The nutritional value of flaxseed meal (FSM), a by-product of the flax crushing industry, has not been evaluated properly for use within swine rations. A series of experiments were conducted to determine the nutritional profile of this novel feed ingredient for pigs.<p>The analysis of FSM revealed that it contains, on a dry matter (DM) basis, 133 g/kg ether extract (EE), 345 g/kg crude protein (CP), 60 g/kg ash, 164 g/kg ADF, 250 g/kg NDF, 102 g/kg crude fibre, 14 g/kg starch and 9 g/kg phosphorus. The gross energy (GE) content of the meal was 5.2 Mcal/kg DM. The ether extract fraction was characterized by, as a percent of total fat, 46.6% á-linolenic acid, an omega-3 fatty acid. Palmitic, stearic, oleic and linoleic acids accounted for 9.5, 4.8, 20.7 and 18.4% of the total fat content respectively. The crude protein content was well balanced for all amino acids with the exception of lysine (4.1% of CP), the level of which falls below that of the requirements for growing pigs (5.3% of CP for pigs 20-50 kg). The apparent digestibility of DM, nitrogen, ash, EE and GE as well as determination of the DE and NE content of FSM was determined for both growing pigs (32 pigs, initial weight 70 ± 3 kg) and gestating sows (26 pigs, parities 2 4). Animals were fed wheat/barley based diets containing 0, 10, 20 or 30% FSM. Faecal grab samples were collected for 3 days after a dietary adaptation period. The apparent digestibility of nutrients in FSM was determined both by regression and by difference calculations. As calculated by difference, the apparent digestibility coefficients for DM, nitrogen, ash, and GE were 63.0, 60.8, 22.3 and 60.5% respectively for growing pigs. The values obtained for sows were 64.1, 58.8, 20.8, 94.9 and 65.4% for DM, nitrogen, ash, EE and GE respectively. The DE content was 3.37 Mcal/kg for growing pigs and 3.52 Mcal/kg for sows. Net energy was then estimated by use of a prediction equation to be 2.34 and 2.44 Mcal/kg for growing pigs and sows. <p>An experiment was conducted to evaluate the growth performances and carcass fatty acid profiles of pigs fed with graded levels of FSM. A total of 200 pigs (100 barrows, 100 gilts; initial weight 32 ± 4 kg) were blocked by gender and housed in groups of 5 pigs per pen. The experiment was divided into three phases for pigs 32-60 kg, 60-85 kg and 85-115 kg. Each group was assigned to one of four dietary treatments containing 0, 5, 10 or 15% FSM at the expense of wheat and soybean meal. At the time of market, 6 pigs per treatment group were randomly selected for carcass fatty acid analysis, and backfat and rib-end loin samples were collected. The average daily gains, average daily feed intakes and gain to feed ratios were not affected by dietary treatment (P > 0.05). Inclusion of 15% dietary FSM increased the ALA content from 11 to 47 (± 0.8) mg/g of backfat (P < 0.001) and from 5 to 10 (± 0.4) mg/g of loin tissue (P < 0.001). Increasing dietary FSM decreased the saturated fatty acid content of backfat (P < 0.01). <p> The final experiment was designed to determine the availability of phosphorus in semi-synthetic diets containing FSM, and to determine the effects of microbial phytase inclusion of this availability. Five treatment groups, 8 barrows (45 ± 4 kg initial weight) each, were fed a diet containing 30% FSM with increasing levels of phytase (0, 575, 1185, 2400 and 2570 FTU/kg). Apparent P digestibility increased from 20.6 to 61.3% with the inclusion of up to 2570 FTU/kg microbial phytase (P < 0.001), and followed a quadratic response pattern with an R2 value of 0.96. A broken-line analysis estimated the optimal phytase inclusion level to be 1415 FTU/kg of diet. Inclusion of just 575 FTU/kg accounted for half of the response, improving the apparent P digestibility by 20% and reducing P excretion by 850 mg/kg dry matter intake.

Two studies on potential approaches for processing low-salt, low-fat (LSLF) bologna were completed. In study 1, the effects of three factors, namely salt type (sea salt vs. regular NaCl), NaCl concentration (0.75%, 1.00%, 1.25% and 2.00%) and holding of stuffed batter before cooking (cooked immediately (CI) vs. delayed cooking (DC)), on the quality of LSLF bologna were investigated. There was no difference between salt type for most of the parameters measured. The holding factor significantly improved the water holding capacity (WHC) and texture of bologna samples containing 0.75% NaCl, as shown by lower (p<0.05) expressible moisture. However, holding factor did not affect WHC and instrumental texture of samples with 1.00%, 1.25% or 2.00% NaCl. A NaCl level by hold effect (p<0.05) was observed for texture profile analysis (TPA) in which there was significant improvement in the texture of samples containing 0.75% NaCl that were subjected to DC, but no effect at other NaCl levels. Panelists were able to detect the positive effect (p<0.05) of DC on the texture of samples with 0.75% or 1.00% NaCl. This study showed that DC is effective in improving the texture of bologna samples with extremely low NaCl (0.75%) content. The biggest challenge in this first study was the difficult sample handling experienced during slicing. Since bologna is commonly sold as thin slices, the bologna must be firm enough for ease of slicing. The second study focused on improving bologna firmness by the addition of microbial transglutaminase (MTG), known for its functionality as a protein cross-linker, and of flaxseed meal (FSM), known for its excellent water holding capacity. The physico-chemical and sensory characteristics of 12 treatment combinations (0, 0.15% and 0.30% MTG; 0, 0.5%, 1.0% and 1.5% FSM) were determined. In general, results showed that MTG significantly improved the textural quality of bologna, but resulted in a higher purge loss during storage of vacuum packaged slices. On the other hand, FSM significantly reduced the expressible moisture content and purge loss of the product. In terms of product colour, MTG had no effect but FSM when added to the formulation at level as low as 0.5%, affected the colour as determined by both instrumental and sensory evaluation. The overall results of the project indicated that texture in LSLF bologna is not a major issue, since processing conditions and combinations of ingredients can be manipulated to improve texture. The biggest challenge, however, is in the area of flavour – improving the flavour of low-salt processed meats warrants further research.

The nutritional value of flaxseed meal (FSM), a by-product of the flax crushing industry, has not been evaluated properly for use within swine rations. A series of experiments were conducted to determine the nutritional profile of this novel feed ingredient for pigs.<p>The analysis of FSM revealed that it contains, on a dry matter (DM) basis, 133 g/kg ether extract (EE), 345 g/kg crude protein (CP), 60 g/kg ash, 164 g/kg ADF, 250 g/kg NDF, 102 g/kg crude fibre, 14 g/kg starch and 9 g/kg phosphorus. The gross energy (GE) content of the meal was 5.2 Mcal/kg DM. The ether extract fraction was characterized by, as a percent of total fat, 46.6% á-linolenic acid, an omega-3 fatty acid. Palmitic, stearic, oleic and linoleic acids accounted for 9.5, 4.8, 20.7 and 18.4% of the total fat content respectively. The crude protein content was well balanced for all amino acids with the exception of lysine (4.1% of CP), the level of which falls below that of the requirements for growing pigs (5.3% of CP for pigs 20-50 kg). The apparent digestibility of DM, nitrogen, ash, EE and GE as well as determination of the DE and NE content of FSM was determined for both growing pigs (32 pigs, initial weight 70 ± 3 kg) and gestating sows (26 pigs, parities 2 4). Animals were fed wheat/barley based diets containing 0, 10, 20 or 30% FSM. Faecal grab samples were collected for 3 days after a dietary adaptation period. The apparent digestibility of nutrients in FSM was determined both by regression and by difference calculations. As calculated by difference, the apparent digestibility coefficients for DM, nitrogen, ash, and GE were 63.0, 60.8, 22.3 and 60.5% respectively for growing pigs. The values obtained for sows were 64.1, 58.8, 20.8, 94.9 and 65.4% for DM, nitrogen, ash, EE and GE respectively. The DE content was 3.37 Mcal/kg for growing pigs and 3.52 Mcal/kg for sows. Net energy was then estimated by use of a prediction equation to be 2.34 and 2.44 Mcal/kg for growing pigs and sows. <p>An experiment was conducted to evaluate the growth performances and carcass fatty acid profiles of pigs fed with graded levels of FSM. A total of 200 pigs (100 barrows, 100 gilts; initial weight 32 ± 4 kg) were blocked by gender and housed in groups of 5 pigs per pen. The experiment was divided into three phases for pigs 32-60 kg, 60-85 kg and 85-115 kg. Each group was assigned to one of four dietary treatments containing 0, 5, 10 or 15% FSM at the expense of wheat and soybean meal. At the time of market, 6 pigs per treatment group were randomly selected for carcass fatty acid analysis, and backfat and rib-end loin samples were collected. The average daily gains, average daily feed intakes and gain to feed ratios were not affected by dietary treatment (P > 0.05). Inclusion of 15% dietary FSM increased the ALA content from 11 to 47 (± 0.8) mg/g of backfat (P < 0.001) and from 5 to 10 (± 0.4) mg/g of loin tissue (P < 0.001). Increasing dietary FSM decreased the saturated fatty acid content of backfat (P < 0.01). <p> The final experiment was designed to determine the availability of phosphorus in semi-synthetic diets containing FSM, and to determine the effects of microbial phytase inclusion of this availability. Five treatment groups, 8 barrows (45 ± 4 kg initial weight) each, were fed a diet containing 30% FSM with increasing levels of phytase (0, 575, 1185, 2400 and 2570 FTU/kg). Apparent P digestibility increased from 20.6 to 61.3% with the inclusion of up to 2570 FTU/kg microbial phytase (P < 0.001), and followed a quadratic response pattern with an R2 value of 0.96. A broken-line analysis estimated the optimal phytase inclusion level to be 1415 FTU/kg of diet. Inclusion of just 575 FTU/kg accounted for half of the response, improving the apparent P digestibility by 20% and reducing P excretion by 850 mg/kg dry matter intake.

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio. / February 2007

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio.

The physiological benefits of flaxseed against pathological disturbances, such as cancers and heart diseases, are mainly attributed to its high lignan content. This study (Experiment 1) examined the application of pressurized low polarity water (PLPW) for extraction of lignans, proteins and carbohydrates from defatted flaxseed meal. Key processing conditions included temperature (130, 160, 190°C), solvent pH (4, 6.5 and 9), solvent to solid ratio (S/S) (90, 150 and 210 mL/g) and introduction of co-packing material (0 and 3 g glass beads). The addition of 3 g glass beads as co-packing material facilitated extraction by enhancing surface contact between the liquid and solid thus shortening extraction time. Elevated temperature accelerated the extraction rate by increasing the solid diffusion coefficient thereby reducing the extraction time. The maximum yield of lignans (99 %) was obtained at temperatures ranging from 160°C to 190°C, with solvent volume of 180 mL (90 mL/g meal) at pH 9. Optimal conditions for protein extraction (70 %) were pH 9, extraction volume of 420 mL (210 mL/g meal) and 160°C. Total carbohydrates yield was maximized at 50% recovery at pH 4 and 160°C with 420 mL solvent (210 mL/g meal). Increased temperature accelerated extraction, thus reducing solvent volume and time to reach equilibrium. For the extraction of proteins, however, a temperature of 130-160°C is recommended, as proteins are vulnerable to thermal degradation due to heat decomposition. The effects of flow rate and geometric dimensions for extraction of lignans and other flaxseed meal bioactives were further investigated in Experiment 2, based on the variables optimized in the previous experiment. Defatted flaxseed meal was extracted with pH 9 buffered water with meal to co-packing glass beads ratio of 1:1.5 at 5.2 MPa (750 psi) and 180°C. The aqueous extracts were analyzed for lignan, protein and carbohydrate using HPLC and colorimetric methods. The optimal extraction yields for lignan, protein and carbohydrate were found at flow rates of 1 to 2 mL/min with bed depth between 20 and 26 cm and a S/S ratio of 40 to 100 mL/g. The combination of low flow rate and high bed depth allowed the use of lower S/S ratio with reduced total solvent volume consumption. This study also evaluated the mass transfer kinetics governing the process of lignan extraction from flaxseed meal in a fixed bed extraction cell. Diffusion of solute into the continuously flowing solvent was mainly responsible for the mass transfer mechanism as flow rate did not increase proportionally with the yield and rate of extraction. The extraction kinetics were studied on the basis of two approaches: Fick’s diffusion equation and a two-site exponential kinetic model. The proposed two-site exponential kinetic model corresponding to the two-stage extraction (rapid and slow phases) successfully described the experimental data. Diffusivities attained from Fick’s diffusion model ranged from 2 x 10-13 to 9 x 10-13 m2s-1 while mass transfer coefficients were between 4.5 x 10-8 and 2.3 x 10-7 ms-1 for extraction of lignans at 180°C, pH 9 with 1:1.5 meal to co-packing material ratio.