Flaxseed: a potential source of food, feed and fiber

Comprehensive analysis of oxidative stability and nutritional values of germinated linseed and sunflower seed oil

Germination of seeds is known to affect the nutritional composition of cold-pressed oils. This study focused on the effects of germination on the antioxidants and oxidative stability of linseed and sunflower seed oil. As hypothesized, germination led to increased antioxidant activities and tocopherol, chlorophyll and carotenoid content. Analysis revealed a 37.2 ± 3.5-fold and 11.6 ± 1.5-fold increase in polyphenol content in linseed and sunflower seed oil from germinated seeds, respectively. Using LC-HRMS/MS, profiles with up to 69 polyphenolic substances were identified in germinated seed oils for the first time. Germination promoted lipid hydrolysis, as evidenced by NMR, with overall significant decreases in triacylglycerol content leading to increased diacylglycerol and free fatty acid values. Rancimat measurements predicted a 4.10 ± 0.52-fold longer shelf-life for germinated linseed oil. This study successfully demonstrated the potential of germination to develop PUFA-rich oils with enhanced antioxidant capacity and oxidative stability.

A comprehensive review on nutritional, nutraceutical, and industrial perspectives of perilla (Perilla frutscens L.) seeds - An orphan oilseed crop

There is a growing need to mainstream orphan or underutilized crops to enhance nutritional security and sustainable agriculture. Among these, Perilla frutescens L. is an important crop due to its rich nutritional and phytochemical content which makes it significant in nutrition, medicine, and industrial sector. Perilla seeds are mainly rich in ω-3 fatty acids, dietary fiber, amino acids, vitamins, and minerals, high α-linolenic acid, which contributes to their health benefits. This review explores the nutritional profile of perilla seeds and highlights its unique composition compared to other oilseed crops. It also analyzes the phytochemical components of perilla seeds and their various biological activities, including antioxidant, antidiabetic, antiobesity, cardioprotective, anticancer, antimicrobial, neuroprotective, and anti-inflammatory effects. These activities demonstrate the potential of perilla seeds in both pharmaceutical and food sectors. The review also covers recent advancements in genomics and transgenic research discussing potential areas for crop improvement. Additionally, it explores the use of perilla seeds in functional foods, blending perilla oil with other oils, and their applications in enhancing product formulations. This review offers valuable insights for researchers, students, policymakers, environmentalists, and industry professionals by detailing the potential of perilla seeds across various sectors. The findings support sustainable agriculture, crop diversification, and innovative product development, thus contributing to the integration of perilla into mainstream agriculture.

An R2R3-MYB Transcriptional Factor LuMYB314 Associated with the Loss of Petal Pigmentation in Flax (Linum usitatissimum L.)

The loss of anthocyanin pigments is one of the most common evolutionary transitions in petal color, yet the genetic basis for these changes in flax remains largely unknown. In this study, we used crossing studies, a bulk segregant analysis, genome-wide association studies, a phylogenetic analysis, and transgenic testing to identify genes responsible for the transition from blue to white petals in flax. This study found no correspondence between the petal color and seed color, refuting the conclusion that a locus controlling the seed coat color is associated with the petal color, as reported in previous studies. The locus controlling the petal color was mapped using a BSA-seq analysis based on the F2 population. However, no significantly associated genomic regions were detected. Our genome-wide association study identified a highly significant QTL (BP4.1) on chromosome 4 associated with flax petal color in the natural population. The combination of a local Manhattan plot and an LD heat map identified LuMYB314, an R2R3-MYB transcription factor, as a potential gene responsible for the natural variations in petal color in flax. The overexpression of LuMYB314 in both Arabidopsis thaliana and Nicotiana tabacum resulted in anthocyanin deposition, indicating that LuMYB314 is a credible candidate gene for controlling the petal color in flax. Additionally, our study highlights the limitations of the BSA-seq method in low-linkage genomic regions, while also demonstrating the powerful detection capabilities of GWAS based on high-density genomic variation mapping. This study enhances our genetic insight into petal color variations and has potential breeding value for engineering LuMYB314 to develop colored petals, bast fibers, and seeds for multifunctional use in flax.

Physicochemical, structural, and functional characterization of guar meal protein isolate (Cyamopsis tetragonoloba)

Guar korma and churi protein isolates were assessed for their physicochemical, nutritional, functional, structural, and digestibility properties for their application in the food industry. The water extracted protein isolate of guar korma showed a protein content of 89.7 % and a yield of 48.7 %. Water extracted protein isolate of guar korma showed an excellent protein efficiency ratio, essential amino acid/total amino acids (34.35 %), amino acid score, and protein digestibility corrected amino acid score values, suggesting the existence of high-quality proteins. Water extracted protein isolate of guar korma contains all the essential amino acids except Methionine and Cysteine, according to World Health Organization recommendations for children and adults. The protein profiling of water extracted protein isolate of guar korma was analyzed using 12 % sodium dodecyl sulfate polyacrylamide gel electrophoresis and indicated the presence of eight major protein bands in the range of 17-100 kDa. In vitro digestibility of water extracted protein isolate of guar korma showed the complete digestion of the abundant protein bands within 15 min. Further, the foaming capacity, water/oil holding capacity, and emulsifying stability of water extracted protein isolate of guar korma were comparable with soy protein isolate. Fourier Transform Infrared and Circular Dichroism spectral analysis revealed the presence of several aromatic groups and β-sheets, random coils respectively in water extracted protein isolate of guar korma. The morphological nature of the guar protein isolate was characterized by Scanning Electron Microscopy. Overall, these findings support that water extracted protein isolate of guar korma has excellent functional and nutritional properties and could be a potential alternative plant protein in food industries.

Unveiling the potential of linseed mucilage, its health benefits, and applications in food packaging

Industrial waste products derived from the oil industry often contain valuable substances and elements with great potential. These by-products can be used for various purposes, including as nutrients, bioactive compounds, fuels, and polymers. Linseed mucilage (LM) is one such example of a beneficial by-product obtained from linseed. It possesses favorable chemical and functional properties, depending on its method of extraction. Different pretreatments, such as enzymatic extraction, microwave-assisted extraction, pulse electric field, and ultrasound-assisted extraction, have been explored by various researchers to enhance both the yield and quality of mucilage. Furthermore, LM has exhibited therapeutic effects in the treatment of obesity, diabetes, constipation, hyperlipidemia, cancer, and other lifestyle diseases. Additionally, it demonstrates favorable functional characteristics that make it suitable to be used in bioplastic production. These properties preserve food quality, prolong shelf life, and confer antimicrobial activity. It also has the potential to be used as a packaging material, especially considering the increasing demand for sustainable and biodegradable alternatives to plastics because of their detrimental impact on environmental health. This review primarily focuses on different extraction techniques used for linseed mucilage, its mechanism of action in terms of health benefits, and potential applications in food packaging.

Dietary flaxseed cake influences on performance, quality, and sensory attributes of eggs, serum, and egg trace minerals of laying hens

Nowadays, there is a global shortage in feed supply for animal nutrition; however, there are a considerable amount of agro-industrial co- and by-products that may offer a reasonable solution. Flaxseed cake (FSC) is a by-product of flaxseed for oil extraction rich in n-3 α-linolenic acid (ALA). Thus, the dietary inclusion of FSC on laying performance, egg quality, and serum and egg trace elements (Se, Zn, and Fe) was evaluated using Hisex White hens. The hens were distributed to three equal experimental treatments and provided diets including 0%, 5%, or 10% FSC from 48 to 58 weeks of age. Findings clarified that up to 10% FSC in the laying hen diet had no detrimental effect on laying rate, egg mass, and feed utilization. It was found that FSC resulted in a valuable source of protein, energy, macro- (Ca and P), micro- (Se, Zn and Fe) elements, and essential amino acids, with arginine being the highest. Dietary FSC did not negatively influence the egg quality traits, as well as egg sensory attributes. Including 5% or 10% FSC in diet did not significantly affect serum total protein and renal function in terms of creatinine, uric acid, and uric acid-to-creatinine ratio. Different FSC levels did not influence the chemical composition of eggs and trace elements in serum and eggs. It could be concluded that FSC is a valuable feedstuff that can provide a good source of energy, protein, amino acids, and macro- and micro-elements for hens' nutrition. The inclusion of up to 10% of FSC in hens diet did not adversely influence egg laying performance, egg quality of both fresh and stored eggs, sensory attributes, and nutritional composition, as well as Se, Zn, and Fe in serum and eggs due to balanced nutrient profile of FSC.

Effects of flaxseed supplementation on weight loss, lipid profiles, glucose, and high-sensitivity C-reactive protein in patients with coronary artery disease: A systematic review and meta-analysis of randomized controlled trials

This meta-analysis aimed to evaluate the effects of flaxseed supplementation on weight loss, lipid profiles, high-sensitivity C-reactive protein (hs-CRP), and glucose levels in patients with coronary artery disease (CAD). A systematic search was performed using various online databases, including Scopus, PubMed, Web of Science, EMBASE, and Cochrane Library, to identify relevant randomized controlled trials (RCTs) until June 2023. To evaluate heterogeneity among the selected studies, the Q-test and I2 statistics were employed. Data were combined using either a fixed- or random-effects model and presented as a weighted mean difference (WMD) with a 95% confidence interval (CI). Of the 428 citations, six RCTs were included. The pooled results did not show significant changes in the WMD of lipid factors (high-density lipoprotein cholesterol, triglycerides (TG), low-density lipoprotein cholesterol, and total cholesterol) following flaxseed intake. However, after performing a sensitivity analysis to determine the source of heterogeneity, flaxseed supplementation resulted in a significant decrease in TG levels (WMD = -18.39 mg/dL; 95% CI: -35.02, -1.75). Moreover, no significant differences were observed in either weight or BMI following flaxseed intake. However, the circulating levels of fasting blood glucose (WMD = -8.35 mg/dL; 95% CI: -15.01, -1.69, p = .01) and hs-CRP (WMD = -1.35 mg/L; 95% CI: -1.93, -0.77, p < .01) significantly decreased after the intervention. Flaxseed supplementation was associated with lowering FBS, hs-CRP, and TG levels but did not affect weight loss parameters and other lipid markers in CAD.

Evaluating the health impact of increased linseed consumption in the Danish population

Consumption of linseeds has been suggested to have beneficial effects on human health. However, toxic constituents of linseed may compromise these benefits. We conducted a quantitative risk-benefit assessment to evaluate the overall health impact of increasing linseed intake up to 45 g/day in the Danish population (15-74 years). We quantified the risks associated with increased cadmium exposure and the benefits associated with increased intake of dietary fibre. Increased intakes of alpha-linoleic acid (ALA) were included in a sensitivity analysis. The overall health impact of different linseed intake scenarios was estimated in terms of Disability-Adjusted Life Years (DALYs). We found that the beneficial effects of linseed due to increased intake of dietary fibre outweighed the adverse health effects due to increased cadmium exposure in all scenarios. Up to 670 DALYs/100,000 individuals could be averted per year by increasing linseed consumption in the Danish population. The estimated beneficial health impact increased further when including ALA in the assessment. Different sources of uncertainty might affect the results, and more research is needed on both the health effects associated with intake of linseed and its constituents, and the bioavailability of ALA and cadmium from linseed to further improve the risk-benefit assessment.

Structure Characterization and Functional Properties of Flaxseed Protein-Chlorogenic Acid Complex

This study aimed to investigate the effects of the covalent binding of flaxseed protein (FP) and chlorogenic acid (CA) on the structure and functional properties of FP-CA complexes fabricated using the alkali method. The results suggested that the encapsulation efficiency of CA encapsulated by FP ranged from 66.11% to 72.20% and the loading capacity of CA increased with an increasing addition ratio of CA with a dose-dependent relationship, which increased from 2.34% to 10.19%. The particle size, turbidity, zeta potential and PDI of FP and the FP-CA complexes had no significant discrepancy. UV-Vis and fluorescence spectra showed the existence of the interaction between FP and CA. SEM images showed that the surface of the FP-0.35%CA complex had more wrinkles compared to FP. Differential scanning calorimetry analysis indicated the decomposition temperature of FP at 198 °C was higher than that (197 °C) of the FP-0.35%CA complex, implying that the stability of the FP-CA complexes was lower than FP. The functional properties suggested that the FP-CA complex with 1.40% CA had a higher water holding capacity (500.81%), lower oil holding capacity (273.495%) and lower surface hydrophobicity. Moreover, the FP-CA complexes had better antioxidant activities than that of FP. Therefore, this study provides more insights for the potential application of FP-CA covalent complexes in functional food processing.

Anti-Cancer Properties of Flaxseed Proteome

Flaxseed has been recognized as a valuable source of nutrients and bioactive compounds, including proteins that possess various health benefits. In recent years, studies have shown that flaxseed proteins, including albumins, globulins, glutelin, and prolamins, possess anti-cancer properties. These properties are attributed to their ability to inhibit cancer cell proliferation, induce apoptosis, and interfere with cancer cell signaling pathways, ultimately leading to the inhibition of metastasis. Moreover, flaxseed proteins have been reported to modulate cancer cell mechanobiology, leading to changes in cell behavior and reduced cancer cell migration and invasion. This review provides an overview of the anti-cancer properties of flaxseed proteins, with a focus on their potential use in cancer treatment. Additionally, it highlights the need for further research to fully establish the potential of flaxseed proteins in cancer therapy.

Investigating the impact of linseed supplementation, rich in omega-3 fatty acids, on the expression of immune genes in Beetal Goats

The present study investigated the effect of linseed supplementation on serum profiling and differential expression levels of IL-2 and TLR 2 genes involved in the immune system of lactating goats. The study was conducted on 15 lactating Beetal goats for 3 months, which were divided into three groups. Treatment group T1 was kept as a control group with no linseed supplementation, whereas treatment group T2 received ground linseed at the rate 10% of concentrate per day per animal, and treatment group T3 received 20% ground linseed. The concentration of triglycerides, cholesterol and LDL concentration were found to be significantly lower (P < 0.05) in both 10% and 20% linseed supplemented group than the control group. Whereas, HDL concentration in T2 and T3 group were found to be significantly higher than the control group. The differential expression of targeted genes comparatively revealed highest relative expression in the group that received 20% linseed supplementation. Although the study did not show a significant effect of linseed supplementation on the expression of TLR-2 and IL-2 genes in goats, it highlights the potential benefits of omega-3 PUFA supplementation on immune system modulation in animals.

Genome-wide association studies using multi-models and multi-SNP datasets provide new insights into pasmo resistance in flax

Introduction

Flax (Linum usitatissimum L.) is an economically important crop due to its oil and fiber. However, it is prone to various diseases, including pasmo caused by the fungus Septoria linicola.

Methods

In this study, we conducted field evaluations of 445 flax accessions over a five-year period (2012-2016) to assess their resistance to pasmo A total of 246,035 single nucleotide polymorphisms (SNPs) were used for genetic analysis. Four statistical models, including the single-locus model GEMMA and the multi-locus models FarmCPU, mrMLM, and 3VmrMLM, were assessed to identify quantitative trait nucleotides (QTNs) associated with pasmo resistance.

Results

We identified 372 significant QTNs or 132 tag QTNs associated with pasmo resistance from five pasmo resistance datasets (PAS2012-PAS2016 and the 5-year average, namely PASmean) and three genotypic datasets (the all SNPs/ALL, the gene-based SNPs/GB and the RGA-based SNPs/RGAB). The tag QTNs had R2 values of 0.66-16.98% from the ALL SNP dataset, 0.68-20.54%from the GB SNP dataset, and 0.52-22.42% from the RGAB SNP dataset. Of these tag QTNs, 93 were novel. Additionally, 37 resistance gene analogs (RGAs)co-localizing with 39 tag QTNs were considered as potential candidates for controlling pasmo resistance in flax and 50 QTN-by-environment interactions(QEIs) were identified to account for genes by environmental interactions. Nine RGAs were predicted as candidate genes for ten QEIs.

Discussion

Our results suggest that pasmo resistance in flax is polygenic and potentially influenced by environmental factors. The identified QTNs provide potential targets for improving pasmo resistance in flax breeding programs. This study sheds light on the genetic basis of pasmo resistance and highlights the importance of considering both genetic and environmental factors in breeding programs for flax.

Effects of Breeds on the Content of Functional Nutrition in Eggs

The purpose of this study was to compare the differences in the content of functional nutrients in eggs, performance parameters, and egg quality parameters of different chicken breeds. In Trial 1, 150 41-week-old hens of each breed, including the Dwarf Layer, White Leghorn, Silky fowl, Beijing-you chicken, and Shouguang chicken, were randomly assigned to the control (CON) and 2.5% flaxseed oil (FSO) groups to compare the difference in n-3 polyunsaturated fatty acid (PUFA) content in eggs. The contents of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total n-3 PUFA in eggs were increased (p < 0.05) in the FSO groups. The ALA (4.28%), DHA (2.03%), and total n-3 PUFA (6.46%) contents in eggs of Dwarf Layer were the highest among the five breeds (p < 0.05). To further verify if other functional nutrients also have such differences, 600 24-week-old White Leghorn and Dwarf Layer were allocated to four groups: CON, FSO, 0.02% selenium-enriched yeast (SEY), and 0.20% marigold flower extract (MFE), in Trial 2. The content of functional nutrients in eggs was significantly increased (p < 0.05) after feeding these additions. After feeding FSO, the eggs of the Dwarf Layer had a higher n-3 PUFA content than the White Leghorn (p < 0.05). However, no significant differences were found in selenium and lutein content in different breeds. Performance and egg quality were not negatively impacted by FSO, SEY, or MFE.

Effect of Different Temperatures on the Storage Stability of Flaxseed Milk

In this study, the physical and oxidative stability of flaxseed milk without food additives at different temperatures (25 °C and 37 °C) was assessed. Over in 206 days in storage, the particle size, Turbiscan stability index (TSI), centrifugal sedimentation rate, and primary and secondary oxidation products of flaxseed milk increased, viscosity decreased, and the absolute value of the potential first decreased and then increased. These phenomena indicated a gradual decrease in the physical stability of flaxseed milk, accompanied by drastic oxidative changes. The antioxidant capacity of flaxseed milk was related to the location of the physical distribution of flaxseed lignin, which was more effective in the aqueous phase compared to the non-aqueous phase. Interestingly, after 171 days in storage at 37 °C, the particle size of flaxseed milk was approximately doubled (6.98 μm → 15.27 μm) and the absolute value of the potential reached its lowest point (-13.49 mV), when the content of primary oxidation products reached its maximum (8.29 mmol/kg oil). The results showed that temperature had a significant effect on the stability of flaxseed milk and that stability decreased with increasing temperature and shortened shelf life. This work provides a theoretical basis for elucidating the stabilization-destabilization mechanism of flaxseed milk.

Linum usitatissimum AccD Enhances Seed Fatty Acid Accumulation and Tolerance to Environmental Stresses during Seed Germination in Arabidopsis thaliana

Flax (Linum usitatissimum L.), as an important oil-producing crop, is widely distributed throughout the world, and its seeds are rich in polyunsaturated fatty acids (FAs). Previous studies have revealed that Arabidopsis thaliana ACETYL-CoA CARBOXYLASE (AtACCase) is vital for FA biosynthesis. However, the functions of L. usitatissimum AccD (LuAccD) on FA accumulation and seed germination remain unclear. In the present study, we cloned the LuAccD coding sequence from the flax cultivar 'Longya 10', identified conserved protein domains, and performed a phylogenetic analysis to elucidate its relationship with homologs from a range of plant species. Ectopic expression of LuAccD in A. thaliana wild-type background enhanced seed FA accumulation without altering seed morphological characteristics, including seed size, 1000-seed weight, and seed coat color. Consistently, the expression of key genes involved in FA biosynthesis was greatly up-regulated in the developing seeds of LuAccD overexpression lines. Additionally, we demonstrated that LuAccD acts as a positive regulator of salt and mannitol tolerance during seed germination in A. thaliana. These results provide important insights into the functions of LuAccD, which facilitates the oil quantity and abiotic stress tolerance of oil-producing crops through genetic manipulation.

Molecular Advances to Combat Different Biotic and Abiotic Stresses in Linseed (Linum usitatissimum L.): A Comprehensive Review

Flax, or linseed, is considered a "superfood", which means that it is a food with diverse health benefits and potentially useful bioactive ingredients. It is a multi-purpose crop that is prized for its seed oil, fibre, nutraceutical, and probiotic qualities. It is suited to various habitats and agro-ecological conditions. Numerous abiotic and biotic stressors that can either have a direct or indirect impact on plant health are experienced by flax plants as a result of changing environmental circumstances. Research on the impact of various stresses and their possible ameliorators is prompted by such expectations. By inducing the loss of specific alleles and using a limited number of selected varieties, modern breeding techniques have decreased the overall genetic variability required for climate-smart agriculture. However, gene banks have well-managed collectionns of landraces, wild linseed accessions, and auxiliary Linum species that serve as an important source of novel alleles. In the past, flax-breeding techniques were prioritised, preserving high yield with other essential traits. Applications of molecular markers in modern breeding have made it easy to identify quantitative trait loci (QTLs) for various agronomic characteristics. The genetic diversity of linseed species and the evaluation of their tolerance to abiotic stresses, including drought, salinity, heavy metal tolerance, and temperature, as well as resistance to biotic stress factors, viz., rust, wilt, powdery mildew, and alternaria blight, despite addressing various morphotypes and the value of linseed as a supplement, are the primary topics of this review.

Influence of Flaxseed (Linum usitatissimum) on Female Reproduction

This review describes the chemical composition of flaxseed (Linum usitatissimum) and its general health effects, as well as the currently available knowledge concerning its action on the female reproductive state, functions on the ovary and ovarian cells and reproductive hormones, as well as possible constituents and extra- and intracellular mediators mediating its effects on female reproductive processes. Flaxseed contains a number of biologically active molecules, which, acting through multiple signalling pathways, can determine numerous physiological, protective and therapeutic effects of flaxseed. The available publications demonstrate the action of flaxseed and its constituents on the female reproductive system - ovarian growth, follicle development, the resulting puberty and reproductive cycles, ovarian cell proliferation and apoptosis, oo- and embryogenesis, hormonal regulators of reproductive processes and their dysfunctions. These effects can be determined by flaxseed lignans, alpha-linolenic acid and their products. Their actions can be mediated by changes in general metabolism, metabolic and reproductive hormones, their binding proteins, receptors and several intracellular signalling pathways, including protein kinases, transcription factors regulating cell proliferation, apoptosis, angiogenesis and malignant transformation. Flaxseed and its active molecules are found potentially useful for improving farm animal reproductive efficiency and treatment of polycystic ovarian syndrome and ovarian cancer.

Drought and Oxidative Stress in Flax (Linum usitatissimum L.) Entails Harnessing Non-Canonical Reference Gene for Precise Quantification of qRT-PCR Gene Expression

Flax (Linum usitatissimum L.) is a self-pollinating, annual, diploid crop grown for multi-utility purposes for its quality oil, shining bast fiber, and industrial solvent. Being a cool (Rabi) season crop, it is affected by unprecedented climatic changes such as high temperature, drought, and associated oxidative stress that, globally, impede its growth, production, and productivity. To precisely assess the imperative changes that are inflicted by drought and associated oxidative stress, gene expression profiling of predominant drought-responsive genes (AREB, DREB/CBF, and ARR) was carried out by qRT-PCR. Nevertheless, for normalization/quantification of data obtained from qRT-PCR results, a stable reference gene is mandatory. Here, we evaluated a panel of four reference genes (Actin, EF1a, ETIF5A, and UBQ) and assessed their suitability as stable reference genes for the normalization of gene expression data obtained during drought-induced oxidative stress in flax. Taking together, from the canonical expression of the proposed reference genes in three different genotypes, we report that EF1a as a stand-alone and EF1a and ETIF5A in tandem are suitable reference genes to be used for the real-time visualization of cellular impact of drought and oxidative stress on flax.

Dietary Supplementation with Linseed Oil Ethyl Esters Improves Sexual Behavior and Chosen Seminal Parameters in Porcine Species

Numerous studies have shown that improvements in the sperm and semen quality of males of many species can be achieved with appropriate dietary supplements added to feed or fodder. Particularly promising seems to be the inclusion of omega polyunsaturated fatty acids in the diets of males. Among other things, it has been shown that linseed oil ethyl esters (EELO can be an excellent source of omega 3 polyunsaturated fatty acids in animal diets. These compounds are more durable and resistant to oxidation, epoxidation and resinification processes, and do not exhibit toxic properties in living organisms. At present, there is a lack of data in the literature on the enrichment of boar diets with EELO. The purpose of this study was to analyze the effects of the addition of EELO to boar diets on the properties of sperm in fresh semen. The study was conducted during the summer on semen collected from 12 boars of the line 990. Linseed oil ethyl esters were administered in each feeding at a rate of 3.0% (45 mL each) in basal diets for each boar on a daily basis for 16 weeks. Ejaculates were collected manually by the gloved-hand technique, at one-week intervals for eight-week periods, from the eighth week onwards after the start of feeding. Eight ejaculates were collected from each boar, totaling 96 samples. The addition of EELO to the diets of boars caused an increase in sperm viability (p < 0.001), semen volume (310 mL versus 216 mL, p < 0.001) and sperm concentration (331 versus 216 million per mL, p < 0.001). Furthermore, in the experimental animals, there was a decrease in the percentage of spermatozoa exhibiting DNA fragmentation. The experimental boars also showed an increase in the percentage of gametes without apoptosis and capacitation and an increase in the percentage of viable spermatozoa not showing lipid peroxidation membranes. Consequently, EELO nutritional supplementation resulted in the improved quality of the fresh semen of boars.

Water Stress and Seed Color Interacting to Impact Seed and Oil Yield, Protein, Mucilage, and Secoisolariciresinol Diglucoside Content in Cultivated Flax (Linum usitatissimum L.)

Flaxseed (Linum usitatissimum L.) is a plant with a wide range of medicinal, health, nutritional, and industrial uses. This study assessed the genetic potential of yellow and brown seeds in thirty F4 families under different water conditions concerning seed yield, oil, protein, fiber, mucilage, and lignans content. Water stress negatively affected seed and oil yield, while it positively affected mucilage, protein, lignans, and fiber content. The total mean comparison showed that under normal moisture conditions, seed yield (209.87 g/m²) and most quality traits, including oil (30.97%), secoisolariciresinol diglucoside (13.89 mg/g), amino acids such as arginine (1.17%) and histidine (1.95%), and mucilage (9.57 g/100 g) were higher in yellow-seeded genotypes than the brown ones ((188.78 g/m²), (30.10%), (11.66 mg/g), (0.62%), (1.87%), and (9.35 g/100 g), respectively). Under water stress conditions, brown-seeded genotypes had a higher amount of fiber (16.74%), seed yield (140.04 g/m²), protein (239.02 mg. g^-1), methionine (5.04%), and secondary metabolites such as secoisolariciresinol diglucoside (17.09 mg/g), while their amounts in families with yellow seeds were 14.79%, 117.33 g/m², 217.12 mg. g^-1, 4.34%, and 13.98 mg/g, respectively. Based on the intended food goals, different seed color genotypes may be appropriate for cultivation under different moisture environments.

Anti-Obesity Effects of Dietary Fibers Extracted from Flaxseed Cake in Diet-Induced Obese Mice

Although many efforts have been made to characterize the functional properties of flaxseed, knowledge concerning the properties of insoluble and soluble dietary fibers in flaxseed is still limited. Here, insoluble and soluble dietary fibers were extracted from flaxseed cake—a valuable resource that has not been fully exploited. Subsequently, their monosaccharide compositions, structural properties, and anti-obesity effects in male mice were characterized. The anti-obesity effects of flaxseed cake insoluble dietary fiber (FIDF), flaxseed cake soluble dietary fiber (FSDF), and FIDF combined with FSDF in diet-induced obese mice were investigated in our study. Supplementation with FSDF alone or FIDF and FSDF together lowered the fat accumulation, improved the serum lipid profile, increased the basal metabolism, and improved the gut microbiota of obese mice. Supplementation with FIDF and FSDF together significantly enriched the abundance of g_Akkermansia and g_Bifidobacterium, which are negatively associated with obesity. Supplementation with FIDF alone improved the liver lipid profile, raised the basal metabolism, and enhanced the short-chain fatty acid levels in the guts of the mice. In conclusion, our results collectively support the therapeutic potential of FIDF and FSDF in obesity treatment and indicate that FIDF and FSDF play different roles in the process of obesity treatment. Furthermore, our results provide critical information for flaxseed cake resource exploitation.

In utero and postnatal exposure to Foeniculum vulgare and Linum usitatissimum seed extracts: modifications of key enzymes involved in epigenetic regulation and estrogen receptors expression in the offspring's ovaries of NMRI mice

BACKGROUND

Early-life exposure to exogenous estrogens such as phytoestrogens (plant-derived estrogens) could affect later health through epigenetic modifications. Foeniculum vulgare (fennel) and Linum usitatissimum (flax) are two common medicinal plants with high phytoestrogen content. Considering the developmental epigenetic programming effect of phytoestrogens, the main goal of the present study was to evaluate the perinatal exposure with life-long exposure to hydroalcoholic extracts of both plants on offspring's ovarian epigenetic changes and estrogen receptors (ESRs) expression level as signaling cascades triggers of phytoestrogens.

METHODS

Pregnant mice were randomly divided into control (CTL) that received no treatment and extract-treated groups that received 500 mg/kg/day of fennel (FV) and flaxseed (FX) alone or in combination (FV + FX) during gestation and lactation. At weaning, female offspring exposed to extracts prenatally remained on the maternal-doses diets until puberty. Then, the ovaries were collected for morphometric studies and quantitative real-time PCR analysis.

RESULTS

A reduction in mRNA transcripts of the epigenetic modifying enzymes DNMTs and HDACs as well as estrogen receptors was observed in the FV and FX groups compared to the CTL group. Interestingly, an increase in ESRα/ESRβ ratio along with HDAC2 overexpression was observed in the FV + FX group.

CONCLUSION

Our findings clearly show a positive relationship between pre and postnatal exposure to fennel and flaxseed extracts, ovarian epigenetic changes, and estrogen receptors expression, which may affect the estrogen signaling pathway. However, due to the high phytoestrogen contents of these extracts, the use of these plants in humans requires more detailed investigations.

Flaxseed supplementation significantly reduces hemoglobin A1c in patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Flaxseed is a functional food because of its high content of alpha-linolenic acid, lignans, and dietary fiber. We hypothesized that flaxseed supplementation would improve cardiometabolic parameters in patients with type 2 diabetes mellitus (T2DM); however, clinical trials have shown conflicting results. Therefore, this systematic review and meta-analysis was conducted to determine the impact of flaxseed supplementation in patients with T2DM. Randomized controlled trials were systematically searched in PubMed, Web of Science, Scopus, Cochrane Library, and Embase until 25 March 2022. A total of 13 studies were included, and the results showed that flaxseed supplementation significantly reduced hemoglobin A1c (HbA1c) in participants with T2DM compared with the control group. In contrast, it had no effects on body weight, body mass index, blood pressure, fasting blood glucose (FBG), homeostatic model assessment for insulin resistance, quantitative insulin sensitivity check index, and lipid parameters. In the subgroup analyses, FBG was significantly reduced with supplementation of flaxseed in participants with baseline FBG ≥8.0 mmol/L or baseline HbA1c ≥7.0%. And a significant decrease in HbA1c in participants with baseline HbA1c ≥7.0% after flaxseed supplementation. In addition, subgroup analyses indicated that whole flaxseed supplementation significantly increased high-density lipoprotein cholesterol and reduced total cholesterol or low-density lipoprotein cholesterol in participants with T2DM. In conclusion, flaxseed supplementation significantly reduced HbA1c in participants with T2DM, especially those with poorly controlled blood sugar levels. However, larger scale studies with better designs are needed to confirm insignificant and/or ambiguous findings.

Total Phenolic Content and Antioxidant Activity of In Vitro Digested Hemp-Based Products

The growth of the world population has prompted research to investigate new food/feed alternatives. Hemp-based products can be considered excellent candidates. Hemp (Cannabis sativa L.) is an environmentally sustainable plant widespread worldwide. Following the reintroduction of its cultivation, hemp is attracting interest, especially in the food/feed industry. To date, scientific research has mainly focused on its nutritional aspect. Therefore, the aim of the work was also to investigate the functional profile (total phenolic content (TPC) and antioxidant activity (Ferric- reducing antioxidant power (FRAP) and 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS)) of hemp-based products (hempseeds (HSs), flowers, and HS protein extract), following methanol extraction and in vitro digestion, to study the behaviour of the molecules involved. The results show an interesting nutritional value, even when compared to matrices used in the food/feed industry, such as soy and flaxseeds. The functional profile revealed a very interesting TPC following methanol extraction for HSs, flowers, and HS protein extract, respectively, (550.3 ± 28.27; 2982.8 ± 167.78; and 568.9 ± 34.18 mg Tannic Acid Equivalent (TAE)/100 g). This trend was also confirmed for FRAP (50.9 ± 4.30; 123.6 ± 8.08; and 29.73 ± 1.32 mg Ascorbic Acid Equivalent (AAE)/100 g), recording values similar/higher than soy protein extract and flaxseeds (17.4 ± 1.55; and 10.4 ± 0.44 mg AAE/100 g). The results were also maintained following physiological digestion. These results, although promising, need further investigation, confirming what has been observed with different antioxidant activity assays and identifying individual molecules involved in functional pathways. This information will be necessary to gain a better understanding of the functional characteristics of these matrices for use in food/feed formulations.

Effect of germination pretreatment on the physicochemical properties and lipid concomitants of flaxseed oil

This study investigated the effects of germination pretreatment on the physicochemical properties, lipid concomitants, and antioxidant activity of flaxseed oil in three varieties. The results indicated that the oil content of flaxseed decreased by 2.29-7.40% during the 5 days germination period. Germinated flaxseed oil showed a significantly higher acid value and lower peroxide value. The unsaturated fatty acid content was slightly increased by germination. Germination pretreatment resulted in significant increases in the α-tocopherol, stigmasterol, pigments, total phenols, and antioxidant activity. As germination time progressed to 5 days, α-tocopherol which was traditionally recognized as having the highest antioxidant activity form of vitamin E in humans increased from 3.07-6.82 mg kg^-1 to 258.11-389.78 mg kg^-1. Germinated oil had 1.63 to 2.05 times higher stigmasterol content than non-germinated oil. The chlorophyll and carotenoid also increased exponentially. The total phenol content of flaxseed oil increased from 64.29-75.85 mg kg^-1 to 236.30-297.78 mg kg^-1. Germinated flaxseed oil showed important antioxidant activity. Compared with other varieties during germination, the oil from Gansu showed a higher level of α-linolenic acid, tocopherols, and carotenoid, and a maximum increase level of tocopherols and phytosterols. The comprehensive evaluation of germination time by correlation and principal component analysis showed that when germination time exceeded 2 days, the lipid concomitants and antioxidant capacity of flaxseed oil were significantly improved.

Composition, processing, and quality control of whole flaxseed products used to fortify foods

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid-amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.

Development and Complex Application of Methods for the Identification of Mutations in the FAD3A and FAD3B Genes Resulting in the Reduced Content of Linolenic Acid in Flax Oil

Flax is grown worldwide for seed and fiber production. Linseed varieties differ in their oil composition and are used in pharmaceutical, food, feed, and industrial production. The field of application primarily depends on the content of linolenic (LIN) and linoleic (LIO) fatty acids. Inactivating mutations in the FAD3A and FAD3B genes lead to a decrease in the LIN content and an increase in the LIO content. For the identification of the three most common low-LIN mutations in flax varieties (G-to-A in exon 1 of FAD3A substituting tryptophan with a stop codon, C-to-T in exon 5 of FAD3A leading to arginine to a stop codon substitution, and C-to-T in exon 2 of FAD3B resulting in histidine to tyrosine substitution), three approaches were proposed: (1) targeted deep sequencing, (2) high resolution melting (HRM) analysis, (3) cleaved amplified polymorphic sequences (CAPS) markers. They were tested on more than a thousand flax samples of various types and showed promising results. The proposed approaches can be used in marker-assisted selection to choose parent pairs for crosses, separate heterogeneous varieties into biotypes, and select genotypes with desired homozygous alleles of the FAD3A and FAD3B genes at the early stages of breeding for the effective development of varieties with a particular LIN and LIO content, as well as in basic studies of the molecular mechanisms of fatty acid synthesis in flax seeds to select genotypes adequate to the tasks.

A review of flaxseed lignan and the extraction and refinement of secoisolariciresinol diglucoside

Lignan is a class of diphenolic compounds that arise from the condensation of two phenylpropanoid moieties. Oilseed and cereal crops (e.g., flaxseed, sesame seed, wheat, barley, oats, rye, etc.) are major sources of plant lignan. Methods for commercial isolation of the lignan secoisolariciresinol diglucoside (SDG) are not well reported, as most publications describing the detection, extraction, and enrichment of SDG use methods that have not been optimized for commercial scale lignan recovery. Simply scaling up laboratory methods would require expensive infrastructure to achieve a marketable yield and reproducible product quality. Therefore, establishing standard protocols to produce SDG and its derivatives on an industrial scale is critical to decrease lignan cost and increase market opportunities. This review summarizes the human health benefits of flaxseed lignan consumption, lignan physicochemical properties, and mammalian lignan metabolism, and describes methods for detecting, extracting, and enriching flaxseed lignan. Refining and optimization of these methods could lead to the development of inexpensive lignan sources for application as an ingredient in medicines, dietary supplements, and other healthy ingredients.

Isolating Linum usitatissimum L. Nuclear DNA Enabled Assembling High-Quality Genome

High-quality genome sequences help to elucidate the genetic basis of numerous biological processes and track species evolution. For flax (Linum usitatissimum L.)—a multifunctional crop, high-quality assemblies from Oxford Nanopore Technologies (ONT) data were unavailable, largely due to the difficulty of isolating pure high-molecular-weight DNA. This article proposes a scheme for gaining a contiguous L. usitatissimum assembly using Nanopore data. We developed a protocol for flax nuclei isolation with subsequent DNA extraction, which allows obtaining about 5 μg of pure high-molecular-weight DNA from 0.5 g of leaves. Such an amount of material can be collected even from a single plant and yields more than 30 Gb of ONT data in two MinION runs. We performed a comparative analysis of different genome assemblers and polishers on the gained data and obtained the final 447.1-Mb assembly of L. usitatissimum line 3896 genome using the Canu—Racon (two iterations)—Medaka combination. The genome comprised 1695 contigs and had an N50 of 6.2 Mb and a completeness of 93.8% of BUSCOs from eudicots_odb10. Our study highlights the impact of the chosen genome construction strategy on the resulting assembly parameters and its eligibility for future genomic studies.

Characterization of ultrasonically extracted flaxseed polysaccharide gum and assessing its lipid-lowering potential in a rat model

Flaxseed polysaccharide gum (FPG) was extracted through the ultrasound-assisted process using water as a solvent with a yield ranging from 8.05 ± 0.32% to 12.23 ± 0.45% by changing different extraction variables. The extracted FPG was analyzed for its functional groups and antioxidant potential. The maximum DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity (≈100%) of FPG was noted at concentrations beyond ≈10 mg·ml^-1. The maximum inhibition percentage through ABTS (2,2'-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid) (72.4% ± 1.9%) was noted at 40 mg·ml^-1, which was observed to be less when compared to DPPH at the same concentration. The total antioxidant potential of the FPG solution at a concentration of 10 mg·ml^-1 was equivalent to 461 mg ascorbic acid, which tends to increase with concentration at a much lower scope. The in vivo trial suggested that the least weight gain was noted in experimental groups G₂ and Gh₂. A significant reduction in total cholesterol was noticed in G₁ (-14.14%) and G₂ (-17.72%) and in Gh₁ (-22.02%) and Gh₂ (-34.68%) after 60 days of the trial compared to the baseline values. The maximum reduction in total triglyceride was observed in Gh₂ (-25.06%) and Gh₁ (-22.01%) after 60 days of the trial. It was an increasing trend in high-density lipoprotein cholesterol (HDL-c) in different experimental groups G₂ (10.51%) than G₁ (5.35%) and Gh₂ (48.96%) and Gh₁ (31.11%), respectively, after 60 days of study interval. Reduction of -5.05% and - 9.45% was observed in G₁ and G₂, while similar results were observed in Gh₁ and Gh₂. Conclusively, results suggested a possible protective role of FPG against hyperlipidemia.

Distribution, biosynthesis and therapeutic potential of lignans

Lignans have long been known for their abundant therapeutic properties due to their polyphenolic structure. Linseed is the richest plant source of lignans and has been studied widely for their properties. The most prevalent lignan, secoisolariciresinol diglucoside (SDG), is consumed with linseed and converted into mammalian lignans, enterodiol (END) and enterolactone (ENL), by the gut microbiota. SDG can easily be assessed using HPLC and its deglycosylated form viz secoisolariciresinol can be asses using GC-MS techniques. Variety of extraction and analysis methods has been reported for plant lignans. SDG is known to have therapeutic properties including anti-oxidant, anti-cancerous, anti-inflammatory, modulation of gene expression, anti-diabetic, estrogenic and anti-estrogenic. Despite a large number of bioactivities, strong evidences for the underlying mechanisms for most of the properties are still unknown. SDG is most studied for its anti-cancerous properties. But the use of lignans as anti-carcinogenic agent is limited and commercially not reported due to challenges of purification at commercial level, rapid metabolism, untargeted delivery and toxic compounds associated with lignans. Exploration of more prominent and active derivatives of SDG and their targeted drug delivery should be an important research toward the use of bioactive lignans of linseed.

Extracts Prepared from Feed Supplements Containing Wood Lignans Improve Intestinal Health by Strengthening Barrier Integrity and Reducing Inflammation

Lignans are known to exhibit a broad spectrum of biological activities, indicating their potential as constituents of feed supplements. This study investigated two extracts derived from the feed supplements ‘ROI’ and ‘Protect’—which contain the wood lignans magnolol and honokiol (‘ROI’), or soluble tannins additional to the aforementioned lignans (‘Protect’)—and their impact on selected parameters of intestinal functionality. The antioxidant and anti-inflammatory properties of the extracts were determined by measuring their effects on reactive oxygen species (ROS) and pro-inflammatory cytokine production in vitro. The impact on intestinal barrier integrity was evaluated in Caco-2 cells and Drosophila melanogaster by examining leaky gut formation. Furthermore, a feeding trial using infected piglets was conducted to study the impact on the levels of superoxide dismutase, glutathione and lipid peroxidation. The Protect extract lowered ROS production in Caco-2 cells and reversed the stress-induced weakening of barrier integrity. The ROI extract inhibited the expression or secretion of interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα). Moreover, the ROI extract decreased leaky gut formation and mortality rates in Drosophila melanogaster. Dietary supplementation with Protect improved the antioxidant status and barrier integrity of the intestines of infected piglets. In conclusion, wood lignan-enriched feed supplements are valuable tools that support intestinal health by exerting antioxidant, anti-inflammatory and barrier-strengthening effects.

Raman spectroscopy mapping of changes in the organization and relative quantities of cell wall polymers in bast fiber cell walls of flax plants exposed to gravitropic stress

Flax is an important fiber crop that is subject to lodging. In order to gain more information about the potential role of the bast fiber cell wall in the return to the vertical position, 6-week-old flax plants were subjected to a long-term (6 week) gravitropic stress by stem tilting in an experimental set-up that excluded autotropism. Stress induced significant morphometric changes (lumen surface, lumen diameter, and cell wall thickness and lumen surface/total fiber surface ratio) in pulling- and opposite-side fibers compared to control fibers. Changes in the relative amounts and spatial distribution of cell wall polymers in flax bast fibers were determined by Raman vibrational spectroscopy. Following spectra acquisition, datasets (control, pulling- and opposite sides) were analyzed by principal component analysis, PC score imaging, and Raman chemical cartography of significant chemical bonds. Our results show that gravitropic stress induces discrete but significant changes in the composition and/or spatial organization of cellulose, hemicelluloses and lignin within the cell walls of both pulling side and opposite side fibers.

Spatiotemporal Transcriptomic Atlas of Developing Embryos and Vegetative Tissues in Flax

Flax (Linum usitatissimum L.) is an important multipurpose crop widely grown for oil and fiber. Despite recent advances in genomics, detailed gene activities during the important reproductive phase of its development are not well defined. In this study, we employed high-throughput RNA-sequencing methods to generate in-depth transcriptome profiles of flax tissues with emphasis on the reproductive phases of five key stages of embryogenesis (globular embryo, heart embryo, torpedo embryo, cotyledon embryo, and mature embryo), mature seed, and vegetative tissues viz. ovary, anther, and root. These datasets were used to establish the co-expression networks covering 36 gene modules based on the expression patterns for each gene through weighted gene co-expression network analysis (WGCNA). Functional interrogation with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) of dominantly expressed genetic modules in tissues revealed pathways involved in the development of different tissues. Moreover, the essential genes in embryo development and synthesis of storage reserves were identified based on their dynamic expression patterns. Together, this comprehensive dataset for developing embryos, mature seeds and vegetative tissues provides new insights into molecular mechanisms of seed development with potential for flax crop improvement.

Structural Characterization and Functional Properties of Flaxseed Hydrocolloids and Their Application

Flaxseed is an excellent source of valuable nutrients and is also considered a functional food. There are two types of hydrocolloids in flaxseed: flaxseed gum and proteins. Flaxseed gum exhibits emulsifying and foaming activities or can be used as a thickening and gelling agent. Due to its form of soluble fiber, flaxseed gum is related to many health benefits. Flaxseed proteins have various functional properties based on their physicochemical properties. While albumins possess the emulsion-forming ability, globulins better serve as foaming agents. Flaxseed proteins may also serve as a source of functional peptides with interesting biological and health-related activities. Functional properties and health-related benefits predetermine the application of these hydrocolloids, mainly in the food industry or medicine. Although these properties of flaxseed hydrocolloids have been recently and extensively studied, they are still not widely used on the industrial scale compared to other popular plant gums and proteins. The aim of this review was to present, discuss and highlight the recent discoveries in the structural characteristics and functional and biological properties of these versatile hydrocolloids with respect to factors affecting their characteristics and offer new insights into their potential applications as comparable alternatives to the other natural hydrocolloids or as the sources of novel functional products.

Integrated omics approaches for flax improvement under abiotic and biotic stress: Current status and future prospects

Flax (Linum usitatissimum L.) or linseed is one of the important industrial crops grown all over the world for seed oil and fiber. Besides oil and fiber, flax offers a wide range of nutritional and therapeutic applications as a feed and food source owing to high amount of α-linolenic acid (omega-3 fatty acid), lignans, protein, minerals, and vitamins. Periodic losses caused by unpredictable environmental stresses such as drought, heat, salinity-alkalinity, and diseases pose a threat to meet the rising market demand. Furthermore, these abiotic and biotic stressors have a negative impact on biological diversity and quality of oil/fiber. Therefore, understanding the interaction of genetic and environmental factors in stress tolerance mechanism and identification of underlying genes for economically important traits is critical for flax improvement and sustainability. In recent technological era, numerous omics techniques such as genomics, transcriptomics, metabolomics, proteomics, phenomics, and ionomics have evolved. The advancements in sequencing technologies accelerated development of genomic resources which facilitated finer genetic mapping, quantitative trait loci (QTL) mapping, genome-wide association studies (GWAS), and genomic selection in major cereal and oilseed crops including flax. Extensive studies in the area of genomics and transcriptomics have been conducted post flax genome sequencing. Interestingly, research has been focused more for abiotic stresses tolerance compared to disease resistance in flax through transcriptomics, while the other areas of omics such as metabolomics, proteomics, ionomics, and phenomics are in the initial stages in flax and several key questions remain unanswered. Little has been explored in the integration of omic-scale data to explain complex genetic, physiological and biochemical basis of stress tolerance in flax. In this review, the current status of various omics approaches for elucidation of molecular pathways underlying abiotic and biotic stress tolerance in flax have been presented and the importance of integrated omics technologies in future research and breeding have been emphasized to ensure sustainable yield in challenging environments.

The Effect of Extraction Method on Physicochemical Properties of Mucilage Extracted from Yellow and Brown Flaxseeds

Background: Mucilage is an important polysaccharide with a broad range of physicochemical properties and antioxidant activity that is widely used for various applications in the medicine and food industries. Objectives: This study aims to evaluate the effect of the extraction method on the physicochemical properties of mucilage extracted from yellow and brown flaxseeds. Methods: Mucilage was extracted by different methods: heating, sonotrode, and bath sonication. The extracted mucilage was evaluated for mucilage extraction efficiency (MEE%), solubility, water-binding capacity (WBC%), antioxidant activity, and foam stability. Results: In all extraction methods, the MEE% of yellow flaxseed was significantly higher than that of brown flaxseed. The antioxidant activity of mucilage extracted from brown and yellow flaxseed was 43.65 ± 1.86% and 12.65 ± 1.23%, respectively (P < 0.001). In all extraction methods, the solubility of mucilage was increased by enhancing the temperature. Significantly, higher solubility (P < 0.01) and stronger foam stability (P < 0.001) was obtained for mucilage extracted from brown flaxseed. The highest foam stability was obtained by the sonotrode method. Mucilage extracted by sonotrode and bath sonication methods showed significantly stronger (P < 0.01) water-binding capacity (WBC%) compared to that of the heating method. Conclusions: Our results showed that the ultrasonic methods, especially sonotrode, due to their positive effects on physicochemical properties of mucilage, could be more appropriate methods for extraction of mucilage.

Phylogenetic Analysis and Flower Color Evolution of the Subfamily Linoideae (Linaceae)

The taxonomy of the subfamily Linoideae at the intergeneric and section levels has been questioned throughout the years, and the evolution of floral characters remains poorly understood. In particular, the evolution of flower color is still uncertain, despite its ecological importance and being one of the most variable and striking traits in Angiospermae. We evaluated the phylogenetic relationships of the genera and sections and used the phylogeny to reconstruct the ancestral state of flower color. The results suggest reevaluating the taxonomic status of segregated genera and re-incorporating them into Linum. Four of the five sections currently accepted were recovered as monophyletic (Cathartolinum, Dasylinum, Linum, and Syllinum). We propose accepting the section Stellerolinon and reevaluating Linopsis, whose representatives were recovered in three separate clades. The ancestral flower color for Linoideae was yellow-white. The flower colors purple and yellow-white were recovered at the deepest nodes of the two main clades. Pink, blue, and red colors were the most recent to evolve. These results appear to be related to diversification events, biogeographical history, and ecological aspects of the subfamily. Our reconstruction constitutes the first plausible scenario that explores the evolution of flower color, leading to new testable hypotheses for future research on the flax group.

Features of Profiles of Biologically Active Compounds of Primary and Secondary Metabolism of Lines from VIR Flax Genetic Collection, Contrasting in Size and Color of Seeds

Flax is one of the oldest oil crops, but only since the end of the twentieth century nutritional use of its whole seeds and flour has been resumed. This crop has been evaluated for its oil fatty acid composition, content of sterols and tocopherols, carbohydrate composition of mucilage, but a comprehensive study has never been carried out, so the aim of the work was to identify differences in the metabolomic profiles of flax lines contrasting in color and size of seeds. The biochemical composition of seeds from 16 lines of the sixth generation of inbreeding was tested using gas chromatography coupled with mass spectrometry. In total, more than 90 compounds related to sugars (78% of the identified substances), free fatty acids (13%), polyatomic alcohols (5%), heterocyclic compounds, free amino acids, phytosterols and organic acids (no more than 2.5% in total) were identified. Statistical analyses revealed six main factors. The first is a factor of sugar content; the second one affects most of organic acids, as well as some free fatty acids, not related to reserve ones, the third factor is related to compounds that play a certain role in the formation of "storage" substances and resistance to stress, the fourth factor is influencing free polar amino acids, some organic and free fatty acids, the fifth one is a factor of phenolic compounds, the sixth factor combined substances not included in the first five groups. Factor analysis made it possible to differentiate all 16 lines, 10 of which occupied a separate position by one or two factors. Interestingly, the first two factors with the highest loads (20 and 15% of the total variability, respectively) showed a separate position of the gc-432 line, which differed from the others, not only by chemical composition, but also by the phenotype of the seeds, while gc-159 differed from the rest ones by the complex of organic acids and other substances taking about 1% of the extracted substances of the seed. Thus, the analysis of metabolomic profiles is promising for a comprehensive assessment of the VIR flax genetic collection, which has wide biochemical diversity.

Flaxseed Mucilage (IQP-LU-104) Reduces Body Weight in Overweight and Moderately Obese Individuals in a 12-week, Three-Arm, Double-Blind, Randomized, and Placebo-Controlled Clinical Study

INTRODUCTION

The aim of this study was to evaluate the benefit and tolerability of two dosages of a proprietary flaxseed mucilage (IQP-LU-104) in reducing body weight in overweight and moderately obese individuals.

METHODS

In a double-blind, randomized, placebo-controlled, bi-center trial, 108 participants (body mass index [BMI] 25-<35 kg/m2) were randomly allocated to receive either IQP-LU-104 high dose (104HD), IQP-LU-104 low dose (104LD), or placebo. Participants were instructed to consume 1 sachet of the investigational product (containing IQP-LU-104 or matching placebo) before or with main meals twice daily and to follow a balanced but hypocaloric diet (20% reduction of individual's daily energy requirements) for 12 weeks. At week 0 (baseline), and weeks 4, 8, and 12 of the intervention periods, the participants' body weight, BMI, body fat composition, and waist and hip circumferences were measured. Blood samples were collected for safety assessment at screening visit (week -2) and at the end of the study. Adverse events were assessed by the investigators through interviewing the participants and were recorded at every visit post screening.

RESULTS

At the end of the 12-week study, body weight reduction was greater in the 104HD group (4.96 ± 1.89 kg, p < 0.001 vs. placebo) and 104LD group (3.70 ± 2.57 kg, p < 0.001 vs. placebo) compared to the placebo group (1.33 ± 2.05 kg). 68% and 46% of participants in the 104HD group (p < 0.001 vs. placebo) and 104LD group (p = 0.002 vs. placebo), respectively, experienced at least 5% weight loss, compared to 9% of participants in the placebo group. Significant decreases in waist and hip circumferences were observed in both the 104HD and 104LD groups compared to the placebo group (each p < 0.001). 104HD group had significantly higher reduction in body fat mass (4.25 ± 5.86 kg) than the placebo group (1.06 ± 3.20 kg) (p = 0.002). Respiratory tract infections and gastrointestinal symptoms were the main adverse events reported and none of the adverse events were related to the intake of IQP-LU-104.

CONCLUSION

Results demonstrated IQP-LU-104 is safe and efficacious in body weight reduction at both dosages in overweight and moderately obese individuals.

Influence of dry air and infrared pre-treatments on oxidative stability, Maillard reaction products and other chemical properties of linseed (Linum usitatissimum L.) oil

In this study, the influence of dry air and infrared pre-treatments on linseed oil (LO) yield, chemical properties, colour, pigment content, total phenolic content (TPC), Maillard reaction products (MRPs), fatty acid composition (FAC), radical scavenging activity (RSA), and oxidative stability index (OSI) were investigated. An increase in dry air and infrared roasting temperature had increased the LO yield, pigment content, a* value, TPC, RSA, OSI, and browning index (BI) while lowered the L* and b* values of LO. Higher OSI (2.24 h), chlorophylls (2.29 mg/kg), carotenoids (3.87 mg/kg), TPC (63.67 mg GAE/100 g), RSA (62.53%), BI (0.330), and MRPs (2.10 mg/kg) were detected in LO by dry air roasting at 180°C for 10 min. Dry air and infrared roasting had slightly affected the FAC of LO. Both dry air and infrared pre-treatments had influenced the LO quality characteristics. However, dry air roasting of linseed at 180°C for 10 min proved more effective in improving oxidative stability, antioxidant activity and other quality characteristics of LO.

SUPPLEMENTARY INFORMATION

The online version of this article at 10.1007/s13197-021-05023-6.