Atmospheric Pressure Photoionization-Mass Spectrometry (APPI-MS) and High Performance Liquid Chromatography (HPLC) are the two analytical methods that were used to characterize Triacylglycerols (TAGs) during flaxseed development. The HPLC method of the oils showed the presence of 15 TAG species. In contrast to the HPLC chromatograms, the APPI-MS showed 17 peaks of TAG. APPI-MS is more rapid than the HPLC method (11 min). The iodine value of the oils showed a gradual increase, while the oil stability continuously decreased. Proximate composition during flaxseed development revealed that flaxseed is potentially a good source of dietary energy and protein. At full maturity, flaxseed contained 37% oil and 24% protein on a dry-weight basis; albumin was the major storage protein (53% of total storage proteins) followed by globulin (33%) and glutelin fractions (11%). Prolamins had the lowest percentage with 3%. α-amylase activity was higher in the mature seeds than the young ones.
Flaxseed (
In the life cycle of higher plants, seed development is a key process connected to distinct generations (Olsen
Although the changes in seed constituents has been studied during flaxseed development (Herchi
HPLC-grade chloroform, acetone, acetonitrile, toluene and isopropanol were purchased from the Fisher Scientific Company (Ottawa, Ontario, Canada-Ottawa Admin. Center 112 Colonnade Road Nepean, Ontario K2E 7L6 Canada). Methanol and Ethanol were purchased from Panreac Quimica SA (Barcelona, Spain). Petroleum ether, ethyl ether and acetic acid were from Fisher Scientific SA (Barcelona, Spain). TLC silica plates (silica gel 60 G F254, 20×20 cm, 0.2 mm thickness) were obtained from Merck (Darmstadt, Germany). All standards were acquired from Sigma Aldrich (Madrid, Spain). Other employed chemicals and solvents used in the experiments were purchased from Aldrich (Milwaukee, WI, USA).
The variety of flaxseed “O116” was obtained from “Institut National Recherche Agronomie Tunis” (INRAT), Tunisia. This variety of flaxseed (
The total lipids were extracted by the method of Folch
Lipid class separation was performed by TLC according to the method of Mangold (
A 50 mg sample of the extracted lipid was fully dissolved in 5 mL of dichloromethane. LC/MS experiments were performed using an Agilent LC system (Agilent Technologies; Palo Alto, CA-2660 Matheson Boulevard East, Mississauga ON, L4W 5M2) coupled to an Applied Biosystem /MDS Sciex QSTAR Elite Q-TOF MS with a photoionization ion source. The TAG extracts were separated using an Ascentis TM C18 LC column (15 cm×2.1 mm, 3 µm) with C18 guard cartridge (Supelco). The mobile phase consisted of A, acetonitrile and B, isopropanol. A solvent gradient program was run from 30 to 90% B for 25 min. Subsequently, the LC system was programmed to return its initial solvent composition over 0.1 min, followed by a 5 min re-equilibration prior to the following injection. The injection volume was 5 µL and the flow rate was 200 µL·min−1. The entire effluent from the column was directly transferred to the MS through the photoionization interface. MS analysis of the analytes was performed using APPI in the positive ion mode. Toluene was used as dopant delivered at a flow rate of 20 µL·min−1 by an isocratic pump (Agilent Technologies; Palo Alto, CA-2660 Matheson Boulevard East, Mississauga ON, L4W 5M2). Analyst QS 2.0 software was used for data acquisition and analysis. Nitrogen was used as curtain gas, nebulizing gas, drying and lamp gas (4 L·min−1). The mass range recorded was from 50 to 1300 amu. The other optimal instrumental conditions were as follows: photoionization voltage 1300V; curtain gas setting 25; gas 1 setting 20 and gas 2 setting 70; de-clustering potential (DP), 35V; focusing potential (FP), 150; second de-clustering potential (DP2), 15V; and ion source temperature: 400 °C. Estimations of TAG concentrations were achieved using the relative peak areas of each TAG. Although this method is only semi-quantitative, likely overestimating highly unsaturated components relative to saturates, it does allow for the evaluation of the estimation of relative TAG concentrations and the evolution of individual TAG species over the course of seed ripening. As examples of the results, the total ion current (TIC) chromatogram of flaxseed oil is given in
% FA: Fatty acid type percentage in individual TAG
% TAG: individual TAG percentage
n: Number of FA type esterified in individual TAG
Total ion chromatogram (TIC) of a flaxseed oil LC/APPI-MS experiment (O116 variety-56 DAF). 1: LnLnLn, 2: LnLLn, 3: LLLn, 4: LnOLn, 5: LnLnP, 6: OLLn, 7: LnLP, 8: OOLn, 9: LnOP, 10: PLnP, 11: OLO, 12: SOLn, 13: OLP, 14: OOO, 15: OOP, 16: SLnS, 17: SOO.
TAGs were analyzed by HPLC on a SCHIMADZU apparatus equipped with an RP-18 stainless steel column (250 mm length×4.6 mm internal diameter), a guard column and a refractive index detector (differential refractometer). The mobile phase was acetonitrile/acetone 1:1 v/v. The flow rate was isocratically controlled at 1.5 mL·min−1. Ten microliters of sample were injected at each run. The identification of TAG peaks was made by comparison of their retention times with authentic standards. The concept of the equivalent carbon number (ECN) was used to rationalize the retention time of TAG. The ECN is defined as the total number of carbon atoms (CN) in the FA acyl chains minus twice the number of double bonds (N) per molecule: ECN=CN-2N. Quantification of the contents of the TAG species (expressed in % of total TAG) was done using the following formula: content (%)=PAi/TPA, where PAi is the peak area of an individual TAG and TPA is the peak area of the total TAG. A typical HPLC chromatogram of flaxseed oil is shown in
TAG profiles of flaxseed oil (O116 variety-56 DAF) analyzed by HPLC. 1: LnLnLn, 2: LnLLn, 3: LLLn, 4: LnOLn, 5: LnLnP, 6: OLLn, 7: LnLP, 8: OOLn, 9: LnOP, 10: OLO, 11: SOLn, 12: OLP, 13: OOO, 14: OOP, 15: SLnS.
The AOCS Official Method was employed for the determinations of iodine value (IV) in the oil samples (AOAC,
Oxidative stability was evaluated by the Rancimat method (Gutiérrez,
Oil was extracted from 20 g of seed powder in a Soxhlet extractor for 5 h using petroleum ether (40–60 °C) as a solvent. The result was expressed as the percentage of lipids (on a wet weight basis) (AOAC,
Protein contents were determined according to the AOAC official method (
Data were expressed as percentages on a dry weight basis.
About 0.5 g of powdered seed samples were ignited and incinerated in a muffle furnace (Amalgam, Sheffield, England) at 550 °C for about 12 h. The total ash was expressed as a percentage on a dry weight basis.
The carbohydrate content was estimated by the difference of the mean values, i.e. [100−(protein+lipids+ash+moisture)].
The calorific value was estimated (in Kcal·100 g−1) by multiplying the percentage of crude protein, crude lipid and carbohydrate by the recommended factor (4, 9 and 4.125 respectively) used in vegetable analysis (Hunt
Digestible crude protein was estimated as follows: Digestible crude protein (g)=(protein (g)×0.96–4.21) (Barrett and Larkin,
Protein fractions were isolated by sequentially extracting flaxseed with different solvents (the seed to solvent ratio was 1:10, w/v, in each case) according to the modified Osborne scheme (Osborne,
Weighed flaxseed (500 mg seeds for each assay) were homogenized with four volumes of extraction buffer containing 50 mmol·L−1 Tris-HCl (pH 7.0), 3 mmol·L−1 CaCl2, and 4 mmol·L−1 NaCl and centrifuged at 8000 g for 20 min. The supernatant was centrifuged at 20 000 g for 20 min. A 200-mL aliquot of the final supernatant was mixed with 50 mL of β-limited dextrin made from potato starch with β-amylase (Kohno and Nanmori,
Statistical analysis was performed using the Proc ANOVA in SAS (software version 8). Results are presented as the means ± SD from three triplicates of each sample.
The stages and seeds lengths are given in
Changes in seed length during flaxseed development
Stages | DAF | Seed length (mm) |
---|---|---|
S1 | 7 | 1–1.5 |
S2 | 14 | 2–2.5 |
S3 | 21 | 3–3.5 |
S4 | 28 | 4–4.5 |
S5 | 35 | 5–5.5 |
S6 | 42 | 5.5–6 |
S7 | 49 | 6–6.5 |
S8 | 56 | 6–6.5 |
The HPLC technique with an RP-18 column separates TAG according to both length and unsaturation degree of their carbon chains. Oil samples were dissolved in acetone and directly injected into an HPLC column without any preliminary chemical derivatization or purification. The identification of TAG peaks was made by comparison of their retention times with authentic standards. The TAG peaks appear between 7 and 34 min retention time (27 min) and this is due to the various TAG species in flaxseed oils. The TAG composition during flaxseed development, expressed as a percentage of total TAG peak area, is presented in
Comparative analysis of triacylglycerols during flaxseed development using HPLC and APPI-MS
TAG | ECN | Rt (min) | 7 | 14 | 21 | 28 | 35 | 42 | 49 | 56 |
---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||
LnLnLn | 36 | 9.51 | 28.50±1.0 | 25.11±0.5 | 23.67±0.9 | 22.58±0.6 | 24.69±0.8 | 23.18±1.1 | 21.74±0.6 | 29.80±0.9 |
LnLLn | 38 | 10.86 | 17.32±0.4 | 14.24±0.1 | 15.51±0.2 | 15.73±0.6 | 12.78±0.5 | 12.76±0.4 | 12.20±0.2 | 16.60±0.3 |
LLLn | 40 | 12.13 | 7.36±0.1 | 8.23±0.2 | 8.50±0.3 | 7.22±0.2 | 6.00±0.1 | 6.22±0.1 | 6.16±0.3 | 7.30±0.3 |
LnOLn | 40 | 12.41 | 17.45±0.4 | 17.52±0.7 | 20.38±1.1 | 18.16±0.9 | 22.82±0.9 | 21.08±0.8 | 22.86±1.3 | 14.60±1.2 |
LnLnP | 40 | 12.81 | 8.43±0.9 | 8.02±0.5 | 6.27±0.5 | 7.60±0.6 | 5.91±0.7 | 6.28±0.6 | 5.84±0.7 | 7.40±1.0 |
OLLn | 42 | 13.81 | 4.32±0.5 | 7.44±0.4 | 6.80±0.8 | 11.48±0.5 | 5.88±0.7 | 7.14±0.6 | 8.44±0.9 | 5.90±0.1 |
LnLP | 42 | 14.30 | 5.87±0.5 | 5.73±0.5 | 6.18±0.6 | 4.20±0.3 | 4.50±0.3 | 3.66±0.1 | 3.62±0.2 | 4.70±0.3 |
OOLn | 44 | 15.36 | 3.52±0.1 | 6.23±0.1 | 5.72±0.2 | 5.40±0.1 | 8.37±0.4 | 10.62±0.6 | 9.45±0.6 | 5.60±0.3 |
LnOP | 44 | 15.79 | 2.64±0.1 | 2.73±0.1 | 2.68±0.1 | 3.26±0.2 | 3.34±0.2 | 3.50±0.1 | 3.51±0.5 | 3.00±0.4 |
PLnP | 44 | 16.19 | 0.02±0.0 | 0.02±0.0 | 0.02±0.0 | 0.01±0.0 | 0.01±0.0 | 0.01±0.0 | 0.01±0.0 | 0.01±0.0 |
OLO | 46 | 16.72 | 0.51±0.1 | 0.53±0.1 | 0.49±0.1 | 0.52±0.1 | 0.67±0.1 | 0.62±0.1 | 0.71±0.2 | 0.60±0.1 |
SOLn | 46 | 17.26 | 2.17±0.1 | 2.34±0.2 | 1.84±0.1 | 1.78±0.1 | 2.39±0.1 | 2.40±0.2 | 2.24±0.2 | 2.20±0.1 |
OLP | 46 | 17.64 | 0.18±0.01 | 0.14±0.01 | 0.19±0.02 | 0.22±0.02 | 0.35±0.01 | 0.21±0.02 | 0.24±0.03 | 0.25±0.05 |
OOO | 48 | 18.24 | 0.66±0.02 | 0.62±0.02 | 0.74±0.01 | 0.81±0.01 | 0.95±0.01 | 0.83±0.02 | 1.70±0.1 | 0.87±0.05 |
OOP | 48 | 18.63 | 0.47±0.01 | 0.43±0.01 | 0.54±0.01 | 0.53±0.01 | 0.74±0.01 | 0.79±0.02 | 0.64±0.01 | 0.60±0.01 |
SLnS | 48 | 19.08 | 0.32±0.01 | 0.38±0.01 | 0.21±0.01 | 0.14±0.01 | 0.18±0.01 | 0.21±0.01 | 0.28±0.01 | 0.20±0.01 |
SOO | 50 | 20.05 | 0.26±0.01 | 0.29±0.01 | 0.26±0.01 | 0.36±0.01 | 0.42±0.01 | 0.49±0.01 | 0.36±0.01 | 0.39±0.02 |
|
||||||||||
LnLnLn | 36 | 7.11 | 21.45±0.7 | 23.28±0.8 | 22.44±0.6 | 22.15±0.5 | 21.25±0.4 | 23.12±0.5 | 22.41±0.6 | 23.62±0.7 |
LnLLn | 38 | 8.60 | 19.32±0.3 | 19.43±0.4 | 19.40±0.3 | 19.25±0.4 | 18.86±0.5 | 19.11±0.4 | 19.47±0.4 | 19.68±0.5 |
LLLn | 40 | 10.04 | 7.13±0.2 | 6.56±0.2 | 6.33±0.4 | 6.38±0.3 | 6.52±0.2 | 7.18±0.3 | 6.47±0.2 | 6.32±0.3 |
LnOLn | 40 | 10.24 | 10.30±0.2 | 10.52±0.3 | 11.28±0.2 | 10.56±0.1 | 11.18±0.3 | 11.10±0.2 | 11.20±0.2 | 10.60±0.3 |
LnLnP | 40 | 11.18 | 8.20±0.2 | 8.69±0.3 | 9.14±0.3 | 7.76±0.1 | 8.60±0.3 | 8.55±0.2 | 8.14±0.2 | 8.26±0.2 |
OLLn | 42 | 13.24 | 8.16±0.3 | 6.81±0.2 | 7.02±0.3 | 8.11±0.4 | 7.10±0.2 | 7.21±0.3 | 7.06±0.2 | 7.08±0.2 |
LnLP | 42 | 14.84 | 5.07±0.1 | 5.24±0.1 | 5.33±0.1 | 5.62±0.1 | 5.93±0.3 | 5.61±0.1 | 5.42±0.2 | 5.51±0.1 |
OOLn | 44 | 17.40 | 6.10±0.1 | 6.19±0.1 | 5.74±0.1 | 6.35±0.1 | 6.38±0.2 | 5.41±0.1 | 5.75±0.1 | 5.64±0.1 |
LnOP | 44 | 18.08 | 4.73±0.1 | 4.90±0.1 | 4.18±0.1 | 5.28±0.2 | 4.13±0.1 | 4.23±0.1 | 4.37±0.1 | 4.13±0.1 |
OLO | 46 | 22.00 | 1.55±0.1 | 1.71±0.1 | 1.48±0.1 | 1.22±0.1 | 1.64±0.1 | 1.52±0.1 | 1.55±0.1 | 1.57±0.1 |
SOLn | 46 | 23.80 | 3.00±0.3 | 2.83±0.1 | 2.77±0.1 | 2.90±0.2 | 2.68±0.1 | 2.72±0.1 | 3.08±0.1 | 2.95±0.2 |
OLP | 46 | 25.94 | 0.70±0.02 | 0.44±0.01 | 0.69±0.02 | 0.55±0.01 | 0.47±0.01 | 0.77±0.02 | 0.80±0.02 | 0.78±0.04 |
OOO | 48 | 29.37 | 2.13±0.2 | 1.50±0.1 | 1.79±0.1 | 1.90±0.1 | 1.81±0.1 | 1.62±0.1 | 1.94±0.1 | 1.96±0.1 |
OOP | 48 | 30.46 | 1.28±0.1 | 1.14±0.1 | 1.68±0.1 | 1.15±0.1 | 1.75±0.1 | 1.17±0.1 | 1.80±0.2 | 1.37±0.1 |
SLnS | 48 | 33.22 | 0.88±0.02 | 0.76±0.01 | 0.73±0.02 | 0.82±0.02 | 0.70±0.01 | 0.68±0.01 | 0.54±0.01 | 0.98±0.1 |
Each value is the mean ± SD of three determinations.
P: palmitic; S: stearic; O: oleic; L: linoleic; Ln: linolenic acid.
The comparative fatty acid composition of TAGs was analyzed during flaxseed development for the first time, using HPLC and LC-APPI-MS (
Comparative analysis of fatty acids of triacylglycerols during flaxseed development as estimated from HPLC and LC/MS data
DAF | C16:0 | C18:0 | C18:1 | C18:2 | C18:3 | ΣSFA | ΣMUFA | ΣPUFA | TU | TU/TS |
---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||
7 | 5.88±0.1 | 1.02±0.01 | 12.75±0.2 | 12.25±0.1 | 68.10±0.3 | 6.90±0.11 | 12.75±0.2 | 80.35±0.4 | 93.10±0.6 | 13.49±0.5 |
14 | 5.70±0.1 | 1.03±0.01 | 15.66±0.2 | 14.84±0.1 | 62.77±0.2 | 6.73±0.11 | 15.66±0.2 | 77.61±0.3 | 93.27±0.5 | 13.86±0.4 |
21 | 5.30±0.1 | 0.84±0.03 | 16.06±0.1 | 15.39±0.2 | 62.41±0.2 | 6.14±0.13 | 16.06±0.1 | 77.80±0.4 | 93.86±0.5 | 15.29±0.3 |
28 | 5.28±0.1 | 0.81±0.01 | 17.00±0.2 | 15.53±0.2 | 61.38±0.2 | 6.09±0.11 | 17.00±0.2 | 76.91±0.4 | 93.91±0.5 | 15.42±0.4 |
35 | 5.00±0.1 | 1.06±0.01 | 19.34±0.1 | 12.06±0.1 | 62.54±0.3 | 6.06±0.11 | 19.34±0.1 | 74.60±0.4 | 93.94±0.5 | 15.50±0.4 |
42 | 4.82±0.1 | 1.10±0.02 | 20.62±0.2 | 12.28±0.1 | 61.18±0.1 | 5.92±0.12 | 20.62±0.2 | 73.46±0.2 | 94.08±0.5 | 15.89±0.4 |
49 | 4.62±0.1 | 1.05±0.01 | 21.57±0.2 | 12.51±0.1 | 60.25±0.3 | 5.67±0.11 | 21.57±0.2 | 72.76±0.4 | 94.33±0.5 | 16.64±0.4 |
56 | 5.30±0.1 | 1.00±0.01 | 14.30±0.1 | 14.00±0.2 | 65.4±0.2 | 6.30±0.11 | 14.30±0.1 | 79.4±0.4 | 93.7±0.5 | 14.87±0.4 |
|
||||||||||
7 | 6.66±0.1 | 1.60±0.02 | 17.04±0.1 | 16.35±0.1 | 58.35±0.3 | 8.26±0.12 | 17.04±0.1 | 74.70±0.4 | 91.74±0.5 | 11.11±0.4 |
14 | 6.80±0.1 | 1.45±0.01 | 16.03±0.2 | 15.58±0.2 | 60.14±0.3 | 8.25±0.11 | 16.03±0.2 | 75.72±0.5 | 91.75±0.7 | 11.12±0.6 |
21 | 7.00±0.1 | 1.41±0.01 | 16.37±0.1 | 15.53±0.2 | 59.69±0.3 | 8.41±0.11 | 16.37±0.1 | 75.22±0.5 | 91.59±0.6 | 10.89±0.5 |
28 | 6.78±0.1 | 1.51±0.02 | 16.85±0.2 | 15.84±0.1 | 59.02±0.3 | 8.29±0.12 | 16.85±0.2 | 74.86±0.4 | 91.71±0.6 | 11.06±0.5 |
35 | 7.00±0.1 | 1.36±0.02 | 16.84±0.1 | 15.68±0.1 | 59.12±0.3 | 8.36±0.12 | 16.84±0.1 | 74.80±0.4 | 91.64±0.5 | 10.96±0.4 |
42 | 6.77±0.1 | 1.36±0.01 | 15.70±0.1 | 16.19±0.2 | 60.00±0.3 | 8.13±0.11 | 15.70±0.1 | 76.19±0.5 | 91.89±0.6 | 11.30±0.5 |
49 | 6.84±0.1 | 1.39±0.03 | 16.84±0.2 | 15.75±0.2 | 59.18±0.3 | 8.23±0.13 | 16.84±0.2 | 74.93±0.5 | 91.77±0.7 | 11.15±0.5 |
56 | 6.68±0.1 | 1.64±0.01 | 16.19±0.1 | 15.75±0.2 | 59.74±0.3 | 8.32±0.11 | 16.19±0.1 | 75.49±0.5 | 91.68±0.6 | 11.02±0.5 |
Each value is the mean ± SD of three determinations.
SFA: saturated fatty acids, MUFA: monounsaturated fatty acids, PUFA: polyunsaturated fatty acids, TU: total unsaturated fatty acids, TU/TS: total unsaturated/total saturated fatty acids.
Changes in Iodine value, Oil stability and triacylglycerol content during flaxseed development
DAF | I.V (g I2·100 g−1 oil) | Oil stability (h) | Triuns TAG (%) | Diuns TAG (%) | Monouns TAG (%) | TAG | ||||
---|---|---|---|---|---|---|---|---|---|---|
|
||||||||||
APPI-MS | HPLC | APPI-MS | HPLC | APPI-MS | HPLC | content (%) |
content (%) |
|||
7 | 155.30±0.82 | 2.4±0.2 | 79.64±2.62 | 76.14±2.10 | 20.02±1.63 | 22.98±0.82 | 0.34±0.01 | 0.88±0.02 | 10.96±1.0 | 8.46±1.4 |
14 | 159.22±0.25 | 2.2±0.1 | 79.92±2.12 | 76.00±1.58 | 19.68±1.33 | 23.24±0.71 | 0.40±0.01 | 0.76±0.01 | 14.99±1.3 | 16.32±0.6 |
21 | 163.55±0.63 | 2.0±0.2 | 81.81±3.61 | 75.48±2.10 | 17.96±1.34 | 23.79±0.72 | 0.23±0.01 | 0.73±0.02 | 22.41±0.9 | 38.55±2.2 |
28 | 165.78±0.70 | 2.0±0.1 | 81.90±3.02 | 75.92±2.00 | 17.95±1.23 | 23.26±0.71 | 0.15±0.01 | 0.82±0.02 | 26.21±0.8 | 56.12±2.6 |
35 | 172.64±0.21 | 1.8±0.1 | 82.16±3.51 | 74.74±2.00 | 17.65±1.33 | 24.56±0.91 | 0.19±0.01 | 0.70±0.01 | 34.51±1.2 | 70.46±1.7 |
42 | 174.32±0.44 | 1.6±0.2 | 82.45±3.72 | 76.27±2.00 | 17.33±1.05 | 23.05±0.62 | 0.22±0.01 | 0.68±0.01 | 80.77±1.1 | 84.60±0.8 |
49 | 175.46±0.76 | 1.5±0.1 | 83.26±4.20 | 75.85±2.27 | 16.45±1.65 | 23.61±0.82 | 0.29±0.01 | 0.54±0.01 | 85.79±1.2 | 90.82±2.7 |
56 | 176.24±0.70 | 1.4±0.1 | 81.27±3.24 | 76.47±2.3 | 18.52±1.88 | 22.55±0.74 | 0.21±0.02 | 0.98±0.1 | 87.47±1.8 | 94.24±3.1 |
by LC-APPI-MS (Herchi
by TLC method.
Each value is the mean ± SD of three determinations.
TriunsTAG: Triunsaturated TAG, DiunsTAG: Diunsaturated TAG, MonounsTAG: Monounsaturated TAG.
The changes in proximate composition during flaxseed development are shown in
Proximate analysis and digestible protein during flaxseed development
DAF | 7 | 14 | 21 | 28 | 35 | 42 | 49 | 56 |
---|---|---|---|---|---|---|---|---|
Moisture (%) | 74.30±0.60 | 60.70±0.91 | 43.60±0.84 | 36.50±0.76 | 24.70±0.42 | 13.20±0.34 | 8.80±0.18 | 5.40±0.20 |
Protein (%) | 7.59±0.24 | 10.09±0.40 | 14.25±0.52 | 20.56±0.71 | 21.67±0.36 | 22.16±0.64 | 24.43±0.78 | 23.84±0.62 |
Oils (%) | 8.04±0.21 | 16.63±0.20 | 21.87±0.57 | 31.42±0.39 | 34.42±0.67 | 38.75±0.61 | 43.70±0.94 | 36.61±0.58 |
Ash (%) | 1.64±0.05 | 1.68±0.03 | 1.92±0.05 | 2.10±0.04 | 2.34±0.04 | 2.76±0.08 | 2.90±0.06 | 3.20±0.10 |
Total carbohydrate (%) | 8.43±0.29 | 10.09±0.80 | 18.36±0.17 | 9.42±0.23 | 16.87±0.95 | 23.13±0.60 | 20.17±0.38 | 30.95±0.72 |
Energy (Kcal·100 g−1) | 137.49±1.88 | 231.65±1.95 | 329.56±1.08 | 403.88±1.55 | 466.06±1.80 | 532.8±0.90 | 574.25±1.20 | 552.52±1.53 |
Energy (Kj·100 g−1) | 575.27±2.23 | 969.25±2.37 | 1378.91±3.18 | 1689.87±2.66 | 1950.04±1.74 | 2229.30±2.84 | 2402.72±1.90 | 2311.80±3.28 |
Digestible protein (%) | 3.07±0.22 | 5.47±0.30 | 9.47±0.72 | 15.52±0.46 | 17.00±0.54 | 17.06±0.81 | 19.24±0.24 | 18.67±0.50 |
Each value is the mean ± SD of three determinations.
Osborne (
Protein fractionation yield (%) during flaxseed development
Osborne protein fraction/DAF | 7 | 14 | 21 | 28 | 35 | 42 | 49 | 56 |
---|---|---|---|---|---|---|---|---|
Albumin | 52.25±0.50 | 50.32±0.30 | 48.75±0.77 | 65.10±1.34 | 55.00±1.10 | 56.06±0.90 | 63.04±1.15 | 52.63±0.90 |
Globulin | 12.50±0.18 | 14.65±0.44 | 14.54±0.20 | 20.86±0.78 | 30.82±0.30 | 31.11±0.90 | 24.63±0.70 | 32.54±0.82 |
Prolamin | 18.23±0.25 | 17.51±0.32 | 16.34±0.10 | 4.31±0.46 | 4.61±0.17 | 3.97±0.10 | 3.17±0.11 | 3.34±0.14 |
Glutelin | 17.01±0.60 | 17.51±0.33 | 20.36±0.56 | 9.72±0.18 | 9.56±0.20 | 8.85±0.38 | 9.15±0.22 | 11.48±0.34 |
Each value is the mean ± SD of three determinations.
A low α-amylase activity was observed at the beginning of seed maturation (
α-amylase activity during flaxseed development (vertical bars indicate standard deviation of the means).
APPI-MS analyses give more information about the separation and molecular distribution of TAG molecules compared to HPLC. Oil characteristics change during flaxseed development. The proximate components are accumulated at different rates. It may be concluded that flaxseed is potentially a good source of dietary energy and protein. These results improve our knowledge about the effect of maturation on flaxseed quality and composition. The major classes of protein were albumins and globulins. The highest α-amylase activity was recorded at 49 DAF.
The authors gratefully acknowledge Dr. Hamadi Ben Saleh at INRAT for technical assistance in conducting the culture of flaxseed.