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Abstract Background Constipation is a very common health problem in the world. Intake of sufficient amount of dietary fibers is a cornerstone in the prevention and treatment of constipation. As a traditional medicine, flaxseed has been used to treat constipation for centuries, but the controlled trials are rare. The purpose of the present study was to assess that whether partially defatted flaxseed meal (PDFM) has the potential role to facilitate fecal output in normal and experimental constipated mice. Methods After supplemented with 2.5%, 5% and 10% (w/w) PDFM (L-, M- and H -PDFM) for 14 days, the constipation models of mice were induced by atropine-diphenoxylate. The small intestinal transit rates, start time of defecation, amount of defecation and wet weight of feces were researched in normal and constipation model mice. Results M- and H-PDFM significantly increase small intestinal transit rates in constipation model mice. All dose of PDFM markedly shortened the start time of defecation and M- and H-PDFM significantly increase stool frequency and weight in both normal and constipation model mice. Conclusions PDFM may be a useful laxative to facilitate fecal output in normal and constipation conditions.

The present study aimed to use a chemometric study to compare the in-vitro antioxidant activities and bioactive compounds of flaxseed based on the variety and geographical origins, and further explore the specific components constructed the endogenous antioxidant system of flaxseed in China. The differential contents of α-linolenic acid (35.83-58.91%), lignans (11.37-33.31 mg/g), total phenolic acids (109.93-246.88 mg/100 g) and phytosterols (56.52-125.12 mg/g) of 32 flaxseed varieties were observed. Concomitantly, the in-vitro antioxidant activities varied from 32.56 to 46.22 mg TE/100 g, 0.58 to 1.08 mg TE/g, and 14.22 to 36.14 mmol TE/g as determined by the 2,2’-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing antioxidant power (FRAP) and 2,2′-azinobis-(3-ethylbenzthiazoline 6-sulfonic acid) (ABTS) assays, respectively. Significant correlations were found between the antioxidant activities and contents of free syringic acid, p-coumaric acid glucoside and secoisolariciresinol diglucoside (SDG) (p < 0.01). Principal component analysis showed a relatively dispersed distribution between samples, which was not effective enough to determine the geographical origins of the flaxseed samples. Hierarchical cluster analysis allowed flaxseed samples to be grouped based on their in-vitro antioxidant activities and bioactive component contents, primarily in relation to variety specificity. [ABSTRACT FROM AUTHOR]

In the present, oil pressing is still the main process for extracting oil from flaxseed in China, but it cannot achieve efficient utilization of functional materials in flaxseed, such as flaxseed gum and lignin secoisolariciresinol diglycoside (SDG). So a comprehensive process that produces multiple products from flaxseed needs to be developed. On the basis of the structural characteristics that the flaxseed gum is in the outermost layer of flaxseeds, the grinding degumming technology using high-speed rotating sand roller grind flaxseed surface is studied before in our laboratory. Model 150 flaxseed degumming machine was designed and manufactured according to this technology, it is composes of motor, sand roller, sieve, gum powder collector etc. Electronic motor is used in the machine to drive the sand roller with high-speed rotation inner the sieve to grind flaxseed, the gum powder flow out the sieve and is collected, the sand roller length and diameter is 800 and 146 mm, the cylindrical sieve diameter is 158 mm with uniform distribution of F1.5 mm sieve size. In this paper, the feasibility of Model 150 flaxseed degumming machine was studied. Based on that, the research work of flaxseed degumming and oil pressing co-process was carried out with the commodity flaxseed from Gansu as the research material. The results showed that: the machine was able to obtain flaxseed gum-powder successfully when flaxseed flow rate was controlled at 40 to 220 kg/h. The rate of gum-powder grinded from flaxseed was 6.5%±0.3%. The viscosity of the defatted gum-powder was (5100 ± 520) mPaos. The oil contents of flaxseed and the degummed flaxseed were 39.30%±0.25% and 41.62%±0.22%, respectively. By using the method of adding 30% flaxseed cake to degummed flaxseed, the oil of degummed flaxseed can be screw pressed successfully. The oil yield pressed from degummed flaxseed was 34.65%±0.43%, higher than that pressed twice from flaxseed (33.94% ± 0.43%)when the flaxseed was pressed with the screw pressing machine without degumming. By the combination of degumming and screw-pressing for flaxseed processing, two benefits were achieved, they were: increase number of products and high pressed oil yield. The research results can provide reference for flaxseed processing. [ABSTRACT FROM AUTHOR]

The digestion of flaxseed polysaccharides (FSP) in simulated saliva, gastric and small intestine conditions was assessed, as well as in vitro fermentation of FSP by human gut microbiota. FSP was not degraded in the simulated digestive systems (there was no change in molecular weight or content of reducing sugars), indicating that ingested FSP would reach the large intestine intact. Changes in carbohydrate content, reducing sugars and culture pH suggested that FSP could be broken down and used by gut microbiota. FSP modulated the composition and structure of the gut microbiota by altering the Firmicutes/Bacteroidetes ratio and increasing the relative abundances of Prevotella, Phascolarctobacterium, Clostridium and Megamonas, which can degrade polysaccharides. Meanwhile, FSP fermentation increased the concentration of short-chain fatty acids, especially propionic and butyric acids. Our results indicate that FSP might be developed as a functional food that benefits gut health. [ABSTRACT FROM AUTHOR]

The linseed gum/cellulose composite hydrogels were successfully fabricated by mixing cellulose and linseed gum solutions dissolved in the NaOH/urea aqueous system and cross-linked with epichlorohydrin. The morphology and structure of the composite hydrogels were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD) and thermogravimetric analysis (TGA). The swelling ratio and water retention properties were investigated. The results revealed that linseed gum mainly contributed to water adsorption, whereas the cellulose acted as a backbone to strengthen the porous structure. This work provided a simple way to prepare cellulose-based superabsorbent hydrogels, which could be potentially applied as an effective water conservation material in agriculture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different structural flaxseed lignans inhibited FO oxidation in HSPC-emulsions. • SECO and FLEH enhanced the physical stability of emulsions. • The free radical membrane permeation was highly inhibited by SECO and FLEH. • The mechanism mainly related to the interactions between HSPC and flaxseed lignans. • The flaxseed lignans decreased the lipolysis by lipase during simulated digestion. The influences of the different structural flaxseed lignans on flaxseed oil (FO) emulsions during storage and digestion were investigated, focusing on their interfacial behavior. From perspective of interface, more than 60% of secoisolariciresinol (SECO) and the acidic hydrolysates of flaxseed lignan macromolecule (FLEH) were located on the interface of FO emulsions. It improved the stability of FO emulsions both during storage and digestion by inhibiting of free radical penetration and improving their targeted antioxidative activity. By comparison, the secoisolariciresinol diglucoside (SDG) and the alkaline hydrolysates of flaxseed lignan macromolecule (FLE) largely located in the aqueous and exerted lower antioxidative efficiency in emulsions. Moreover, SDG, SECO, FLE and FLEH slowed down the digestive rate of FO in emulsions, which might be due to flaxseed lignans inhibited the activity of digestive enzymes. These findings suggested that the different structural flaxseed lignans had the potential as antioxidants in emulsions during storage and digestion. [ABSTRACT FROM AUTHOR]

• Flaxseed polyphenols exerted differential antioxidant effects in nanoemulsion. • SECO and flaxseed lignan macromolecule inhibited lipid oxidation in nanoemulsion. • The mechanism mainly related to the partitioning of polyphenols in nanoemulsion. • The glucoside in phenolic extracts decreased their association with lipid droplets. Recent studies have shown that the high susceptibility of flaxseed oil nanoemulsions to lipid oxidation limits their incorporation into functional foods and beverages. For this reason, the impact of various flaxseed phenolic extracts on the physical and oxidative stability of flaxseed oil nanoemulsions was investigated. Flaxseed lignan extract (FLE) and secoisolariciresinol (SECO) exhibited antioxidant activity whereas secoisolariciresinol diglucoside (SDG) and p -coumaric acid (CouA) exhibited prooxidant activity in the flaxseed oil nanoemulsions. The antioxidant potential of flaxseed phenolics in the nanoemulsions was as follows: SECO < CouA < SDG ≈ FLE. Moreover, the antioxidant/prooxidant activity of the phenolics was also related to their free radical scavenging activity and partitioning in the nanoemulsions. Our results suggested that both SECO and FLE were good plant-based antioxidants for improving the stability of flaxseed oil nanoemulsions. [ABSTRACT FROM AUTHOR]