studied. Determination of unsaturated fatty acid composition (C18:N = 1-3, ω3 C20:5, ω3 C22:6), polyunsaturated fatty esters (PUFEs), saturated fatty acids (SFAs), unsaturated fatty acids (UFAs), free fatty acids (FFAs), and iodine value were achieved from a single (1)H NMR spectral analysis. The results were validated by (13)C NMR and GC-MS analyses. It was demonstrated that newly developed methods based on (1)H and (13)C NMR techniques are direct, rapid, and convenient for monitoring the microalgae cultivation process for enhancement of lipid productivity and their quality aspects in the solvent extracts of microalgal biomasses without any sample treatment and prior separation compared to other methods. The fatty acid composition of algae extracts was found to be similar to vegetable and fish oils, mostly rich in C16:0, C18:N (N = 0 to 3), and n-3 omega polyunsaturated fatty acids (PUFAs). The lipid content, particularly neutral lipids, as well as most of the quality parameters were found to be medium specific by both the strains. The newly developed methods based on NMR and ultrasonic procedure developed for efficient extraction of neutral lipids are cost economic and can be an effective aid for rapid screening of algae strains for modulation of lipid productivity with desired biodiesel quality and value-added products including fatty acid profile.