Lavender (Lavandula angustifolia) and lavandin (a sterile hybrid of L. angustifolia × L. latifolia) essential oils are among those most commonly used in the world for various industrial purposes, including perfumes, pharmaceuticals and cosmetics. The solid residues from aromatic plant distillation such as lavender- and lavandin-distilled straws are generally considered as wastes, and consequently either left in the fields or burnt. However, lavender- and lavandin-distilled straws are a potentially renewable plant biomass as they are cheap, non-food materials that can be used as raw feedstocks for green chemistry industry. The objective of this work was to assess different pathways of valorization of these straws as bio-based platform chemicals and fungal enzymes of interest in biorefinery. Sugar and lignin composition analyses and saccharification potential of the straw fractions revealed that these industrial by-products could be suitable for second-generation bioethanol prospective. The solvent extraction processes, developed specifically for these straws, released terpene derivatives (e.g. τ-cadinol, β-caryophyllene), lactones (e.g. coumarin, herniarin) and phenolic compounds of industrial interest, including rosmarinic acid which contributed to the high antioxidant activity of the straw extracts. Lavender and lavandin straws were also suitable inducers for the secretion of a wide panel of lignocellulose-acting enzymes (cellulases, hemicellulases and oxido-reductases) from the white-rot model fungus Pycnoporus cinnabarinus. Interestingly, high amounts of laccase and several lytic polysaccharide monooxygenases were identified in the lavender and lavandin straw secretomes using proteomics. The present study demonstrated that the distilled straws of lavender and lavandin are lignocellulosic-rich materials that can be used as raw feedstocks for producing high-added value compounds (antioxidants, aroma) and fungal oxidative enzymes, which represent opportunities to improve the decomposition of recalcitrant lignocellulose into biofuel. Hence, the structure and the physico-chemical properties of these straws clearly open new perspectives for use in biotechnological processes involving especially filamentous fungi. These approaches represent sustainable strategies to foster the development of a local circular bioeconomy.

Rapeseed meal is a cheap and abundant raw material, particularly rich in phenolic compounds of biotechnological interest. In this study, we developed a two-step bioconversion process of naturally occurring sinapic acid (4-hydroxy-3,5-dimethoxycinnamic acid) from rapeseed meal into canolol by combining the complementary potentialities of two filamentous fungi, the micromycete Aspergillus niger and the basidiomycete Neolentinus lepideus. Canolol could display numerous industrial applications because of its high antioxidant, antimutagenic and anticarcinogenic properties. In the first step of the process, the use of the enzyme feruloyl esterase type-A (named AnFaeA) produced with the recombinant strain A. niger BRFM451 made it possible to release free sinapic acid from the raw meal by hydrolysing the conjugated forms of sinapic acid in the meal (mainly sinapine and glucopyranosyl sinapate). An amount of 39 nkat AnFaeA per gram of raw meal, at 55 °C and pH 5, led to the recovery of 6.6 to 7.4 mg of free sinapic acid per gram raw meal, which corresponded to a global hydrolysis yield of 68 to 76% and a 100% hydrolysis of sinapine. Then, the XAD2 adsorbent (a styrene and divinylbenzene copolymer resin), used at pH 4, enabled the efficient recovery of the released sinapic acid, and its concentration after elution with ethanol. In the second step, 3-day-old submerged cultures of the strain N. lepideus BRFM15 were supplied with the recovered sinapic acid as the substrate of bioconversion into canolol by a non-oxidative decarboxylation pathway. Canolol production reached 1.3 g/L with a molar yield of bioconversion of 80% and a productivity of 100 mg/L day. The same XAD2 resin, when used at pH 7, allowed the recovery and purification of canolol from the culture broth of N. lepideus. The two-step process used mild conditions compatible with green chemistry.

In the effort of innovation towards green analytical chemistry concepts and considering the six principles of green extraction, the industrial turbodistillation process was downscaled into a laboratory apparatus turbo-Clevenger (TC) for the extraction of essential oils. Turbodistillation is used as an industrial purpose for the extraction of essential oils from hard matrixes such as wood, barks, seeds. In this work, a TC and the conventional technique of hydrodistillation (HD, Clevenger apparatus) are used for the extraction of essential oils from three spices with hard structures (Illicium verum, Schinus terebinthifolius, and Cinnamomum cassia) and are compared. This study shows that the essential oils extracted by TC in 30 min were quantitatively (yield and kinetics profile) and qualitatively (aromatic profile) similar to those obtained using conventional hydrodistillation in 3 h. This process, which gave a reduced extraction time, was perfectly adapted to the extraction of hard matrixes.

We assessed the atheroprotective efficiency of modified dairy fats in hyperlipidemic hamsters. A systems biology approach was implemented to reveal and quantify the dietary fat-related components of the disease. Three modified dairy fats (40% energy) were prepared from regular butter by mixing with a plant oil mixture, by removing cholesterol alone, or by removing cholesterol in combination with reducing saturated fatty acids. A plant oil mixture and a regular butter were used as control diets. The atherosclerosis severity (aortic cholesteryl-ester level) was higher in the regular butter-fed hamsters than in the other four groups ( P < 0.05). Eighty-seven of the 1,666 variables measured from multiplatform analysis were found to be strongly associated with the disease. When aggregated into 10 biological clusters combined into a multivariate predictive equation, these 87 variables explained 81% of the disease variability. The biological cluster “regulation of lipid transport and metabolism” appeared central to atherogenic development relative to diets. The “vitamin E metabolism” cluster was the main driver of atheroprotection with the best performing transformed dairy fat. Under conditions that promote atherosclerosis, the impact of dairy fats on atherogenesis could be greatly ameliorated by technological modifications. Our modeling approach allowed for identifying and quantifying the contribution of complex factors to atherogenic development in each dietary setup.