Rapeseed and sunflower meal: a review on biotechnology status and challenges

Screening of alternative nitrogen sources for sophorolipid production through submerged fermentation using Starmerella bombicola

To explore a sustainable sophorolipid production, several hydrolysates from agricultural byproducts, such as wheat feed, rapeseed meal, coconut waste and palm waste were used as nitrogen sources. The four hydrolysates overperformed the controls after 168 h of fermentation using Starmerella bombicola ATCC 22214. Wheat feed and coconut waste hydrolysates were the most promising feedstocks presenting a linear relationship between yeast growth and diacetylated lactonic C18:1 production at total nitrogen concentrations below 1.5 g/L (R2 = 0.90 and 0.83, respectively). At 0.31 g/L total nitrogen, wheat feed hydrolysate achieved the highest production, yielding 72.20 ± 1.53 g/L of sophorolipid crude extract and 60.05 ± 0.56 g/L of diacetylated lactonic C18:1 at shake flask scale with productivities of 0.43 and 0.36 g/L/h, respectively. Results were confirmed in a 2-L bioreactor increasing 15 % diacetylated lactonic C18:1 production. Moreover, wheat feed hydrolysate supplemented only with a hydrophobic carbon source was able to produce mainly diacetylated lactonic C18:1 congener (88.5 % wt.), suggesting that the composition of the hydrolysate significantly influences the congeners profile. Overall, this study provides valuable insights into agricultural byproduct hydrolysates as potential nitrogen feedstocks for sophorolipid production and their further application on industrial biotechnology.

Productivity of two Brassica oilseed crops in a Mediterranean environment and assessment of the qualitative characteristics of raw materials for bioenergy purposes

Rapeseed (Brassica napus var. oleifera D.C.) and Ethiopian mustard (Brassica carinata A. Braun) are promising industrial crops for cultivation in the Southern Mediterranean area due to profitable yields under semi-arid conditions. The exploitation of raw materials produced by these crops is very convenient for farmers to produce bioenergy directly on-farm and permits them to create a short agri-energy supply chain. The purpose of this study was to determine their yield performance under rainfed conditions and make an economic assessment of a combined heat and power plant (CHP) system operating on pure vegetable oil (PVO). Tests were conducted in Sicily (Italy) from 2012 to 2014. Seed and crop residue yields were detected. The analysis of seed, defatted seed meal and crop residue, and the chemical-physical aspects of PVO were carried out according to conventional protocols. A pilot CHP system was used for cogenerating electricity and heat. In general, rapeseed had the highest seed (2.27 t ha-1) and oil (1.11 t ha-1) yields. The average oil content ranged from 44.88 % (Ethiopian mustard) to 45.73 % dry matter (rapeseed). Ethiopian mustard performed better than rapeseed in terms of aboveground biomass yield (5.49 t ha-1), in both years. The two crops showed different fatty acid profiles of the oil mainly due to diverse content of erucic and oleic acids. The CHP system had an average consumption of 14.41 kg PVO h-1. These results confirm that the productivity of the species can be appreciable in the Southern Mediterranean area and indicate the use of raw materials of these crops as crucial to the development a sustainable short agri-energy supply chain.

Effects of Rhizopus-arrhizus-31-Assisted Pretreatment on the Extraction and Bioactivity of Total Flavonoids from Hibiscus manihot L

The Hibiscus manihot L. (HML) Medic, an edible hibiscus of the Malvaceae family, is abundant with flavonoids. The study investigated how Rhizopus-arrhizus-31-assisted pretreatment affects the extraction and bioactivity of flavonoids from HML. The fiber structure of the fermented flavonoid sample (RFF) appears looser, more porous, and more disordered than the unfermented flavonoid sample (RUF). RFF demonstrates milder conditions and yields higher extraction rates. According to the Box-Behnken response surface optimization experiment, the optimal conditions for RFF include a material-liquid ratio of 1:41 g/mL, a 2 h extraction time, a 57% ethanol concentration, and an extraction temperature of 800 °C, resulting in a 3.69% extraction yield, which is 39.25% higher than that of RUF. Additionally, RFF exhibits greater activity than RUF in the radical-scavenging system. The IC50 values for DPPH, OH, and ABTS radicals are 83.43 μg/mL and 82.62 μg/mL, 208.38 μg/mL and 175.99 μg/mL, and 108.59 μg/mL and 75.39 μg/mL for RUF and RFF, respectively. UPLC-QTOF-MS analysis of the active components in the HML flavonoid sample revealed significant differences in the chromatograms of RUF and RFF, indicating that biofermentation led to substantial changes in composition and content from HML.

A New Phenolic Acid Decarboxylase from the Brown-Rot Fungus Neolentinus lepideus Natively Decarboxylates Biosourced Sinapic Acid into Canolol, a Bioactive Phenolic Compound

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.

Composition, functional properties, health benefits and applications of oilseed proteins: A systematic review

Common oilseeds, such as soybean, peanut, rapeseed, sunflower seed, sesame seed and chia seed, are key sources of edible vegetable oils. Their defatted meals are excellent natural sources of plant proteins that can meet consumers' demand for health and sustainable substitutes for animal proteins. Oilseed proteins and their derived peptides are also associated with many health benefits, including weight loss and reduced risks of diabetes, hypertension, metabolic syndrome and cardiovascular events. This review summarizes the current status of knowledge on the protein and amino acid composition of common oilseeds as well as the functional properties, nutrition, health benefits and food applications of oilseed protein. Currently, oilseeds are widely applied in the food industry regarding for their health benefits and good functional properties. However, most oilseed proteins are incomplete proteins and their functional properties are not promising compared to animal proteins. They are also limited in the food industry due to their off-flavor, allergenic and antinutritional factors. These properties can be improved by protein modification. Therefore, in order to make better use of oilseed proteins, methods for improving their nutrition value, bioactive activity, functional and sensory characteristics, as well as the strategies for reducing their allergenicity were also discussed in this paper. Finally, examples for the application of oilseed proteins in the food industry are presented. Limitations and future perspectives for developing oilseed proteins as food ingredients are also pointed out. This review aims to foster thinking and generate novel ideas for future research. It will also provide novel ideas and broad prospects for the application of oilseeds in the food industry.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Sunflower seed cake as a source of nutrients in gluten-free bread

An increase in the demand for cold-pressed vegetable oils can be observed, e.g. from sunflower. The press cake formed during sunflower oil production can also be an important source of protein, carbohydrates, and phenolic compounds. The aim of the study was to examine the quality of gluten-free breads fortified with sunflower seed cake. The fortified products were characterized by lower moisture content (49.35-48.87%). The bake loss parameter decreased after the use of the highest 15% dose of the sunflower cake. The addition of the sunflower cake caused an increase in the content of nutrients, compared to the control sample: protein (7.44-9.69%_d.b.), fat (3.41-10.72%_d.b.), crude fiber (1.23-2.34%_d.b.), polyphenols (89.3-222.3 mg·100 g_d.b.^-1), and soluble sugars (2.42-2.73%_d.b.). The gluten-free breads with the sunflower seed cake exhibited lower hardness, springiness, and chewiness but higher cohesiveness. The use of the additive contributed to the darkening of the gluten-free bread crumb. The appearance, consistency, aroma, and palatability of the sunflower cake-fortified gluten-free bread were found to be much more attractive than the parameters of the unmodified bread. The conducted research has shown that, thanks to sunflower cake addition, it is possible to obtain a highly nutritious product with desirable sensory quality.

Biotransformation of gallate esters by a pH-stable tannase of mangrove-derived yeast Debaryomyces hansenii

Introduction: Tannase is a crucial enzyme that finds wide applications in the pharmaceutical industry, feed processing, and beverage manufacturing. Although extensive studies have been conducted on tannases from fungi and bacteria, reports on tannases exhibiting favorable pH stability are relatively limited. Methods: In this study, a tannin-degrading strain Debaryomyces hansenii was screened to induce tannase production, and the corresponding tannase coding gene TANF was successfully cloned and expressed in Yarrowia lipolytica. SDS-PAGE analysis revealed that the purified TanF tannase had a molecular weight of approximately 70 kDa. Results and Discussion: The enzyme demonstrated optimal activity at 40°C and retained over 80% of its activity in the range of 35°C-60°C. Of particular interest, TanF exhibited remarkable enzyme activity at pH 5.0 and retained more than 70% of its relative activity across a wide pH range of 3.0-8.0. Furthermore, TanF exhibited broad substrate specificity for gallate esters. The final gallic acid production by TanF from tannic acid achieved 18.32 g/L. Therefore, the excellent properties TanF has been demonstrated to be an efficient tool for the preparation of gallic acid.

Phytoestrogens as Biomarkers of Plant Raw Materials Used for Fish Feed Production

The intensive use of plant materials as a sustainable alternative for fish feed production, combined with their phytochemical content, which affects the growth and production characteristics of farmed fishes, necessitates their monitoring for the presence of raw materials of plant origin. This study reported herein concerns the development, validation and application of a workflow using high-performance liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) for the quantification of 67 natural phytoestrogens in plant-derived raw materials that were used to produce fish feeds. Specifically, we verified the presence of 8 phytoestrogens in rapeseed meal samples, 20 in soybean meal samples, 12 in sunflower meal samples and only 1 in wheat meal samples in quantities enabling their efficient incorporation into clusters. Among the various constituents, the soybean phytoestrogens daidzein, genistein, daidzin, glycitin, apigenin, calycosin and coumestrol, as well as the sunflower neochlorogenic, caffeic and chlorogenic phenolic acids, displayed the highest correlations with their origin descriptions. A hierarchical cluster analysis of the studied samples, based on their phytoestrogen contents, led to the efficient clustering of raw materials. The accuracy and efficiency of this clustering were tested through the incorporation of additional samples of soybean meal, wheat meal and maize meal, which verified the utilization of the phytoestrogen content as a valuable biomarker for the discrimination of raw materials used for fish feed production.

Carbohydrate-active enzymes in animal feed

Considering an ever-growing global population, which hit 8 billion people in the fall of 2022, it is essential to find solutions to avoid the competition between human food and animal feed for croplands. Agricultural co-products have become important components of the circular economy with their use in animal feed. Their implementation was made possible by the addition of exogenous enzymes in the diet, especially carbohydrate-active enzymes (CAZymes). In this review, we describe the diversity and versatility of microbial CAZymes targeting non-starch polysaccharides to improve the nutritional potential of diets containing cereals and protein meals. We focused our attention on cellulases, hemicellulases, pectinases which were often found to be crucial in vivo. We also highlight the performance and health benefits brought by the exogenous addition of enzymatic cocktails containing CAZymes in the diets of monogastric animals. Taking the example of the well-studied commercial cocktail Rovabio™, we discuss the evolution, constraints and future challenges faced by feed enzymes suppliers. We hope that this review will promote the use and development of enzyme solutions for industries to sustainably feed humans in the future.

Turning Food Protein Waste into Sustainable Technologies

For each kilogram of food protein wasted, between 15 and 750 kg of CO₂ end up in the atmosphere. With this alarming carbon footprint, food protein waste not only contributes to climate change but also significantly impacts other environmental boundaries, such as nitrogen and phosphorus cycles, global freshwater use, change in land composition, chemical pollution, and biodiversity loss. This contrasts sharply with both the high nutritional value of proteins, as well as their unique chemical and physical versatility, which enable their use in new materials and innovative technologies. In this review, we discuss how food protein waste can be efficiently valorized not only by reintroduction into the food chain supply but also as a template for the development of sustainable technologies by allowing it to exit the food-value chain, thus alleviating some of the most urgent global challenges. We showcase three technologies of immediate significance and environmental impact: biodegradable plastics, water purification, and renewable energy. We discuss, by carefully reviewing the current state of the art, how proteins extracted from food waste can be valorized into key players to facilitate these technologies. We furthermore support analysis of the extant literature by original life cycle assessment (LCA) examples run ad hoc on both plant and animal waste proteins in the context of the technologies considered, and against realistic benchmarks, to quantitatively demonstrate their efficacy and potential. We finally conclude the review with an outlook on how such a comprehensive management of food protein waste is anticipated to transform its carbon footprint from positive to negative and, more generally, have a favorable impact on several other important planetary boundaries.

Hornification: Lessons learned from the wood industry for attenuating this phenomenon in plant-based dietary fibers from food wastes

A significant amount of waste is annually generated worldwide by the supply chain of the food industry. Considering the population growth, the environmental concerns, and the economic opportunities, waste recovery is a promising solution to produce valuable and innovative ingredients for food and nonfood industries. Indeed, plant-based wastes are rich in dietary fibers (DF), which have relevant technical functionalities such as water/oil holding capacity, swelling capacity, viscosity, texture, and physiological properties such as antioxidant activity, cholesterol, and glucose adsorption capacities. Different drying technologies could be applied to extend the shelf life of fresh DF. However, inappropriate drying technologies or process conditions could adversely affect the functionalities of DF via the hornification phenomenon. Hornification is related to the formation of irreversible hydrogen bindings, van der Waals interactions, and covalent lactone bridges between cellulose fibrils during drying. This review aims to capitalize on the knowledge developed in the wood industry to tackle the hornification phenomenon occurring in the food industry. The mechanisms and the parameters affecting hornification as well as the mitigation strategies used in the wood industry that could be successfully applied to foods are summarized. The application of conventional drying technologies such as air or spray-drying increased the occurrence of hornification. In contrast, solvent exchange, supercritical drying, freeze-drying, and spray-freeze-drying approaches were considered effective strategies to limit the consequences of this phenomenon. In addition, incorporating capping agents before drying attenuated the hornification. The knowledge summarized in this review can be used as a basis for process design in the valorization of plant-based wastes and the production of functional DF that present relevant features for the food and packaging industries.

Optimization of Grinding Process of Sunflower Meal for Obtaining Protein-Enriched Fractions

In this study, dry fractionation process was proposed in order to obtain protein-enriched sunflower meal fractions. The process includes two-stage grinding using a hammer mill and a roll mill, and fractionation of sunflower meal by sieving. Central composite design (CCD) with four variables on three levels within response surface methodology was applied in order to estimate the influence of grinding parameters (sieve openings diameter of the hammer mill: 2, 4, and 6 mm, roll gap: 0.15, 0.2, and 0.25 mm, feed rate: 0.1, 0.175, and 0.25 kg/cm min, and roll speed: 400, 500, and 600 rpm) on responses (protein content, fraction yield and grinding energy consumption). Sieve openings diameter expressed the highest impact on fraction yield while roll gap expressed the most dominant influence on protein content in the fraction and grinding energy consumption. The highest protein content obtained was 48.06%(dm) with fraction yield of 77.22%. A multi-response optimization procedure was performed and optimal values were: sieve openings diameter of 2 mm, roll gap of 0.25 mm, feed rate of 0.2 kg/cm min, and roll speed of 400 rpm, while predicted values for a desired range of responses were: protein content 45.5%(dm), fraction yield 77.89%, and grinding energy consumption 8.31 Wh/kg.

Valorization of by-products from vegetable oil industries: Enzymes production by Yarrowia lipolytica through solid state fermentation

Vegetable oil extraction generates high amounts of by-products, which are designated as oil cakes. Since the current strategies employed for oil cakes' reuse are linked with some drawbacks, identification of alternative approaches to decrease the environmental impact and promote a circular economy is of vital importance. In general, these materials are characterized by high fiber content, making them suitable to be employed in solid state fermentation (SSF). Filamentous fungi have been the microorganisms mostly applied in SSF and yeasts were applied in less extent. In the present work, three by-products from the extraction of olive, sunflower, and rapeseed oils were used as solid substrates in SSF for lipase and protease production by Yarrowia lipolytica W29. Oil cakes mixtures composition was optimized for the production of each enzyme using a simplex-centroid design of experiments. A 50% (w/w) mixture of olive cake (OC) and sunflower cake (SC) led to the highest lipase production, while a combination of the three oil cakes was most suitable for maximum protease production. Both enzymes were produced at maximum levels in a short period of 48 h. This work demonstrated that enzyme production by Y. lipolytica W29 in SSF can be modulated by the different combinations of oil cakes in the substrate mixture. Additionally, the potential of using by-products from vegetable oil industries in SSF processes was also demonstrated, showing alternative strategies for their valorization.

Enzymes and microorganisms jointly promote the fermentation of rapeseed cake

Rapeseed cake is a by-product of rapeseed oil separation. The nutritional components of rapeseed cake mainly include a variety of carbohydrates, proteins, and minerals. In order to improve the conversion rate of rapeseed cake, we studied the physicochemical properties, the structure of microbial communities, and the composition of metabolites in rapeseed cake after enzymatic fermentation. The results showed that the addition of enzymatic preparation increased microbial diversity. The relative abundance of Bacillus, Lysinibacillus, Empedobacter, Debaryomyces, Hyphopichia, and Komagataella in enzymatic fermentation was significantly higher than that in natural fermentation. Unlike natural fermentation, microbial diversity during enzymatic fermentation is specific, which improves the efficiency of fermentation. Otherwise, enzymatic fermentation promotes the conversion of macromolecular substances in rapeseed cake, which increases small metabolites, such as fatty acids, organic acids, amino acids and their derivatives. The metabolite enrichment pathway is mostly concentrated in sugar metabolism and fatty acid metabolism. In conclusion, after adding enzymatic preparation, enzymes and microorganisms jointly promote the transformation of macromolecules during the fermentation of rapeseed cake, which laid a good foundation for further utilization of rapeseed cake.

Proximate Composition, Physicochemical, and Lipids Profiling and Elemental Profiling of Rapeseed (Brassica napus L.) and Sunflower (Helianthus annuus L.) Grown in Morocco

We investigate and compare the nutritional and physicochemical properties of rapeseed and sunflower grown in Morocco. In order to examine a complete physicochemical characterization, various parameters such as mineral profile, fatty acid composition, sterols contents, total flavonoids content (TFC), total polyphenols content (TPC), and quality oil parameters were evaluated. The results showed a relatively small difference in the physicochemical composition of the seeds, as sunflower seeds recorded higher amounts of protein and oil content (22.98 ± 0.01 g/100 g and 41.30 ± 0.50 g/100 g) than rapeseed (22.98 ± 0.01 and 38.80 ± 0.50), while mineral elements profile was observed to be statistically different. Nevertheless, both seeds were rich in K, Ca, P, Mg, and Na and they were relatively poor in Na, Fe, Mn, Cu, and Zn. The most represented macroelement was K with the amount of 7936.53 ± 63.87 mg/Kg in rapeseed and 7739.22 ± 59.50 mg/Kg in sunflower. On the other hand, Cu was present in the analyzed samples the least, mostly below 20 mg/kg. For TPC and TFC, the sunflower recorded higher values (49.73 ± 0.50 and 25.37 ± 0.39 mg GAE/g) than rapeseed (38.49 ± 0.24 and 22.55 ± 1.76 mg QE/g). The fatty acid composition showed that both extracted oils have beneficial proprieties, as they are rich in unsaturated fatty acids; namely, rapeseed oil contains a high level of oleic acid (C18 : 1) (62.19%), while sunflower oil was richer in linoleic acid (C18 : 2) (55.7%). As a result, we conclude that the studied varieties have major importance in terms of both nutritional and seed improvement potentials.

Simultaneous Mass Spectrometric Detection of Proteins of Ten Oilseed Species in Meat Products

Food fraud is a common issue in the modern food industry. The undeclared use of foreign proteins in meat products is a major concern in this context. Oilseeds are ideal for this purpose due to their high protein content and since huge amounts of oil meal are obtained as a by-product of oil production. Therefore, a UHPLC-MS/MS method was developed for the simultaneous detection of chia, coconut, flaxseed, hemp, peanut, pumpkin, rapeseed, sesame, soy, and sunflower proteins in meat products. Potential tryptic peptide markers were identified by high-resolution mass spectrometry. The final twenty peptide markers selected, which are specific for one of the ten species targeted, were each measured by multiple reaction monitoring. To the best of our knowledge, twelve new heat-stable marker peptides for chia, coconut, flaxseed, pumpkin, rapeseed, sesame and sunflower have not been reported previously. Emulsion-type sausages with 0.01, 0.25, 0.50, 0.75 and 1.00% protein addition by each oilseed species were produced for matrix calibration. No false-positive results were recorded. In the quantification of the ten oilseed species, 466 of 480 measuring data points of the recovery rate in unknown sausages (0.15 and 0.85% protein addition by each oilseed species) were in the accepted range of 80–120%.

Determination of glucosinolates in rapeseed meal and their degradation by myrosinase from rapeseed sprouts

The utilization of rapeseed meal in food is limited due to its abundant glucosinolates (GLs). In this study, an LC-MS/MS method for GLs determination in rapeseed meal was developed. Then, the degradation of GLs using rapeseed sprouts derived myrosinase (MYR) was investigated. Results showed that 11 kinds of GLs were identified in rapeseed meal. The LC-MS/MS method had a high linearity (R² greater than 0.9999), repeatability (RSD < 5%) and recovery rate (92%-102%). The optimum condition for hydrolyzing GLs in rapeseed meal was reacting for 4 h with the addition of 2236.35 U/g MYR, 9.63 μg/g ascorbic acid and 26.68 μg/g EDTA. Under this condition, more than 80% of GLs were degraded and the yields of isothiocyanates and oxazolidinone-2-thione were 859.30 μg/g and 685.59 μg/g, respectively. To conclude, this study reported a reliable method for GLs determination and an effective way to degrade GLs in rapeseed meal.

Bio-Refinery of Oilseeds: Oil Extraction, Secondary Metabolites Separation towards Protein Meal Valorisation—A Review

Edible oil extraction is a large and well-developed sector based on solvent assisted extraction using volatile organic compounds such as hexane. The extraction of oil from oilseeds generates large volumes of oilseed by-products rich in proteins, fibres, minerals and secondary metabolites that can be valued. This work reviews the current status and the bio-macro-composition of oilseeds, namely soybean, rapeseed, sunflower and flaxseed, and the refining process, comprising the extraction of oil, the valorisation and separation of valuable secondary metabolites such as phenolic compounds, and the removal of anti-nutritional factors such as glucosinolates, while retaining the protein in the oilseed meal. It also provides an overview of alternative solvents and some of the unconventional processes used as a replacement to the conventional extraction of edible oil, as well as the solvents used for the extraction of secondary metabolites and anti-nutritional factors. These biologically active compounds, including oils, are primordial raw materials for several industries such as food, pharmaceutical or cosmetics.

A critical review on biogas production from edible and non-edible oil cakes

The circular economy is at the core of sustainable development. The generation of biogas from the massive quantity of agricultural waste biomass is one of the critical drivers of the circular economy. Biogas has enormous renewable energy potential and has multitudes of applications in today's energy-intensive society. Oil cakes, a known Agri-waste, are the by-product of oil processing, and are rich in nutrients. The edible oil cakes mostly have been used as a cattle feed; however, non-edible oil cakes do not find many applications. Their production is continuously escalating as non-edible oils are increasingly used in biodiesel production. Recently, there is a lot of emphasis on biogas production from these oil cakes. This paper reviews in detail biogas production from both edible and non-edible oil cakes. Chemical composition and various other applications of the cakes are also reviewed in brief. The survey illustrates that multiple parameters such as inoculum sources, co-digestion and reactor design affect the biogas production. All those factors, along with biogas upgrading and the economy of the process, are reviewed. Finally, future research opportunities are suggested to improve the viability of the biogas production from oil cakes.

Breeding Canola (Brassica napus L.) for Protein in Feed and Food

Interest in canola (Brassica napus L.). In response to this interest, scientists have been tasked with altering and optimizing the protein production chain to ensure canola proteins are safe for consumption and economical to produce. Specifically, the role of plant breeders in developing suitable varieties with the necessary protein profiles is crucial to this interdisciplinary endeavour. In this article, we aim to provide an overarching review of the canola protein chain from the perspective of a plant breeder, spanning from the genetic regulation of seed storage proteins in the crop to advancements of novel breeding technologies and their application in improving protein quality in canola. A review on the current uses of canola meal in animal husbandry is presented to underscore potential limitations for the consumption of canola meal in mammals. General discussions on the allergenic potential of canola proteins and the regulation of novel food products are provided to highlight some of the challenges that will be encountered on the road to commercialization and general acceptance of canola protein as a dietary protein source.

Identification and Capture of Phenolic Compounds from a Rapeseed Meal Protein Isolate Production Process By-Product by Macroporous Resin and Valorization Their Antioxidant Properties

In this study, phenolic compounds from an aqueous protein by-product from rapeseed meal (RSM) were identified by HPLC-DAD and HPLC-ESI-MS, including sinapine, sinapic acid, sinapoyl glucose, and 1,2-di-sinapoyl gentibiose. The main phenolic compound in this by-product was sinapine. We also performed acid hydrolysis to convert sinapine, and sinapic acid derivatives present in the permeate, to sinapic acid. The adsorption of phenolic compounds was investigated using five macroporous resins, including XAD4, XAD7, XAD16, XAD1180, and HP20. Among them, XAD16 showed the highest total phenolic contents adsorption capacities. The adsorption behavior of phenolic compounds was described by pseudo-second-order and Langmuir models. Moreover, thermodynamics tests demonstrated that the adsorption process of phenolic compounds was exothermic and spontaneous. The highest desorption ratio was obtained with 30% (v/v) and 70% (v/v) ethanol for sinapine and sinapic acid, respectively, with a desorption ratio of 63.19 ± 0.03% and 94.68 ± 0.013%. DPPH and ABTS tests revealed that the antioxidant activity of the hydrolyzed fraction was higher than the non-hydrolyzed fraction and higher than the one of vitamin C. Antioxidant tests demonstrated that these phenolic compounds could be used as natural antioxidants, which can be applied in the food industry.

Preliminary Characterisation of Wastes Generated from the Rapeseed and Sunflower Protein Isolation Process and Their Valorisation in Delaying Oil Oxidation

Since rapeseed and sunflower meals are two of the most representative oilseed crops in the world, this study was focused on ethanol-wash solutes (EWS) obtained as wastes from the protein isolation process of rapeseed and sunflower meals. These meals have been previously valorised; however, the use of the EWS is unexplored. The present study is aimed at the characterisation of their phenolic profile, and antioxidant capacity for preventing lipid oxidation in rapeseed, sunflower, and soybean oil, which has been used as a reference oil. The sunflower EWS exhibited more total phenolic compounds (TPC) and antioxidant activity (119.39 ± 1.13 mg GA/g and 193.97 ± 9.77 mg TE/g, respectively) than the rapeseed one (103.44 ± 5.94 mg GA/g and 89.51 ± 3.17 mg TE/g). The phenolic identification showed hydroxybenzoic and protocatechuic acid in the rapeseed EWS, and pyrogallol and caffeic acid in the sunflower EWS, as the main representative phenols. Both EWS at 15% increased significantly (p < 0.05) the oxidative stability of the oils in the Rancimat equipment with values of antioxidant activity index (AAI) from 1.01 to 1.20, depending on the type of oil employed. In conclusion, the rapeseed and sunflower EWS showed great potential, and they could be used as a source of natural antioxidants within the food industry, replacing the synthetic ones, and promoting the circular economy since they are agro-food wastes.

Escherichia coli AraJ boosts utilization of arabinose in metabolically engineered cyanobacterium Synechocystis sp. PCC 6803

Lignocellulosic biomass can serve as an inexpensive and renewable source of carbon for the biosynthesis of commercially important compounds. L-arabinose is the second most abundant pentose sugar present in the plant materials. Model cyanobacterium Synechocystis sp. PCC 6803 is incapable of catabolism of L-arabinose as a source of carbon and energy. In this study, all the heterologous genes expressed in Synechocystis were derived from Escherichia coli K-12. Initially we constructed four Synechocystis strains that expressed AraBAD enzymes involved in L-arabinose catabolism, either in combination with or without one of the three arabinose transporters, AraE, AraFGH or AraJ. Among the recombinants, the strain possessing AraJ transporter was observed to be the most efficient in terms of dry biomass production and L-arabinose consumption. Later, an additional strain was generated by the expression of AraJ in the AraE-possessing strain. The resultant strain was shown to be advantageous over its parent. This study demonstrates that AraJ, a protein with hitherto unknown function plays a role in the uptake of L-arabinose to boost its catabolism in the transgenic Synechocystis strains. The work also contributes to the current knowledge regarding metabolic engineering of cyanobacteria for the utilization of pentose sugars.

Extrusion Processing of Rapeseed Press Cake-Starch Blends: Effect of Starch Type and Treatment Temperature on Protein, Fiber and Starch Solubility

For the valorization of oilseed press cakes into food products, extrusion can be used. A common way of applying the protein- and fiber-rich press cakes in directly expanded products is the combination thereof with starch, since starch gives a favourable texture, which correlates directly to expansion. To control product properties like expansion of protein and fiber-rich extruded products, the underlying physicochemical changes of proteins, fibers and starch due to thermomechanical input need to be comprehensively described. In this study, rapeseed press cake (RPC) was extruded and treated under defined thermomechanical conditions in a closed-cavity rheometer, pure and in combination with four starches. The impact of starch type (potato PS, waxy potato WPS, maize MS, high-amylose maize HAMS) and temperature (20/25, 80, 100, 120, 140 °C) on protein solubility, starch gelatinization (D_gel), starch hydrolysis (S_H) and fiber solubility of the blends was evaluated. The extrusion process conditions were significantly affected by the starch type. In the extruded blends, the starch type had a significant impact on the protein solubility which decreased with increasing barrel temperature. Increasing barrel temperatures significantly increased the amount of soluble fiber fractions in the blends. At defined thermomechanical conditions, the starch type showed no significant impact on the protein solubility of the blends. Therefore, the observed effects of starch type on the protein solubility of extruded blends could be attributed to the indistinct process conditions due to differences in the rheological properties of the starches rather than to molecular interactions of the starches with the rapeseed proteins in the blends.

A Structured Approach to Recover Valuable Compounds from Agri-food Side Streams

Food side streams contain useful compounds such as proteins, sugars, polyphenols, and amino acids that might get discarded during processing. The concentration of these components may be low (e.g., fruit side streams are mainly composed by water, around 90%, while polyphenol content in rapeseed meal is less than 3% dry weight) and therefore effective separation techniques should be evaluated. The aim of this review is to identify the different process steps (like pretreatment, volume reduction, phase change, solid removal, purification, and formulation) required to recover high-value products from agri-food residues. It reviews different plant-based byproducts as sources (cereal bran, fruit pomace, oilseed meals, fruit wastewater) of valuable compounds and discusses the relevant technologies required for processing (such as extraction, adsorption, crystallization, drying, among others). A structured approach to design recovery processes presented focused on high purity products. This work demonstrates that multiple high-value products can be recovered from a single agri-food side stream depending on the processing steps and the origin source (strong and soft structures and wastewater).

Sunflower seed byproduct and its fractions for food application: An attempt to improve the sustainability of the oil process

The sunflower (Helianthus annus L.) is one of the main oil crops in the world grown for the production of edible and biodiesel oil. Byproducts of the extraction of sunflower oil constitute a raw material with potential for several applications in the food area due to its chemical composition, including the high content of proteins and phenolic compounds. Thoughtful of a consumer increasingly concerned with the environmental impact, we try to clarify in this review the potential of using sunflower seed byproducts and their fractions to enhance the production of potentially functional foods. The applications of sunflower seed byproduct include its transformation into flours/ingredients that are capable of improving the nutritional and functional value of foods. In addition, the protein isolates obtained from sunflower seed byproduct have good technological properties and improve the nutritional value of food products. These protein isolates can be used to obtain protein hydrolysates with technological and bioactive properties and as matrices for the development of edible, biodegradable, and active films for food. The sunflower seed byproduct is also a source of phenolic compounds with bioactive properties, mainly chlorogenic acid, which can be extracted by different methods and applied in the development of functional foods and active and bioactive food packaging. The use of sunflower seed byproduct and its fractions are promising ingredients for the development of healthier and less expensive foods as well as the alternative to decrease the environmental problems caused by the sunflower oil industry.

A review on protein extracts from sunflower cake: techno-functional properties and promising modification methods

De-oiled sunflower cake is a sustainable and promising protein source with high phenolic and fiber contents. The cake, which is an industrial by-product has been the subject of many studies investigating various aspects such as protein extraction, functional properties, interaction with other ingredients, and its performance in a wide range of food products. Innovative and conventional techniques of protein extraction from sunflower cake have been investigated to increase extraction yield and improve desired functional characteristics. Modulation of structure of plant-based proteins helps to control their techno-functional properties and widen their applications. Structure modification of proteins by physical methods including ultrasound treatment and gamma irradiation as well as enzymatic and chemical methods has been used to improve the functional properties of sunflower protein. This review collects and critically discusses the available information on techno-functional properties of protein extracts from sunflower cake and how its techno-functional properties can be tailored using various structure modification methods.

Sunflower Proteins at Air-Water and Oil-Water Interfaces

The adsorption of a sunflower protein extract at two air-water and oil-water interfaces is investigated using tensiometry, dilational viscoelasticity, and ellipsometry. For both interfaces, a three step mechanism was evidenced thanks to master curve representations of the data taken at different aging times and protein concentrations. At short times, a diffusion limited adsorption of proteins at interfaces is demonstrated. First, a two-dimensional protein film is formed with a partition of the polypeptide chains in the two phases that depends strongly on the nature of the hydrophobic phase: most of the film is in the aqueous phase at the air-water interface, while it is mostly in the organic phase at the oil-water interface. Then a three-dimensional saturated monolayer of proteins is formed. At short times, adsorption mechanisms are analogous to those found with typical globular proteins, while strong divergences are observed at longer adsorption times. Following the saturation step, a thick layer expands in the aqueous phase and appears associated with the release of large objects in the bulk. The kinetic evolution of this second layer is compatible with a diffusion limited adsorption of the minor population of polymeric complexes with hydrodynamic radius R_H ∼ 80 nm, evidenced in equilibrium with hexameric globulins (R_H ∼ 6 nm) in solution. These complexes could result from the presence of residual polyphenols in the extract and raise the question of the role of these compounds in the interfacial properties of plant protein extracts.

Characterisation of Muffins with Upcycled Sunflower Flour

There is an increased interest and need to make our economy more circular and our diets healthier and more sustainable. One way to achieve this is to develop upcycled foods that contain food industry by-products in their formulation. In this context, the aim of this study was to develop muffins containing upcycled sunflower flour (a by-product from the sunflower oil industry) and assess the effects of sunflower flour addition on the fibre, protein, amino acid, mineral content, and antioxidant activity measured by a Ferric Reducing Antioxidant Power (FRAP) assay and Photo chemiluminescence (PCL) assay. Results show that the sunflower flour inclusion significantly improved all the parameters analysed as part of this study. A more balanced muffin amino acid profile was achieved, thanks to the increased levels of lysine, threonine, and methionine, the limiting essential amino acids of wheat flour. We can conclude that upcycled ingredients, such as sunflower flour, could be used for the nutritional improvement of baked goods, such as muffins. Their addition can result in several nutritional advantages that could be communicated on packaging through the use of the appropriate EU nutrition claims, such as those on protein, fibre, and mineral content.

Issues of Corrosion and Degradation under Dusty Deposits of Energy Biomass

The aim of the study is to identify and determine the role of microbial degradation taking place in dusty deposits in potential threats (i.e., destruction of protective coatings and development of corrosion) to the means of transport in conditions of transshipment of energy biomass. This paper presents the results of research on the impact of powdery fractions of wood biomass and biomass obtained from oil plants in the degradation of paint coatings and corrosion processes. During the research, exposure to simulated port climate, OM, SEM, and EDS studies were used. It has been found that the presence of the fraction containing protein compounds and amino acids (e.g., dust of rapeseed meal) stimulates the growth of microorganisms whose metabolism products favour the destruction of protective coatings and the development of corrosion. Under the same conditions, the destruction of protective zinc coatings has been observed. It was found that already 14 days of exposure to oily biomass deposits results in damage to paint coatings caused by microbiological processes. The 8-week exposure causes serious degradation of protective coatings and the base material itself. The biomass of wood origin, containing compounds of the tannin type, did not show as much aggressive activity as the biomass with protein compounds.

Linking Expansion Behaviour of Extruded Potato Starch/Rapeseed Press Cake Blends to Rheological and Technofunctional Properties

In order to valorise food by-products into healthy and sustainable products, extrusion technology can be used. Thereby, a high expansion rate is often a targeted product property. Rapeseed press cake (RPC) is a protein- and fibre-rich side product of oil pressing. Although there is detailed knowledge about the expansion mechanism of starch, only a few studies describe the influence of press cake addition on the expansion and the physical quality of the extruded products. This study assessed the effect of RPC inclusion on the physical and technofunctional properties of starch-containing directly expanded products. The effect of starch type (native and waxy), RPC level (10, 40, 70 g/100 g), extrusion moisture content (24, 29 g/100 g) and barrel temperature (20-140 °C) on expansion, hardness, water absorption, and solubility of the extrudates and extruder response was evaluated. At temperatures above 120 °C, 70 g/100 g of RPC increased the sectional and volumetric expansion of extrudates, irrespective of starch type. Since expansion correlates with the rheological properties of the melt, RPC and RPC/starch blends were investigated pre- and postextrusion in a closed cavity rheometer at extrusion-like conditions. It was shown that with increasing RPC level the complex viscosity |ƞ*| of extruded starch/RPC blends increased, which could be linked to expansion behaviour.

Oil Press-Cakes and Meals Valorization through Circular Economy Approaches: A Review

The food industry generates a large amount of waste every year, which opens up a research field aimed at minimizing and efficiently managing this issue to support the concept of zero waste. From the extraction process of oilseeds results oil cakes. These residues are a source of bioactive compounds (protein, dietary fiber, antioxidants) with beneficial properties for health, that can be used in foods, cosmetics, textile, and pharmaceutical industries. They can also serve as substrates for the production of enzymes, antibiotics, biosurfactants, and mushrooms. Other applications are in animal feedstuff and for composites, bio-fuel, and films production. This review discusses the importance of oilseed and possible valorization methods for the residues obtained in the oil industry.

The unconventional adverse effects of fungal pretreatment on iturin A fermentation by Bacillus amyloliquefaciens CX-20

Fungal pretreatment is the most common strategy for improving the conversion of rapeseed meal (RSM) into value-added microbial products. It was demonstrated that Bacillus amyloliquefaciens CX-20 could directly use RSM as the sole source of all nutrients except the carbon source for iturin A fermentation with high productivity. However, whether fungal pretreatment has an impact on iturin A production is still unknown. In this study, the effects of fungal pretreatment and direct bio-utilization of RSM for iturin A fermentation were comparatively analysed through screening suitable fungal species, and evaluating the relationships between iturin A production and the composition of solid fermented RSM and liquid hydrolysates. Three main unconventional adverse effects were identified. (1) Solid-state fermentation by fungi resulted in a decrease of the total nitrogen for B. amyloliquefaciens CX-20 growth and metabolism, which caused nitrogen waste from RSM. (2) The released free ammonium nitrogen in liquid hydrolysates by fungal pretreatment led to the reduction of iturin A. (3) The insoluble precipitates of hydrolysates, which were mostly ignored and wasted in previous studies, were found to have beneficial effects on producing iturin A. In conclusion, our study verifies the unconventional adverse effects of fungal pretreatment on iturin A production by B. amyloliquefaciens CX-20 compared with direct bio-utilization of RSM.

Investigation of Heating and Freezing Pretreatments on Mechanical, Chemical and Spectral Properties of Bulk Sunflower Seeds and Oil

The present study examined the effects of heating and freezing pretreatments on the mechanical, chemical, and spectral characteristics of sunflower seeds and oil under a linear compression process involving a universal compression-testing machine and a pressing vessel of diameter 60 mm with a plunger. The heating temperatures ranged from 40 to 80 °C and freezing temperatures from −2 to −36 °C at constant heating time of 30 min. The pretreated samples of initial height of 80 mm (22.6 × 10−5 m3) were compressed under a preset load of 100 kN and a speed of 5 mm/min. The results showed that oil expression efficiency significantly increased (p < 0.05) with increased heating temperatures but decreased with freezing temperatures. The lowest energy per volume oil of 22.55 ± 0.919 kJ/L was recorded at 80 °C compared to 26.40 ± 0.307 kJ/L noticed at −2 °C and control (25 °C) of 33.93 ± 3.866 kJ/L. The linear regression equations expressing oil expression efficiency, energy per volume oil, peroxide value, and free fatty acid, dependent on heating and freezing temperatures, were described with coefficients of determination between 0.373 and 0.908. Increased heating temperatures increased the UV absorption rate of the oil samples at a wavelength of 350 nm. The study is part of the continuing research on linear compression modeling of all processing factors, whereby the results are intended to be applied to the non-linear process dealing with a mechanical screw press to improve the oil extraction process.

Rapeseed meal valorization strategies via nitrogen- and oxygen-limited production of polyhydroxyalkanoates with Pseudomonas putida

Rapeseed meal (RSM) is a candidate for biopolymer production due to its abundance, low cost and potential integration with other rapeseed-derived products. However, existing studies pursuing such schemes are limited. The feasibility of different strategies for RSM valorization via protein extraction and polyhydroxyalkanoate production were evaluated. Nitrogen-limited RSM media was produced from hydrolysis of residues which had undergone extensive protein extraction using sodium hydroxide. A study of oxygen-limited fermentation was also performed on hydrolysate of untreated RSM via batch feeding. The typical strategy of using a high carbon-to-nitrogen ratio may not be the most suitable route for polyhydroxyalkanoate (PHA) production using nitrogen-rich biomass as a feedstock. Central composite design-based experiments show that due to mass transfer limitations protein extraction at 1-L scale could only achieve yields around 50% and 69%, at room temperature and 60 °C, respectively. Protein extraction yields reduced with successive extractions, meaning that whilst the RSM hydrolysate is viable for growth, designing a valorization scheme which has the fermentation step dictated by the protein extraction may not be practical/economical. A better route which utilizes oxygen-limitation to initially induce stationary phase was identified, giving accumulation of polyhydroxyalkanoate once the oxygen levels began to recover; 8.93% and 1.75% PHA accumulation in fed-batch cultures of synthetic and RSM media, respectively. The findings demonstrate that decoupling of protein extraction performance from PHA synthesis is feasible. This study provides important insight into the degrees of freedom available in the design of a holistic valorization scheme of rapeseed meal, and high protein lignocellulosic biomass in general.

Limited Cu(II) binding to biochar DOM: Evidence from C K-edge NEXAFS and EEM-PARAFAC combined with two-dimensional correlation analysis

Multiple spectroscopic technologies and chemometric analyses were combined to explore the compositional characteristics and Cu binding performance of biochar-derived dissolved organic matter (DOM). The DOM samples were extracted from biochars produced from lignocellulose-rich rapeseed cake (RSC) by pyrolysis at 300, 500, and 700 °C (i.e., RSC300, RSC500, RSC700). Fourier transform infrared spectroscopy (FTIR) and carbon K-edge near-edge X-ray absorption fine structure spectroscopy (NEXAFS) analyses were combined to elucidate the molecular-level C species in the DOM. With the increasing pyrolysis temperature, DOM aromaticity increased, whereas the proportion of metal complexing sites (e.g., carboxyl and phenolic groups) decreased. Fluorescence excitation-emission matrix (EEM) spectroscopy with parallel factor analysis (PARAFAC) indicated that biochar DOM, irrespective of pyrolysis temperature, was mostly composed of three types of humic-like components (C1-C3), and a small amount of a protein-like component (C4). As charring temperature increased, DOM concentrations decreased substantially, but the humic-like C3 with abundant aromatic structures became predominant. Fluorescence quenching experiment and two-dimensional correlation spectroscopy (2D-COS) analysis suggested that the preferential Cu(II) binding fractions of the DOM were the humic-like substances. Moreover, the quenching curve fitting results for individual components indicated that despite the Cu(II) binding affinity was slightly enhanced as the pyrolysis temperature increased, the binding capacities of the four components decreased. In general, the DOM components from RSC biochar exhibited limited Cu(II) binding capacities (2.18-17.7 μmol L^-1). Results from this study improved understanding of the mechanisms by which biochar DOM interacts with Cu, and provided tools for fast screening of biochars to reduce their environmental risks.

Dip-coated rapeseed meal composite as a green carrier for light-induced controlled release of pesticide

4-Aminoazobenzene moieties act as light-driven “stirrers” to stimulate the release of pesticide.

Establishment of a rapeseed meal fermentation model for iturin A production by Bacillus amyloliquefaciens CX-20

Iturin A is an important broad-spectrum antifungal cyclic lipopeptide used as an ideal potential biological control agent. However, its application is limited mainly due to the producer strains' low productivity and the high production costs. Here, a potentially industrial strain Bacillus amyloliquefaciens CX-20 was proved to use low-cost rapeseed meal (RSM) as the sole source of all nutrients except the carbon source for the high productivity of iturin A. A fermentation model was first established to analyse the specific roles of different RSM components on iturin A production. Proteins and minerals in RSM were confirmed to play positive role, whereas fibre had negative effect. And the maximal concentration of iturin A was predicted to be more than 1.64 g l-1 by the established evaluation model. Moreover, submerged fermentation of B. amyloliquefaciens CX-20 demonstrated a strong ability to hydrolyse RSM and release water-soluble nutrients. This fermentation broth, a mixture of Bacillus, iturin A and RSM hydrolysate, could simultaneously combat clubroot disease and promote the growth of Brassica napus. In conclusion, this study provides a promising strategy to achieve full utilization of RSM for the production of a combination of value-added biological control agent and biofertilizer.