The antioxidant interactions of α- and γ-tocopherol with curcumin and quercetin were assessed in an oil-in-water emulsion using the WIM-CAT assay, a method integrating Weibull interaction modeling with the conjugated autoxidizable triene technique. Synergistic effects were strongest for γ-tocopherol with curcumin and for α-tocopherol with quercetin, particularly at low tocopherol concentrations (0.2 μM in emulsion, 380 ppm in oil) and high molar ratios (3:1). Increasing tocopherol concentration to 0.6 μM in emulsion (1140 ppm in oil) reduced synergy, likely reflecting pro-oxidant activity. The presence of ferrous ions accelerated oxidation but did not influence synergistic interactions, while acidic conditions reduced tocopherol pro-oxidation and modified the effects of curcumin and quercetin. Weibull modeling revealed isoform-dependent differences during the propagation phase of oxidation. Cyclic voltammetry further suggested that the synergy of α-tocopherol may involve antioxidant regeneration mechanisms, whereas γ-tocopherol appears to act through alternative redox processes. Together, kinetic and electrochemical analyses provide complementary insights into the conditions governing antioxidant interactions.

This study presents a novel method based on a spectrophotometric assay coupled with mathematical modeling (Weibull interactions modeling CAT) to evaluate synergistic interactions of antioxidants in an oil-in-water model emulsion. The approach addresses a major limitation in current assays by eliminating interference from pro-/antioxidant pathways induced by exogenous radical initiators or buffers, allowing for a more accurate assessment of antioxidant efficacy. Using the Weibull equation, key kinetic parameters (LagP, α, β) were extracted to characterize the impact of antioxidant combinations on lipid oxidation. Results showed that certain combinations, such as α-tocopherol with carnosic acid, dieckol, and myricetin, exhibited concentration-dependent synergistic effects. Among these, carnosic acid in equimolar ratios demonstrated particularly promising interactions. In contrast, ascorbic acid revealed antagonistic behaviour when combined with α-tocopherol. Additionally, the presence of ferrous ions significantly influenced antioxidant interactions, highlighting their role in modulating underlying mechanisms. Overall, carnosic acid and dieckol emerged as strong candidates for use in combination with α-tocopherol under specific conditions. This method provides a refined approach for screening antioxidant synergies and contributes to the development of more effective antioxidant formulations in emulsified systems.

Rapeseed meal (RSM) is a cheap, abundant and renewable feedstock, whose biorefinery is a current challenge for the sustainability of the oilseed sector. RSM is rich in sinapic acid (SA), a p-hydroxycinnamic acid that can be decarboxylated into canolol (2,6-dimethoxy-4-vinylphenol), a valuable bioactive compound. Microbial phenolic acid decarboxylases (PADs), mainly described for the non-oxidative decarboxylation of ferulic and p-coumaric acids, remain very poorly documented to date, for SA decarboxylation. The species Neolentinus lepideus has previously been shown to biotransform SA into canolol in vivo, but the enzyme responsible for bioconversion of the acid has never been characterized. In this study, we purified and characterized a new PAD from the canolol-overproducing strain N. lepideus BRFM15. Proteomic analysis highlighted a sole PAD-type protein sequence in the intracellular proteome of the strain. The native enzyme (NlePAD) displayed an unusual outstanding activity for decarboxylating SA (Vmax of 600 U.mg−1, kcat of 6.3 s−1 and kcat/KM of 1.6 s−1.mM−1). We showed that NlePAD (a homodimer of 2 × 22 kDa) is fully active in a pH range of 5.5–7.5 and a temperature range of 30–55 °C, with optima of pH 6–6.5 and 37–45 °C, and is highly stable at 4 °C and pH 6–8. Relative ratios of specific activities on ferulic, sinapic, p-coumaric and caffeic acids, respectively, were 100:24.9:13.4:3.9. The enzyme demonstrated in vitro effectiveness as a biocatalyst for the synthesis of canolol in aqueous medium from commercial SA, with a molar yield of 92%. Then, we developed processes to biotransform naturally-occurring SA from RSM into canolol by combining the complementary potentialities of an Aspergillus niger feruloyl esterase type-A, which is able to release free SA from the raw meal by hydrolyzing its conjugated forms, and NlePAD, in aqueous medium and mild conditions. NlePAD decarboxylation of biobased SA led to an overall yield of 1.6–3.8 mg canolol per gram of initial meal. Besides being the first characterization of a fungal PAD able to decarboxylate SA, this report shows that NlePAD is very promising as new biotechnological tool to generate biobased vinylphenols of industrial interest (especially canolol) as valuable platform chemicals for health, nutrition, cosmetics and green chemistry.

An optimized proteolysis process was applied to rapeseed meal proteins (RP) and the hydrolysate was separated by membrane filtration allowing the production of highly metal-chelating peptides in the permeate. In order to identify the chemical structure of the most active obtained metal-chelating peptides, immobilized metal affinity chromatography (IMAC) was applied. The RP-IMAC peptide fraction was mainly composed of small peptides from 2 to 20 amino acids. Using the Ferrozine assay, RP-IMAC peptides showed a significant chelating efficiency higher than sodium citrate and close to that of EDTA. The peptide sequences were identified by UHPLC-MS and several possible iron binding sites were found. β-carotene oxidation assay and lipid oxidation in bulk oils or emulsion were carried out to evaluate the potential of such peptides as efficient antioxidants to protect lipids from oxidation. While chelating peptides showed a limited efficiency in bulk oil, they performed more efficiently in emulsion.

Preventing lipid oxidation, especially with the polyunsaturated fat-based products, is a major concern in sectors as agri-food and cosmetic. Even though the efficiency of synthetic antioxidants has been recognized, both consumers and manufacturers are looking for more innovative, healthy and quality products while rejecting synthetic additives due to their concern about safety, along with their environmental impact issues. In this context, plant biomass, which have shown to be rich in compounds, have raised interest for the isolation of novel naturally occurring antioxidants. Among their myriad of molecules, bioactive peptides, which are biologically active sequence of amino acid residues of proteins, seem to be of a great interest. Therefore, the number of identified amino acids sequences of bioactive peptides from plant biomass with potential antioxidant action is progressively increasing. Thus, this review provides a description of 129 works that have been made to produce bioactive peptides (hydrolysate, fraction and/or isolate peptide) from 55 plant biomass, along with the procedure to examine their antioxidant capacity (until 2019 included). The protein name, the process, and the method to concentrate or isolate antioxidant bioactive peptides, along with their identification and/or specificity were described. Considering the complex, dynamic and multifactorial physico-chemical mechanisms of the lipid oxidation, an appropriate in-vitro methodology should be better performed to efficiently probe the antioxidant potential of bioactive peptides. Therefore, the results were discussed, and perspective for antioxidant applications of bioactive peptides from plant biomass was argued.

Rapeseed meal proteins (RP) are enzymatically hydrolyzed using three individual proteases (Alcalase, Flavourzyme, and Prolyve) and the enzymatic mechanism is studied. Rapeseed hydrolysates are produced under controlled conditions and the Prolyve hydrolysate is separated by membrane filtration. Their capacity to reduce free radicals (by transfer of hydrogen or electron) or transition metals (by electron transfer) in the absence of an oxidizable substrate, their metal chelating capacity as well as the antioxidant performances in model (conjugated autoxidizable triene assay) are investigated. All hydrolysates show a reduction capacity (by transfer of hydrogen or electron) and antioxidant activities, in a dose-dependent manner, which are however not significantly increased in comparison to the native proteins. A noteworthy metal chelating activity of the peptides produced with Prolyve is highlighted. These results indicate the potential of valorization of RP as a source of high metal chelating peptides to counteract lipid oxidation in foods. Practical applications: Over the last decade, the antioxidative potential of peptides from plant biomass has been evidenced by much research. Considering the myriad of possible sources and the diversity of technology and means to obtain peptides from protein materials, it is reasonable to expect more applications. Concomitantly, preventing lipid oxidation, especially with the polyunsaturated fat-based products, is a major concern in sectors such as agri-food and cosmetic. Although the efficacy of synthetic antioxidants is recognized, both consumers and manufacturers are looking for more innovative, healthy, environmental-friendly processes and quality products. In this context, a controlled proteolysis of proteins from plant by-products can be used as a sustainable strategy to produce antioxidant peptides. Among them, new peptides released from rapeseed proteins with Prolyve can provide interesting metal chelators to counteract lipid oxidation in foods.

Beside oil, oilseed rape (Brassica napus) seeds contains nutritional bioactives such as polyphenols and glucosinolates. However, to date their nutritional properties have been overlooked in the new "double zero" breeds. Seed alcoholic extracts from two B. napus cultivars most contrasting in their phytochemical contents as measured by mass-spectrometry were given to ob-mice. Biological outcomes including clinical metrics, gut and plasma metabolomes, liver transcriptome and metabolome were compared to ob-mice given a similar broccoli extract (Brassica oleracea). One B. napus extract induced a reduction of the oxidative stress indicated by the decrease of plasma isoprostanoids. This was associated to the regulation of the antioxidant stress defense Nrf2 pathway, to 'omic' oxidative stress functions, metabolic and cell process regulations, and the metabolomics microbiota profile. Extracts of B. napus seeds demonstrated health effects that may be improved by selecting appropriate agronomical traits, highlighting the potential benefits of better utilizing agronomy for improved human and animal nutrition.

Rapeseed and sunflower meal are mainly used as animal feed but they can also be considered as a potential source of bioactive phenolic compounds. However, the desolventization/toasting processes that are needed to produce these meals might influence concentration and chemical structure of phenolic compounds, and change their bioactive properties. Moreover, the recovery processes of these molecules from meals are based on the use of solvent that generates effluents and might affect the integrity of the other constituents of the meals. Knowing this, the PHENOLEO project, funded by the SAS PIVERT, was a research program based on the biorefinery of rapeseed and sunflower meals that aimed to develop new routes of valorization of these materials mostly by the separation and valorization of their simple phenolic compounds. Thus, we decided to focus this study on the impact of the desolventization process on the biochemical composition of meals, the separation process of their simple phenolic compounds, the production of phenolic acids from meals and the potential valorization routes of the phenolic fraction.

Novel hydroxyalkyl esters and bis-aryl esters were synthesized from sinapic and caffeic acids and aliphatic α,ω-diols of increasing chain lengths from 2 to 12 carbon atoms. Then, their antiradical reactivity (DPPH assay) and their antioxidant activity in a model oil-in-water emulsion (CAT assay) were evaluated. All the esters showed lower antiradical activities compared to their corresponding phenolic acid. This decrease was associated with the steric hindrance in hydroxyalkyl esters, and intramolecular interactions in bis-aryl esters. Regarding the two bis-aryl esters series in emulsion, the antioxidant capacity was improved with alkyl chain lengthening up to four carbons, after which it decreased for longer chains. This "cutoff" effect was not observed for both hydroxyalkyl esters series for which the alkyl chain lengthening results in a decrease of the antioxidant activity.

This study was designed to elucidate the biological variation in expression of many metabolites due to environment, genotype, or both, and to investigate the potential utility of metabolomics to supplement compositional analysis for the design of a new resilient cultivar of Brassica napus that can be steady in phytochemicals in different regions in France. Eight rapeseed varieties, grown in eight regions of France, were compared using a non-targeted metabolomics approach. The statistical analysis highlighted the distance and closeness between the samples in terms of both genotypes and geographical regions. A major environmental impact was observed on the polar metabolome, with different trends, depending on the varieties. Some varieties were very sensitive to the environment, while others were quite resilient. The identified secondary metabolites were mapped into the KEGG pathway database to reveal the most sensitive target proteins susceptible to environmental influences. A glucosyl-transferase encoded by the UGT84A1 gene involved in the biosynthesis of phenylpropanoid was identified. This protein could be rate limiting/promoting in this pathway depending on environmental conditions. The metabolomics approach used in this study demonstrated its efficiency to characterize the environmental influence on various cultivars of Brassica napus seeds and may help identify targets for crop improvement.

Sunflower and rapeseed meals are agro-industrial coproducts that contain high amount of phenolics (1-4 % dry matter), mostly as esters of caffeic acid (CA) and sinapic acid (SA), respectively. The enzymatic hydrolysis of the ester bonds enables to recover the corresponding free phenolic acids that are bioactive compounds and platform molecules for various applications in green chemistry. Here we aimed to find the best route for producing free CA and SA by applying various fungal carboxylic ester hydrolases from recombinant Aspergillus niger strains either directly on crude meal or on their phenolic extracts obtained by methanolic extraction. Two types of meals were studied: (i) industrial (commercial) meals (I-meals), produced by a process that includes cooking at 95-100 degrees C and steam desolventizing at 105-107 degrees C, and (ii) non-industrial meals (NI-meals) obtained at pilot-scale with much milder heat treatment, that offer a higher total phenolic content. CA release through hydrolysis of sunflower meal (SFM) was successfully achieved with A. niger type-B feruloyl esterase (AnFaeB) and chlorogenic acid esterase (ChlE). Maximal amount of free CA released was of 54.0 +/- 1.1 to 59.8 +/- 2.1 mu mol/g defatted dry matter (DDM) from I-SFM (94-100% hydrolysis yield) against 42.0 +/- 1.1 to 52.3 +/- 0.2 mu mol/g DDM (59-73% hydrolysis yield) from NI- SFM in which CA release was hampered by a phenolic oxidation side-reaction, seemingly due to meal endogenous polyphenol oxidase activities. AnFaeB and ChlE hydrolysis of phenolic extracts from NI-SFM increased the CA amount obtained to 55.0-68.1 mu mol/g DDM (77-95% hydrolysis yield). In all cases, AnFaeB showed broader specificity towards SFM caffeoyl quinic acid isomers than ChlE. In particular, ChlE did not hydrolyze 3-O-caffeoylquinic acid. The maximal amount of free SA released by AnFaeA hydrolysis was 41.3 +/- 0.3 mu mol/g DDM from NI-SFM (50% hydrolysis yield) and 32.3 +/- 0.4 mu mol/g DDM from the phenolic extract (64% hydrolysis yield), with AnFaeA also having sinapine transesterification activity that led to the synthesis of 1,2-di-O-sinapoyl-beta-D-glucose. Finally, of all the substrates tested for enzymatic hydrolysis in our conditions, I-RSM and NI-SFM extract showed the best compromise between initial total phenolic content, hydrolysis yields and amounts of CA/SA released.

Rapeseed (RSM) and sunflower (SFM) meals are highly abundant and protein-rich by-products from the oilseed industry. Besides their basic use as animal feed, they are seen nowadays as interesting raw materials for the production of high value added products such as protein isolates, peptides, emulsifiers and biomaterials. In other respects, they contain significant amounts of phenolic compounds exhibiting antioxidant or antimicrobial properties but widely untapped so far. Therefore, any process allowing the single-step separation of both the protein and phenolic parts of meals would be beneficial to the whole oilseed sector. To achieve this double objective this study attempted to separate the RSM and the SFM into their major constituents by using dry fractionation technologies. In a first step, ultrafine milling was applied to the meals. As a function of raw material type, the grid size turned out to be decisive on the particle size distribution and its modality. Then two separation technologies based either on particle charge (electrostatic sorting - ES) or density (turbo-separation - TS) were applied to the previously obtained fractions. Regardless the separation technique, the best results were obtained from fractions of an average particle diameter by mass (D-50) of 23.7 +/- 1.0 mu m and 105.5 +/- 8.3 mu m, for RSM and SFM respectively. Electrostatic sorting allowed increasing simultaneously the protein and phenolic contents by 50-55% and 80-100% for RSM and SFM respectively, while a lower increase was observed for turbo separation (23-29% and 58-64% for RSM and SFM respectively). Finally, depending on the process and meal types, the overall recovery yield of the most enriched fractions was in the range of 30-40%.

This study investigated alternative solvents: ethanol and isopropanol, to replace hexane and enhance the quality and value of oil and meal. Rapeseed oil extraction was carried out using ethanol (92 wt.% or 96 wt.%), isopropanol (84 wt.% or 88 wt.%) or hexane (as reference). Results show that hydroalcoholic extraction increased meal protein content by 13% compared to hexane extraction, but without significant influence of alcohol and water content. However, increasing water content improved glucosinolate extractability. Isopropanol 84 wt.% eliminated most glucosinolates from the seeds, decreasing glucosinolate concentration by 49–73% compared to meals extracted by the other alcohols.

In this study, extraction of soluble proteins from rapeseed cake using different conventional and innovative extraction processes in order to maximize the extraction yield has been investigated. Firstly, various extraction techniques including ultrasound, microwave, and percolation were tested to increase the protein recovery efficiency. Secondly, response surface methodology (RSM) using a central composite design (CCD) approach was applied to investigate the influence of process variables on ultrasound-assisted extraction (UAE). Statistical analysis revealed that the optimized conditions providing a protein yield of 4.24 g/100 g DM were an ultrasound power of 5.6 W·cm−2 and temperature of 45 °C. Quantitatively UAE followed by two stages of conventional extraction gave the best total protein yield of 9.81 g/100 g DM. Qualitatively, the protein efficiency ratio (PER) used as measure of the nutritive value (12S/2S ratio) which indicates protein quality in terms of S-containing essential amino acids, was similar to that of the conventional extraction method. Small amounts of protein aggregate were observed in the HPLC profile of the extract.

Rapeseed and sunflower meals are the co-products of the pressing and de-oiling process of rapeseed and sunflower seeds and are usually used as animal feed. Rapeseed and sunflower hulls are other minor co-product of the oil industry. Among other major components (lignin, proteins, polysaccharides) these co-products contain a relatively high content of phenolic compounds which can be valorized. Most of the phenolic compounds remain in the meals (and the hulls) after processing the seeds. The aim of this work was to separate these meals and hulls into its major components using dry fractionation and separation technologies. More specifically, the combination of the ultrafine milling (UFM) with the electrostatic separation and the turbo separation technologies was studied. The different fractions obtained were analyzed in terms of total phenolic compounds (TPC), chemical composition, yield and energy consumption. Then, we studied the enzymatic pretreatment of the different raw materials and fractions containing the most interesting chemical composition. This step was done to try to enhance the extractability of the phenolic compounds or their bioavailability. Following, we developed and optimized the extraction methodologies. To do this, we compared the classic extractions methodology using methanol at 75 °C, the ultrasound assisted extractions (UAE) and the microwave assisted extractions (MAE). Their efficiency in terms of yield, selectivity and preservation of the phenolic compounds was studied.

Due to an unfortunate turn of events, the names of the authors appeared incorrectly in the original publication as given names and family names have been reversed. The correct representation of the authors’ names is listed above and below and should be treated as definitive.

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.