This article reviews the current state of the historiography of the Canadian North, connecting scholarly writing on the region to the rapid and profound developments that have occurred in the North in recent years. It summarizes the priorities and imperatives of post-Second World War historical writing on the North but looks more specifically at developments in the past two decades. The rapid growth of Indigenous-focused and North-centred scholarship is considered in detail, with particular emphasis placed on the manner in which academics have collaborated with Aboriginal peoples on the advancement of historical understanding. Despite the growth in the number, quality and diversity of historical works on the North, this article argues that the national historical profession continues to largely ignore northern developments and has yet to integrate the region into the national narrative. The article concludes by reviewing the prospects for further development in the field, suggesting that significant challenges lie ahead, including a growing disconnect between southern and northern historical work, the rising costs of working closely with Indigenous communities, and the general decline of regional history in Canada.

The characteristics of the ligands in inclusion complexes formed from stearic, palmitic, oleic, linoleic, linolenic and docosahexaenoic acids, glycerol monooleate (GMO), glycerol monopalmitate (GMP) and lysophosphatidylcholine (LPC) have been studied by13C NMR in dry and hydrated forms of the complexes, with13C labels being used for the car☐yl and C-1(3) glycerol carbons in stearic acid and GMO, respectively.13C NMR provides definitive proof that V-amylose inclusion complexes have been formed with the mono-car☐ylic fatty acids of varying degrees of unsaturation, GMO, GMP and LPC. The chemical shift of the mid-chain methylenes in stearic acid moves about 1.5 ppm upfield upon complexation with the1H rotating frame relaxation times becoming identical for the lipid and amylose. With the exception of docosahexaenoic acid, the mid-chain methylenes inside the V-helical segments have essentially the same chemical shift for all the other unsaturated fatty acids and lipids investigated. The cross-polarisation dynamics for the car☐yl and glycerol groups in stearic acid and GMO, respectively, have indicated that these bulky polar groups occupy highly mobile conformations in the hydrated complexes which must lie outside the V-helical segments adjacent to the amorphous domains.

The thermal properties of water-insoluble amylose-stearic acid (18:0) complexes prepared under various conditions were studied by differential scanning calorimetry (DSC). Complexes were studied normally at a concentration of 5% in water at pH ∼7. Type I complexes formed at ≤ 60°C had dissociation temperatures (Tm) in the range 96–104°C. Type IIa polymorphs formed at ≥ 90°C had Tm = 114–121°C. Various ratios of types I and IIa were formed at 80°C depending on the duration of heating, but no intermediate form was detected. Annealing of the type IIa complex at 105°C and at 115°C gave rise to increasing proportions of type IIb polymorphs with Tm = 121–125°C and dissociation enthalpies of 32–34 J/g of amylose, depending on the temperature and time of annealing. Conversion into the higher polymorphs was retarded at a higher concentration (10%) of the complex under identical conditions, and was delayed at pH ∼ 4.7. The dissociation temperatures of amylose complexes with the cis-unsaturated fatty acids oleic (18:1), linoleic (18:2), and linolenic (18:3) also depended on the temperature of formation, and three distinct types were obtained (I, IIa, and IIb). Significant decreases in the Tm of the three polymorphs were observed for each double bond in the fatty acid guest molecule. When type I and type II complexes were made using various proportions of 18:0 and 18:2, mixed acid complexes were obtained with Tm values intermediate between those of the monoacid complexes. The origin of the endothermic transitions on heating the three types of complexes is discussed.

Crops of winter wheat (cv. Hereward) were grown in the field under double-skinned polyethylene tunnels in two consecutive seasons (1991–92 and 1992–93). Air containing ambient (350 ppm) or elevated (700 ppm) concentrations of carbon dioxide was circulated through the tunnels, and temperature gradients, typically from 1°C below ambient to 4–7°C above ambient, were maintained within each tunnel. Despite a shorter crop duration and warmer temperatures in the first season, most grain and starch properties showed a similar response to temperature between seasons. Thousand grain weight and grain starch content declined with increase in temperature (from 55±5 mg to 18±2 mg, and from 31±3 mg to 7±2 mg, respectively), the latter reflecting both decreases in granule sizes and fewer amyloplasts per endosperm. Contents of total amylose and lipid-free amylose increased with temperature (from 26±1% to 31±1%, and from 21±1% to 25±1%, respectively), but the contents of lipid-complexed amylose (5·2±1·5%) and lysophospholipids (0·9±0·2%) varied independently of temperature. Starch gelatinisation temperatures ranged from 57·5 to 64·5°C in the first season, and from 58·0 to 61·9°C in the second season, increasing with increase in temperature in both seasons, the data for the two seasons providing almost separate clusters. Gelatinisation enthalpy was constant in the first season (12·6±1 J/g amylopectin) and in the second season (15·5±0·5 J/g amylopectin) with no effect of temperature. The differences in carbon dioxide concentration had no consistent effects on the parameters measured, but small effects were discernible on thousand grain weight, starch content and lipid-free amylose content. There were also effects in certain treatment combinations, specifically at warmer temperatures in the first season and at cooler temperatures in the second season, on thousand grain weight, non-starch solids and lipid-complexed amylose contents.

Waxy barley starches (0.8–4.0% lipid-complexed amylose = L·AM, 0.9–3.4% lipid-free amylose = F·AM) and non-waxy barley starches (6.1–7.2% L·AM, 23.1–25.9% F·AM) were lintnerised by steeping in 2 M HCl at 35°C for 140 h. Material solubilised from the waxy starches was estimated to be 70.7% of their amylopectin (AP) plus 3.7% of their L·AM and F·AM, and material solubilised from the non-waxy starches was estimated to be 70.7% of their AP plus 28.9% of their L·AM and F·AM. The polysaccharide components of the insoluble residue were characterised by HPLC, GPC, and λmax of the polyiodide complex. I was concluded that short chain-length (CL 16) material was from external chains of AP, intermediate material (modal CL 46) was from retrogated F·AM, and longer chain residues (CL 77, 120–130_ were from lipid-complexed segments of L·AM. The starch lysophospholipids were completely hydrolysed to free fatty acids which remained complexed with L·AM residues. This was shown by the 13C CP/MAS-NMR spectrum which had a clear resonance at 31 ppm from mid-chin methylene carbons of fatty acids in complexes. The C-1 signal of the L·AM residues also included a feature at 104 ppm indicative of single V6 AM helices. The wide-angle X-ray diffraction patterns of the residues of non-waxy starches were Cc-type ( = mixed A + B types), whereas the spectra of the original starches were A-type. It is suggested that, during the early stages of lintnerisation, amorphous (F·AM was partially hydrolysed into material (CL < 120) that retrogated into double helices (with B-type crystallinity) that were resistant to hydrolysis. Evidence for some B-crystalline polymorph was also obtained from the 13C CP/MAS-NMR spectra, which were consistent with a mixture of double helices and V-type glycosidic conformations, with only a small proportion of non-ordered regions. Broad DSC endotherms were found for both waxy (50–110°C) and non-waxy (50–110°C) lintner residues, which were assigned to disordering of double helices from short chains (modal CL 16) for waxy residues, together with disordering of longer chains (modal CL 46) in double-helix residues of F·AM and also V-helix residues of L·AM for non-waxy starch residues.

Abstract According to the classical texts (Banks and Greenwood 1975; Whistler et al. 1984; Kainuma 1988) cereal starches are composed of two types of polysaccharide, amylopectin and amylose, and little attention is given to the minor components of the granules such as the integral proteins and lipids. The integral proteins consist of a major polypeptide (58–60 kDa) identified as granule-bound starch synthase, with traces of polypeptides of higher molecular weight (Echt and Schwarz 1981; Sano 1984; Goldner and Boyer 1989). The major integral protein (the so-called waxy protein) is generally determined by a single gene (Wx), and in the waxy mutants of the diploid cereals where the gene (wx) is not expressed there is no detectable waxy protein and typically less than 2 per cent amylose (Villareal and Juliano 1986; Goldner and Boyer I 989). In the triploid endosperm intermediate states between normal (Wx Wx Wx) and waxy (wx wx wx) are possible, and both Wx Wx wx and Wx wx wx genotypes have slightly less waxy protein and amylose than in the normal starches (Nelson 1980).

Cereal Chem. 67(6):558-563 The swelling and gelatinization properties of waxy rice starches (essenlatter also responded a little to annealing. It is concluded that the lowtially pure amylopectin) were studied. Low gelatinization temperature GT starches have less crystallinity and less perfect crystallites than the (low-GT, 64-670 C), intermediate-GT (68-710 C), and high-GT (75-790 C) high-GT starches due to minor structural differences in their amylopectins. starches exhibited a range of swelling factors at 800C (low = 24 42, Partial hydrolysis of amorphous regions caused a large decrease in swelling intermediate = 28-42, high = 29-40; maximum values were not attained factor but had only a small effect on gelatinization enthalpy. It is suggested by the high-GT starches). Structural analysis showed that the low-GT that crystallites within the amylopectin molecule determine the onset of and high-GT starches had very similar chain lengths after debranching swelling and gelatinization, and that maximum swelling factors may relate and on debranching of insoluble residues after lintnerization. The lowto the molecular weight and shape of the whole amylopectin molecule. GT starches could be annealed to behave like high-GT starches, but the In the preceding paper (Tester and Morrison 1990), the swelling behavior of cereal starches was shown to be primarily a property of their amylopectin (AP) content; amylose (AM) acts both as a diluent and as an inhibitor of swelling, especially in the presence of lipids (natural components of nonwaxy cereal starch granules), which can form insoluble complexes with some of the AM during swelling and gelatinization. Interpretation of results was complicated because so many factors affected swelling, and further studies were therefore carried out using waxy rice starches, which, being essentially pure AP, are not subject to interference from AM and lipids. Rice, more than any other cereal, exhibits very wide ranges of cooking quality and rheological properties that are largely determined by the swelling, gelatinization, pasting, and retrogradation characteristics of its starch (Juliano 1985). Being a diploid cereal, rice has numerous stable starch variants commonly classified as high-, intermediate-, and low-AM and waxy (zero-AM). Each of these types normally includes varieties with low, intermediate, and high gelatinization temperatures (GT). In this study, six lowGT and six high-GT waxy rice starches with contrasting gel properties were used. In addition, swelling factor was measured using some waxy rice starches described previously (Morrison et al 1984, Morrison and Nasir Azudin 1987). MATERIALS AND METHODS Starches Eleven samples of waxy rice (indica type) grown under comparable conditions at the International Rice Research Institute (IRRI), Philippines, and one sample grown in Vietnam were obtained. The varieties were RD6, IR65, Khao Khao (from Vietnam), IR29, Malagkit Sungsong, IR39368-31-1-2, Inilang-ilang, Perurutong NBA, Nathasiq, Tapol, Pya Gyi Taung, and RD4. Starches from the above were isolated from milled white rice by steeping, aqueous extraction, and centrifuging through 80% (w/v) CsCl (Tester and Morrison 1990). Other starches were as described previously (Morrison et al 1984). Analytical Methods Methods for the determination of total amylose (colorimetric), a-glucan, lipids, swelling factor (SF), and gelatinization temperature (GT), and enthalpy (I\H) by differential scanning calorimetry (DSC) were the same as in our previous paper (Tester and Morrison 1990). Starch granules were lintnerized by steeping 'Part of this paper was presented at the AACC 73rd Annual Meeting, San Diego, CA, October 1988. 2 Food Science Division, Department of Bioscience and Biotechnology, University of Strathclyde, 131 Albion Street, Glasgow Gl ISD, Scotland, U.K. © 1990 American Association of Cereal Chemists, Inc. 558 CEREAL CHEMISTRY for various times in 2.2M HCl at 350C, then washing six times with water to remove the acid, and air-drying. This causes hydrolysis of a-glucan, initially confined to the amorphous regions of the starch granules. Solubilized glucan was measured in the original supernatant before washing. Native and lintnerized starches were debranched enzymically, and the a-glucan chains released were analyzed by gel permeation chromatography (GPC) and by high-performance liquid chromatography (HPLC). Native starch (5 mg) was dissolved in 990 ,1 u of acetate buffer (pH 3.8, 0.01M) by boiling briefly. After cooling, 10 ,l of buffer containing 540 units of isoamylase from Pseudomonas amyloderamosa (Hayashibara Biochemicals, Osaka) was added. The samples were incubated at 30°C for 24 hr, with toluene present to prevent microbial growth, then boiled for 10 min to inactivate the enzyme. The insoluble residue from lintnerized starch (approximately 6.5 mg) was dissolved in 800 ,l of sodium acetate (0.OlM) by boiling for 10 min, and cooled to 20-25°C; 200 ,ul of acetate buffer (pH 3.72, 0.01M) containing 540 units of isoamylase and 100 , 1 of buffer containing two units of pullulanase (BDH) were added to effect debranching. The samples were incubated at 37°C for 24 hr, then boiled for 10 min, cooled, centrifuged (1,550 X g, 5 min), and the supernatant was used for GPC or HPLC. For GPC, 1-ml aliquots of debranched material were fractionated on a column (1,000 X 16 mm) of Sepharose CL6B (Pharmacia) eluted with 0.01M KOH containing 0.005% thiomersal at 1 ml/ min, and fractions were collected for analysis. The average chain length (CL) of the a-glucan chains was estimated by measuring Xmax of the I2 /KI complex (Morrison and Laignelet 1983), using the relationship CL = 3,290/(635 Xmax) (Morrison and Karkalas 1990). Smaller aliquots were also fractionated by HPLC (Hizukuri 1986). The HPLC columns were calibrated with linear ct-glucans of CL 38, 54, 98, 178, 237, and 407, synthesized from maltohexaose primer and glucose-i-phosphate using potato phosphorylase (Banks et al 1971). Native starches were also separated by GPC on a column of Sepharose CL2B (Morrison et al 1984). RESULTS AND DISCUSSION Only small quantities of starch from waxy rice varieties grown in France and Vietnam were available. Since these were all lowto intermediate-GT starches, single measurements of swelling were made at 80°C (Table I), approximately 10°C above GT. This is comparable with measuring the swelling factor of wheat and barley starches (GT = 57-65°C) at 700C (Tester and Morrison 1990). The results show a range of SF (28.1-43.8) that was not correlated with GT (67.3-72.0°C) or AH (12.8-14.9 J/g), indicating different swelling curves of the type shown in Figure 1. Interestingly, E100 starch from rice grown in France differed appreciably from the same variety grown in Vietnam. Swelling differences were not due to the apparent AM content (discussed below) since the correlation was very poor (r = 0.506, n = 8), and swelling factors recalculated on AP content were equally variable. Three nonwaxy starches (24.0-28.1% AM, 632-821 mg/100 g of lipid) from the same study were also available. Their GTs (73.8-74.60C) were a little lower than for the high-GT starches described below, and their AH values (13.8-14.1 J/g) were normal, but SF80 was only 11.5-12.6. Because all low-GT and high-GT waxy starches in the present study had SF 80 > 26, AM and lipids inhibited swelling in rice starches as much as in other cereal starches (Tester and Morrison 1990). The 12 waxy starches used in the main part of this study had very low levels of AM (colorimetric) and lipids (Table II) and were thus nearly pure AP. In fact, the iodine-binding capacity of rice AP, particularly from indica varieties (Hizukuri 1986, Takeda et al 1987), is sufficient to account for all of the colorimetrically determined AM in these starches. This was confirmed by GPC and HPLC of the debranched starches, which revealed negligible material at the void volume which is where debranched AM would have appeared. Swelling curves for the 12 starches over the range 50-80'C are shown in Figure 1. Onset of swelling began a little above To (Table II), unlike wheat, normal and waxy barley, and maize starches, where swelling begins at or below To (Tester and Morrison 1990). The curves for the low-GT starches all reached plateau values (maximum SF) at 70-750C, ranging from SF = TABLE I Composition, Gelatinization Properties, and Swelling Factors (at 800C) of Nine Waxy Rice Starches from a Previous Studya AMb Lipid GT AH Cultivar (%) (mg/100 mg) (C) (J/g) SF80 B122 nd nd 68.4 12.9 36.0 B124 0.4 54 72.0 13.7 39.1 B129 0.3 34 67.7 12.8 43.8 B136 0.5 24 70.5 12.8 33.4 E73 0.7 40 67.3 14.9 41.9 ElOO(VN)C 1.1 47 69.0 14.2 39.0 ElOO(Fr)c 0.4 23 70.7 12.9 35.4 E148 0 27 69.6 14.7 28.1 F13 0.3 24 69.9 14.7 31.0 aAmylose (AM), lipid, gelatinization temperature (GT), and AH data from Morrison and Nasir Azudin (1987). b Measured as amylose, but probably superlong B-chains in amylopectin, as discussed in text. cVN = grown in Vietnam, Fr = grown in France. 26 (Khao Khao and RD6) to 42 (Malagkit Sungsong). Comparable values for the high-GT starches were not determined, but extrapolation of their curves indicated a SF range of 30-50, approximately. An explanation for these characteristic gelatinization and swelling properties was sought in terms of crystalline organization within the granule and the molecular structure of its AP. For this discussion, the reader is referred to the models of French (1972, 1984), Robin et al (1974, 1975), Nikuni (1978), Manners and Matheson (1981), Enevoldsen (1985), and Hizukuri (1986), N ,~~~~~~~~~~01 IT 40 Mf r ' /

Bread was made using a long fermentation process and an activated (chemical) dough development process from four soft-milling and six hard-milling varieties of Greek wheat. Breadmaking quality was reliably predicted using results from sedimentation tests and Farinograph dough mixing tests. The damaging effects of proteolytic enzymes in flour from insect-damaged wheat, added at the 3% level, were evaluated. The superior qualities of the newer harder wheats were confirmed and it seems that their loaf volume may be unaffected by moderate levels of insect damage. The activated dough development process seems to be very suitable for hard Greek wheats.

Free (hexane-extractable) polar lipids (PoL) were determined in flours milled from wheats differing only in their group 5 chromosomes. Ditelosomic lines lacking the short arm of chromosome 5D (DT5DL) were much harder and had less free PoL than normal wheats or the corresponding 5A ditelosomics (DT5AL). Substitution of chromosome 5D of Chinese Spring (CS) by homologous chromosomes from other varieties or by 5U from Aegilops umbellulata, and of chromosome 5A of CS by 5U, gave a series in which increasing hardness was strongly correlated with decreasing free PoL. Analysis of CS x CS(Hope 5D) crosses that were non-recombinant or recombinant for the genes Vrn3/vrn3 (spring/winter habit) and Ha/ha (soft/hard endosperm texture) showed that there was transgressive segregation of two (or, possibly more) genes controlling levels of free PoL. One of these genes could be allelic to Ha, or is closely linked to it. The second gene is probably located on the long-arm proximal to Vrn3. The new genes have been given provisionally the symbols Fpl-1 and Fpl-2. Loaves made by the Chorleywood Bread Process with flour from ditelosomic and substitution lines showed marked decreases in loaf volume with decreasing free PoL. Limited evidence from recombinant lines supported the link between Fpl-1 and Fpl-2 and loaf volume.

Starches in the endosperm of cereals may be unique in having appreciable quantities of monoacyl lipids inside the starch granules. These lipids are almost exclusively lysophospholipids in wheat, barley, rye and triticale, but include substantial proportions of free fatty acids (FFA) in other cereals. In addition, the starch granules may acquire surface lipids, which are mostly FFA, from the endosperm non-starch lipids. Methods for isolating suitably purified starch are discussed and lipid composition data are given. The relationship between amylose content and lipid content in wheat, barley, maize and rice starches is described and the biological significance of the lipids is discussed. The question whether lipids exist as inclusion complexes with amylose in native starch granules or not is debated, but cannot be resolved conclusively with present experimental techniques.

Starches isolated from 23 bread wheats (Triticum aestivum) and 26 durum wheats (T. durum) contained 26.3-30.6% (mean 29.1%) total amylose, 19.3–25.1% (mean 22.9%) apparent amylose and 783–1144mg 100g−1 (mean 977 mg 100g−1) lysophos-pholipids. Gelatinisation temperatures were 57.3–64.9°C (mean 61.8°C) and enthalpies 6.4–11.8 Jg−1 (mean 9.7Jg−1) in excess water, measured by differential scanning calorimetry. There were no correlations between any of these parameters. Starch granule size distributions were determined with a Coulter Counter and 100–channel analyser. A-granule mean volumes were 1235–2585μm3 (av. 1778), modal volumes 863–1804μm3 (av. 1264), mean diameters 13.9–16.0μm (av. 13.99), and specific surface areas 0.236–0.302m2g−1. B-granule mean volumes were 35.4–100.4μm3 (av. 55.9), modal volumes 16.5–54.5μm3 (av. 27.7), mean diameters 3.66–5.07μm (av. 4.09), and specific surface areas 0.684–0.920m2g−1. The B-granule contents of the starches were 12.8–34.6% (av. 27.3) by weight (sedimentation method) and 13.0–37.3% (av. 24.0) by volume (Coulter method), the latter being the more accurate method.

AbstractStarch was isolated from six types of wheat and separated into large A‐granule and small B‐granule fractions which exhibited a suitable range of properties. Respective amylose contents were 28.6–31.0% and 25.1–31.5%, lysophospholipids 707–1014mg 100 g−1, and 1058–1398 mg 100 g−1, and gelatinisation temperatures (GT) by differential scanning calorimetry (DSC) 58.4–62.7°C and 60.5–64.5°C. The A‐ and B‐granule fractions were remixed in various proportions and reconstituted with freeze‐dried gluten and freeze‐dried water‐solubles from flour to test the effects of changes in the properties of the total starch, A‐granule or B‐granule fractions, and the effects of various proportions of B‐granules on the quality of bread. The specific volumes of the loaves were not affected by starch amylose or lipid content, but were significantly correlated with either the GT of the total starches or their A‐granules. The optimum proportion of B‐granules was 25–35% by weight, but their GT had no effect on loaf specific volume. Staling changes were quantified from crumb compressibility measurements and the enthalpy of the endotherm for gelatinisation of retrograded amylopectin in stored breadcrumb, measured by DSC. Initial and limiting moduli of crumb firmness were correlated with loaf specific volume and starch GT, but rate and time constants calculated from the Avrami equation were independent. Rate and time constants and limiting enthalpy values calculated from the DSC results were independent of all other measured parameters.

Total galactosyldiglycerides were quantified in purified endosperm and flour from tetraploid and hexaploid wheats. Mean levels of monogalactosyldiglycerides and digalactosyldiglycerides were not significantly different between tetraploids and hexaploids. Studies with aneuploids of hexaploid breadwheats failed to reveal consistent differences in either type of glycolipid that could be attributed to a single chromosome, and a prior claim that the short arms of homologous group 5 chromosomes control the levels of total galactosyldiglycerides was shown to be unjustified. However, deletion of the short arm of chromosome 5D (but not of 5A) did cause a large decrease in the amounts of free galactosyldiglycerides that could be extracted from Koga II hexaploid wheat with light petroleum.

An improved method for the colorimetric determination of amylose as its blue polyiodide complex is described. Starch is dissolved in urea—dimethylsulphoxide and aliquots of the solution are used to determine apparent amylose (measured in the presence of any amylose complexing monoacyl lipids which may be present) and total amylose (measured on lipid-free starch, precipitated from urea—dimethylsulphoxide solution with ethanol). When factors such as ionic concentration, sequence and timing of steps in the procedure and solution temperature are controlled, the coefficient of variation in replicate determinations (n = 6) is 0·2–10·0%, except with waxy starches, where it is 10·6–10·8%. The limitations of the method and sources of error in published methods for the preparation of lipid-free starches and in the development of stable amylose-polyiodide colour complexes are discussed. In some wheat and non-waxy rice starches the difference between total and apparent amylose is 30·5–7·4% amylose.

AbstractKernels from a mixed hard wheat grist were dissected into germ, bran (pericarp, testa and aleurone), and starchy endosperm for direct analysis of tocopherols in lipid extracts by high‐performance liquid chromatography. α‐ and β‐tocopherols were almost exclusively in the germ, α‐tocotrienol was mostly in the bran, and β‐tocotrienol was equally distributed between the bran and the starchy endosperm. Acyl lipids and tocopherols were quantified in 23 millstreams obtained from this grist. Components related to germ and bran (triglyceride, diacylphospholipids, ã‐ and β‐tocopherols) and testa (flour colour) showed the highest coefficients of variation whereas endosperm components (glycolipids, N‐acylphospholipids and β‐T‐3) showed exceptionally low variation. The quantities of marker tocopherols in the streams were used to calculate the composition of the lipid transferred to the flour from germ and aleurone, and to predict the composition of the basic endosperm, free of aleurone and germ lipids. Low proportions of diacylphospholipids in the lipid transferred to high‐grade millstreams indicated the transfer of spherosome lipid. The low‐grade streams exhibited high proportions of phospholipids suggesting additional transfer of germ tissue and aleurone tissue containing membrane lipids. Protein and ash contents of the transferred fraction confirmed that a substantial proportion of the transferred lipid was probably accompanied by protein bodies or by tissue fragments. It is estimated that aleurone contributed less than one‐quarter of the transferred lipid in any stream. Hexane‐extractable free lipids in four representative streams consisted of almost all the non‐polar lipids, 40–67% of the glycolipids, 47–54% of the diacylphospholipids and 30–60% of the lysophospholipids.

AbstractSamples of whole and manually degermed Atou wheat were milled on a micro‐mill to give straight‐run flour, coarse offal, fine offal, finished bran and bran finisher flour. The non‐starch lipids in these products were compared with non‐starch lipids in the aleurone‐free starchy endosperm, and with lipids in the germ and aleurone of the original wheat. About half of the triglyceride in flour was derived from the germ; no glycolipids or phospholipids were derived from germ, and no lipids of any kind were derived from the aleurone. Non‐starch lipids in the aleurone‐free endosperm of a mixed English soft wheat grist were then compared with the non‐starch lipids in 11 flour streams from a commercial mill. All flours had much more triglyceride than the endosperm. In flours from the reduction system there were significant correlations between flour colour grade, sterylester, triglyceride, diglyceride, free fatty acid and diacylphospholipids, but none between ash or protein and colour or any class of lipid. Analysis of the principal components of variation in a simplified matrix describing all 11 flours placed triglyceride, diglyceride, free fatty acid, and diacylphospholipids close together in one group, and all glycolipids and N‐acylphospholipids in a separate unrelated group. Sterylester and colour were loosely associated with the first group but could also be regarded as part of a third loose group with ash and protein. The results are interpreted in terms of lipid distribution within the wheat kernel, and their significance in milling and baking practice.

AbstractMethods are described for the extraction and quantification of total lipids in cereal grains and other similar tissues, and for the determination of all the major classes of acyl lipid found in these extracts. Total lipids, obtained by direct solvent extraction or after acid hydrolysis, are quantified as fatty acid methyl esters (FAME) by gas chromatography (g.c.), using heptadecanoate (17:0) as internal standard. Individual lipid classes are separated by thin‐layer chromatography; non‐polar lipids and glycolipids are measured as FAME by g.c., while phospholipids are determined from phosphorus distribution. Crude lipid extracts are used to avoid losses during purification, and methanolysis of lipid classes is always performed without extracting the lipids from silica gel in order to minimise autoxidation, handling losses and contamination. Corrections are described for minor losses during experimental procedures, and factors are given for conversion of weights of FAME or phosphorus into weights of original lipid. In the authors' laboratory the precision of routine determinations (variations expressed as percentage of mean values) are usually well within the limits: total lipids, 1.5%; major lipid classes, 1.5%; minor lipid classes, 5%.