Further compositional analyses of flax: Mucilage,trypsin inhibitors and hydrocyanic acid

Registered Canadian cultivars of flax, and laboratory-prepared and commercially obtained samples of linseed meal (LM), were used to determine extract viscosity and mucilage, trypsin inhibitors and hydrocyanic acid (HCN) concentrations. The mucilage readily leached out from the seed coat (hull) fragments soaked in water, leaving behind pentagon-shaped cells that could be seen clearly in scanning electron micrographs. Extract viscosity significantly varied in the laboratory-prepared (23–48 cS) and commercially obtained (30–68 cS) samples of LM and may be used to obtain an indirect, qualitative estimate of flax mucilage. Mucilage was extracted from whole seed in 5.0–5.3% yields and contained 20–24% protein (about 10% ash and 30% total carbohydrates). Laboratory-prepared LM (raw) contained 42–51 units of trypsin inhibitor activity, commercially obtained samples, 14–37 units, and raw rapeseed and soybean meals, 99 and 1650 units, respectively. Picric acid tests (qualitative) showed only traces of HCN in ten cultivars of freshly ground flax. The acid silver nitrate titration procedure measured HCN quantitatively, but showed its presence only in three of the five cultivars investigated. HCN was conveniently measured by a colorimetric procedure (barbituric acidpyridine reaction), which may be used to screen flax cultivars. HCN content of flax was significantly influenced by environments (growth location and season) and, to a less extent, by cultivar.     

Lipid Class and Fatty Acid Composition of Psoralia corylifolia Seed

The purified crude lipid of Psoralia corylifolia seeds was subjected to lipid class and fatty acid analysis by thin layer and gas chromatography. The lipid classes identified were triacyl glycerol, free fatty acid, diacyl glycerol, mono acyl glycerol, hydrocarbon-waxester and polar lipid fractions. Most of the fractions were found to contain high level of C_18:1 while C_18:0, C_18:3 and C_20:0 were also found to be present in all the lipid fractions. It has been observed that the diacyl and monoacyl glycerol fractions contain significant amounts of C_14:0 and C_18:0 while the hydrocarbon-waxester fraction was rich in C_22:0. The polar lipids contain high level of C_18:3 and low level of C_18:1 as compared to other lipid fractions. The fatty acid composition of the whole oil was also determined and found to be similar to other fractions. Unidentified long chain fatty acids were also present in significant amounts in all the lipid fractions.     

Measurement of α-linolenic acid in the development of edible oil flax

A thiobarbituric acid-gas liquid chromatograph combination procedure is described for rapid screening of individual or half-seeds of flax for α-linolenic acid (ALA) in the development of an edible oil flax. The thiobarbituric acid test may be used to screen as many as 1000 seeds in a single day. However, the test needs to be complemented by quantitative determination of fatty acids by gas chromatography. The latter technique has been used to analyze half-seed of flax. The combination has worked extremely well for the isolation of low ALA mutants of flax.     

Diffusion extraction of rapeseed glucosinolates with ethanolic sodium hydroxide

Glucosinolates are readily diffused from whole rapeseed by repeated extractions with ethanolic sodium hydroxide. Four 2 hr extractions or six 1 hr extractions were most efficient for the diffusion of glucosinolates with minimum losses of other seed constituents. The ethanolic sodium hydroxide treatment inhibited myrosinase activity and lowered sulfur concentration in the oil. The oil from treated seed gave a higher hydrogenation number than the oil from untreated seed. The oil content of rapeseed was not substantially affected by the diffusion extraction process. Loss of diffused solids was ca. 15%, and loss of nitrogen did not exceed 10%. Most of the nitrogen diffused from the seed was nonprotein nitrogen. The principal disadvantages of the ethanolic sodium hydroxide procedure were reduced solubility of the rapeseed proteins and the higher fiber levels in the meals. The treated seed may be suitable, after partial dehulling or air classification, for the preparation of protein concentrates.     

Enhancement of Resistant Starch (RS3) in Amylomaize,Barley, Field Pea and Lentil Starches

Native starches isolated from amylomaize. Glacier high amylose barley, field peas and lentils contained 3–5% (w/w) resistant starch (RS3). Retrograded gels that were prepared from these starches had higher RS3 (6–9%) contents. The effects of gel concentration (% starch), storage temperature and time on the RS3 content of the retrograded gels were investigated; the optimum RS3 content was determined in gels prepared at = 10% (w/v) starch concentration and stored under = 20°C for = 5 days. Annealing of the retrograded starch gels by heating and cooling cycles, further enhanced RS3 content to 9–19%; the effect of annealing temperature and number of heat-cool cycles on the RS3 content of the annealed gel were studied. The hydrolysis of retrograded starch gels by pulanase enzyme or acid (2.2 N HCl), prior to annealing, enhanced the RS3 formation during annealing; the enzyme or acid treatment increased RS3 content of the annealed gel to 15–24% or 17–24%, respectively. The potential molecular mechanism that is responsible for the RS3 increase is discussed.     

Silicic acid-silver nitrate chromatography as an enrichment technique in fatty acid analysis

Silicic acid-silver nitrate chromatography as developed by De Vries (8,9) is a valuable tech-nique for the quantitative determination of satu-rated fatty acids, and enrichment of fractions which permit the analysis of trace quantities of unusual fatty acids. Odd numbered fatty acids have been found in both saturated and monoene fractions of vegetable oils, such as olive, rapeseed and sunflowerseed. This technique coupled to oxi-dative degradation is useful for establishing the presence of minor quantities of positional isomers. Samples of purified polyunsaturated fatty acid esters are readily prepared using the technique as displacement chromatography. Presented in part at the AOCS Meeting in Minneapolis, 1963. Issued as NBC No. 7983. National Research Council of Canada Postdoctorate Fellow 1962-.     

Aspects of the chemistry of poly(ethylene terephthalate): 5. Polymerization of bis(hydroxyethyl)terephthalate by various metallic catalysts

Bis(hydroxyethyl)terephthalate (BHET) was polymerized to poly(ethylene terephthalate) (PET) in the presence of various metallic catalysts. The influence of the nature and concentration of these catalysts on the rate of polymerization has been investigated. The effect of the reaction temperature has also been studied. The order of decreasing catalytic influence of various metal ions, on the polymerization of BHET was found to be: Ti>Sn>Mn>Zn>Pb>No.     

Nutritional value of mung bean (Vigna radiata) as effected by cooking and supplementation

The study was conducted to improve the nutritional value of Mung (Vigna radiata) by supplementation with different kinds of meat. Diets were prepared using raw and cooked Mung and then cooked Mung was supplemented with poultry, mutton and beef at 10, 15, and 20 percent levels. Nutritional value of Mung was determined by chemical analysis as well as by rat assay. Mung had 25 percent protein and minor losses were observed during cooking. It had 1.21 percent lysine which was reduced by 43 percent on cooking. Other amino acids also showed losses during cooking. The Protein Efficiency Ratio (PER) of diet containing Mung was significantly reduced on cooking (1.86 vs 1.40). On the contrary cooking resulted in some improvement of Net Protein utilization (NPU) and True Digestibility (TD) of the Mung based diets. Twenty percent level of different meats showed better results in terms of PER, NPU and TD.     

Studies on the Lipid Production by Penicillium lilacinum

Lipid production by Penicillium lilacinum in media containing various ratios of carbon and nitrogen has been studied. Factors affecting the lipid synthesis from diverse sources of carbon and nitrogen have been observed. Out of the nitrogen sources studied sodium nitrate produced 22.5% fat. Sucrose proved to be a better source of carbon than xylose and maltose. The same yield of fat was obtained by replacing sucrose with molasses and sulphite waste liquor. Chemical examination of the fat reveals that it is composed of the usually occurring fatty acid glycerides.