Crowding as an Agronomic Factor Determining the Development of Plants and the Productivity of Linseed (Linum usitatissimum L.)

ABSTRACT

Nine sowing densities of linseed were compared in a two-year experiment. Self-regulation of the density of a linseed stand resulted in a differentiated branching of the plants. The number of capsules on a linseed shoot, as well as seeds in the capsule, and the number of seeds from the shoot were highly varied from year to year, and there is even a stronger differentiation in the weight of 1000 seeds. Linear relationships were noted between the mass of seeds from the linseed plant and the number of capsules. The yield of linseed was affected by both factors. An increasing sowing rate reduced the seed yield from the shoot and the plant. At lower seeding rates, the lateral shoots contributed in the seeds yield of the plant to a higher degree compared to the main ones.     

Development of extruded snacks using jatobá (Hymenaea stigonocarpaMart) flour and cassava starch blends

The use of the jatobá trees (Hymenaea stigonocarpa Mart) by the timber industry poses an ecological problem in Brazil. The objective of this research was to investigate the use of jatobá flour for the production of snacks by the thermoplastic extrusion of a composite flour consisting of jatobá and cassava starch. Chemical analysis showed that the jatobá fruit provides high-fibre flour (486 g kg⁻¹) with 66 g kg⁻¹ protein, and 398 and 88 g kg⁻¹ of insoluble and soluble fibre, respectively. Such flour is of potential use for the production of high-fibre snacks, allowing for the economical exploitation of the jatobá while preserving the tree. Composite flours with jatobá flour and cassava starch mixtures (150: 850, 300: 700, 450: 550), conditioned to moisture levels of 170, 200 and 230 g kg⁻¹ were processed in a Brabender single-screw extruder. The extrusion conditions were 150 rpm screw speed, 4 mm die diameter and 125, 150 and 175°C of barrel temperatures. The snacks produced were evaluated as to their sensory characteristics and response surface methodology was used to optimise the extrusion process. Response surface and contour diagrams revealed that all mixtures conditioned to 170 g kg⁻¹ moisture and extruded at 150°C produced snacks of acceptable quality, higher levels of jatobá flour leading to significant quality losses with respect to sensory characteristics. © 1998 Society of Chemical Industry.     

Chemical composition and physical properties of extruded snacks containing crab‐processing by‐product

The crab‐processing industries generate millions of pounds of by‐product annually, which results in a loss of edible product and presents a considerable waste disposal problem. The purpose of this research was to investigate the use of crab‐processing by‐product (CB) in the development of a calcium‐rich expanded snack. The specific objectives were to examine the effects of type of CB (wet or dry), feed composition and screw speed (150 or 250 rpm) on selected properties of extruded snacks. Product formulations consisting of 0–400 g kg^?1 CB combined with corn meal and potato flakes were processed in a twin‐screw extruder. The resulting extrudates were analysed for proximate and mineral (calcium, sodium) composition, pH, water activity (a_w), total plate count, bulk density, expansion ratio and colour. Both CB type and level of incorporation had significant effects (P < 0.05) on the calcium content, expansion ratio, bulk density and pH of the extrudates. Increasing the CB level resulted in increased calcium content (from 5.1 to 52.4 mg g^?1) and pH (from 6.1 to 8.8). Screw speed had no significant effects (P > 0.05) on expansion ratio and bulk density. A high processing temperature (157 °C) and low a_w resulted in undetectable microbial growth on the extrudates. This research demonstrates that ground crab‐processing by‐product can be successfully incorporated into an expanded snack product. Further research will evaluate consumer response to this novel value‐added product. Copyright © 2003 Society of Chemical Industry     

The use of FT‐IR microspectroscopic mapping to study the effects of enzymatic retting of flax (Linum usitatissimum L) stems

Fourier transform infrared (FT‐IR) microspectroscopic mapping was investigated as a tool to study the effects of enzymatic retting of flax stems. The FT‐IR technique permitted the elucidation of the relative loss or changes in the distribution of key chemical components after treatment with enzymes or enzyme/chelator mixtures in association with visible changes in structure. Cross‐sections of Ariane flax stems were treated with SP 249 (a pectinase‐rich enzyme mixture from Novo Nordisk) at 0.5, 0.7 or 1.0 ml l^?1 concentration in pH 5 acetate buffer for 6 h at 40 °C. Flax stems treated with 0.5 or 0.7 ml l^?1 SP 249 and 50 mM oxalic acid as a chelator were also investigated by the technique. The results indicated that treatment with 0.5 ml l^?1 SP 249 alone was ineffective in releasing the fibre bundles from the surrounding tissue, but the release was increased by the addition of 50 mM oxalic acid as a likely chelator for the cations of pectate salts. However, the IR spectra of the bundles indicated that an insoluble oxalate salt remained on the tissue after this treatment. Increasing the concentration of SP 249 to 0.7 ml l^?1 plus 50 mM oxalic acid was effective in releasing the fibre bundles and generating some ultimate fibres with no detectable oxalate expectate salt residues. Increasing the SP 249 concentration to 1.0 ml l^?1 without using oxalic acid was effective in separating the fibre bundles into ultimate (individual) fibres, leaving no pectate salt residue and only a trace of pectic esters and/or acids. The use of infrared mapping, or so‐called chemical imaging, is shown to have advantages over visible imaging alone in that it can detect and locate the chemical species present after each treatment in relation to the anatomical features of the flax stem. This analytical tool shows promise as a technique by which to study the effects of enzymatic treatment of natural fibre materials. Published in 2002 for SCI by John Wiley & Sons, Ltd     

Nitrogen extractability and buffer capacity of defatted linseed (Linum usitatissimum L.) flour

Defatted linseed flour was prepared from cold-pressed seed meal via hexane extraction of the residual oil, followed by removal of the major portion of the hulls through grinding and sieving (sieve size 0.25 mm). The resulting flour had 50% protein on a dry basis compared with 40% contained by the whole seed on an oil-free dry basis. Nitrogen extractability of the defatted flour in water was not influenced by the length of the extraction period but an increased extraction was observed at higher solid:liquid ratios up to the studied limit of 1:40. The smallest amount of nitrogen (20%) was extracted in the pH range 4.0–4.6 and the greatest (80%) at pH 12.0. Addition of NaCl (0.1–1.0 M) broadened the pH range of minimum nitrogen extractability and shifted it towards lower pH region. At higher concentrations (0.6 and 1.0 M) NaCl markedly increased nitrogen extractability in the pH range of 4.0 to 8.0. Precipitation of protein from an extract at pH 10.0 was maximum (77%) at pH 4.1. A higher buffer capacity of the flour was observed in the acidic medium (0.204 mmol HCl g^?1 flour) than in the alkaline medium (0.096 mmol NaOH g^?1 flour).     

Carboxymethyl derivatives of flaxseed (Linum usitatissimum L.) gum: characterisation and solution rheology

Carboxymethyl ether moieties were introduced to flaxseed (Linum usitatissimum L.) gum (FG) by reacting gum with monochloroacetic acid (MCA). Effects of ether forming reaction conditions, temperature, NaOH concentration and molar ratio of FG (anhydroxylose equivalent) to MCA, on the degree of substitution (DS) were investigated. Treatment at 70 °C, with 7.0 m NaOH, and molar ratio of MCA to FG of 10:1 over 3 h produced a polysaccharide with a DS of 0.824 ± 0.012. Both surface morphology and thermal behaviour were modified. Solutions of FG (0.5–4.0%, w/v) exhibited shear‐thinning behaviour where viscosity decreased with decreased FG concentration. After carboxymethylation, modified polymer solutions also exhibited shear‐thinning behaviour, where dynamic viscosity was lower than that of native FG solutions at the same concentration. The dynamic viscosities were lower for solutions of modified FG with higher DS and also lower for solutions made at lower FG concentrations (0.5–4.0%, w/v). A more liquid‐like behaviour with increasing FG DS was indicated as storage modulus G′ and loss modulus G″ decreased and became more frequency dependent. The substitution of hydroxyl groups with carboxymethyl groups suppressed entanglement between FG polysaccharide chains by reducing intermolecular association.     

The effect of rice bran on physicochemical,textural and glycaemic properties of ready-to-eat extruded corn snacks

In this work, corn extruded snack products were enriched with rice bran (RB) at 10% and 15%. A co-rotating twin-screw extruder was used with a feed moisture content of 16 g 100 g⁻¹, a screw speed of 240 r.p.m. and four heating sections of the barrel (100, 140, 150 and 150 °C). The impact of RB inclusion on nutritional profile, starch digestion, physicochemical and textural properties of snack products was evaluated. RB-enriched extrudates showed a lower specific volume and hardness and higher crispness than control. RB at 15% gave a water-holding capacity lower than control. Rheology of extrudate dispersions indicated an increase in elastic interactions and solid-like behaviour with RB supplementation. Differences in rheological properties resulted in attenuation of predictive glycaemic response for RB-enriched snacks.     

Reduction of Cyanogenic Compounds in Flaxseed (Linum usitatissimum L.) Meal Using Thermal Treatment

Flaxseed (Linum usitatissimum L.) provides multiple nutritional benefits, including high quality protein, dietary fiber, and is the most abundant source of α-linolenic acid (C_18:3). However, the presence of anti-nutritional factors, such as cyanogenic compounds, restricts flaxseed's consumption as a food or feed. This study investigated the reduction of cyanogenic compounds, measured as hydrocyanic acid (HCN), in full-fat flaxseed using extrusion processing without a die by following the response surface methodology. The ranges of processing variables selected were: barrel exit temperature of 76.3–143.6°C; screw speed of 59.6–160.5 rpm; and feed rate of 26.4–93.6 kg/h. The experimental values of HCN reduction obtained were from 60.8 to 86.6%. Optimum extrusion conditions of barrel exit temperature, screw speed, and feed rate were found to be 143.6°C, 133.5 rpm, and 57.8 kg/h for maximum (89.1%) reduction of HCN. This effect was mainly dependent on barrel exit temperature, whereas screw speed and feed rate had no or minimal effect. The mutual interaction effect of barrel exit temperature and screw speed was found to be significant (p ≤ 0.01). The degree of correlation (R²) for HCN reduction was 97.2%, which showed the validity of applied second-order response model. The results of this study demonstrated that significant reduction of HCN in flaxseed can be achieved commercially using an extruder without a die.     

Polyphenolic composition,antioxidant and antiproliferative effects of wild and cultivated blackberries (Rubus fruticosus L.) pomace

The content of total polyphenolics, antioxidative capacity and antiproliferative activity were tested in wild and cultivated blackberry pomace. Wild blackberry pomace extract Tw2 showed the highest following contents: total polyphenolics (50.16 mg GAE g⁻¹ dw), flavonoids (7.73 mg Qc g⁻¹ dw), flavonols (6.63 mg Qc g⁻¹ dw) and total monomeric anthocyanins (13.40 mg Cy g⁻¹). Tw2 extract significantly inhibited free radicals: IC₅₀^DPPH = 127.76 μg mL⁻¹, IC₅₀^ABTS = 26.53 μg mL⁻¹ and IC₅₀ ^{˙ OH} = 168.62 μg mL⁻¹, and the growth of breast adenocarcinoma IC₅₀^MCF7 = 306.68 μg mL⁻¹ and cervix epitheloid carcinoma cell lines IC₅₀^HeLa = 315.49 μg mL⁻¹. Wild blackberry varieties had higher extraction yields, higher total polyphenolic contents and possessed stronger biological effects compared to cultivated blackberries (P < 0.05). All blackberry extracts showed high biological potential that could be attributed to high total polyphenols and flavonoids content and could be utilised as value-added functional food.     

Effect of seed moisture content on flaxseed (Linum usitatissimum L.) milling and milled product characteristics

BACKGROUND: Research was conducted to determine the effect of seed moisture content on flaxseed milling and milled product characteristics. Flaxseed with 55, 80, and 105 g kg^?1 moisture contents were milled on a centrifugal cutting mill (CCM) configured with a 0.475 and 9.5 kg min^?1 feed rate; a hammer mill configured with a blunt hammer face, 0.35 kg min^?1 feed rate, 3.1 mm screen, and 2,795 m min^?1 hammer tip speed; and a hammer mill configured with a sharp hammer face, 0.35 kg min^?1 feed rate, 2.7 mm screen, and 3,870 m min^?1 hammer tip speed. RESULTS: Fine‐particle fraction (≤600 µm) yield was greater from flaxseed with 55 than with 105 g kg^?1 moisture content. Surface lipid content correlated positively with fine‐particle yield (r = 0.82, P = 0.01). At each moisture level, the surface lipid extracted from the fine‐particle fraction was greater with 9.5 than 0.475 kg min^?1 configuration of CCM and tended to be greater with the blunt than with the sharp hammer configuration of the hammer mill. CONCLUSION: Results indicated that flaxseed was more difficult to mill to a fine particle size at high than at low moisture content regardless of the mill configuration. Enhanced lipid oxidation was not detected in freshly milled flaxseed. Copyright © 2009 Society of Chemical Industry     

Comparison of lignans and phenolic acids in different varieties of germinated flaxseed (Linum usitatissimum L.)

The study aimed to evaluate the biosynthesis and accumulation of lignans, phenolic acids and also the antioxidant activities in 15 varieties of flax sprouts. The differential contents of lignans (13.30–8987 μg g⁻¹) and phenolic acids (72.55–597.1 μg g⁻¹) among 15 varieties of flax sprouts were observed. The total antioxidant activities ranged from 147.2 to 332.8 μmol TE g⁻¹ in the flax sprouts. The expression levels of five genes in the lignin synthetic pathway were analysed using RT-qPCR, and the results showed dramatical differences among different flax sprouts. Relatively dispersed analysis was showed by principal component analysis (PCA), and 15 flax sprouts were grouped by hierarchical cluster analysis (HCA) based on their phenolic acids, lignan compounds, length, gene expression and antioxidants after germination, primarily in relation to variety specificity. Present results would be instructive guidance for bio-fortification breeding and functional foods innovation in flaxseeds.     

Enrichment of carotenoids in flaxseed (Linum usitatissimum) by metabolic engineering with introduction of bacterial phytoene synthase gene crtB

Linseed flax (Linum usitatissimum L.) is an industrially important oil crop, which includes large amounts of alpha-linolenic acid (18:3) and lignan in its seed oil. We report here the metabolic engineering of flax plants to increase carotenoid amount in seeds. Agrobacterium-mediated transformation of flax was performed to express the phytoene synthase gene (crtB) derived from the soil bacterium Pantoea ananatis (formerly called Erwinia uredovora 20D3) under the control of the cauliflower mosaic virus (CaMV) 35S constitutive promoter or the Arabidopsis thaliana fatty acid elongase 1 gene (FAE1) seed-specific promoter. As a result, eight transgenic flax plants were generated. They formed orange seeds (embryos), in which phytoene, alpha-carotene, and beta-carotene were newly accumulated in addition to increased amounts of lutein, while untransformed flax plants formed light-yellow seeds, in which only lutein was detected. Interestingly, despite the control of the CaMV 35S promoter, the expression of crtB was not observed in the leaves but in the seeds in the transgenic flax plants. Total carotenoid amounts in these seeds were 65.4-156.3 microg/g fresh weight, which corresponded to 7.8- to 18.6-fold increase, compared with those of untransformed controls. These results suggest that the flux of phytoene synthesis from geranylgeranyl diphosphate was first promoted by the expressed crtB gene product (CrtB), and then phytoene was consecutively decomposed to the downstream metabolites alpha-carotene, beta-carotene, and lutein, as catalyzed by endogenous carotenoid biosynthetic enzymes in seeds. The transgenic flaxseeds enriched with the carotenoids could be valuable as nutritional sources for human health.     

Variation of composition and functional properties of gum from six Canadian flaxseed (Linum usitatissimum L.) cultivars

Flaxseed gum (FG) was prepared from six Canadian flaxseed (Linum usitatissimum L.) cultivars. Yield, neutral sugar content, acidic sugar content and protein content varied significantly among cultivar FG extracts. Zeta potential (?16.4 to ?27.4 mV) and rheological properties of solution were cultivar dependent. Solutions prepared with CDC Glas FG had the highest viscosity (2.984 Pa?s), while CDC Sorrel produced the lowest (0.048 Pa?s). FG solutions exhibited pseudoplastic shear‐thinning behaviour. Viscosity of FG solution increased with concentration, while viscosity and pseudoplasticity decreased with increased temperature. NaCl addition decreased solution viscosity while adding sucrose increased viscosity. FG solutions prepared from Flanders and CDC Sorrel had the highest and lowest emulsion activity index, respectively, while solutions of CDC Arras and CDC Bethune FG had the lowest and highest emulsion stability, respectively. Findings presented here provide information that could enable greater utilisation in food, cosmetic and pharmaceutical industries as thickeners and/or emulsifiers.     

Effect of dehydration on phenolic compounds and antioxidant activity of blackcurrant (Ribes nigrum L.) pomace

This study examined the effect of dehydration on the phenolic compounds and antioxidant activity of blackcurrant (Ribes nigrum L.) pomaces (DBP) subjected to hot air oven drying (HOD), industrial rotary drying (IRD) and freeze drying (FD). Temperature and residence time were evaluated for HOD, whereas air-on and air-off temperature, ratio of drum rotor speed to air speed and particle size were evaluated for IRD. The highest total anthocyanins (ATC) and flavonols (FLV) were obtained in particle size of> 5.0 mm using IRD at 475°C/97°C (air-on/air-off) and higher ratio of drum rotor speed to air speed. Smaller size particles were found susceptible to degradation due to high temperature and retention time applied in IRD, resulting in loss of phenolic compounds in DBP, and thus, HOD was deemed more suitable. Overall, drying method selection and parameters of operation are key in preserving the concentrations of individual HCA and FLV in DBP.     

Cultivation of Fiber and Oil Flax (Linum usitatissimum L.) in No-Tillage and Conventional Systems. Part II. Influence of No-Tillage and Use of Herbicides on Yield and Weed Infestation of Oil Flax and the Physical and Biological Properties of the Soil

No-tillage methods can help to reduce expenditures and improve profitability of the agricultural production. This issue has been widely discussed for the cultivation of many species, but there are no data on the subject concerning oilseed flax. The field experiments were conducted in the years that vary widely in the course of temperature and precipitation. Tillage method significantly affected the yield of flax in the interaction with the weather conditions. In the dry year, the cultivation method did not differentiate the flax yield, while in the optimum moisture year no-till resulted in a reduction of yield compared to conventional tillage. Weed control with herbicide has contributed to increased yield of linseed but the level of increase was higher with no-till compared to conventional cultivation. The number and weight of weeds in no-tillage flax was 50% lower comparing to conventional plowing in both variants of weed control. Weed control decreased the number and weight of weeds also by 50% regardless of cultivation method applied. Cultivation systems affect the size and composition of the soil microbial populations. No-tillage contributed to an increase of humic substances content in the soil environment, the quantity of soil bacteria, and the population structure.